351W Max Re-Bore

BEagles68 · #1 (**permalink**) 11-08-2002, 01:26 AM

Looking for some expertise on Ford 351W. Due to an overheating problem I am looking at having to bore it another 0.010 - 0.020" It is already bored to 0.060". Can anyone tell me how far I can go, and where I can get the new pistons if it is a total of 0.070-0.080" ? Thanks

Thomas Gayer · #2 (**permalink**) 11-08-2002, 03:27 AM

you are kidding right?
40 thousand is max bore on 351 without experiencing
los problemas

RICK LAKE · #3 (**permalink**) 11-08-2002, 07:29 AM

Beagles68 30 over is a safe overbore. Find a good machinist and have the block slevied. If done right you will have a new motor inside with a seasoned block on the outside. best way to go. 60 over is partially why you are running hot. what thermostat is in the motor? What radiator do you have? Does the waterpump have a plate on the impellior to help flow? Check out this first. Get or borrow a infared temp checking gun and make sure the radiator is not partially clogged and you have full flow. I would replace the thermostat anyway just because. Do the basics first, this will save time and money down the road. Rick Lake

Cobra20646 · #4 (**permalink**) 11-08-2002, 07:51 AM

Regular street production 351's are spec'ed to go .030 max overbore. Some Ford SVO 351's (w/siamesed cylinders) can go out to 4.125 max bore.
Like Rick said above, have a good machine shop sleeve the block, it's the only way your going to save this block...... or spend the bucks and replace the block.

- Jim -

RICK LAKE · #5 (**permalink**) 11-08-2002, 05:55 PM

Beagles68 There is a special proceedure for sleeveing the motor. Ask the machinist to tell you how he is going to do it. Bore the motor out with a head plate on and torked to spec. Leave a self down at the bottom of the cylinder. Cut the bore to .002 of the sleeve. MAKE SURE THE MOTOR is at room tempature. Put the sleeves in the freezer and chill. Seal the bottom of the bore with pipe glue. Put sleeve in motor. Mill top of block after all don. Put head plate back on and tork to spec. hone cylinders for pistons. I think this is correct. Ask George Anderson at Gessford machine. Double check I want to give the right info. I have not done this kind of work in 25 years. Rick Lake

Jack21 · #6 (**permalink**) 11-17-2002, 11:36 AM

Unless you have a lot of expensive machine work invested in the block, it might be cheaper and easier to swap the rotating components into a new block. Your machine shop should be able to source one for you for $100 - $200 if you don't feel like scrounging one up yourself out of a wrecking yard or Want Advertizer.