T-III Reliability improvement

[1BADVAN]

I am picking up a spirit r/t this week and would like to know any tips you might have to help the reliability. The last one we had we sold cause we got sick of fixing it. Such as head gaskets leaking the head itself leaking, intermediate shaft problems etc.

Does anyone have links of info on how to help these be more reliable?

[Simsy]

make sure you get a belt tension gauge, tension is critical on TIIIs. Ebay is a good source for them. As far as the head leaking check in the valley between the core plugs(especially between the 2nd and 3rd). Usually if the HG is leaking the most common spots are the rear left side of the head and the right side of the head between the to cam pulleys as far as I'm concerned. I'd def. get a cometic HG on it asap if it doesnt have one already, especially if your looking to run more boost. LMK if you have any other questions..I'm sure Jackson will even be posting in here soon as well :thumb:

BTW we must have pics of this ASAP :nod:

[iTurbo]

I bought my Spirit R/T back in '03. It's the same one you saw when I went down to SLC to pick up that shortblock. Anyway, after I bought it I tore the drivetrain out, completely went over the whole drivetrain, new gaskets, seals, clutch, motor mounts etc....didn't get too crazy on mods but I did add a ported exhaust manifold, 3" exhaust (no cat), LWP stage I cams, Ti retainers, FWDP lifters, and a TurboXS BOV. The car has been VERY reliable. I put about 1100 miles on the car the day I went to SLC....pretty much drove right back and the car never had a hiccup.

In the last five years I've put a LOT of miles on the car, mostly delivering pizza. As far as failures in that time, I had a timing belt tensioner failure that took out some other parts on a long road trip to buy my white Spirit R/T. Thankfully Adam Lengel makes a really nice tensioner that is rebuildable. I've also gone through a few clutch cables (stock clutch), had to totally redo my battery cables due to corrosion, and a timing belt which was probably the result of my tensioner failure. Oh and shifter cables, probably 3-4 of those. The aftermarket ones just aren't as tough as the original Mopar ones it seems.

Other than that, the titanium valve spring retainers should help belt life. The lifters that FWDP sells are also very nice and actually stay together while you assemble them unlike the stockers that usually fall apart and fall into the head. Unfortunately the lifters are pretty expensive so I would only replace them if yours are already falling apart. FWDP also sells modified stock retainers that accomplish the same thing as the Ti retainers (lower valve spring pressure) but are chromoly and less expensive.

[1BADVAN]

make sure you get a belt tension gauge, tension is critical on TIIIs. Ebay is a good source for them. As far as the head leaking check in the valley between the core plugs(especially between the 2nd and 3rd). Usually if the HG is leaking the most common spots are the rear left side of the head and the right side of the head between the to cam pulleys as far as I'm concerned. I'd def. get a cometic HG on it asap if it doesnt have one already, especially if your looking to run more boost. LMK if you have any other questions..I'm sure Jackson will even be posting in here soon as well :thumb:

BTW we must have pics of this ASAP :nod:

whats a good price for a belt tension gauge? I have seen those leaking spots, this head was re-done 16k ago and driven by an old man so i hope it still is good :)
Why should i go cometic? I heard the surfaced has to have a very fine surface to work, and i know a bunch of 8v guys hate the cometic and say that the MP gasket works much better, I am guessing you think different for the T3s.

For sure i will post pics when i get it home :)

[Simsy]

you want to get a gauge like this one http://cgi.ebay.com/ebaymotors/Belt-Tension-Gauge-Gage-Drive-Belts-Dial-Tensiometer_W0QQcmdZViewItemQQhashZitem27af891608Q QitemZ170448721416QQptZMotorsQ5fAutomotiveQ5fTools

i have one that is similar that id maybe sell if you want it.
As far as the cometic goes it is a must in my opinion for TIIIs when it comes to running big boost. When i got my first spirit r/t i ran 15psi with a stock HG and blew it within 500 miles. I installed a Cometic on it and ran 18-20psi all day and never had any trouble since. And yes you do want a nice fine smooth surface on both the head and block to get the best seal..be sure to use a feeler gauge to check the surfaces of both the head and block.

Can't wait to see those pics man :thumb: Is the Spirit a 91 or 92?

[raccoon]

swap in a T1

[1BADVAN]

And yes you do want a nice fine smooth surface on both the head and block to get the best seal..be sure to use a feeler gauge to check the surfaces of both the head and block.

Can't wait to see those pics man :thumb: Is the Spirit a 91 or 92?

91 White :) What do you mean by use a feeler gauge? AFAIK a feeler gauge is used to measure a gap between 2 things how would i use it to check it the head is "fine" enough to use a cometic?


swap in a T1

:lol: LOL thats what my dad used to say when he got sick of fixing his R/T, but the top end power of a 16v just is to hard for me to get rid of.
Thanks Guys!

[Simsy]

91 White :) What do you mean by use a feeler gauge? AFAIK a feeler gauge is used to measure a gap between 2 things how would i use it to check it the head is "fine" enough to use a cometic?



:lol: LOL thats what my dad used to say when he got sick of fixing his R/T, but the top end power of a 16v just is to hard for me to get rid of.
Thanks Guys!

what i did was took a straight edge and used a feeler gauge between that and the deck..it seemed to work pretty good..Sorry, i should have clarified that lol:D

[Simsy]

swap in a T1

ugghhhh noooooo:yuck:

[Lotashelbys]

Just for the record I drive TIII cars everyday. Thats all I have to say....

[1BADVAN]

Just for the record I drive TIII cars everyday. Thats all I have to say....

Yeah thats my plan too, I trust them i just want to do preventitive things so it is even more reliable, i think we just had a bad string of problems like any car can have. But now with more knowledge it should work better!

[raccoon]

But now with more knowledge it should work better!


thats what i tell myself year after year.

how about a neon head? do a hybird, or is that a even worse can of worms.

[Simsy]

thats what i tell myself year after year.

how about a neon head? do a hybird, or is that a even worse can of worms.

if everything is done right the first time TIII's can be more reliable than 8 valves :amen:

[1BADVAN]

if everything is done right the first time TIII's can be more reliable than 8 valves :amen:

:amen: again i believe it there are many 12 sec T3s that are driven regularly, this is why i am going to get one, Heading up there in about 10 mins :D

[Simsy]

:amen: again i believe it there are many 12 sec T3s that are driven regularly, this is why i am going to get one, Heading up there in about 10 mins :D

shwweettt:) cant wait to see it:clap:

[Turbodave]

Just for the record I drive TIII cars everyday. Thats all I have to say....

