cylinder head, block decks, intake manifold alignment (2024)

Hello

I am in the High Performance Engine Machining Program in Bemidji MN.

My question is about head, block, and intake manifold geometry. When you resurface a cylinder head or the block deck a considerable amount this will affect how the cylinder head and intake manifold will align, seal, and flow. Is there a formula that is being used to calculate how much to mill off these parts to make them realign correctly?

If I were to mill the block deck how much do I have to mill the intake rail of the block to correct the alignment? If I were to mill the cylinder heads how much does the intake manifold need to be milled to correct the alignment?

I understand that I could do trial and error and mock up these parts until it gets close but I am looking for something a little more solid. I am not afraid of math and if there is a way to calculate this I would give it a shot.

thanks.

https://www.google.com/#q=formulas+for+ ... olds+angle

It's a "yes, no, maybe" question. You should know by now that most every V-type engine uses a different head-to-manifold angle. Then, there those which touch the block front and rear and those which don't.

Jack vines

Install a pair of log intake manifolds on any v-8 engine along with a custom valley cover with needed dizzy mount and you don't have to worry about any of this stuff.

Usually they are two 3x2 jobbers that mount 6x2's on an engine and they have rubber hoses between them to balance out the flow.

Tried posting a pic, to no avail?????????

pdq67

Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.

Do a search here there is some links to details.
But any trade school should have this basic detail available to the students there.If the school is affiliated with AERA they can provide the common engine machining formulas for calculating how much to cut from the intake sides and ends on the big 3 engine lines.
There are many formulas based on what engine you are working on.

I use a commonly available list of formulas that are accurate for most engines out in the world today and if you PM me an email address I can send it to you

Dave

https://www.hastingsmfg.com/ServiceTips ... _heads.htm

http://www.goodson.com/blog/2012/01/13/ ... e-milling/

From Jeffery Diamond's site Victorylibrary.com.
http://victorylibrary.com/mopar/intake-mill-c.htm

Mike
Lewis Racing Engines
4axis CNC block machining

A few of the cars I have driven & owned
A tour of my shop
The Dyno
And a few pics of the gang

"Life is tough. Life is even tougher if you're stupid"
John Wayne

Shouldn't need a formula, it should be common sense learned from geometry in school?

That's if kids actually learn anything in school these days?

Normal skimming takes off so little that the gaskets make up the difference.
Taking off lots is pretty much a bad idea anyway due to weakening the parts, as in making a cylinder head deck face too thin causing headgasket sealing problems.

joe 90 wrote:Shouldn't need a formula, it should be common sense learned from geometry in school?

That's if kids actually learn anything in school these days?

Normal skimming takes off so little that the gaskets make up the difference.
Taking off lots is pretty much a bad idea anyway due to weakening the parts, as in making a cylinder head deck face too thin causing headgasket sealing problems.

Really/
Did you bother to read your first sentence before posting it??
Don't need a formula but use geometry............... WTF??

Gentleman asked if there was a formula
Yes there is but It is not set in stone as anyone who has been doing this stuff for a while can tell you
Theory is great & the formulas above are the standard ones used in the industry based on geometry & as close as you are going to get ON PAPER
Just don't expect the hunk of cast iron to read them it tends not to follow directions well,,,,,, there is a reason for measuring everything

Mike
Lewis Racing Engines
4axis CNC block machining

A few of the cars I have driven & owned
A tour of my shop
The Dyno
And a few pics of the gang

"Life is tough. Life is even tougher if you're stupid"
John Wayne

Wolfplace wrote:Did you bother to read your first sentence before posting it??
Don't need a formula but use geometry............... WTF??

Gentleman asked if there was a formula

Engines are all different with different angles......that's unless all you ever deal with is a SBC.

OK as an example......take 1mm off the block each side of a sooby.

What's the formula for how much you take off the intake manifold face to fix it?

Answer.......throw it in the scrap bin where it belongs.

joe 90 wrote:

Wolfplace wrote:Did you bother to read your first sentence before posting it??
Don't need a formula but use geometry............... WTF??

Gentleman asked if there was a formula

Engines are all different with different angles......that's unless all you ever deal with is a SBC.

OK as an example......take 1mm off the block each side of a sooby.

What's the formula for how much you take off the intake manifold face to fix it?

Answer.......throw it in the scrap bin where it belongs.

What is your point?
I think most of us know engines have different angles & if you bothered to look at the links you would find more than SBC's,,
My point was you stated in the same sentence to both use & not use a formula,,,
And I have no clue what a sooby is

Mike
Lewis Racing Engines
4axis CNC block machining

A few of the cars I have driven & owned
A tour of my shop
The Dyno
And a few pics of the gang

"Life is tough. Life is even tougher if you're stupid"
John Wayne

Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.

An example here is all!!

The old mag article about the 400hp/305 that DF put together and then beat hell out of until it came unglued!! Just for the fun of it??

The heads were like -041's cut say right at .080" to get the CR they wanted. Doing this required cutting the intake manifold as well as shorter P/R's to make everything work!

All is well EXCEPT the engine and parts are now a one-off dedicated use together combination because of the drastic cut!

I like to use this saying!!

"Well, it's a "feelie" deal here!". What does that mean, well "empirically/by a formula" it works fine, but just make sure it goes together by hand!! THE FEELIE THING HERE!!

pdq67