a 221 mystery?

B

britman

Member
I just tore down my 39 221 flathead from my deluxe sedan for a rebuild (my first flathead)(it was “nasty” inside). Appears to have not been disassembled previously. It has three ring pistons in it. I was expecting four ring pistons. Does it matter? In addition, the flanges on the rear main bearings were missing and the bearing was “split in two” but there was no obvious evidence of damage and I found no metal pieces in the sludge but it could have easily went unnoticed. Any thoughts/advice on these?
Thanks,
newby in KY
 
Britman, I've seen some broken flanges on the rear main but never both sides missing. It must have had alot of end play on the crank. Most of the earlier 221's had 3 ring pistons, some one might have had a set 35-36 3 ring pistons and used them. Is it std. bore or oversize? The thing to do is eye ball it the best you can, if looks good have it cleaned at a shop that will make sure the water jacket is spotless. Have the crank and cyl bore mic and do what's nessasry, like bore cys, grind crank, build a nice engine. Walt
 
It has probably been apart before, several times. The three ring pistons are common. The four ring were truck and steel sleeve. Rear main?? split in two, how so, through the oil groove? It really doesn't matter since your in the rebuild mode. Keep it in mind and check out the crank and the rear main throughly before reassembly, the reasons will become clear after everything is checked out.
 
It appears to be standard bore/crank (didn't mic it). It had considerable power considering that the rings were stuck in four of eight pistons--I am surprised it ran at all--but it was a smoker with major blowby. I took it to a machine shop to be checked out, cleaned/magnifluxed, etc. It will need boring--probably about 60 over. Crank will need at least 10k taken off.
thanks for the reply.
b.davis
 
yes, the rear main was split right down the middle as if done deliberately. It appeared that the bearing was "floating" around the journal.
 
britman said:
yes, the rear main was split right down the middle as if done deliberately. It appeared that the bearing was "floating" around the journal.
Click to expand...

How clean was the separation point of the pieces? Possibly, someone used front or middle journal bearings, for lack of a rear?
 
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