what would be the biggest bore job for a early model (73 and below) 351w block, .040, .060 etc that would still be safe without running hot etc? I have an idea in my mind...Jim
my friend has a 030 bore on the winsor in his maverick. runs great all day long. I think any think over 040 on almost any block and your taking a chance. you should get the block tested at the shop to be on the safe side .
I am at .040 over on a 393 stroker. Ran 100,000 miles on .030 over. You are taking chances at .060, but if the block checks out, it can be done. I don't think I would run a strong performance motor at .060, regardless of how it checked out.
You need to sonic check the block. Typically....they will go .060" over but may run into some heat issues in "daily driving" situations. Going .040" over usually gives no problems but, again, have the block sonic checked to see where and how thick the metal may be.
Don't know about a 351, but my dad's 302 was bored .060 and ran just fine all day long on the street. Temp gauge never went above 170.
Both my truck and mustang have the bore at .060 I'm using speed pro hyperutectic pistons.............sorry for the spelling.
Like stated above, get it tested to see what YOUR block can handle. I wouldn't recommend boring all the way though, as you will not be able to bore the block anymore for a rebuild or incase you have a problem. I am the conservative type though.
I've been told that .040" is max overbore. However, I have run several at .060+ and haven't had any problems at all, but all were concreted. I see no reason that you couldn't safely go .060" on a mild build. 351 blocks are a lot beefier than 302's.....
When I was dirt tracking, I ran 351W's always .040 never had any over heating problems. Was running stock radiators not the better alum. ones.
My dad's Comet had a totally stock cooling system, with the exception of the braided radiator hoses, which were only cosmetic.
If you are trying to find cubic inches you should be looking at stroking not boring it. .030 will give you 5 Cu" and .060 will give you 11 Cu" If you are just cleaning up the bore go .030 and that will leave enough to bore it once more. I know that Ford recommends nothing over .030 but that is for racing where there is a lot of compression and RPMs. Do what you got to do man. Just think about all that can happen.
