Just talked to the machine shop and they said that they would have to pull everything apart, vat the block, and then put in the new bearings.

I am just putting in a hotcam and want some extra insurance since I have 105k on the clock and just blew a head gasket.

Is this true, or can I pull the motor out, and have someone pound out the old cam bearings and put in new ones? I am also planning on doing the main and rod bearings, but I know I can do those by simply pulling the crank out.

Thanks,
James

 

you can but i am guessing they want to make sure everything is clean plus it would be a very good idea to change out the main and rod bearings as most likely your gonna spin a rod bearing and not a cam bearing

 

you have two choices...

leave it alone

or pull it all apart, do any needed machine work, ect and rebuild the motor.



just because you have 100k+ on the cam bearings doesnt mean they're bad.. or even worn.


just whatever you do, dont go replacing crank/rod bearings without machine work. thats begging for problems.

 

i beg to differ i own a machine shop krs machining in erie,pa and i take out my motor and re ring and re bearing it every 20k because its a 396 ci lt1 with loose tolerences and a nx 300 shot so that puts me somewhere in the 800 hp range but you wont hurt anything from putting in new mains and rods and cam bearings

 

When you say "Vat the block". I assume you mean hot-tank it?

If they're going to hot tank the block, they have to remove the cam bearings because the hot-tank solvent will destroy them. (And any other soft metal, such as aluminum)

So normally they have to disassemble the whole thing to clean it in the tank.

But I agree that you only have to replace the bearings if they're bad. So if they are good, then just change the cam and be done with it. Changing the main and rod bearings is a good idea, but you'll have to have the crank journals polished. No big deal, but slightly more cost. If it gets out of tolerance by polishing then they'll have to cut it and put in oversize bearings. Again no big deal, but slight added cost.

And if you're going that far, just change the rings too. The rings are what wear the most anyways. But then you have to hone the cylinders....blah blah blah...man you're spending alot of money!


-Dave C. '97 Z28

 

then as a machine shop owner, you know its a far streach to compare a sub 20k, loose tolerance race motor to a over 100k street motor.

 

I think what you need to do first is check the bearings. The cam bearings might be fine.

Most likely with that many miles you might need some machine work if you tear everything apart but there isn't anyway to know until it's apart and clearances are checked

There are also some things that could give you a indication of your engines condition.

A leak down & compression test
oil pressure
any oil consumption?
maintenance

 

you can put all the cam bearings in without removing the pistions with the proper tool on the engine on a stand. You can put 4 of the 5 in with the motor in the car again with the proper tool and assuming you pull the pan off. It can be done in the car not easy. You may not need them take a close look the front one seems to be the high wear item on the LTx's. I notice you are in DFW area an i am happy to loan you such a tool if need be. One made just for the LTx's. If you are doing rods and mains it is REAL easy with said tool and engine on a stand and the crank out.

Ps come to my place on the right day and i'll give / get you a demo ride around the track