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Looking for your opinion on the front cam bearing pictured below. This is. ~115k mi 94 LT1, stock cam just came out and a relatively mild cam will be going in (cc502).
I’ve seen worse on the front bearing in other motors. What worries me is there is a tiny groove on back half of the bearing that I can catch my fingernail on. I think I may have dragged the oil pump gear a bit at the end.
With a good flashlight, the other cam bearings appear normal, but again this is looking through the cam bore so not the greatest if viewing angle. That said, I don’t see much gold coloring back there or any grooves. Just this front bearing.
Thinking I’m best off replacing it, that tiny groove worries me. I’ve never done cam bearings. I’ve read it’s a complete pain, but what about just the front bearing?
Whose done it? Tools needed? What bearing did you buy?
All else has gone smoothly so far and no other surprises found, save for a timing chain with a laughable amount of slop.
From: Las Vegas - Just stop perpetuating myths please.
What was your oil press reading before disassembly? Low oil pressure is a good indicator of cam bearing wear/damage. I always have had the machine shop replace the cam bearings so never had to R&R them myself but they do sell tools for this and the front bearing would be the easiest though the radiator would be in the way if done while in the car.
Now that the cam is out you could use an USB connected endoscope to look at the rest of the bearings. I paid less than $15 for my endoscope and it displays on a smart phone or laptop.
It's always the details that extend the frustration and labor.
Yes, excellent idea on using an endoscope. I’ll look into ordering one this evening.
Engine had normal oil pressure right before coming out. Hot idled around 30-35 psi, up from there with revs. This is from the analog gauge on the dash. The cam journals show no signs of scoring. Pretty sure I must have created the scratch on the way out with the gear. There’s soft bearing material showing in the pic, typical of front bearing with timing chain and water pump load? Motor is on a stand so work is easy. Cam tools I’ve seen are meant to be used on a motor with no bottom end in it and the cam plug out. I have no intention is disturbing the bottom end. Is there a tool that can get the front bearing out from the front?
Found this on third gen.org, I can’t think of another way other than a blind hole puller, but can’t find one with an adapter sized right for sbc cam bearing.
here it is: A quick and dirty method would be to tie a string or wire through the bearing and front opening in the lifter valley. Start the wire through the drain in the lifter valley and catch it through the front cam bearing with needlenosed pliers. Tie it off in a loose loop to retain the bearing shell and prevent it from falling into the crank area. Carefully drive the bearing back into the block with a suitable punch, walking the bearing out by tapping at various places around the perimeter. Be careful to avoid damage to the bearing bore, or you WILL be pulling the engine for machining.
Once the bearing is driven back out of its bore, the wire should be holding it. You can grab the shell with a small pair of pliers and pull it through. You may have to flatten the shell slightly to provide clearance.
The new shell can be driven in with a suitable drift. Be sure to align the oil hole(s) correctly before installing it.
Bearing isn't going up through valley on a Chevy V8. You may be able to use a bearing puller intended for transmission repair to pull front bearing but the others maybe worn the same. So if it had good oil pressure before disassembly you could leave it alone or pull pan replace front 4 or transmission and all 5. If oil pressure was sketchy I would replace all five and take a peak at number 1 & 2 rod and main bearings. There is an order and they need to be correctly orientated.
I think the idea was to knock it in, string keeps it from falling, crush a bit it with pliers then pull it out the front cam bore. Sound far fetched?
It did have normal oil pressure before. I’m struggling to leave it in there because it seems so accessible plus maybe there is a scratch in it. Planning on using an endoscope to review the rest of them.
I assume the engine is still in the car? I would change it, but you can also take some fine sandpaper and knock down that ridge. If you do change it, just use a long rod to keep it from falling and knock it in. Once you have it sideways it will be easy to pull out.
It’s not in the car - out on the stand. Last night I ordered a borescope camera that works with my iPhone so I can view the other bearings and get a better idea of their condition. I also ordered a blind hold bearing pulled with an adapter that seems large enough for the cam bearing, idea being to knock it out the front vs into the engine. Anyone think of a reason this wouldn’t work? Also grabbed a set of cam standard cam bearings since it doesn’t seem you can buy them individually.
Yep, that’s the plan. I was debating the best way to get it out. I was leery to knock it inward and try to fish it out, seemed risky on getting debris into the bowels of the engine. Going to try a blind hole bearing puller - it’s all arriving tomorrow. Whether or not I have time tomorrow is up in the air.
Following up on my thread.... a blind hole bearing puller did work. Kit came with a puller and a slide hammer. I didn’t have any success with the slide hammer but the puller brought it out. Installing new bearing was tough, but eventually got it going straight and tapped all the way in.
Front Cam Bearing