Is that why you need so many of them? :lol:


I do like the timing idler modification Jackson does, that looks like it would help belt life and possibly be easier on the intermediate shaft as well.

That and making sure the 02 sensor wiring is routed away from the exhaust pipes are a few things you can do improve reliability.

[black86glhs]

Just for the record I drive TIII cars everyday. Thats all I have to say....

And he works on them all the time too!:drum:

[Lotashelbys]

And he works on them all the time too!:drum:

Actually I havent opened the hood on my DD for some time now. I wonder if it still has any oil left in it......

[black86glhs]

Actually I havent opened the hood on my DD for some time now. I wonder if it still has any oil left in it......LMAO!!! The way you build them, it probably wouldn't hurt it.:hail:

[Simsy]

LMAO!!! The way you build them, it probably wouldn't hurt it.:hail:

he doesnt need anymore of an ego boost:lol:

[black86glhs]

he doesnt need anymore of an ego boost:lol:

Oh god.....what have I done??!!:cool:

[turbovanman²]

I don't like Cometic's on our engines, they leak.

Just fix the regular maintenance stuff, timing belt tension, oil change's etc, and look over the cams to make sure they aren't going flat, Jackson's mod, valve spring tension, that's all I got, ;)

[1BADVAN]

I don't like Cometic's on our engines, they leak.

Just fix the regular maintenance stuff, timing belt tension, oil change's etc, and look over the cams to make sure they aren't going flat, Jackson's mod, valve spring tension, that's all I got, ;)

Jackson's mod= move the pulley?

Valve spring tension = different retainers?

[black86glhs]

Jackson's mod= move the pulley?

Valve spring tension = different retainers?

I think Jackson has a set of retainers that lower the valve spring tension and reduce the wear and tear on the belt.

[1BADVAN]

Anyone know where to get these? cheaper than $260 from FWD

[iTurbo]

FWDP has the modified stock ones too. I just remembered I sent Jackson a couple A/C brackets for the idler relocation; can't wait to try it myself.

[Simsy]

Anyone know where to get these? cheaper than $260 from FWD

i believe the modified retainers on FWD are about $150..

[1BADVAN]

so are modified stock ones just milled down? so the spring has less tension? If so can't a local place do it cheaper?

[turbovanman²]

Jackson's mod= move the pulley?

Valve spring tension = different retainers?

Yes, you put the timing belt idler pulley on the a/c bracket.

Valve spring tension, either Ti retainers or modded stockers, FWD has both.

[turbovanman²]

Anyone know where to get these? cheaper than $260 from FWD

Your talking a one off item for a TIII, $260 is a reasonable price. If your doing to own a TIII, get ready to spend.


so are modified stock ones just milled down? so the spring has less tension? If so can't a local place do it cheaper?

Its possible I guess, talk to a local machine shop, your probably looking at 2 hours labour, so around $150 or more, :eyebrows:

[black86glhs]

Your talking a one off item for a TIII, $260 is a reasonable price. If your doing to own a TIII, get ready to spend.



Its possible I guess, talk to a local machine shop, your probably looking at 2 hours labour, so around $150 or more, :eyebrows:

Nevermind, I had the wrong info.:o

[turbovanman²]

The hole in the retainers is opened up slightly to allow the retainer to slide up the keepers slightly. This lessens the spring tension.

Not last time I talked with Jackson, the stockers are milled.

The Ti's are designed to sit higher, so maybe thru the keeper hole or the spring pad is machined higher.

[black86glhs]

Not last time I talked with Jackson, the stockers are milled.

The Ti's are designed to sit higher, so maybe thru the keeper hole or the spring pad is machined higher.

Ok. Last time I talked with him(a while ago), we were talking about opening it up. I thought that is what he did. Thanks for the info.:thumb:

[1BADVAN]

I would think that with all the DOHC cars out there you would be able to find a spring ,stock or aftermarket, that will fit the T3 and have lower tension, idk maybe they are too unique

[omnigoestohell]

x2 on the suggestions for

1) the ti or other retainers to lower valve spring pressure
2) rerouting the O2 sensor wiring if it hasn't already melted
3) installing a T1 instead


in addition be sure to watch your oil pressure and belt tension at all times..
do not drive it if either of those has any uncertainty!

otherwise, have fun and watch out for tire spin at the top of 3rd gear


Is that why you need so many of them? :lol:


I do like the timing idler modification Jackson does, that looks like it would help belt life and possibly be easier on the intermediate shaft as well.

That and making sure the 02 sensor wiring is routed away from the exhaust pipes are a few things you can do improve reliability.

[turbovanman²]

I would think that with all the DOHC cars out there you would be able to find a spring ,stock or aftermarket, that will fit the T3 and have lower tension, idk maybe they are too unique

Nope, I and others have tried to find springs, they will be custom job, the retainers are cheaper.

BUT for some odd reason, one of my heads has factory low tension springs, so I don't need retainers, in fact, I had to shim them up to make them stiffer, :lol:

[Turbo224]

I would suggest trashing the entire stock vacuum system, its all junk. Get a cheap vacuum block and you really only need to run four or five lines directly off the intake. 180 degree thermostat with a couple holes drilled in it should also be on the to-do list. Stock bov is questionable at best, I would replace that as well.

If I would have got my tax returns a tad sooner I definitely would have been up there to check it out. :)

[turbovanman²]

I would suggest trashing the entire stock vacuum system, its all junk. Get a cheap vacuum block and you really only need to run four or five lines directly off the intake. 180 degree thermostat with a couple holes drilled in it should also be on the to-do list. Stock bov is questionable at best, I would replace that as well.

If I would have got my tax returns a tad sooner I definitely would have been up there to check it out. :)

And the stock PCV setup and either run a catch can or an 8 valve type setup.

[1BADVAN]

And the stock PCV setup and either run a catch can or an 8 valve type setup.

In what way do you run the pcv? put a port in the valve cover? any links with pics

[turbovanman²]

In what way do you run the pcv? put a port in the valve cover? any links with pics

I don't run a pcv, just a catch can hooked into the air intake tube.

Others a similiar setup. Search my name and catch in this section or the project log. RX2mazda has done something similar.

