Narrow block 262 trivia

SuperDave

I cleaned up my 49 Super Six head today. i noticed that the # 6 chamber was different than #1 thru 5. I remembered that Bernie Siegfried (sp?) said that in early production of the 262, they had an unusual number of cars suffer a knock in number 6 cylinder. It did not show up in early testing, only after the car was inproduction. I quick review of the oiling system and failure analysis of the afflicted cars yielded nothing.. They decided to increase the combustion chamber size on number six to lower the compresion ratio on that cylinder. The problem seemed to go away, even on the engines that had the originsl head. .No one knew why the problerm occured in the first place. They never corrected the chamber size through the narrow block production. So if you look at a 252 head, you may see what I saw. on my Aug. '49 production 262 head.

http://s276.photobucket.com/albums/kk4/SuperDave1939/?albumview=grid&mediafilter=all



This is my first attempt to post a picture from photbucket.. got my fingers crossed..:eek:

SuperDave

I also failed to mention that the chamber is deeper in the head by about 1/16 inch. I measured the depth at the intake valve flat on all chambers and the #6 was about 1/16 deeper. The head had been milled .009". I don't know what the difference in CC's is, but it sure must be significant.