1986 Dodge Daytona Turbo Z T3 DOHC Tuned at FwdPerformance

[5DIGITS]

Awesome build, looks great and love those rear wheels.

I would say aftermarket cams are needed or for my setup they sure were.
My Stage 2 cams made power to at least 7500rpm, and she was still pulling.
I took them out and put stockers in, blah, stopped pulling around 6200 rpm IIRC.
I could have spun that sucker to probably 8500 and it would still have made power.
I miss my van,

Cam regrinds alter the opening and closing events relative to the base circle.
This along with camshaft installation angles (stock or regrind) will impact where the power is realized.
Considering that the stock T-III valve train was designed to support 8500+RPM, it's no surprise they can be installed in a manner to do so.
It comes down to preference for a high advertised peak number or a potentially lower peak for wide power bands and area under the curve.
This is how cars making less peak power with wider power bands out accelerate the narrow peaks of higher RPM vehicles.

[turbovanman²]

Cam regrinds alter the opening and closing events relative to the base circle.
This along with camshaft installation angles (stock or regrind) will impact where the power is realized.
Considering that the stock T-III valve train was designed to support 8500+RPM, it's no surprise they can be installed in a manner to do so.
It comes down to preference for a high advertised peak number or a potentially lower peak for wide power bands and area under the curve.
This is how cars making less peak power with wider power bands out accelerate the narrow peaks of higher RPM vehicles.

Totally agree, I"d still have the Stage 2 cams but the lower vacuum didn't play well with the auto at idle in D. They had power all over the place, including the bottom end. Now I am going to a 5 speed, wouldn't mind getting another set.

[turboshelbys]

I have a set of performance cams in my other motor, but am more than happy with how this one is spinning. I want so bad to hit this motor with a 35psi pull, but the stock rods worry me.

[5DIGITS]

I have a set of performance cams in my other motor, but am more than happy with how this one is spinning. I want so bad to hit this motor with a 35psi pull, but the stock rods worry me.

Run the pistons out of the hole by .035-.040", raise the compression ratio and these boost levels are no longer needed.
In other words, induction system thermal rejection demands decrease, compressor efficiency increases and the engine makes the same power at 20-22 psi as it would at 30+ PSI.
I simply cringe at the 'blow on it harder' approach when so many other areas can gain power.

[turboshelbys]

Run the pistons out of the hole by .035-.040", raise the compression ratio and these boost levels are no longer needed.
In other words, induction system thermal rejection demands decrease, compressor efficiency increases and the engine makes the same power at 20-22 psi as it would at 30+ PSI.
I simply cringe at the 'blow on it harder' approach when so many other areas can gain power.

It's funny that you wrote that because that is exactly how my other motor is set up! Trust me I am all for getting more power with less spinning and boost.

We have taken this engine up 6950rpm. I know there is more to be had as the power has not yet dropped off, but with the stock rods I am not willing to scud bomb a perfectly good motor by revving the snot out of it or cranking up the boost. Honestly I thought we would get 350-375whp out of this test motor. I was blown away that James was able to get 474whp @ 26psi at 6950rpm on pump gas.

[Vigo]

Now you just have to do like he did with that 2.4L CSX and go run some 10s first time out.

[5DIGITS]

It's funny that you wrote that because that is exactly how my other motor is set up! Trust me I am all for getting more power with less spinning and boost.

We have taken this engine up 6950rpm.
I know there is more to be had as the power has not yet dropped off, but with the stock rods I am not willing to scud bomb a perfectly good motor by revving the snot out of it or cranking up the boost.
Honestly I thought we would get 350-375whp out of this test motor.
I was blown away that James was able to get 474whp @ 26psi at 6950rpm on pump gas.

That's smart.. it'll be around to enjoy !

[turbovanman²]

Run the pistons out of the hole by .035-.040", raise the compression ratio and these boost levels are no longer needed.
In other words, induction system thermal rejection demands decrease, compressor efficiency increases and the engine makes the same power at 20-22 psi as it would at 30+ PSI.
I simply cringe at the 'blow on it harder' approach when so many other areas can gain power.

But doesn't higher compression mean a hotter charge at the same boost, IE 20 psi? So more chance of detonation? Do you mill the block to get them that high out of the hole?

[5DIGITS]

But doesn't higher compression mean a hotter charge at the same boost, IE 20 psi? So more chance of detonation? Do you mill the block to get them that high out of the hole?

Yes - I mill the block.
When milling the head, there's no gain in squish and knock suppression.
If nothing else were considered, then the combustion charge would indeed go up.
You end up with an engine that runs more spark advance, better heat rejection from the piston into the head, at higher compression/combustion efficiency, with lower inlet temps, after re-calibrating for A/F and EGT's.

[turbovanman²]

Great advice, thanks. Just learned something new.

[Reaper1]

How does milling the block affect block deck flex?

With being able to have very good control over the engine (well, and better engine technology all around), it's not uncommon to hear about people running 9.0-10.5:1 compression on pump gas in mid-boost engines. There are tons of advantages to doing this, but I think part of the issue with doing it on a TM is the fact that we can't leave anything alone! LOL Having the "cushion" to be able to turn the dial-a-death (more boost) is not only comforting, but in some cases it's just plain needed (like a straight jacket and a rubber room).