[1BADVAN]

will a belt tension gauge like this work?
http://www.techsourceky.net/mpmp_7564.JPG
I hope so cause i bought one for $26 shipped, if not i guess i could re-sell it

[Turbo3Iroc]

It looks like basically the same thing but with an offset. Before you take the car apart I would test it out on the current belt and see what you get for a reading.

[Lotashelbys]

I dont think that one works very well.....

[1BADVAN]

I dont think that one works very well.....

Why? Not that i don't believe you i am just wondering

[iTurbo]

That's the tension gauge I use. It works although I haven't ever tried another kind.

[Lotashelbys]

I dont think it fits between the cam gears very well and the gauge will be back almost to the firewall if you can even get it in place. Just try to find the correct one and be done with it....

[iTurbo]

While the offset is a little funky it still fits just fine. I have mine on the other way so the dial sticks out above the A/C compressor so the dial face is facing the driver side which is a little awkward. It's actually very easy to use, but you gotta make sure the claw is clasping the entire width of the belt. I do like the other gauge that everybody else uses and would like to get one to replace mine someday.

[5DIGITS]

The well publicized high spring rate on the T-III is a popular topic when discussing belt failure. What is worth mentioning is that because of the smaller spring coil diameter, the wire diameter, and the amount of coils; the differential spring load, on the T-III, is higher than the 8V spring. This is the significant offender to belt durability. The rotating turning torque rises and falls with such amplitude that it generates belt tooth shearing force, on pulleys that have insufficient belt wrap. Specifically, the excessive rotational loading and unloading is met across only 9 teeth of the intake pulley. The raised retainers lower the closed and open spring rates but more significantly reduce the differential loading. These directionally correct retainers, at a .075"-.085" higher installed height, can reduce the differential load by approx. 15-20%, depending on the actual spring rate. Although, this still produces closed seat pressures that exceed the stock 8V roller spring. Machining an additional groove in the valve-stem allows for the original retainer to be raised .100" and places the installed spring load closer to the 8-valve stock spec. This increase in installed height has further impact on the differential (open vs. closed) spring pressure. This reduces the rotating oscillation torque by an additional 5-10%, which was not addressed in a retainer vs. stem-groove discussion months ago.

To potentially accomplish the ideal position would require machining the additional groove in the valve stem and the use of a .010”-.025" modified offset retainer. Please note that the total amount required for a specific application is based on the actual measured load of the spring being used and the desired RPM range. Doing this can yield nearly a 25-35% drop in rotating oscillation torque depending on the total offset amount chosen. At this point, the resulting closed valve seat pressures are nearly at stock 8V roller specification, which was capable of 6500-6800 RPM. This may now be applied to a T-III valve that has less head area and opens nearly .100” less.

Another contributing factor that doesn’t seem to surface is the modification of cam timing, on the T-III. The position of the cams relative to each other and their relative position to the crank are sometimes altered to increase performance. The belt tensioning tool is required to properly maintain a critical tension set-point and a specific belt operating frequency, for reasons mentioned above. When the cams are aggressively adjusted, relative to each other and the crank, the “normal” belt operating frequency is disturbed which can require a tension change to compensate for the resulting change in belt frequency. This can sometimes be visually observed or tested by maintaining the specified belt tension and modifying the cam angles, primarily the intake cam. As the engine is transitioned through an RPM operating range, the notable belt resonant RPM will change as a function of cam angles, tension, and the belt being used.

The intermediate pulley reduction size and resulting speed increase of the oil pump, on the T-III, was due to anticipated valve train oil demands. This over-taxing change later required the introduction of “matched” Melonized set which generated an “equal” surface finish for the intermediate shaft and oil pump gears. The anticipated oil demand increase was required to over-come the compounding losses realized at the balance shaft assembly, while still being able to deliver adequate oil to an increase in valve train hardware. This was all expected from a pump that was designed without ever considering these added demands. If consideration is being made to reduce the intermediate shaft speeds, to standard 8V levels; it would strongly be advised to remove the balance shaft assembly and block the oil delivery hole, as many do. On high RPM applications, it should be noted that the balance shaft assembly maintains a 14,500 RPM durability limitation, due to bearing failure. This equates to an engine speed limit of 7250rpm caused by balance shaft sprocket gearing.

If the decision has been made to reduce the oil pump speed - there are adjustable sprockets for both 8V and 16V applications. The thought may be to use the inner adjustable hub for 8V with an adjustable 16V sprocket and modify accordingly for offset purposes. This will support the proper hub diameter, pulley width, profile, and pitch required to slow the oil pump to standard speed. While an 8V pulley can be utilized, the production Mopar belt consumes 100% of the usable surface, permits zero tolerance for of center positioning, and does not mesh with full accuracy to the 16V belt. Combining the adjustable components for the reasons listed above can make for an accurate replacement pulley that meets stock specification requirements.

Note that valuable belt length is being consumed. To counter-act this without the need for tensioner relocation, compare a production idler pulley to a tensioner-pulley and a significant commonality becomes apparent. The outer bearing race hub OD, on the idler, is incredibly close to the inner bearing race hub of the tensioner-pulley. With careful machining the outer tensioner-pulley OD can be eliminated and an adjustable idler is the result. This modified tensioner can be used in the standard location for an increase in usable belt length and also provides an additional belt/cam angle adjustment point, when installed on the front side of the engine. Adding an idler with minimal reverse flex loading while providing some increase in cam pulley belt wrap is a considerable improvement; while thorough rotational torque load reduction, balance shaft removal, and oil pump speed reduction can secure proven gains in durability.

I hope this helps.
Thanks

[Pat]

The well publicized high spring rate on the T-III is a popular topic when discussing belt failure. What is worth mentioning is that because of the smaller spring coil diameter, the wire diameter, and the amount of coils; the differential spring load, on the T-III, is higher than the 8V spring. This is the significant offender to belt durability. The rotating turning torque rises and falls with such amplitude that it generates belt tooth shearing force, on pulleys that have insufficient belt wrap. Specifically, the excessive rotational loading and unloading is met across only 9 teeth of the intake pulley. The raised retainers lower the closed and open spring rates but more significantly reduce the differential loading. These directionally correct retainers, at a .075"-.085" higher installed height, can reduce the differential load by approx. 15-20%, depending on the actual spring rate. Although, this still produces closed seat pressures that exceed the stock 8V roller spring. Machining an additional groove in the valve-stem allows for the original retainer to be raised .100" and places the installed spring load closer to the 8-valve stock spec. This increase in installed height has further impact on the differential (open vs. closed) spring pressure. This reduces the rotating oscillation torque by an additional 5-10%, which was not addressed in a retainer vs. stem-groove discussion months ago.

