Reboring a small block V8

pasini s · #1 (**permalink**) 16-11-10, 02:26 PM

Dear friends,

the block of my 409 is at the machining shop (is it the correct term?) now, waiting to have the bores remachined to fit the new +.030" pistons that I bought in USA. The shop asked only today if I can find the measures of the tolerances prescribed for this kind of job on this engine, as the Bristol workshop manual, apparently, does not give too many exact measures about it. if they had told me before....

I have bought the Plymouth Fury 318 workshop manual on CD this morning but it will take 1-2 weeks to arrive and I would like to see the work going on. So, if anyone has some measures that I can give to those guys, I would really appreciate the help. Thank you!

Stefano

RGSchmitt · #2 (**permalink**) 16-11-10, 03:05 PM

Stefano -

You could start at http://www.allpar.com/mopar/318.html and follow
the links. I don't have anything at home with boring tolerances, but
probably could find it at the Burbank library if nothing turns up.

Bob

Kevin H · #3 (**permalink**) 19-11-10, 09:05 AM

Hi Stephano,

This article might have some useful information for you...

Looks like the original bore was 3.91 inches.

Regards,
Kevin

Thor · #4 (**permalink**) 19-11-10, 01:09 PM

Stefano, it really is the job of the piston supplier to give this information.

As a guess, if they are newly made modern pistons, it should be possible to put them in with 1.5 to 2 thousandths of an inch skirt clearance, but if they are older, or old-fashioned type pistons, then the clearance might need to be much more, maybe up to 4 thousandths.