If I were planning to build an engine with a specific power level in mind and I knew I was never going to mess with it again...I would run as high static compression as I could get away with. At least that would be my blanket decision right now...I would certainly do a lot of research before I actually built it and then my answer might change, so YMMV.

[5DIGITS]

How does milling the block affect block deck flex?

With being able to have very good control over the engine (well, and better engine technology all around), it's not uncommon to hear about people running 9.0-10.5:1 compression on pump gas in mid-boost engines. There are tons of advantages to doing this, but I think part of the issue with doing it on a TM is the fact that we can't leave anything alone! LOL Having the "cushion" to be able to turn the dial-a-death (more boost) is not only comforting, but in some cases it's just plain needed (like a straight jacket and a rubber room).

If I were planning to build an engine with a specific power level in mind and I knew I was never going to mess with it again...I would run as high static compression as I could get away with. At least that would be my blanket decision right now...I would certainly do a lot of research before I actually built it and then my answer might change, so YMMV.

"Dial-a-death".. That is the best way I've ever heard it said.. "Heck, if it feels this good at 18psi then it must be amazing at 25+... lets try it!!"

It all comes down to the intended duty cycle of the vehicle and the associated 'time at load'.
Light cars can run higher boost, leaner and with more spark and the other way around with heavy vehicles.
This is where "I have a great cal in my Omni, wanna try it in your minivan?" goes terribly wrong.
In either case, anything that can be done to suppress knock and increase combustion efficiency will benefit both.
This can be achieved partly by increasing squish and condensing the combustion charge near TDC, to extend the 'active' burn.
To your excellent point, knowing the system limit is key and the poor choice of crossing that threshold comes with risk.

The later blocks handle the milling better due to the webbing mods made through the years.
Although, this has been completed on pre-common block with ARP studs without issue.

[Reaper1]

"Dial-a-death".. That is the best way I've ever heard it said.. "Heck, if it feels this good at 18psi then it must be amazing at 25+... lets try it!!"

The later blocks handle the milling better due to the webbing mods made through the years.
Although, this has been completed on pre-common block with ARP studs without issue.

I got the "dial-a-death" from a air-cooled Porsche guy. Apparently that's the knickname given to the boost control knob that they would run on the race cars (it was a pretty big knob, too). From what I understand it's a well earned name!

Good to know on the block. Have you played around with running longer rods and a milled deck? If so, did you end up with piston ring rail plugs?

[glhs875]

"Dial-a-death".. That is the best way I've ever heard it said.. "Heck, if it feels this good at 18psi then it must be amazing at 25+... lets try it!!"

It all comes down to the intended duty cycle of the vehicle and the associated 'time at load'.
Light cars can run higher boost, leaner and with more spark and the other way around with heavy vehicles.
This is where "I have a great cal in my Omni, wanna try it in your minivan?" goes terribly wrong.
In either case, anything that can be done to suppress knock and increase combustion efficiency will benefit both.
This can be achieved partly by increasing squish and condensing the combustion charge near TDC, to extend the 'active' burn.
To your excellent point, knowing the system limit is key and the poor choice of crossing that threshold comes with risk.

The later blocks handle the milling better due to the webbing mods made through the years.
Although, this has been completed on pre-common block with ARP studs without issue.

I plan on using a .027 Cometic headgasket instead of milling the deck.

[turbovanman²]

"Dial-a-death".. That is the best way I've ever heard it said.. "Heck, if it feels this good at 18psi then it must be amazing at 25+... lets try it!!"
.

I've killed many an engine with that damn knob. The red mist takes over,

[turboshelbys]

Yes - I mill the block.
When milling the head, there's no gain in squish and knock suppression.
If nothing else were considered, then the combustion charge would indeed go up.
You end up with an engine that runs more spark advance, better heat rejection from the piston into the head, at higher compression/combustion efficiency, with lower inlet temps, after re-calibrating for A/F and EGT's.

I milled the block as well and had a custom cometic headgasket made. Was able to use stock length BC rods, so all will hopefully be well

[turboshelbys]

I plan on using a .027 Cometic headgasket instead of milling the deck.

This has been done with fairly good results as well on lower boosted cars(18-24psi). Not sure how the headgasket will hold up as a combustion chamber on high boost

MY BAD, I read that wrong, thinner lol

[turboshelbys]

on a side note, this should ship some more air in

[turbovanman²]

Like.

[turboshelbys]

"Dial-a-death".. That is the best way I've ever heard it said.. "Heck, if it feels this good at 18psi then it must be amazing at 25+... lets try it!!"

It all comes down to the intended duty cycle of the vehicle and the associated 'time at load'.
Light cars can run higher boost, leaner and with more spark and the other way around with heavy vehicles.
This is where "I have a great cal in my Omni, wanna try it in your minivan?" goes terribly wrong.
In either case, anything that can be done to suppress knock and increase combustion efficiency will benefit both.
This can be achieved partly by increasing squish and condensing the combustion charge near TDC, to extend the 'active' burn.
To your excellent point, knowing the system limit is key and the poor choice of crossing that threshold comes with risk.

I have to tell you that having a fully controllable stand alone system definitely helps

- - - Updated - - -

Like.

Thanks, cant wait to get this assembled on the new motor. Working on the exhaust manifold...