john deere G(need helpadvise)

hi my name is zach,

i recently purcashed a 1952 serial#56800 G john deere this tractor came from an older gentlemen an he bought the tractor the way it was an didnt really know anything about it.the tractor is set up for pulling 15.5-38, .125,high compression pistons,f49r flat head,51 carb. my problem is i blew the head gasket when testing it out, i dont know if the 87 octane he had in it that caused it to pre detinate before the pistons to hit top dead center & it was black smoking alot and the tractor sounded like it was beating the bearings out of the crank!so i took the head off an replaced with a copper head gasket from murphys,torqued the head down to 215-lbs. adjusted the valves an ran a compression test,left hand side had 60psi@right hand side had 120psi.and that sounds pretty low. so what im asking is do you guys think i could've cracked the rings or block or even hurt my head?i took the head to a machine shop an they said every thing checked out ok . but when i blew the head gasket there was water blowing out the rader cape hard core!& if its the rings can i just replace a new set and rehone the cylinders and get by and recheck the compression? and any advice on what compression i should be getting ball bark? also had another question the tractor has press steal wheels and for me to pull in a plow class they wont let me use suite case weights,can i use 4020 wheel weights on these rims? im really under weight!

thanks,zach wilmington,oh

Recheck your valve lash adjustment. See if that helps the low cyl pressure. Get rid of the 87 octane,, go up to atleast 93, or E85 ethanol. Its possible it may have busted a ring land off the piston,,,,, it may show some unexplained scratches in the cyl wall which could be the dead giveaway of broken parts. Hope this helps. Chad

pull the top cover & check inside before you do some more damage...flat head & hi. comp. pistons should run way more comp. than that...might have bent a rod...Kent

hi there zac sorry i cant give any info but was wondering if you could give me a little info, we have a 51 john deere g set up for pulling also this was my dads tractor and he passed away about 1 12yrs ago . this tractor has a power block in it and i guess like 7 or 714 pistons im a girl it doesnt mean too much for me but anyways we also are having head problems there is anti- or water getting into engine oil and a little white smoke coming from exhaust we did comp test and came up with 125 on each side we changed oil ran it again and the same thing went into the oil. how much of a job was it to change gasket we really dont want to take such a loss with the head as is i dont know how much you paid for yours but we were going to ask 6000.00 before we found out that the head gasket was gone or possible more dont know yet now we have had an offer of 4500.00 for tractor and also have other parts the person wants with it like extra block extra head extra pistons and extra crank, so now we really dont know what to do was yours all painted also. ours is redone it needs a few touchups on the block where gas dripped on the paint but anyways i would appreciate in info you have thanks , peggy