Now that the heads are on the 460 I crank it by hand and I can hear a tiny bit of air getting by each piston and echoing in the crankcase on it's compression stroke. Is this normal? I thought perhaps the rings need to be warm and expand to seal entirely, but it worries me.
Thanks,
Matt

 

Hi Matt, there will always be some compression that "blows by" the rings. The rings will never make a perfect seal, so I dont think it is cause for concern. my 2 cents

Wayne
e-mail
http://home.pacbell.net/whomrig

 

Like whomrig said, there will always be an amount of compression lost on the stroke due to the gap in the rings, the small gap between the rings and cylinder, and the small gap between the rings and piston. This amount ranges from less than 1 percent of the compression (top or the line rings and pistons) up to as much as 10 percent (cheesy rings and pistons) depending on the assembly tolerances and how much work you are willing to put into getting a perfect seal.

J/.c

1965 Ford Galaxie 500 (okay, so not quite a truck)
460/C6 transplant @ 389hp/491 lb.ft.
14.29@103.8, 13-14 mpg heheheheheh