Engine Rebuild (1 Viewer)

[Tommy Shumpert]

Some maybe a stupid question, but....

I have a extra 2F I was going to rebuild. The main bearings have minimal wear and tear.
Can I just replace the bearings throughout? Or do I have to send to a machine shop?

Replacing all bearings and piston rings.

thanks!

 

[DougAustinTx]

You can plasti-gauge with the existing bearings and see if they are reusable. No machining of the crank journals is necessary unless you have grooves worn in them (assuming the plasti-gauge readings are ok). If this was a racing engine, then you would want to use a micrometer on the main and rod journals and determine the wear. On a 3,000 rpm engine like we have, if there is no visible scarring on the journals, and the plasti-gauge checks out at 2 or 3 thousandths, I would put it back together and save it as a spare engine. Are you sure it needs rings? What are the compression readings at cranking speed with the carb wired fully open?

For me, the bigger question is the condition of the valves. I would be more likely to take the head off a working engine to check and face the valves (and replace the valve stem seals), than to change the bearings and rings unless there were some strange noises coming from the block when it is running.

 

[Tommy Shumpert]

You can plasti-gauge with the existing bearings and see if they are reusable. No machining of the crank journals is necessary unless you have grooves worn in them (assuming the plasti-gauge readings are ok). If this was a racing engine, then you would want to use a micrometer on the main and rod journals and determine the wear. On a 3,000 rpm engine like we have, if there is no visible scarring on the journals, and the plasti-gauge checks out at 2 or 3 thousandths, I would put it back together and save it as a spare engine. Are you sure it needs rings? What are the compression readings at cranking speed with the carb wired fully open?

For me, the bigger question is the condition of the valves. I would be more likely to take the head off a working engine to check and face the valves (and replace the valve stem seals), than to change the bearings and rings unless there were some strange noises coming from the block when it is running.

Thanks for the info! I am not sure what the compression is/was. It sitting on a engine stand right now. I have rebuilt the head. as for the bearings there are no grooves, just some wear on the bearings. I suspect normal for 100k+ miles.

i figured Might as well change rings while I’m in it.

 

[DougAustinTx]

I highly recommend using either an original Toyota head gasket, or one of the Stone brand (Stone JA-11149)
that I mentioned in a post about a month ago on this site. Stone is the OEM brand for Toyota. They are about $65 online. Best wishes
Doug