To potentially accomplish the ideal position would require machining the additional groove in the valve stem and the use of a .010”-.025" modified offset retainer. Please note that the total amount required for a specific application is based on the actual measured load of the spring being used and the desired RPM range. Doing this can yield nearly a 25-35% drop in rotating oscillation torque depending on the total offset amount chosen. At this point, the resulting closed valve seat pressures are nearly at stock 8V roller specification, which was capable of 6500-6800 RPM. This may now be applied to a T-III valve that has less head area and opens nearly .100” less.

Another contributing factor that doesn’t seem to surface is the modification of cam timing, on the T-III. The position of the cams relative to each other and their relative position to the crank are sometimes altered to increase performance. The belt tensioning tool is required to properly maintain a critical tension set-point and a specific belt operating frequency, for reasons mentioned above. When the cams are aggressively adjusted, relative to each other and the crank, the “normal” belt operating frequency is disturbed which can require a tension change to compensate for the resulting change in belt frequency. This can sometimes be visually observed or tested by maintaining the specified belt tension and modifying the cam angles, primarily the intake cam. As the engine is transitioned through an RPM operating range, the notable belt resonant RPM will change as a function of cam angles, tension, and the belt being used.

The intermediate pulley reduction size and resulting speed increase of the oil pump, on the T-III, was due to anticipated valve train oil demands. This over-taxing change later required the introduction of “matched” Melonized set which generated an “equal” surface finish for the intermediate shaft and oil pump gears. The anticipated oil demand increase was required to over-come the compounding losses realized at the balance shaft assembly, while still being able to deliver adequate oil to an increase in valve train hardware. This was all expected from a pump that was designed without ever considering these added demands. If consideration is being made to reduce the intermediate shaft speeds, to standard 8V levels; it would strongly be advised to remove the balance shaft assembly and block the oil delivery hole, as many do. On high RPM applications, it should be noted that the balance shaft assembly maintains a 14,500 RPM durability limitation, due to bearing failure. This equates to an engine speed limit of 7250rpm caused by balance shaft sprocket gearing.

If the decision has been made to reduce the oil pump speed - there are adjustable sprockets for both 8V and 16V applications. The thought may be to use the inner adjustable hub for 8V with an adjustable 16V sprocket and modify accordingly for offset purposes. This will support the proper hub diameter, pulley width, profile, and pitch required to slow the oil pump to standard speed. While an 8V pulley can be utilized, the production Mopar belt consumes 100% of the usable surface, permits zero tolerance for of center positioning, and does not mesh with full accuracy to the 16V belt. Combining the adjustable components for the reasons listed above can make for an accurate replacement pulley that meets stock specification requirements.

Note that valuable belt length is being consumed. To counter-act this without the need for tensioner relocation, compare a production idler pulley to a tensioner-pulley and a significant commonality becomes apparent. The outer bearing race hub OD, on the idler, is incredibly close to the inner bearing race hub of the tensioner-pulley. With careful machining the outer tensioner-pulley OD can be eliminated and an adjustable idler is the result. This modified tensioner can be used in the standard location for an increase in usable belt length and also provides an additional belt/cam angle adjustment point, when installed on the front side of the engine. Adding an idler with minimal reverse flex loading while providing some increase in cam pulley belt wrap is a considerable improvement; while thorough rotational torque load reduction, balance shaft removal, and oil pump speed reduction can secure proven gains in durability.

I hope this helps.
Thanks

Great info.

Question thought..if one were to machine the extra groove in the valve to raise the installed spring height .100", instead of using an offset retainer to bring that height down to .075-.085, coulnd't a shim be used under a stock dimensioned retainer? Might be a simpler solution, plus, you'd have the ability to fine tune spring tension by use of smaller or larger shims if need be.

[2.216VTurbo]

Meh, what do you know Ken:lol::lol:

I had to read that post twice man, some serious pearls hidden amongst the words I had to sound out ;)(BTW Melonized? A surface finish of some sort but?)I've never read anywhere about the balance shaft max RPM, thanks for that,:hail: I had kinda figured they weren't really 'hurting me' so I had left them until now but I'll be dropping the pan soon as 7250 is a joke with a well set up TIII.

The way I remember it when I bought the Ti raised height retainers years ago (RDI Performance ones) that they were advertised as .100 raised, have you ever had your hands on a set from him? Got me wondering now if I need to do something more.

I like Jackson's idea for an additional idler and reducing the OD of the other idler is another great tip:clap: You should hang around here more:amen:

BTW, there was another smart guy around a while back, 4DIGITS+1, is he like a cousin of yours or something;)

[5DIGITS]

Hi Pat.

I can see how this could be confusing and could require clarification.

To potentially accomplish the ideal position would require machining the additional groove in the valve stem with the additional height of a .010”-.025" higher modified offset retainer, for a total of .100"+ installed height.

I hope this helps.
Thanks

[5DIGITS]

Hello and thanks, Alan.

" ...4DIGITS+1, is he like a cousin of yours or something":lol:

Distant relative that mathematically carried the 1.

Good to hear from you.
Keep in touch.

[Pat]

Hi Pat.

I can see how this could be confusing and could require clarification.

To potentially accomplish the ideal position would require machining the additional groove in the valve stem with the additional height of a .010”-.025" higher modified offset retainer, for a total of .100"+ installed height.

I hope this helps.
Thanks

Thanks for the reply...but I have another question (or two, or three as we go along! Hope you don't mind!:))

Why is a .100" increase the ideal? If I read your post correctly, that gets you closed to stock 8v closed valve pressure, which you mentioned are good to 6400-6800 rpm (although I admit, I'm not sure I understand how signficant total valve lift and head area effects necessary closed pressure to control valve float)

Ideally, I would think reducing spring tension as much as possible without getting into valve float is the ideal. The rpm range the engine is built for would then alter what the ideal deviation from the stock height would be, wouldn't it?

[BadFastGTC]

I cannot recall, are the TIII keepers a multi-groove? If not, an offset keeper would be the hot ticket to add to the installed height.




Hi Pat.

I can see how this could be confusing and could require clarification.

