john73bb

I have been having trouble with my cam moving forward and bumping the inside of the timing chain cover. I finally pulled the intake manifold and valve covers so I could pull the lifters. The first couple of lifters had some minor nicks around the edges at the base of the lifter, but the third one I pulled was cupped pretty badly instead of having a slight convex surface. The wear was probably .025" or more deep! I haven't pulled the cam yet to see how it looks.

What would cause this? Any ideas?




[Modified by john73bb, 7:04 AM 1/25/2002]

Jeff73454

Low oil pressure while idling. You could just have a lot of miles on the motor.

Just replace the cam & lifters if you think the motor is in cgood shape :D

john73bb

The motor was rebuilt about 5K miles ago, and has a high volume oil pump. The pressure, at idle, is never below about 35 psi.

The cam was made by a local grinder, and is a copy of the Crower Baja, I'm not sure what the lifters are (were).

Gordonm

My guess would be not properly broken in or a lack of lube at the initial firing up of the motor. You can ruin a cam in a couple of minutes if not lubed and broken in properly.

mountainmotor

Sounds like the cam is a regrind :nono:
Did you see signs of metal in the valley or in the drained oil on top of the rockers ect?

john73bb

I did not assemble the engine, but presume that the shop that put the block together did it right, although they screwed up enough other things that they may not have. I don't remember what startup procedure I did, but I probably didn't do it right.

What are the issues with regrinds? I didn't know it was a regrind until a year or so after I rebuilt the engine, but the shop that did it does bazillions of cams from briggs and stratton to cams that are longer than I am tall that go in ships.

John.

mountainmotor

John
On the block behind the timing chain there are 3 screw in plugs that cap the oil journals.On the driver side does the plug have a small hole in it? That hole bleeds the air out of the journal on BB Chevy's and will let the oil lube much quicker after oil change ect.This was a Factory fix.If it don't have one it needs this done. A # 20 drill bit will work but remove the plug first.





[Modified by mountainmotor, 11:00 AM 1/25/2002]

john73bb

Great info. I'll check and see. I only remember two plugs, above the cam. There must be another that I don't remember.

mountainmotor

There might only be two.I am getting old :D

MasterDave

Use all the cam break-in lube that will stay on the lobes and lifters. At start up stay at 2000 rpm's for 20 minutes. :cool:

GregP

I had a SB wipe off a couple cam lobes once after a 105 mile one hour run (you do the math, we even stopped and let one person and their luggage out). Put in a new cam and lifters and the problem never recurred, so it can be a one time type thing. (This was when the motor already had 30-40,000 miles)

-Greg

john73bb

You musta been in a horrible hurry :D Are you sure you actually stopped to let the person off or did you just open the door and kick real hard? :lol:

I think I'm going to get a Comp Cams XE268, with 114 degree lobe center and 110 degree centerline (recommended by Comp Cams to work with my fuel injection and other options) and see how it works.

Maurice

I had this problem on 4-5 of my lifters, but mine was a direct result of not having my rocker arms adjusted correctly. The would get too loose and bounce around cause this problem. I had always adjusted my rocker arms without the engine running and I think that is why it happened. Good luck figuring it out.

john73bb

Hmmmm, that might explain the nicks, since that is exactly what I did with my engine afterI rebuilt it. I set it correctly (hot, running) after a couple thousand miles.

Now if I can figure out why the lifter got worn into a cupped shape. :confused:

The Dude

And now for something completely different...

Maurice, tell me about the wheels on your car. I've always thought that style looked hot and period-correct on the sharks. Lots of manufacturers make that style, but what about backspacing and offfset?

Bob Turner

Mountainmotor,

Now I understand what you are talking about regarding drilling that hole.

Thanks,
Bob

Maurice

The rims are centerlines and it is the same backspacing and offset as the ralley rims, I do not need any spacers or anything, they fit perfectly. I bought these from Cappy (8t1-7t9 Bionic Vette) and I will find out where he purchased them from. I really like the look of these also! Thank you.

Kyle69-71 BBs

I had almost the same problem with the 327 in my 63.
It ate two cams very fast.
Look at your heads ....I had worn springs ...(you can remove a few and squeeze them with your hand if you can crush them much, you have a problem)It helps if you have a good one to get the feel with.
Some good mach. shops have a tester but I couldnt get my hands on one.
I ordered a matched set of springs,lifters and cam from edelbrock.
I have driven the car a few hundered miles and this cam is still good.
It wiped the others out in just a few minutes,so that might have solved it all.
My post is not that old so you sould be able to find it in the archives.
l got lots of good replys.

:mad :mad :mad ;) ;) ;) ;)

john73bb

My springs are brand new, with virtually no miles on them (I've been working on the car since I put them in, haven't driven it except once around the block). I pulled the lifters all out, and there are at least 5 or 6 that are seriously cupped, perhaps as much as 1/16"-1/8" of metal removed on some of them. Wow! I've got the radiator out. Tomorrow I plan to pull off the hood, lift the condensor, and pull out the cam to see just how badly it has been destroyed too. I just need to get my brother over to help me pull the hood so I can continue.

kenincanada

of my thirty or so years in the auto repair trade Ihave seen more chev cams and lifters worn out than you can shake a stick at . poor steel ? dont know