Engine milling maths

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mini

mini

Small Bore Long Stroke
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Going to be taking my Eddie 60779s to the machine shop soon. According to Mopar1 in order to lose 5cc combustion chamber volume I will need to mill my heads .024. And according to that I will need to take .028 off the intake side of the head and .03456 off the intake ends.

Does everyone use these handy charts when milling? Are they accurate.
 
Any automotive machine shop worth their salt will know how much to remove to get where you want to go. The guys that walk in and say "mill *** from here" usually get themselves in trouble.
 
Funny you say that. When I was younger I went to the one of two machine shops in my town and they did just that. I said I needed .030 taken off and they didn't do anything else. Asked them about intake milling and they said figure it out and come back. Ffs
 
The closed chambers will require more to get a cc off than open chambers....IIRC, you will need to mill off about .006" per cc, or .030" total for 5 cc's. If you take off a bit over 5 cc's, a touch with the grinder in the chambers will get it back down.

I would not count on all machine shops to know this... so good that you are checking.
 
I never ever take any materiel from the intake side of the head unless it’s to get a port volume for some class thing or something.

The big ***** is if you do that, any intake will fit. So what? What about when you put the heads on a different block and now it’s jacked up.

Take it off the face of the intake manifold. Gaskets are cheap. Heads are not.
 
There is my last experience... Scope into the intake revealed a lot

IMG_6910.jpg
 
yellow rose said:
I never ever take any materiel from the intake side of the head unless it’s to get a port volume for some class thing or something.

The big ***** is if you do that, any intake will fit. So what? What about when you put the heads on a different block and now it’s jacked up.

Take it off the face of the intake manifold. Gaskets are cheap. Heads are not.
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That was my next thought. Thank you. Totally agree.
 
My experience is they seem to take to much off the intake side and I have to get Cometic to make custom gaskets to make the intake fit.
 
That is a fear of mine. They charged me 75 bucks each time to mill the intake side so I want to get it right the first, or second time.
 
If they are small block heads, mill the intake side of the head .0095" for every .0100" from the block side. So, .020 off the block side means .019 off the intake side. Know what you want, get what you want. Why would you mill new heads? I'd never mill an intake. Heads are a matched set, do it this way and you will never have a problem.
 
66fs said:
If they are small block heads, mill the intake side of the head .0095" for every .0100" from the block side. So, .020 off the block side means .019 off the intake side. Know what you want, get what you want. Why would you mill new heads? I'd never mill an intake. Heads are a matched set, do it this way and you will never have a problem.
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How so? If you mill the heads, and use them on a different block, or with a different intake manifold you will be screwed up. An intake manifold and gaskets are much cheaper than heads.

Again, unless you need to meet a port volume for a class, you mill the intake manifold, not the head. I won’t mill a head, ever. I’d send you away first.
 
yellow rose said:
How so? If you mill the heads, and use them on a different block, or with a different intake manifold you will be screwed up. An intake manifold and gaskets are much cheaper than heads.

Again, unless you need to meet a port volume for a class, you mill the intake manifold, not the head. I won’t mill a head, ever. I’d send you away first.
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No, it won't. Do it all the time. The only relationship that changes is the heads get closer to the block. The ports all line up perfectly. I can swap any intake I want. And I did't ruin an intake manifold.
You would not send me away, when I heard your ideas, I'd walk away with my all stuff and never come back.
 
If my heads require milling I always have both surfaces milled and have never had any issues with intakes fitting.
 
If you mill the heads have them mill the intake surfaces too. That way any intake will fit. I milled my 273 heads and had them all bolted on with valve train. Damn, the intake wouldn't fit so we milled the intake. Now the intake and heads need to be used together ( unless i use 2 or 3 intake gaskets)
 
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I measure end chamber depth and mill to equalize
and mill the intake face never the intake
it ruins them for any other build
we did a lot to NHRA specs
 
66fs said:
No, it won't. Do it all the time. The only relationship that changes is the heads get closer to the block. The ports all line up perfectly. I can swap any intake I want. And I did't ruin an intake manifold.
You would not send me away, when I heard your ideas, I'd walk away with my all stuff and never come back.
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No ****? But you can’t swap any intake you want because the same intake from the same manufacturer are never exactly the same width.

Let me know when you actually machine something up.
 
yellow rose said:
No ****? But you can’t swap any intake you want because the same intake from the same manufacturer are never exactly the same width.

Let me know when you actually machine something up.
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That's what gaskets are for.

I don't need to do everything. I have no problem paying for what I want. I don't do Bench Racing or any related BS such as the nonsense above. Try and belittle someone else with your nonsense.
 
66fs said:
That's what gaskets are for.

I don't need to do everything. I have no problem paying for what I want. I don't do Bench Racing or any related BS such as the nonsense above. Try and belittle someone else with your nonsense.
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LOL.
 
The heads and intake on my race motor are ported to match so using another intake is a moot point.

This whole discussion reminds me to talk to my machinist who is resurfacing my block and heads as we speak...
 
yellow rose said:
I never ever take any materiel from the intake side of the head unless it’s to get a port volume for some class thing or something.

The big ***** is if you do that, any intake will fit. So what? What about when you put the heads on a different block and now it’s jacked up.

Take it off the face of the intake manifold. Gaskets are cheap. Heads are not.
Click to expand...
No, sir. I don't think you have it right.
By milling both faces, yes, any intake will fit. That is a good thing. Putting heads on a different block isn't a problem either because.....any intake will fit. "jacked up" ??? WTF is that?
Are you feeling okay? Been drinking tonight ?

Doing it your way, the intake is now only a direct fit to the milled heads.
Doing it the right way, every intake fits not only the milled heads but ALL other heads.
Try some humility sometime. Being so sure of yourself sets you up to look foolish when you are proven wrong.
 
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