To potentially accomplish the ideal position would require machining the additional groove in the valve stem with the additional height of a .010”-.025" higher modified offset retainer, for a total of .100"+ installed height.

I hope this helps.
Thanks

[5DIGITS]

Thanks for the reply...but I have another question (or two, or three as we go along! Hope you don't mind!:))

Why is a .100" increase the ideal? If I read your post correctly, that gets you closed to stock 8v closed valve pressure, which you mentioned are good to 6400-6800 rpm (although I admit, I'm not sure I understand how signficant total valve lift and head area effects necessary closed pressure to control valve float)

Ideally, I would think reducing spring tension as much as possible without getting into valve float is the ideal. The rpm range the engine is built for would then alter what the ideal deviation from the stock height would be, wouldn't it?

The .100" is important because when another groove is added, above the existing grooves (equally spaced), the retainer moves up .100", when the keepers utilize the new groove.

Your second comment is correct, which is why we are discussing going from .075"-.085" retainer to a .100" stem-groove modification and then suggesting an additional increased retainer height.

The T-III valve realizes approx. .100" less lift and has less back-side valve area. This reduces dutycycle severity and minimizes the spring pressure required, to overcome closing the valve.

Thanks for your comments, Pat.
I hope this helps.

[turbovanman²]

Do you know of any TIII valve springs that are softer than the production one's? I bought a head and had the springs checked out like I always do, and they are around 8 valve spring rates, I have them posted up on this forum somewhere? I don't get it, never heard of these before and it was a stock head. I actually had to shim them up a bit as i was scared they were going to float on me at 7000 rpm.




If the decision has been made to reduce the oil pump speed - there are adjustable sprockets for both 8V and 16V applications. The thought may be to use the inner adjustable hub for 8V with an adjustable 16V sprocket and modify accordingly for offset purposes. This will support the proper hub diameter, pulley width, profile, and pitch required to slow the oil pump to standard speed. While an 8V pulley can be utilized, the production Mopar belt consumes 100% of the usable surface, permits zero tolerance for of center positioning, and does not mesh with full accuracy to the 16V belt. Combining the adjustable components for the reasons listed above can make for an accurate replacement pulley that meets stock specification requirements.

I did use an 8 valve sprocket for over a year, didn't seem to do any damage to the belt etc, and yes, it isn't perfect fit but being in the place it is, it still works.

Then I had someone whip this up for me, and he was supposed to make me a bunch but that didn't happen, :(

http://i12.photobucket.com/albums/a228/turbovanman/TIII%20stuff/Sonywork273.jpg

http://i12.photobucket.com/albums/a228/turbovanman/TIII%20stuff/Sonywork275.jpg




Note that valuable belt length is being consumed. To counter-act this without the need for tensioner relocation, compare a production idler pulley to a tensioner-pulley and a significant commonality becomes apparent. The outer bearing race hub OD, on the idler, is incredibly close to the inner bearing race hub of the tensioner-pulley. With careful machining the outer tensioner-pulley OD can be eliminated and an adjustable idler is the result. This modified tensioner can be used in the standard location for an increase in usable belt length and also provides an additional belt/cam angle adjustment point, when installed on the front side of the engine. Adding an idler with minimal reverse flex loading while providing some increase in cam pulley belt wrap is a considerable improvement; while thorough rotational torque load reduction, balance shaft removal, and oil pump speed reduction can secure proven gains in durability.

I hope this helps.
Thanks

Have you seen Jackson's mod, moving the idler pulley, its genius, lol.

http://www.turbo-mopar.com/forums/showthread.php?t=28041

[5DIGITS]

I cannot recall, are the TIII keepers a multi-groove? If not, an offset keeper would be the hot ticket to add to the installed height.

Hi Steve.
The intakes are single groove while the exhausts are multi-groove.
Hot ticket indeed, if possible.

Keep in touch.
Thanks

[Pat]

The .100" is important because when another groove is added, above the existing grooves (equally spaced), the retainer moves up .100", when the keepers utilize the new groove.

Your second comment is correct, which is why we are discussing going from .075"-.085" retainer to a .100" stem-groove modification and then suggesting an additional increased retainer height.

The T-III valve realizes approx. .100" less lift and has less back-side valve area. This reduces dutycycle severity and minimizes the spring pressure required, to overcome closing the valve.

Thanks for your comments, Pat.
I hope this helps.

Got it...thanks for clarifying.

I see the advantage lowering that spring pressure further, but at what closed pressure and rpm does float become a concern? Based on the valve size and lift, is there a closed spring pressure that you're targeting?

I've run the raised retainers the vendors sell for years, which I think raises the spring height .070" and have had no belt, oil pump or I shaft bearing issues. I've also had no valve float issues running to 7000 or so. I'm wondering at what point does the float risk outweigh the benefits of lightening the spring.

[turbovanman²]

Got it...thanks for clarifying.

I see the advantage lowering that spring pressure further, but at what closed pressure and rpm does float become a concern? Based on the valve size and lift, is there a closed spring pressure that you're targeting?

I've run the raised retainers the vendors sell for years, which I think raises the spring height .070" and have had no belt, oil pump or I shaft bearing issues. I've also had no valve float issues running to 7000 or so. I'm wondering at what point does the float risk outweigh the benefits of lightening the spring.


Like I posted earlier, mine are close to S60 8 valve specs, no float at 7000+ rpm.

[Pat]

http://i12.photobucket.com/albums/a228/turbovanman/TIII%20stuff/Sonywork273.jpg

]

Hard to see in the picture, but is that pulley keyed?

[turbovanman²]

Hard to see in the picture, but is that pulley keyed?

Yep, its the same one in the engine pics, I must have the keyway facing the camera.

[omnigoestohell]

Thanks Ken, glad to see you pop in here --- the concept of the amplitude of the differential in spring rates coming into play in shearing the teeth is an interesting additonal aspect to contemplate.

Have you, or do you know anyone who has used an idler-sized tensioner on the front and a increased diameter sprocket as you were suggesting?

Does the additonal tooth engagement (2 teeth?) on the intake cam by using an idler/tensioner up front make enough of an impact that you think it would play a role in fixing the belt problems?

Do you think these changes were well known within Chrysler back in the early-mid nineties (but deemend too expensive or complicated to implement to a fleet of several thousand cars through a TSB) or is this something that was learned through the development of the later twin cam motors and SRT4?

