Pontiac Street Performance
Home | Profile | Register | Active Topics | Members | Search | FAQ
Username:
Password:
Save Password

 All Forums
 Pontiac Performance
 Blocks / Cranks/ Rods and Pistons
 bore length
 New Topic  Reply to Topic
 Printer Friendly
Author  Topic Next Topic  

Miles
Sitting Bull

Canada
154 Posts

Posted - 04 Dec 2017 :  11:32:03 AM  Show Profile  Reply with Quote
Is the length of the bore in a 455 the same as a 428?
Have my 428 bored to 4.185" and have a 4.21 crank. The equivalent of a 455 bored 30 over. Now that I have it apart I see the bottom of a couple of the pistons have some scrapes on them. Not from the metal in the oil due to the rocker failure but looks like they scraped on the bottom of the bore.
The pistons have 0.006" clearance as recommended by Ross.
I just wondered if the 455 had a longer cylinder bore due the longer stroke. Maybe the piston is coming out the bottom of the bore too far and tilting then scraping on the bottom of the bore.
Piston is approx 2-1/2" from top to bottom and the top ring is approx 1/4" from the top of the piston.

Miles
Sitting Bull

Canada
154 Posts

Posted - 04 Dec 2017 :  11:58:48 AM  Show Profile  Reply with Quote
My cylinder is approx 6.156" from top to bottom, but I had it zero decked. I don't know how much was taken off the deck to zero it to the piston tops. The piston is approx 2.50" top to bottom. Stroke is 4.21"
6.156"-4.21"-2.50"=0.554" That is how far the bottom of the piston protrudes from the cylinder at bottom dead center and approx length of the scrapes on the bottom of the piston skirts.
Go to Top of Page
   Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
Pontiac Street Performance © 2006-2017 Go To Top Of Page
This page was generated in 0.06 seconds. This Site Sponsored By:
Powered By: Snitz Forums 2000 Version 3.4.05