Valve Springs

[ssjkakkarotx]

I am looking for help on choosing new valve springs. I have a new cam going in. It's a Comp Cam 68-231-4 462in 485ex. I know the stock springs are good for 430 so i don't think they can handle the new cam. So what kind of springs should i be using to replace them? Does anyone have expirience with this problem. any help will be great

 

[5-90]

Get the ones that are recommended for that cam - I'm fairly sure that Comp recommends springs for each cam. If you haven't ordered your stick yet, you might be able to get it as a kit with springs, lifters, and associated parts.

5-90

 

[ssjkakkarotx]

I already got the cam. It came with my stroker kit. I have checked Comps site and they have a spring but virtually no info on the spring. Do I need to mill the head ? Do i need special locks? I am hoping someone here has been through this before, and has some advice

 

[5-90]

Can't say as I have - yet - but I'd think if there were special issues, you'd have it called out fairly quickly. It's always possible to email or call them and ask, if you'd like to be sure.

5-90

 

[Cjmartz2k]

The compcams springs do require the valve seats to be milled. You can get the mopar performance springs, locks, and retainers for the 318 I believe, and they will fit on the stock seats just fine, and can handle up to .500 lift if I remember correctly. I ran them on my old 4.0 with a crane cam running .484 lift and they worked great. Do a search on here or maybe JU and you'll be able to get part numbers, or just go to Dino's site. My new stroker has compcams springs with one of there bumpsticks pushing .513 lift.

 

[Dr. Dyno]

The compcams springs do require the valve seats to be milled.

Indeed they do. I think the installed height of the CompCams springs is something like 1.80" whereas the stock springs and Mopar Performance springs install at 1.64".

You can get the mopar performance springs, locks, and retainers for the 318 I believe, and they will fit on the stock seats just fine, and can handle up to .500 lift if I remember correctly. I ran them on my old 4.0 with a crane cam running .484 lift and they worked great. Do a search on here or maybe JU and you'll be able to get part numbers, or just go to Dino's site. My new stroker has compcams springs with one of there bumpsticks pushing .513 lift.

The Mopar springs that I used on my stroker with the Crane 753905 cam (0.456/0.484 lift) are rated up to 0.525" of lift. The part nos. of the springs, retainers, and locks that I used are on this page of my stroker site.

 

[FUNKYTEE5]

I used the Comp recommended 926 springs with the 68-232-4 cam 460in 476ex lift. The springs were installed at the recommended 1.8". I ended up with alot of valvetrain noise. It was ticking at idle and got progressively louder as the rpms increased and was clearly audible inside cab while driving. The rocker geometry was dead on as far as: valve tip contact, bind clearances, pushrod length etc... I figured it must be a bad set of lifters that were bleeding too fast??? After some looking into the 926 spring specs, I found that they are pretty aggressive with a 415lb/in spring rate making my open pressure over 300lbs and seat pressure around 115lbs seat (tested). Randomly, I looked up some stock specs for 4.0 springs and they were around 70lbs seat and 210lbs open, that gave me an idea. In a last ditch effort to quiet my valvetrain down I found some Crane 99833 springs off Ebay. They are much less aggressive at 328lbs/in spring rate and 98lbs at 1.7" install height. I installed them and instantly my valvetrain was MUCH quieter. Curious, I took more spring shims out and installed them at 1.76", which would make about 80-85lbs seat and around 240lbs open. Now, with this cam and way less spring pressure than recommended, would valve float be an issue? I fired it up and it was again quieter and showed zero signs of float all the way to the rev limiter. It's been running flawlessly for 8k now with zero ticking at idle. I was very suprised in how dropping the spring pressure greatly reduced the amount of noise coming from the valvetrain. Which again makes me wonder why the Comp tech's insisted on 926 springs for this application. Is there any advantages of having excessive spring pressure?

 

[5-90]

Reduces spring float at high RPM - tradeoff being higher potential camshaft/lifter wear.

5-90

 

[Dr. Dyno]

After some looking into the 926 spring specs, I found that they are pretty aggressive with a 415lb/in spring rate making my open pressure over 300lbs and seat pressure around 115lbs seat (tested).

Definitely too aggressive. A 109lb closed pressure and 300+lb open pressure is way too much for a relatively mild cam like the Compcams 68-232-4. While it increases the rpm threshold for valve float, the price you pay is more rapid cam lobe/lifter wear.

In a last ditch effort to quiet my valvetrain down I found some Crane 99833 springs off Ebay. They are much less aggressive at 328lbs/in spring rate and 98lbs at 1.7" install height. I installed them and instantly my valvetrain was MUCH quieter. Curious, I took more spring shims out and installed them at 1.76", which would make about 80-85lbs seat and around 240lbs open. Now, with this cam and way less spring pressure than recommended, would valve float be an issue? I fired it up and it was again quieter and showed zero signs of float all the way to the rev limiter.

Sounds like you've made the right choice of valve springs and you shouldn't get valve float until at least 5400rpm which is beyond the rev limiter.

 

[MudDawg]

Cam lobe ramp rates have a lot to do with required spring pressure. Short duration "torque" cams require less spring than long duration "race" cams of similar lift.

 

[xj92]

I realize this is an old post, but it seems more appropriate than starting another one on the exact same topic.

My question relates to a 2.5, but everything should apply from the 4.0 knowledge some of you guys have. I'm looking at a Mopar Stage 3 cam for the 2.5 (PN P4529658, Lift .450, Duration 256, Overlap 40, Centerline 106). Will I need new springs for it, and if so, can somebody point me to which ones? This is an out of production cam, but new in box with the tappets. Also, how agressive a profile is this? Will it still idle smooth and run quietly? Thanks.

 

[old_man]

I ran the Mopar Stage III aka purple cam with the stock springs just fine. The engine lasted many years until it got hydrolocked.

 

[xj92]

Any adjustments necessary to the valve spring height or just run it as-is? I had the head rebuilt and ported a year ago so it's pretty fresh already.

 

[gradon]

I have the stage 3 mopar cam in my stroker(same specs as your stage 3) and I used the springs that mopar recommended for them: P5249464 springs, P4452032 retainers , & P4529218 locks. These springs are good for lifts up to .525" and require no machining of the seat. The valve cover might require some clearancing on the driver's side. I bought them through Jeepconnection/Mopartsracing.com.

 

[xj92]

Old Man, did you get any valve float between 4000 and 5000 rpm using the stock springs? I've read elsewhere of that issue and I like to be able to take it all the way to 5000 rpms when necessary.

 

[xj92]

After discussing everything with the machine shop that has previously rebuilt two heads for me, I think I am going to get the springs Mopar recommends for my cam. Gradon or anybody else that has run the P5249464 springs, are the retainers and locks necessary as well or can I keep those stock components? www.monicattichrysler.com seems to have the best prices I have found.

 

[gradon]

I never compared the stock retainers and locks with the ones I mentioned previously to see if they were compatible. . .

 

[Talyn]

IIRC the stock retainer aren't compatible but the locks are.

 

[sdryde]

this is what I used it works great

ho 7120 head
comp cam 68-232-4
comp lifters
mopar springs 5249464
mopar retainers 4452032

---Justin

 

[xj92]

Any of you guys that have modded these engines ever dyno'd them? I don't know if I will or not, but I was just curious. I went ahead and orderd the mopar springs, retainers, and keepers. I also talked with my machine shop and they're going to deck the block for me to get a .040" quench height (with the head gasket installed). Now I'm on to researching pistons to see if it's worth swapping them out or not because the engine currently has .030 over dished pistons which combats the high cr I'm trying to achieve.