Any thoughts on what is more likely the oil pump killer -- the tension on the end of the belt end of the the intermediate shaft or the speed at which the shaft and pump are made to turn? The front idler addition without changing the sprocket diameter would address the concern of reducing some of the bearing loading on the pump shaft but it seems difficult to determine which is causing the pump failure --- shaft movement from bearing failure or pump failure from over speed/lubrication issues.




Note that valuable belt length is being consumed. To counter-act this without the need for tensioner relocation, compare a production idler pulley to a tensioner-pulley and a significant commonality becomes apparent. The outer bearing race hub OD, on the idler, is incredibly close to the inner bearing race hub of the tensioner-pulley. With careful machining the outer tensioner-pulley OD can be eliminated and an adjustable idler is the result. This modified tensioner can be used in the standard location for an increase in usable belt length and also provides an additional belt/cam angle adjustment point, when installed on the front side of the engine. Adding an idler with minimal reverse flex loading while providing some increase in cam pulley belt wrap is a considerable improvement; while thorough rotational torque load reduction, balance shaft removal, and oil pump speed reduction can secure proven gains in durability.

I hope this helps.
Thanks

[Ondonti]

I would be fine with splitting the difference. If you are unwilling to change timing belts on schedule with a TIII then sell it to someone who will! Rare cars are not for the lazy person who wants to put big mileage on them.
Then do Jackson's pulley mod. I really wouldn't have a problem with keeping the stock install height if the only worry is the timing belt. As long as the intermediate shaft can be made to survive, that is what I would care about.

[Lotashelbys]

Does the additonal tooth engagement (2 teeth?) on the intake cam by using an idler/tensioner up front make enough of an impact that you think it would play a role in fixing the belt problems?
.Im sure the extra belt wrap helps but I did this idler mod more to put an idler between the intake cam and the I-shaft. I thought it would help on any unwanted harmonics that were created between that run of the belt. I would say it helps out more in the life of the I-shaft and pump teeth and the I-shaft bearing life. I also noticed that I could run less tension when running them with the idler in the front. I would think that would help on bearing life.


Any thoughts on what is more likely the oil pump killer -- the tension on the end of the belt end of the the intermediate shaft or the speed at which the shaft and pump are made to turn? The front idler addition without changing the sprocket diameter would address the concern of reducing some of the bearing loading on the pump shaft but it seems difficult to determine which is causing the pump failure --- shaft movement from bearing failure or pump failure from over speed/lubrication issues.

I really think it more to do with belt tension. Every failure I have personally dealt with(not my own) has proven to be way too loose of a belt. I checked a few of them with the gauge before I pulled them apart and two of them were right at 45LBS. I was almost thinking that there is a certain number that causes just the right harmonics to cause the failure. Almost like how a certain frequecy will break glass I think its the same concept here. I have even seen a few pumps break off at the mounting flange instead of sheering teeth.

Another thing that I have been wondering is has anyone had the warranty shaft ever strip out on them? Its the one starting with the 466 P/N. My first TIII car I owned had a very loose belt for the first few years didnt have any issues but had the 466 shaft in it. I wonder if that saved it?

[Lotashelbys]

Ken
What are your thoughts on the idler relocation? When we talked at SDAC 19 it was almost like you didnt think it would work or have any advantages. I should of showed you in person cause we brought 3 TIII cars down from WI that had that done to them......

[Pat]

Im sure the extra belt wrap helps but I did this idler mod more to put an idler between the intake cam and the I-shaft. I thought it would help on any unwanted harmonics that were created between that run of the belt. I would say it helps out more in the life of the I-shaft and pump teeth and the I-shaft bearing life. I also noticed that I could run less tension when running them with the idler in the front. I would think that would help on bearing life.


I really think it more to do with belt tension. Every failure I have personally dealt with(not my own) has proven to be way too loose of a belt. I checked a few of them with the gauge before I pulled them apart and two of them were right at 45LBS. I was almost thinking that there is a certain number that causes just the right harmonics to cause the failure. Almost like how a certain frequecy will break glass I think its the same concept here. I have even seen a few pumps break off at the mounting flange instead of sheering teeth.

Another thing that I have been wondering is has anyone had the warranty shaft ever strip out on them? Its the one starting with the 466 P/N. My first TIII car I owned had a very loose belt for the first few years didnt have any issues but had the 466 shaft in it. I wonder if that saved it?

Did those two with pump/ishaft failure also have stock retainers in them?

[Lotashelbys]

Did those two with pump/ishaft failure also have stock retainers in them?

Those did IIRC. Although I have heard of a few that failed with Titaniums in them. I checked with the owners of thoe and they told me that they didnt use a gauge and the belts were in fact loose.

[5DIGITS]

Ken
What are your thoughts on the idler relocation? When we talked at SDAC 19 it was almost like you didnt think it would work or have any advantages. I should of showed you in person cause we brought 3 TIII cars down from WI that had that done to them......

Good to hear from you!

I support the idea of having something to touch the belt as it doesn’t take much contact to have an impact on belt resonation/oscillation. On the other hand packaging does come with its limitations and does contribute to where it should or could be placed.

Additionally, I saw a post asking whether the added contact, on the intake cam, was worth it. This would rely on the extent of valve-train modification. If the spring rates have been sufficiently addressed, the impact is reduced. On the other hand, it would be greatly welcomed on an engine with upper-tolerance spring rates and corresponding load.


Keep in touch.

[5DIGITS]

Got it...thanks for clarifying.

I see the advantage lowering that spring pressure further, but at what closed pressure and rpm does float become a concern? Based on the valve size and lift, is there a closed spring pressure that you're targeting?

I've run the raised retainers the vendors sell for years, which I think raises the spring height .070" and have had no belt, oil pump or I shaft bearing issues. I've also had no valve float issues running to 7000 or so. I'm wondering at what point does the float risk outweigh the benefits of lightening the spring.

The best target is the lowest level of differential spring rate that provides the greatest return for the modification being made.


Stock CLOSED valve pressures:
The 8V roller installed spring rate: 110-120lb.
The T-III roller installed spring rate: 115-127lb.

Stock OPEN valve pressures:
The 8V roller peak spring rate @.430”: 200 - 215lb.
The T-III roller peak spring rate @.335”: 250 - 275lb.

