RandomTask

Should be "How DO these bearings look?"

Pulled from 3 and 4 main. No grooves or anything that I can catch with my fingernail. Motor had 78k. LT4. Going in a chump car. These look good to go?




7

84 4+3

I mean I'd reuse them lol.

You could check their bore size torqued down to get an idea what the clearance would be. They look fine but it's hard to tell from a photo.

billschroeder5842

Ooooowww.....Why do you ask these questions?

The hard work of pulling the crank is over and bearings are relatively cheap. Just put in new ones.

(the bottom shot looks icky)

ChumpVette

Agreed, get some new bearings, send off to calico to be coated and put it back together.

confab

cardo0

You will always see some discoloration and contact marks on the bottom shells because that's where the crankshaft sits when the engine is off and there's no oil pressure. It takes a little RPM to get enough oil pressure to move the crankshaft up. Unless you have a pre-oiler system.

I've heard but not sostanchiated the majority of bearing wear on street car motors occurs during startup. But I can think of to many variables to make that true.

Plastigage is cheap and now is the time to nail your bearing clearances. You can buy individual bearings by the 0.001" over and under sizes.

QCVette

I would put new bearings in too. They are inexpensive and all the work is done by tearing it down already.

I don't think those bearings are anywhere near failure and at 78k miles they look pretty good, but it concerns me that there is uneven wear on them, especially the bottom picture.

Need A Vette

Absolutely new bearings, as you need to set your end play as well. Just cheap insurance.

D.

mtwoolford

I'd worry more about the rod bearings; and as far as mains, the number 5 also has the thrust surfaces.

RandomTask

Thanks guys. Since this motor is going to live out it's final days under hellfire (24hour track stints) I've opted to take it to a local builder and have them go through it; rather not risk it.

Thanks!

ctmccloskey

Do it "right" and replace the bearings.

Any time I open any engine I always replace the bearings.

It is cheap insurance and it helps the engine last longer.

RandomTask

Soooo I took the block to a machine shop. . . This is what I got back. . . I really just wanted the bearings replaced and they went over board. Should I be doing the rest of this stuff as insurance?

I'm a little urked by the fact I told them not to touch the heads and they completely dismantled them and now want to do a valve job on them + clean the surface. . .

84 4+3

I had a 350 bored 30 over clearanced for 383 internals. Washed, maged honed and everything else done ready for assembly for about 650. I think that quote is a little... actually very high.

mtwoolford

Is this like a 24 hour endurance race? If so, what are the hot shots running? pure stock; mildly modified "claimer engines" full on race engines? What do the rules allow and how badly do you want to win; as in how much are you willing to spend to win?

With that said there's a whole lot on that list that I wouldn't spend money on especially if all you wanted was some new bearings rolled into the engine.

ANYONE HERE IS ENTITLED TO THEIR OWN OPINIONS< and, FLAME ME IF YOU MUST but on that list,

(1) $150 to disassemble and clean engine? forget it, clean and disassemble it yourself, maybe reassemble with everything in its proper position with fasteners hand tight...the MAYBE negotiate a dip in the hot tank...for a lot less than $150.

(2) $200 for an align hone? If when the engine is assembled with the correct size main bearings and then it didn't turn easily by hand then consider a align hone. If everything turns easily with no binding an align hone is just paying to fix a problem that didn't exist.

(3) $220 to parallel deck the block? I understand the theory but unless there was some reason to spend an extra $220 and the block sealing surfaces cleaned up without any apparent damage that could affect the head gasket, skip this step.

(4) $120 plus $66.50 to "recondition" your rods, that close to the cost of a new set of rods with the good stuff already installed.

(5) now as to honing the cylinder walls and pistons. A lot depends on the condition of the cylinder walls. If I expected to see a failure, it would be from reusing your old pistons. I'm not saying that they would fail, in which case deglazing the cylinder walls and a set of new piston rings may be all you need, but I'd get a set of new pistons. They don't have to be expensive / custom. And depending, on piston to cylinder wall clearances, hopefully a hone job would be all that's required...if not pony up for an oversize bore with pistons to match.

(6) Rebuilding the heads is your call, but it looks like a valve job is in order...whether you wanted one or not.

(7) $800 to reassemble a long block? personally, I'd rather do it myself.

RandomTask

Yes, 24 chump racing. Starts at Noon on Sat, ends noon on sunday. Hot shots are running ARP but most are running e30’s. Mostly pure stock. I just want the car to last 24 hours at this point. Last motor was a LT1 out of a Camaro that lasted 4 races before a rod bolt stretched and the nut backed off.

1.) Too late. That also covered them to inspect everything.
2.) Makes sense.
3.) Agreed.
4.) I get what you’re saying, but stock rods are plenty strong for what I’m doing; still cheaper than getting new. I do want to find out what “reconditioning” entails.
5.) K.
6.) Will do.
7.) Going to myself.

Since I’m not going to do the align hone, going to skip the ARP HW on it at first. On stock power, the mains aren’t moving around any/at all. From my understanding, the real weak link on these motors are the rods bolts.

JasonAndrew

Always replace bearings when the engine is apart. Isn't that a no brainer? Rebuilding an engine VS buying a long block will ALWAYS be more expensive, especially paying a shop to do the work. You can probably get a long block with a warranty for a decent price.

ctmccloskey

Hello there Randomtask,
I too live in the hell of Northern Virginia. Which shop did you go to? Those prices are ridiculous even for our area. I have not done anything like that in a few years but wow the prices are going up.

I try to find shops who will give me the "Jobbers Rate" otherwise known as the "robbers rate". The rate is that which the local shops get not just off the street prices.

I hope that your project goes along smoother as you have a nice Long-block!

Good luck and hope to run into you someday!

RandomTask

Clinton machine in MD. Look for a ratted out C4; I have antique tags

So talking to the machine shop, decided to skip the following:

ARP main studs. No need. Skipping this also allows me to skip the align hone.
Skip decking the block. Surface was good and flat. This would have been $200 to make a surface look pretty.
Skip assembly. I can get it together; will just need to check to make sure everything is to spec.

Out the door it's about $1200 which to me is very reasonable.

mtwoolford

since it includes the valve job, I agree. I would ask about having the whole lower end balanced as a unit including flywheel or flexplate, clutch or torque converter; last time I had a lower end balanced the price seemed reasonable, but that was awhile ago.

mtwoolford

Are you going to reuse the original pistons? if not, consider rather than investing $180 to "recondition" the stock rods, for $310 you can get a set of forged Eagle rods from summit , summit # ESP-FS15700B, with 7/16th inch (not oem 3/8ths inch) rod bolts which should eliminate "the real weak llnk on these motors".

These rods are for a bushed / floating wrist pin so (you see where this is going) you would need a new set of pistons also. But that would allow you to get a true flat top piston, and the stockers are far from "flat" for a small bump in compression; say 9.5 to 10.0; or in the case of a 350 I built with 58 c.c. heads, a thin shim style head gasket and flat top pistons, from whatever stock was with a stock (thick) composition head gasket and stock pistons (slight dish and four valve reliefs) to 10.9. And no, I had no problems with pre ignition or "pinging" but I was running a cam with a considerable amount of duration (first generation chevy 345 horse crate motor cam). And I used 91 octane gas...but I bet you use that already.