PDA

View Full Version : Main journal sizes......


Gary Kubisch
03-05-2006, 02:23 PM
I was looking through a catalog from Federal-Mogul and noticed that a Buick 350 has a 3.00 main and uses a Bearing the same "length'' as the 455 except for that huge #5 bearing........

Anyone ever hear of this being done?
Seems like a way to use even a stock crank w/ the benefits of a smaller main
kingfish
03-06-2006, 02:38 PM
Gary,

have you ever seen or heard of turning the 455 main to 3.00 and using bearing spacers to take of the difference?


Regards,
George
alan
03-06-2006, 07:51 PM
My 2 cent guess is this would go against the reason the mains were made larger in the first place, and lead to increased block flex.
Gary Kubisch
03-06-2006, 08:45 PM
I've never bought into that Alan..Think about it,"The Block is weak so let's make it weaker by removing more material by drilling bigger holes in it to fit larger main journals"........Doesn't make much sense.

I'm just thinking along the lines of the people over the years that have used Naihead Cranks in their 455's......They're 2.500 Mains,I was just thinking the 350 Mains might be a nice compromise.
10sec 455
03-07-2006, 10:44 AM
I've never bought into that Alan..Think about it,"The Block is weak so let's make it weaker by removing more material by drilling bigger holes in it to fit larger main journals"........Doesn't make much sense.

I'm just thinking along the lines of the people over the years that have used Naihead Cranks in their 455's......They're 2.500 Mains,I was just thinking the 350 Mains might be a nice compromise.

Gary,
I think it has something to do with the block can't handle the flexing of the block and crank so they made the crank more ridged. If that makes any sense to you. How much power were the guys with nailhead cranks making? Probably not a real lot. The shorter nailhead stroke has got to help out on the blocks end too.
Bigwedgie
12-30-2008, 12:38 PM
All I have to say on this subject is the blocks would have been way stonger if they would have left some material in the dam things. After distroying to high dollar 455's I'm saying that a 2.750" or smaller main and some more material around the cylinders and lifter bore sure would saved a ton of money in the long run. I'm not going to build another 455 until these issues are taken care of.