Please notice that the following occurrences are based on nominal spring rates.
An 8V spring goes from approx. 115lbs @ 0” lift to 207lbs @ .430” lift.
This is a differential pressure of 92lbs

A T-III spring goes from approx. 121lbs @ 0” lift to 262.5lbs @ .335” lift.
This is a differential pressure of 141.5lbs

The aggressive characteristic of the T-III spring realizes a greater change in pressure as the valve is compressed and less change in pressure as it nears its free-length and therefore is able to exceed twice its spring pressure, within a shorter travel distance. This is accomplished even though the springs are within 6 lbs of each other when the valve is closed. The impact level of .075” and the considerations of increased offsets are now realized.

It would not be unreasonable for the smaller T-III valve to be run near the early T-II spring spec of approx. 90lbs due to spring characteristics, having a lower peak lift and being a smaller valve.

In this case:
A T-III spring now goes from approx. 90lbs @ 0” lift to 190lbs @ .335” lift.
This is a differential pressure of 100lbs
This equates to a 30% reduction in differential loading while functioning within 8V specifications.
This also explains how a smaller valve realizing less lift can support 7000+RPM while improving belt durability.

Thanks

[turbovanman²]

Stock one's I measured were 120 closed, 240 open.

The springs on my head are 78 closed, 150 open.

I was looking up SRT specs and most aftermarket ones are around 188-220 ish open.

[Pat]

The best target is the lowest level of differential spring rate that provides the greatest return for the modification being made.


Stock CLOSED valve pressures:
The 8V roller installed spring rate: 110-120lb.
The T-III roller installed spring rate: 115-127lb.

Stock OPEN valve pressures:
The 8V roller peak spring rate @.430”: 200 - 215lb.
The T-III roller peak spring rate @.335”: 250 - 275lb.

Please notice that the following occurrences are based on nominal spring rates.
An 8V spring goes from approx. 115lbs @ 0” lift to 207lbs @ .430” lift.
This is a differential pressure of 92lbs

A T-III spring goes from approx. 121lbs @ 0” lift to 262.5lbs @ .335” lift.
This is a differential pressure of 141.5lbs

The aggressive characteristic of the T-III spring realizes a greater change in pressure as the valve is compressed and less change in pressure as it nears its free-length and therefore is able to exceed twice its spring pressure, within a shorter travel distance. This is accomplished even though the springs are within 6 lbs of each other when the valve is closed. The impact level of .075” and the considerations of increased offsets are now realized.

It would not be unreasonable for the smaller T-III valve to be run near the early T-II spring spec of approx. 90lbs due to spring characteristics, having a lower peak lift and being a smaller valve.

In this case:
A T-III spring now goes from approx. 90lbs @ 0” lift to 190lbs @ .335” lift.
This is a differential pressure of 100lbs
This equates to a 30% reduction in differential loading while functioning within 8V specifications.
This also explains how a smaller valve realizing less lift can support 7000+RPM while improving belt durability.

Thanks


Great info...thanks.

[5DIGITS]

Thanks Ken, glad to see you pop in here --- the concept of the amplitude of the differential in spring rates coming into play in shearing the teeth is an interesting additonal aspect to contemplate.

Have you, or do you know anyone who has used an idler-sized tensioner on the front and a increased diameter sprocket as you were suggesting?

Does the additonal tooth engagement (2 teeth?) on the intake cam by using an idler/tensioner up front make enough of an impact that you think it would play a role in fixing the belt problems?

Do you think these changes were well known within Chrysler back in the early-mid nineties (but deemend too expensive or complicated to implement to a fleet of several thousand cars through a TSB) or is this something that was learned through the development of the later twin cam motors and SRT4?

Any thoughts on what is more likely the oil pump killer -- the tension on the end of the belt end of the the intermediate shaft or the speed at which the shaft and pump are made to turn? The front idler addition without changing the sprocket diameter would address the concern of reducing some of the bearing loading on the pump shaft but it seems difficult to determine which is causing the pump failure --- shaft movement from bearing failure or pump failure from over speed/lubrication issues.

Idler tensioner and front sprocket:
Yes and the adjustment capability served well by supporting multiple purposes.
The popular use of an 8V pulley does work and it has been successfully utilized.
The added steps required to use the various adjustment pulley parts is entirely up to the desired level of component accuracy. Knowing the parts exist to accomplish this is a good foundation for a potential future item.

Additional concepts tested:
A center idler was an approach that had the belt coming down between the sprockets. This used a much longer belt for obvious reasons.
The “squeeze” assembly did not use the current tensioner and had a bracket with two idlers at each end and was located above the block mid-line. This looked like a bar-bell with pulleys or as one side of a roller skate.

Tooth engagement:
This is determined by the valve-train hardware. If the hardware is stock, the returns of increased belt-wrap are greater. Likewise, the return of added belt-wrap on modified valve hardware is reduced.

Design changes/issues:
There were many things that were known risks. With the T-III, it started as a complete engine that Lotus had prepared and eventually ending up with what we have today. That is a substantial deviation from what was intended. Unfortunately, the valve train hardware was developed for their higher revving engine and was never revisited after there engine concept was thrifted, due to cost and complexity.

Gears and shaft wear:
Much of this can be answered with “yes”. Tension and speed aggravate the front intermediate shaft bearing while speed and the increased pump gear resistance causes the gulling that fails the gears. The TSB shaft and pump addressed the dissimilar gear surface issues but failed to address the root cause - The design was a bad idea and pushed the assembly beyond its limit.

Thanks and I hope this helps.

[TurboRon25]

I really think it more to do with belt tension. Every failure I have personally dealt with(not my own) has proven to be way too loose of a belt. I checked a few of them with the gauge before I pulled them apart and two of them were right at 45LBS. I was almost thinking that there is a certain number that causes just the right harmonics to cause the failure. Almost like how a certain frequecy will break glass I think its the same concept here. I have even seen a few pumps break off at the mounting flange instead of sheering teeth.



I've never owned or worked on a TIII so I maybe way off base. Anyway.

Is it possible that the I-shaft bearings wore enough to cause the belt tension to drop to 45LBS?

It's like the chicken and the egg, right?

Ron

btw. great thread!

[turbovanman²]

I've never owned or worked on a TIII so I maybe way off base. Anyway.

Is it possible that the I-shaft bearings wore enough to cause the belt tension to drop to 45LBS?

It's like the chicken and the egg, right?

Ron

btw. great thread!

Nah, that would be a ton of slop and things would get messy fast.

[iTurbo]

What kind of wear are you guys seeing on the I-shaft bearing? All the messed up ones I see are cracked with large chips missing.

