Blue Smoke

[Little Indy]

Recently bought a farmall cub 1951 model. The engine makes a lot of blue smoke when running. If I decide to rebuild the engine
do I go for a short block?
Rebore the existing block and get oversize psitons and rings? Source?
Any steps I should take before deciding on a rebuild?
Breather tube check?
Run at high temp for a while?
Any ideas?

[Bigdog]

You don't mention the rate of oil consumption but I'd wager it's time for a rebuild. You might check J.P. Tractor Salvage for a short block. Or, check with Justin Weber (nosih on this forum) to see if he still has any of the nos blocks available. You could check with a local machine shop to see what they would charge for a rebore and associated parts. Certainly you should check the vent tube but if it's blowing blue smoke all of the time, it's no doubt more than that.

Price out the options available to you and you will then know which one makes the most sense.

[Eugene]

Run a compression check if you haven't already done so.

Clean the breather tube, air cleaner and cap on the dip stick. Change the oil (use detergent oil), filter and add some type of solvent to loosen up stuck rings. Run the tractor for a while (10 to 20 hours) to see what happens. This will give you a chance to check oil consumption and the condition of the oil. Check the oil condition after a couple of hours of operation. You may need to do a couple of rapid oil changes.

If the engine needs rebuilding these won't help but will give you a head start on the overhaul.

Eugene

[Eugene]

One more thought. Check the fuel level in the carburator bowl. If the fuel level is set to high you will get a lot of smoke.