Are my lifters/cam cooked? PICS

[Dan H.]

If I recall correct, I was told that lifters should have a convex surface. If they are flat or concave they are wore out and the cam and lifters should be replaced.

Car is a 1971 LT-1. 49,000 miles. Motor all original, never apart until now. I have pulled 5 lifters now and they all look like this.........

Looks concave to me



Heres how I set up the pic

[Gene M.]

Re: Are my lifters/cam cooked? PICS

I think the lifter crown should be reverse of what your picture shows.

[Dan H.]

Re: Are my lifters/cam cooked? PICS

I think your right but I'm a newbie so I'm aksing the guru's

[Clem Z.]

Re: Are my lifters/cam cooked? PICS

the convex surface is there to cause the lifters to rotate and and to complement the slight taper ground into each lobe that causes the camshaft to be pushed rearward in the engine. you can not just change liters as you need to change the cam also. if the lifters look like they are still rotating and you can install them back in the original place they should run without a problem for many miles as they are worn in together.

[Dan H.]

Re: Are my lifters/cam cooked? PICS

Pics without the knife in the way. Different angles of the same lifter.

[Gene M.]

Re: Are my lifters/cam cooked? PICS

With that much wear why not replace cam and lifters and have peace of mind? I would. It only takes one cam lobe to make it all junk and run like crap.

[Joe L.]

Re: Are my lifters/cam cooked? PICS

the convex surface is there to cause the lifters to rotate and and to complement the slight taper ground into each lobe that causes the camshaft to be pushed rearward in the engine. you can not just change liters as you need to change the cam also. if the lifters look like they are still rotating and you can install them back in the original place they should run without a problem for many miles as they are worn in together.

clem-----


I agree.

[Joe L.]

Re: Are my lifters/cam cooked? PICS

Pics without the knife in the way. Different angles of the same lifter.

Dan------


One slight problem if you decide to replace. These are what's called "edge orifice" mechanical lifters. This type was used for most small blocks with mechanical lifters, including all LT-1. I know of no source for this type of mechanical lifter from any current manufacturing source. If you replace the cam and lifters you will have to go with piddle valve type lifters (the type originally used on all big blocks with mechanical lifters). These will work OK but they're not what was originally used.

[Timothy B.]

Re: Are my lifters/cam cooked? PICS

Dan,

A few years ago when I had the intake manifold manifold off my 67 to find the dropped heat crossover freeze plug, (another story), the lifters looked about the same as yours. The car ran fine before and all showed about the same wear so I re-used them and all is still fine.

It's a judgement call as these are wearing parts and consider what Joe say's above about the edge orifice solid lifter. If you don't put high milage on the car it may be better to assemble without changing lifters. Removing the radiator and oil pan etc. is a much larger job than intake manifold. How did the engine run before and why did you take it apart..

[Duke W.]

Re: Are my lifters/cam cooked? PICS

Granted, the lifters seem to be "out of spec", but measure some cam lobes to see if there is any wear on them. The LT1 cam's gross lobe lifts are .306/.323"

Duke

[Dan H.]

Re: Are my lifters/cam cooked? PICS

Thank you all for your responses. I have a pretty big decision to make. Heads are already off to get overhauled.

[Terry D.]

Re: Are my lifters/cam cooked? PICS

Dan
Why did the heads need overhauled? I'd ask myself, if heads need redone and cam is wearing, what's the bottom end like? Did you take a compression or leak down test before you took heads off? Seen lots of guys redo a top end only to have the bottom let go a little while later. If it was me and I planned on keeping the car I'd rebuild the whole motor. Just my two cents.
Terry