Piston Installation and combustion chamber overbore

[JeremyHoward]

Hi All.

My 1964 MEL 430 is at the machine shop and looks like it may need bored close to .60 over.

were having custom pistons made with the factory wedge design to come close to the factory specs of the 1963-1965 430 with the 4bbl intake manifold.

It appears that MELs had a factory overbore at the top of the cylinder (the combustion chamber).
I suspect this was done to accomodate the special ring compressor for piston intallation due to the deck angle.

The machinest is worried about overboring the top of the cylinder to mimic the factory design because it may be too weak considering the large overbore size already needed.

Ive searched on here and on the lincoln forum and see some people making ring compressor reccomendations.
I also see some reccomending just taking advantage of the deck angle and using fingers and finess to get the pistons in without a ring compressor.

if the "finger method" is used i believe an overbored combustion chamber would pose a problem with the rings expanding in the larger bore prohibiting them from beeing advanced further down the narrower cylinder.

So; If the "finger method" is used does the cylinder top (combustion chamber) overbore become unnecissary?

Im hoping yes as it would solve a lot of problems.

If somone with experiance on this matter could weigh in I would greatly appreciate it.

Thank You!
Jeremy Howard

[JeremyHoward]

I guess I should have use spell check prior to posting. LOL

Anyways, Im hoping I can find the answer to this.

Thanks

[Chris430]

I guess I should have use spell check prior to posting. LOL

Anyways, Im hoping I can find the answer to this.

Thanks

Jeremy, if no one gives you a good answer on the upper pocket you may try e-mailing Ted Eaton. He has the Yblocksforever web site. I know he has done several MEL engines as of recent with the correct wedge custom piston.