I recently got the heads on my 1976 460 redone. There were new exhaust seats installed and i got new intake and exhaust valves. I reused my old valve springs and keepers. The heads were not shaved. I took the opportunity to install an Edelbrock Performer cam and lifters with a timing set for a pre 72 motor. All the pushrods were the same length. The problem I have is that after following Edelbrocks recommended break in procedure, I had a nasty timing problem. No, the distributor wasnt 180 degrees out. The motor has low compression (around 90 psi) and kept backfiring through the carb. After not receiving a good answer from any manufactures tech lines, I tore the motor back down. I found that the lifters in cylinders 2 and 6 and one on the exhaust side of 7 were badly worn down. The cam is ruined. Anybody know what causes this? Could I have a bad set of lifters? Pushrod length wrong? Im using the stock nonadjustable rockers. Any help would be much appreciated since this damn truck is driving me NUTS.

 

Did you change the cam bearings before you installed the new cam? Also did you soak the cam lobes and lifter bottoms in assembly lube? Sometimes the cam lobes get wipes from a lack of lube. I know you said you followed the directions but you can't let it sit for a long time or the lube will drip off. One more thing that came to mind, you mentioned that you reused your old springs and keepers. What are the seat pressures at? If they are too heavy you will wipe the lobes everytime. BTW 90 psi seems really low, are you piston rings worn?

 

I can't give you a solid answer, but I read alot about people installing cams-lifters etc and having trouble. I read alot of responses from people, but nothing makes sense to me. I started building engines in 1965, in auto shop at high school. I ended building engines professional 1986. The last boss I had was a Crew Chief at the Indy 500. and I never saw cam lifter failures like today. The only thing that makes sense to me is cams too soft, lifters too hard, etc. We import alot of our metal from overseas. NOBODY IS GOING TO CONVINCE ME THAT THE PROBLEM IS ANYTHING BUT THE MANUFACTURES, PERIOD, they won't own it, and most people won't believe what I just said, they blame oil lack of, or wrong type, and any one of a hundred things. I do alot of blacksmithing today and you can harden & temper USA made metal & import metal to the same Rockwell and get different wear factors, why impurities in the metal.

 

https://www.ford-trucks.com/forums/s...d.php?t=439087

 

https://www.ford-trucks.com/forums/s...d.php?t=436146

 

You can, but one shouldn't expect such things in a $79.95 rebuilder cam.

 

well a few things come to mind. did you follow cam break in? the secind you start it it must be brought up to 2500 rpm then vary it +/- 300 rpm for 30 minutes. also did resuse old pushrods? the last thing is what oil did you run? could be a lack of zddp.

 

That was a thought I had after posting, Race cams & lifters what $600 +. These $200 cam & lifer kits I'm sure are made with cheaper steels, heck,a CNC machine will cut a stock cam as fast as a racing cam, so why are race cams three times as expensive?

 

most are roller cams, require special programs to cut and quailty steel cores.

 

There are also several posts that state that the new API SAE spec oils do not have sufficient additives due to smog regs, so many performance cams do not get sufficient lubrication and more importantly protection that the additives gave. Several cam manufacturers recommend oils that are not aththe current spec(SM or SL??).

The posts recommend using a diesel spec oil since they still have the proper additives for perfromance cams.

Also, historically, occasionally you got a soft load of lifters or cams. I guess it can still happen.

Good Luck,

Jim Henderson