How much can theses be milled, machinist told me he cut .025, new guy tells me the heads are still 79cc, so he thinks it will need alot more cut, I need the heads around 60cc for a 10-1 engine, so can theses be milled another .080 or .090 or so. Out of box they were advertised as 77cc but mine must have been like 83 or 84 cc

 

That sucks Dave, good thing you got them checked! Mark has said they are 81 to 83 cc out of box, not the 77 advertised. You are not even at 8.5 to 1! Hopefully the experts will chime in but I'm pretty sure removing that much is no issue for the deck. There will be some work milling and aligning the intake as well. Sorry to see this.

 

You are looking at getting another 20cc out of them ? That is a bunch. Most heads take about .006" per cc so you would need to take closer to .120 off to get where you want to be.

I don't know how much they can be milled but keep in mind that once you get past about .025" you start getting into issues with intake manifold fit. If you cut another .100 or so you will absolutely have to mill a bunch off the intake or the intake surface of the heads or both to make everything work. Then you also have to worry about valve to piston clearance ?

Probably need to mock it up the way it is now and see what you have before cutting any more.

 

I knew it by his math there was no way he had them close to 70 as he claimed, another lie in a long list.

 

yes the new builder will have to cut the intake up alot.

 

I dont know where you are in your build but I would think different pistons would be a lot less hassle in the long run.

 

You can cut the crap out of them..they are over .500” thick.

it’s better to slot the bolt holes in the intake than to mill it to fit. The port in the int and head will actually be more in line with each other after the heads are whacked a bunch

stock as they are, the big block intake port is way higher than a small block int manifold port..so what you are doing is bringing the tops of the ports more in line with each other….that’s a good thing

cut the heads as much as what’s needed ..bolt them on the block and then sit the intake on and look down through the int manifold bolt holes to see how much they need to be ground lower

 

Yes they can be cut .080 or more no problem

 

Thanks alot guys, much appreciated.

 

They have been a hassle lol, I have been told by a few that I should have used other pistons but the journey has been like 2 years or so probably closer to 3. I really hope it gets done by end of year 2023 and it will be dyno tuned. Hope the new guy saves my butt on this build but he didnt get right deep into it, I have to hope the damn machinist did a few things right like clearance's and what not.

 

Problem is, you basically have Speedpro flat top pistons as your only off the shelf option for higher compression. It sounds like you have someone decent finishing this motor, good luck.

 

Here’s the bottom line. The problem starts with the fact that the Speedmaster heads are already at about 82cc out of the box, which is about the same as a typical BB head.
So having to cut an additional .030-.040 or so off of them because you used a different piston is a moot point as far as I’m concerned.
I’m doing a set now that were cut .100, went from 82cc to 64. Decks are plenty thick enough. And seeing as how most people don’t check vertical alignment on their intakes anyway, if this forces them to do that that’s a plus in my book.

 

No…there are other options. Here one that’s off the shelf in either 2618 or 4032 with half the cc valve reliefs and an increase deck height. It’s available in all kinds of oversizes from standard, 4.100” and 4.125”

 

Here’s another with just 3cc reliefs. I’m using these in a 400 E block build but are designed for the 350…same pin height


can easily be used with aftermarket rods that have the .984” mopar pin or stay with stock pin

 

There’s also CP bullet shelf ones that have about 1.5cc reliefs

 

Good to see those 3cc and 5cc, could only find their 12cc version online, last I looked. I thought they quit the 3cc version for some reason, maybe out of stock? The 3cc Mahle should be good with very milled Procomp heads if they release them as well. The CP are only available in the hone to fit 4.065" and 3.5" stroke in 4.125" off the shelf, that I have seen. The 10.2cc Mahle work for me, 87 should be even possible with the iron heads, EFi and just below 9.5 to 1.

 

The only aftermarket rod with a .984 pin that would even come close to working in a 350, is the 6.123 Mopar rod. Never saw a Mopar rod in a 6.00” length that would work with this piston. Who makes those? I’ll look into that combo too.

 

these will be on stock 7” bushed rods. they can also be pressed..the pins are ok

your rods work with .980” and 984” don’t they? If not then hone the piston for the .984” or supply your rods unhoned..that’ll work for either

 

I didn’t ask about 7.00” rods. Based on your statement, you missed my question.

 

I didn’t miss anything. I said any rod that is for a .980 Olds……that would be a factory rod , Molnar rod or that one sold by Olds Rocket Parts can work with a .984” pin with a simple hone or pressed if using the factory rod.

instead of saying I missed the question, maybe explain your question more clearly… why won’t any of the above work?

then explain to me how if any of those scenarios won’t work, how did I do it and they are in running engines?