Engine Rebuild DIY or farm it out?

[Steve Ruddy]

I'm in the process of rebuilding an Oliver HGR-42. I'm wondering if I should attempt the engine rebuild myself or send it out. I don't have any specialty tools other than a piston ring compressor and a cylinder honer the type you put in a drill. I'm good at disassembly and re assembly. Actually the tractor is in a million pieces right now. The other thing is I don't know of any local engine shops that do antique tractors. I'm in Sonoma County CA if anyone knows of a good shop.
Here is the engine plate.

[Jim Leap]

Hello Steve,

Does your engine have insert bearings or "babbited" bearings? The earlier HG's had the babbited bearings. There is a shop in San Jose that can pour babbited bearings but it is very expensive. Sometimes it is cheaper to find a later model block that has insert bearing. If you do have the babbited bearings and if they have excessive wear then they will need to be re-poured and then line bored. All depends on how much wear of course. Might need to turn the crank too. The babbit bearings do have shims that can be removed to tighten clearance. You can use plastgage to check crank shaft bearing clearances but it is probably better to have a shop do this. You can easily tear down the engine but you will need to have some expensive measuring tools (e.g. an engine cylinder caliper to measure the cylinders to determine the amount of wear). The cylinders may require boring to fit oversize pistons or they may need to be sleeved. It is always good to have a block magnafluxed to check for cracks too. You may get lucky and have minimal wear and just get away with honing the cylinders, installing new rings and doing a valve job. The crankshaft may be fine too. All depends on the clearances and clearances are often best left to the experts. Hope this is helpful.

Jim

[Steve Ruddy]

looks like I may have the insert type. I haven't looked at them yet but according to the engine serial number I should be safe. I'm waiting on a caliper set and a cylinder mic. I'm not sure yet what other tools I'll need besides the piston ring compressor and honer.

[Dianne]

Check your cylinder walls, particularly the area where the rings travel. If you have any scratches or non-circular wear, it will need to be bored over-size and that requires a  special machine 'cause you need to end up with an exact diameter (usually 25, 50, or 75 thou over) to match new pistons and rings.

15 years ago I found an automotive shop who  was willing (and excited!) to do my 3 cylinder Hercules.