[tsiconquest88]

i will full in with my failure details tomorrow morning when i drop the pan/pump. (have a post in the help section on this ordeal). 495 miles and mine lost oil pressure this afternoon. BTW jackson i seen you post the first 3 numbers in that warranty p/n thing, do you know the rest? i wouldnt mind finding that kit. Just seen one on ebay a few days back but it was missing the I-shaft and pump, as the guy said he used them, but through an a new oem pump lol. No i-shaft still though he said, but included some other parts the kit has. Something around 4 or 5 or so, parts.

[Lotashelbys]

What kind of wear are you guys seeing on the I-shaft bearing? All the messed up ones I see are cracked with large chips missing.

That sounds about right. EVERY TIII I have ever had apart with the factory bearings in it still looked this way.

[Simsy]

That sounds about right. EVERY TIII I have ever had apart with the factory bearings in it still looked this way.

not the two i had apart;)

[turbovanman²]

i will full in with my failure details tomorrow morning when i drop the pan/pump. (have a post in the help section on this ordeal). 495 miles and mine lost oil pressure this afternoon. BTW jackson i seen you post the first 3 numbers in that warranty p/n thing, do you know the rest? i wouldnt mind finding that kit. Just seen one on ebay a few days back but it was missing the I-shaft and pump, as the guy said he used them, but through an a new oem pump lol. No i-shaft still though he said, but included some other parts the kit has. Something around 4 or 5 or so, parts.

Just use an 8 valve int shaft, stock oil pump that's in good shape.

[tsiconquest88]

well i was thinking of getting the cryo shaft from fwd. I was trying to find that warranty recall kit which has the i-shaft, pump and some other pieces. But the chrysler p/n C3940462 from the moores mopar site isnt matching to anything when i google, the moores mopar site even has the whole bulletin on the site and how to do the recall and all still listed under spirit r/t tab. But i guess that kit isnt available anymore, it came from the national depot's i found out, and i went to their main site and left an email about it and see what they can come up with. Jackson mentioned a p/n for the recall parts under a 466 but cant remember the rest of it. Maybe thats the same kit but changed to the 466 numbers after a while.

[turbovanman²]

The kits pop up on Ebay but you don't need the kit, just get 8 valve stuff, cheaper too.

[omnigoestohell]

Thanks Ken, Jackson for the replies.

Jackson, similar to what Ondonti said I can't think that measuring the tension after the belt has stripped the teeth around the crankshaft could come up with a good number for what belt tension was previously. Whenever I've had belts fail they've been missing all the teeth around the crankshaft --- not having those teeth I'd think would relieve a bunch of the pressure on the whole belt and make the tension read much lower.

Anyway, I'm going to try to fit a idler to the front of my 8v accessory setup today, I think the alternator bracket might have a spot where that would work.

[tsiconquest88]

why do that on the 8 valve? this isnt an issue on them. For whatever reason.

[lengel]

Thanks Ken, Jackson for the replies.

Jackson, similar to what Ondonti said I can't think that measuring the tension after the belt has stripped the teeth around the crankshaft could come up with a good number for what belt tension was previously. Whenever I've had belts fail they've been missing all the teeth around the crankshaft --- not having those teeth I'd think would relieve a bunch of the pressure on the whole belt and make the tension read much lower.

Anyway, I'm going to try to fit a idler to the front of my 8v accessory setup today, I think the alternator bracket might have a spot where that would work.

I think Jackson is talking about when the gears strip on the I-shaft/oil pump. He checks the tension before he takes it apart, and find that they are too loose. I dont think he is talking about a stripped timing belt.

[tsiconquest88]

your right lengel, thats exactly whats being discussed here. If omnigoes is indeed talking about stripped teeth on a tbelt its usually cus the thing is old and needs to be replaced haha. Not i shaft failure. I have seen teeth missing on tbelts. And its a matter of old belt. OR of course teeth on cam.crank gears being damaged causing tearing of the belt.

[Lotashelbys]

I think Jackson is talking about when the gears strip on the I-shaft/oil pump. He checks the tension before he takes it apart, and find that they are too loose. I dont think he is talking about a stripped timing belt.

yep thats what I meant.

[omnigoestohell]

why do that on the 8 valve? this isnt an issue on them. For whatever reason.

This is the T3 forum of course! I guess to most guys in this forum the concept of running 8v accessories on a T3 motor is not on the top of their head. I didn't get my 8v alt bracket idler mocked up the other day but hopefully will get to do it soon.

Thanks for the clarification Jackson on meaning the oil pump gear. My brain was thinking timing belts because thats what I went through the most of.

[MNmopar]

Just bumping this because it's a great thread in case someone else like myself, missed it...

[Directconnection]

How did I miss out on all of Ken's great posts in this thread??? Just finding it now....

[ScottD]

Good thread.

This is what I have done to my R/T to help it's reliability. Though I would like to note I've owned this car since 1998 and other than shifter bushings and an SBEC that was installed right after purchase, the head gasket I installed last fall was the first major work I've had to do to it. Now granted I've put about 15k on the car during my ownership and don't drive it daily, but when it does come out it tends to go on extended drives.

1. Titanium retainers
2. Wrap 02 wires in thermal tape. Also made a little heat barrier out of bar stock that the 02 wires now lay across. It attaches using the air box nuts/bolts.
3. New timing belt. Bought a belt tension gauge and set belt tension at 95lbs per Jackson's recommendation. Also it is important to re-check belt tension after installing a new belt because the belt stretches. I initially set my belt at 100 thinking it would stretch and go down to 95, after driving for a bit I was surprised to see tension had dropped to 80.
4. New outer intermediate shaft bearing. Ideally I would have replaced the inner as well when I did this but it's a bit tough to do in car and my outer was just starting to flake and not that bad. If your outer is bad def replace both. This is something all T3 owners should check if it has not been done.
5. Cometic head gasket with ARP studs. The stock gasket tends to leak at back corner.
6. Poly shifter bushings - stock ones tend to fall apart over the years.
7. Used Carroll's idea for the GM Vortec V6 valve cover gaskets.

My car still has the stock vacuum lines on it, I was really careful when I removed them to do the head gasket and they are in good shape. I wanted to keep the car original, otherwise I would have gone to a vacuum block set up like I did on my 86 GLHS.

[Force Fed Mopar]

Thread rez for great info :nod: