Valve spring ?

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71swing

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Im pondering the idea of going with a bigger cam for my 408. Comp cams recommened their 20-228-4 cam.
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=632&sb=2

It states below in the link that this cam is not to be used with stock springs. I have eddlebrock rpm heads that come with springs good to .575 lift. will these springs do the job or should I really make the switch to a double spring?

If I need to buy new springs?
I understand the the inner spring on the double springs needs to be removed for the cam break in. If this is the case can I install the cam and break it in under my current springs then replace them with double springs or should I do it with the new springs outer spring only?
 
I think you are close to the limit of that spring but I believe you are on the right track. I would brake it in with your current rpm spring and see how it performs making sure check for coil bind at full lift.
 
i was looking at that same cam the kit for it has a double spring if u go to a 229-4 u need more stall if you have the stall and headers go with the 305 h kit gr8 bottomend tourque and pull thru midrange all the way thru top if not go thru the break in prosess right dont bite your self in the *** because a couple hrs work or you might eat a lobe or worse eat a motor took you this long whats another day and u got brand new springs
 
ya I got a 3800 stall right now. I have no problem getting the springs. just asking. I just wasn't looking forward to changing the springs twice. If I can break it in with the current springs then change them out for the doubles it would save me alot of work and time. Justa not thrilled to drop $500 on the complete kit
 
The issue isn't as much of will the Eddy springs handle the lift is do they have enough pressure to keep the valves seated properly at higher RPM's. The stock Eddy springs should work fine for break-in but I'd swap them out for the spring the cam calls for after that because the springs they want used on that cam are pretty stout. I don't know what the spring installed ht. is with your Eddy springs but you need to check to see if that matches the springs they recommend. If it doesn't you may need to call Comp and see if they have another dual spring set that will work.
 
Valve spring spec for eddy heads...

For Hydro. Flat Tappet Cam
Valve Spring Installed Height: 1.800"
Valve Spring Seat Pressure: 120 lbs.
Max. Valve Lift: .575"
 
yeah..was looking all over the place for specs...found those on the instruction sheet for the heads....was looking to use the stock eddy springs with a new cam....but the look kind of weak .....
 
 
71swing said:
http://www.edelbrock.com/automotive_new/mc/valvetrain/springs_retainers.shtml

Well here is what their website shows. It shows the springs for rpm performer heads are the 5777's. It list the 5767's as a ford spring.

------------------------Seat pressure-------O.D / I.D.----Spring height
Chrysler
318-340-360 V8 5777 91-100 lbs----1.500"/1.075"----1.650"
Click to expand...

The 5777 spring is for the performer rpm cam used on stock heads.

Look here....http://www.summitracing.com/parts/edl-60779/replacementparts/part-type/valve-springs
 
Does anyone happen to know the right install centerline for my current cam? Any ideas on what it will pull on vacuum?

[email protected]/L-- Cen/line-------Lift-------RPMs

*P5007695______ 284/284___ 241/241_ 56____114____.484/.484__2800-6000
 
71swing said:
Does anyone happen to know the right install centerline for my current cam? Any ideas on what it will pull on vacuum?

[email protected]/L-- Cen/line-------Lift-------RPMs

*P5007695______ 284/284___ 241/241_ 56____114____.484/.484__2800-6000
Click to expand...

Here is my dilemma. Switching my current cam out for more cam is becoming more than I was looking for. I'm already way over my intended budget. I originally threw out the idea because I’m not sure of what I have in the car now. I know the cam; I still have the receipt for it when purchased 5 years ago. But I never had a cam card for it and at the time I thought it was to be installed at 112* so I did. But soon after I questioned that and never could find anything to prove otherwise. While my 408 was at the builder being assembled I thought I came across something that said to install it and 114* so that what I told the builder to degree it to. Now that the motor is back home I tried to confirm that before dropping it back into the car and now can’t find anything on it. My may concern is I don’t know the install centerline and were I’m at now if advanced/retarded. I could be as far as 6* if the install centerline should be 108*. So I looked into getting a new cam to start fresh. I am also concerned with the vacuum. Never ran a gauge on the old motor so I don’t know what it was before because I’m installing a FAST Ez efi this time around and I need at least -10 at idle.

If you haven’t figured it out yet cam spec are way over my head. I have no understanding of them. I cant find crap on the cam I have now, It doesnt even appear they sell it anymore.
 
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