Dr. Fred Cam problem

chadder1313

Registered User
Dr. Fred Cam problem PLEASE HELP

Ive installed the cam and im having some valve train problems. It sounds like im having a lifter not pump up but there brand new. I am running stock springs. Can i run stock springs? Its making a taping/ knocking sound that it has not made before. Thanks for any help
 
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the cam that fred made will not work with stock springs. They will coil bind. Not sure if thats your problem, but i would not run the car, as you are just asking to damage parts. Pull everything apart and look things over.
 
you can push the .520 cam with stock springs, barely, and it requires pushrods from like a 92ish Chevrolet 350, whatever is slightly longer than a stock SCs
 
Thanks guys

Ok if i need longer pushrods then how much longer do they need to be, where can i get these and how much would they run me? Thanks alot guys. :D
 
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OK who here is already scared??? :eek:

So you installed a 520 lift cam?

If you installed a Dr Fred 520 lift cam you must replace the valve springs and pushrods. If you install a cam you should really really really install a set of 1.73 roller rockers.

Ford 1.73 roller rockers and RM-7808-16 5-16" Pushrods 7.195" (1993-97 350 LT1) hardened steel. Check your valve lash and shim as needed.

Valve springs needed are the 942.

You cannot adjust valve lash without shims. Ford Racing sells Roller rocker shims too.
 
I have the same cam. As assclown said you can just get away with the stock springs, but I changed mine anyway. YOU DO NEED LONGER PUSHRODS. good luck with it.
 
Oh My God!!!

Rich Thomson said:
OK who here is already scared??? :eek:

So you installed a 520 lift cam?

If you installed a Dr Fred 520 lift cam you must replace the valve springs and pushrods. If you install a cam you should really really really install a set of 1.73 roller rockers.

Ford 1.73 roller rockers and RM-7808-16 5-16" Pushrods 7.195" (1993-97 350 LT1) hardened steel. Check your valve lash and shim as needed.

Valve springs needed are the 942.

You cannot adjust valve lash without shims. Ford Racing sells Roller rocker shims too.


Well, This is where that almighty "search" function comes in handy. A word to the wise:

DO YOUR HOMEWORK!!!

You can't just install things and hope for the best. This is where people get into trouble. Not being crass, just worried that after putting all that stuff together, you are now going to have to take them off. Nevermind the hassle of getting new springs (means heads are coming off....) and such.

I would NOT I REPEAT not start the car. You will bind a spring and cause valvetrain damage along with possibly damaging the bottom end if something lets loose.


Don
 
My how misinformation abounds.....

The .520 cam will not cause coil bind on the stock springs. The stock springs coil bind at roughly .560" meaning that you have .040" to coil bind which is not enough to run the springs safely, but it won't result in broken parts just from starting up the motor either.

Also, it is not necessary to remove the heads to change valve springs. To change valve springs, all you need to do is pressurize the cylinder with air and then use a lever type spring compressor to remove the locks and retainers. If you get the right springs, then they will drop right in and you will be on your way.

And yes, you will need the longer pushrods and quite possibly pedestal shims. You will have to set lifter pre-load.
 
i agree...its not the springs that are causing this noise, but they should be swapped out.

Your noise is most likely coming from your pushrods being way to short. They are too short, and they are not providing the correct lifter preload. All this play in there is prob. causing noise and the lifters are not being pumped enough.

Pull it apart, change the springs, and get some longer pushrods. Once you swap those two out, then you can check lifter preload and shim if needed. I got lucky and my preload was within spec and I didn't need to shim anything.
 
like i said if you want to HALFASS IT (nothing to do with my name :rolleyes: ), run the stock springs with no more than 18PSI of boost and 6 grand redline and use the chevrolet pushrods FROM ANY PARTS STORE, you can even re-use the stock rockers, the stock push rods might work 1 out of say 234534 times but not this time, you need at least 1/4 turn past contact on the pedestal bolts for pre-load and 1 turn or so max<--you have no idea what this is so just buy the GM rods :rolleyes:
 
Yes guys it is his .520 lift cam. So i can go to a parts store and buy some LT1 push rods and they will work fine. And i will pick some roller rockers up. Thanks guys for all the advise. i really appreciate it. :)
 
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