Engine Bearings

[Aiken Racing]

Well I took my engine totally apart and I got major bearing damage. All the main and connecting rod bearings are shot.

The connecting rods are using 5795 STD. bearings. The main crank bearings are using 4477 bearings but they aren't marked STD. So I assume that the crank has been turned down before.

How do I know what 4477 stands for? I assume the answer is simple but I don't know since this is the first time inside my engine.

The cam bearings look fine but I'm still going to replace them. Do I need a special tool remove the camshaft bearings?

Thanks,
Chris
[url="http://www.chrismore.com/ff.asp"]http://www.chrismore.com/ff.asp[/url]

[JJ]

On the cam bearings you will need a tool for installing them. Here is a photo of a tool I made to install mine. These bearings have to go in straight or you will destroy them. If you don't have a tool or can't make one (lathe needed) take it to the shop. It doesn't cost much to have them do it.

[url="http://groups.msn.com/TheSechristFamilyPatJackie/shoebox.msnw?action=ShowPhoto&PhotoID=36[/IMG]"]http://groups.msn.com/TheSechristFamilyPatJackie/shoebox.msnw?action=ShowPhoto&PhotoID=36[/IMG][/url]

[size="1"][ September 26, 2002, 08:03 AM: Message edited by: Pat Sechrist ][/size]

[Dale Carter]

Chris - The bearings should be marked if they are .010" or whatever. If the rod brgs. are standard, the mains would also be standard. You can measure them. Std. bearings are .072" thick. If they are .077", they are .010" under, etc. If you cooked all of them you probably had a major oil pressure failure - pump failure, hose failure, starvation or some such. You need to have an experienced eye look over all your parts or you run the risk of not determining what actually happened. As far as cam bearings are concerned - if you're asking if you need a tool to do it, that tells me you need a machine shop to do it! By the way, was there any oil in the water or vice/versa?

[size="1"][ September 25, 2002, 01:46 PM: Message edited by: John Merriman ][/size]

[Aiken Racing]

Does anyone know the stock journal size for the main and rod end on the crankshaft?

Mine are scored pretty deep and I want to find out if I can turn it down or if I need a new crankshaft.

Thanks,
Chris

[Aiken Racing]

I looked all over the bearings and the only number is 4477 so I assume the 77 is for .10 under. Does that seem logical?

The rod end bearings are marked STD so they will have to be turned down to some side under.

I'm going to send my BAT oil pump back to them so that they cam go over it and make sure there is nothing wrong. I'm going to take my engine and have a hot bath and go though and make sure nothing is plugged.

Chris

[Aiken Racing]

Also, no, there was no oil/water mixture anywhere. I think something failed in the oil pump. Is it possible for the oil pump sealant of got into the pump and veins and gummed things up?

Chris

[Dale Carter]

Chris - no it's not possible. Have you asked BAT if they'll actually look into the pump? They are a supplier so I would be surprised if they actually looked at the inside to determine what failed! The shear pin may have sheared due to a metal piece getting caught in the impellers? The cam may have broken thus the pump ceased pumping? It is not likely that anyone with any brains would turn the rods journals down .010" but not the main! Possible, I guess but not likely. I sure wish you could dis-assemble the engine with someone there who has experience with them! i have a new set of .010" mains that are marked 4477.

[size="1"][ September 25, 2002, 05:04 PM: Message edited by: John Merriman ][/size]

[Aiken Racing]

Yeah there just isn't people around here that know much about this motor but that's why I have you guys isn't it? [img]smile.gif[/img]

Well it looks to be the case... the main bearings are turned down .010 and the rod bearings are stock... I have no idea why though.... but those are the bearings I have in there now. The crank is at a machine shop now. They are looking it over and measuring the journals to see if turing down is possible now.

The wear on the main bearings are elongated on oneside noticable with just your fingers.

I have the oil pump all the way apart and I don't see anything wrong with it. I didn't know if Bat did repairs or if they were just a distributor... but they do sell a repair kit for mine for about $125.

Chris

[Matt Satchell]

Chris:

Measuring the bearings is not the best way to go unless you built the engine, in which case you'd already know what is there. From Jake's book, page 139:

Main Journal Diameter: 2.1253-2.1255" (STD)
Rod Journal Diameter: 1.9372-1.9373" (STD)

A lot of cranks are turned on the rod journals but not the mains, as this is how the crank is indexed (journals exactly at 180 degrees) and stroked to 3.060" (legal maximum); not a problem, that's whats in my motor presently. Turning the mains but not the rods is usually a response to main journal damage; not ideal, but it shouldn't cause a problem. Be sure to check to see if the pump is still rotating, the gears (cam and pump drive) look good. If the pump is jammed, check the timing chain for missing rollers, check the pan trough for other pieces, etc. If nothing mechanically wrong is found, you have what is called "an oiling problem", and that may require a re-think of the entire system.

[JJ]

Finally you can see the photo I tried to post earlier.

[Aiken Racing]

Ok, from measuring the main bearings they are exactly STD size. So the rod and main bearings are both standard but the main bearing just isn't stampted STD as I assume it would be.

A friend of mine who has been rebuilding motors for long time is working with me. A local engine shop is doing the actual machine work.

Thanks,
Chris