400 motor- block casting 230

[Cranky]

Nickel. The underappreciated Stepchild of metals.

Have you ever heard what a Ford big block sounds like when it's being bored? Geez and petes.....it's scary sounding with all the hard spots! Well, at least the ones I had the pleasure? of being around were scary sounding.

 

[fratzog lover]

Have you ever heard what a Ford big block sounds like when it's being bored? Geez and petes.....it's scary sounding with all the hard spots! Well, at least the ones I had the pleasure? of being around were scary sounding.

428 and 390 family or 429? Or both. Never had a Ford from the Glory Era.

 

[Cranky]

428 and 390 family or 429? Or both. Never had a Ford from the Glory Era.

The FE engines were the ones I've been around the most besides their skinny blocks.

 

[Heimedw]

Very few BB Chevy blocks have core shift and most of them have very thick cylinder walls.

I think that chevrolet can thank Mercury for the great engine block castings. Mercury at one time made the best engine castings in the world!

 

[Garys1969RR]

Does anyone know what the desired cylinder wall thickness should be after boring to the final piston size? We talking .100"? Or ..200"? I think the early 413s had pretty thick cylinder walls. After all, I think Chrysler just took those 4.19 bore blocks, and bored them
060" to make them 4.25 size
Presto, a 426! With plenty of wall thickness left over to bore it out further. Is that right?

 

[Heimedw]

Does anyone know what the desired cylinder wall thickness should be after boring to the final piston size? We talking .100"? Or ..200"? I think the early 413s had pretty thick cylinder walls. After all, I think Chrysler just took those 4.19 bore blocks, and bored them
060" to make them 4.25 size
Presto, a 426! With plenty of wall thickness left over to bore it out further. Is that right?

Im fairly new to the mopar game but the most I have see any bores go oversized is 60 thou. .060. I have seen Chevrolet's go 80 thou .080 oversized and that is getting very thin. This is factory blocks go aftermarket like dart or Keith black totally different ball game.

 

[Garys1969RR]

So how much cyl wall thickness do we need on say, a 500 cubic inch street/strip motor, That may see 550 to 600 horsepower. What is a safe wall thickness , on the cast iron cyl wall?

 

[Cranky]

https://www.forbbodiesonly.com/moparforum/threads/big-block-minimum-wall-thickness.36750/

 

[Garys1969RR]

Just looked at that thread again. Some good info on block selection there!

 

[wyrmrider]

keep your cyl walls as thick as possible
like .020 over
forget overbore as a way to more power
back in the day we bored some blocks to the max for the class and made less power

 

[moparmarks]

Yep just bore what is needed to get a perfectly round cylinder. My last few builds only needed .020 over.

 

[66Satellite47]

Mopar block cast iron is much "harder" than Chev. That's why they don't have the wear (ridge) a Chev block does. Wall thickness is the key for any max power motor. I have done big over bores that in hindsight I wish I'd gone smaller. OOPs. I'll look at my 400 blocks, they ran great. Not sure which casting they are, I'll look.