I need some valve spring info.

[94GTC]

I need a little info on the TIII valve springs.
1. Installed height. 1.73"
2. Desired p.s.i. installed 80 p.s.i.??
3. max valve lift. ??
4. coil bind. .???
5. p.s.i. @max lift.
6. Diameter @ top and bottom of spring.
Thanks

[Directconnection]

Nobody seems to have a clue as I posted the same Q's last year. There is a MAJOR discrepancy of the 1991 FSM and the 1992 FSM when it comes to the specs. I compared a few heads and measured things accurately and with a calibrated valve spring tester. If you do a search... you can find my thread and the posts that follow (I might have done 2 threads...)

I have the #s someplace... just have to dig them out. I seem to recall 110lbs closed and 220 open and .342 lift.... 1.73 seems to ring a bell, but don't go by my crappy memory.

[turbovanman²]

Bah, I've posted more than you on this issue, :p

Dodge used a few suppliers when they built these engines, so there are a few different sets running around. Installed height is 1.73" sounds right, or 1.7", coil bind, you'll never bind them unless your cam is something like .600 of lift.

Most stock are 120 closed, 240 open.

I have some weird springs that are 78 closed, 150 open.

Diameter is 1.17", 2.110" tall.

The 240 open springs are too much, designed for 9000 rpm or higher, causes timing belt issues etc, FWD sells ti retainers to lower the spring tension, I think Jackson sells modified stockers if your on a budget.

Some more info too on cam specs etc-

http://www.turbo-mopar.com/forums/showthread.php?19219-TIII-Valvetrain-information&p=224465&viewfull=1#post224465

[94GTC]

I am looking at a behive spring, that is about 85 on the seat designed for a 4.6 Ford. It would be under 220 open. I would like to get the weight in grams also. I am trying to compare mass to see how much lighter open pressure can be. It would also be easier on rockers and everything else, in addition to being 110,000 miles newer. Valve springs will at some point break from fatigue.

[turbovanman²]

Weight has nothing really to with performance and doesn't affect open and closed pressures, that's built in.

[94GTC]

So you are saying a ti retainer has nothing to do with the spring pressure that is needed? The retainer is lighter on a behive and the upper portion of the spring has less mass.

[turbovanman²]

So you are saying a ti retainer has nothing to do with the spring pressure that is needed? The retainer is lighter on a behive and the upper portion of the spring has less mass.

The retainer yeah, but you said spring, :p Your not going to find anything lighter than the Ti retainer, the stock one is pretty small and light already, hence why they can rev.

The retainer only affects spring pressure by where it sits, that's why the Ti retainers lower the spring pressure as they sit higher on the valve. The keepers on a TIII are very small and not sure what angle they are, so finding something else to use might be hard, but if you find something, schweet, :nod:

[94GTC]

Any mass that has to be slowed down/ stopped will have an effect on needed p.s.i. of the spring from the rocker to the valve. The springs I am looking at, off the shelf, have 81 p.s.i. at 1.75 and 177 p.s.i. at .350 lift and 191 p.s.i. at .400 lift. I don't know if this is enough open p.s.i. Does anyone know the lift of the FWD stage I cams? I might call Crower and ask them their thoughts on how much is needed.

[turbovanman²]

True but the TIII retainer is pretty light already so your not gaining much by finding or making a lighter one. I am using the above rates and spinning to 7500 with no problems.

Can't find my notes but the stage one's should be around .350-.370 lift.

[94GTC]

There is another spring that is 81 p.s.i. on the seat and 186 p.s.i. at .350 lift. That is close to SRT4 pressure with stage 1 cams. Shimmed .050 it would be 96 on the seat and 201 @.350.

[turbovanman²]

There is another spring that is 81 p.s.i. on the seat and 186 p.s.i. at .350 lift. That is close to SRT4 pressure with stage 1 cams. Shimmed .050 it would be 96 on the seat and 201 @.350.

Those are like mine, I would say if they fit, use them.

[GLHNSLHT2]

A beehive should also require less seat pressure because of it's design.

[turbovanman²]

A beehive should also require less seat pressure because of it's design.

True but we have to be careful, the rocker arm weigh's alot, whereas the SRT has a lighter valve train.

[94GTC]

Very true.

[Directconnection]

Me and simon have bashed around this many times... but we are pals.

The stock valves due to the LONG design are HEAVY. Compare their length/weight to any other DOHC 16v design and you'll agree (except for Mr. Sim-o ;-)

I'm not so sold on reducing the spring rates *too much*, but Jackson has experience running high rpms with high boost w/out any valve float. Ti retainers I am sure help with the mass reduction, and I don't disagree with you wanting info on your spring weight, as that does play a factor, too... but obviously a small one.

When I had my custom cams made (basically a Stg.1 at best) the cam designer wanted tons of info. I sent him a rocker/lift combo, too, along with spring, valve, valve lock, lifter, etc... weights. He then did some calculations and his spring recommendations were just a tad shy of stock spec for a 7,500 (or was it 8k? I forget) max rpm motor.

So I'll say.... reduce some weight and don't have any fear reducing the spring pressures at the same time.

Just remember (and this is the basis of my *gut* feeling on why I stayed with stock pressures...which happened to be a bit lower than the FSM specs) High boost requires more spring pressures to overcome the boost pressures acting on the backside of the intake valve (I gave this info to the cam designer, too)

Food for thought...