[Farmall] Another O-12 project, part 4

Karl Olmstead kolmstead4 at msn.com
Fri Feb 20 20:26:38 PST 2009


Spent two or three hours today with a needle scaler knocking rust, grease and old paint off O-12 parts in preparation for sandblasting and painting.  Got the front motor mount basket, the sides of the radiator and three of the radiator hose connections cleaned up.  Now there's a huge red spot in my shop, all around where I was working.  Needle scaling is not clean work.  Should have done it outside.  I'll probably set up an electrolysis bath to clean up the top and bottom radiator tanks.  But I'll zap them with the needle scaler first. Nothing beats a needle scaler for fast removal of deep rust and old paint.  Cuts way down on sandblasting time, and it also knocks off old gasket material.

I try and keep about 350 feet of dirt road leading to my property graded.  We had a lot of rain last weekend, so the road was pretty rough.  I fired up an O-12 today and dragged my 350#, 8' I-beam up and down the road.  Ordinarily I consider my Farmall C with big bore, high compression pistons to be about the lowest power tractor that can pull the drag, but the O-12 did all right.  I tried this once before, back when I first got the tractor, but it wouldn't pull the drag then.  Apparently the improvements I've made are paying off.  Ignition timing and governor adjustment.

I could run the O-12 in third (high) gear, which is good for about 10 mph.  The little engine had about all it could handle; it wouldn't accelerate to full RPM.  I found that I could pick up speed a bit if I played with spark advance.  More is better, at full load.

This was the same O-12 that I fixed up a couple of months ago so that it could be in the movies.  That deal fell through, but I figured this was my best old tractor for pulling the road drag.  While I was fixing up the tractor, I put in a new radiator core and flushed out the engine cooling jacket.  Must have worked; I only saw small wisps of steam coming out of the radiator as the tractor worked hard.  The O-12 I'm working on now will need more cleanup; there are signs that the cooling system is just about plugged up.  Time to break out the pressure washer.  With the radiator fan mount and bottom coolant elbow removed, I can spray high pressure water into the cooling jacket and knock out some of the rust.

I'm hoping to get most of the radiator and motor mount parts cleaned up and painted this weekend.  Still need to rebuild a magneto and fuel pump.  Maybe next weekend.  I'm still at least a month away from getting the tractor running.  This is going to be an odd looking tractor; only the stuff I've worked on will be painted.  Makes it much easier to go back in a year or three and figure out what's done and what's not.

-Karl



More information about the AT mailing list