milling the intake

[frederick]

Hi,

I've got the following question:
When milling the heads say 0.010" the intake has to be milled by 0.0123.
But do each of the intake faces have to be milled by this amount or do you have to halve this, so 0.00615 for each of the 2 faces?
I'm 90% sure it's 0.0123, I just want to make sure it's correct before milling.

Engine is a 383 B series.

Frederick

[62 Max]

Hi,

I've got the following question:
When milling the heads say 0.010" the intake has to be milled by 0.0123.
But do each of the intake faces have to be milled by this amount or do you have to halve this, so 0.00615 for each of the 2 faces?
I'm 90% sure it's 0.0123, I just want to make sure it's correct before milling.

Engine is a 383 B series.

Frederick

I'm assuming you mean the head intake surface.The numbers are  correct.

[firefighter3931]

  mill both sides of the intake .012 for every .010 of head surfacing.



Ron

[tecmopar]

Why not cut the intake side of the heads, this way you can use any manifold without needing to have it cut. Once you cut the intake it will really only fit on heads that have been milled. To me the 2 have always gone hand in hand, plus any competent machine shop knows this already.

[frederick]

Thanks guys

I was almost certain it was 0.012 from both sides but my machinist had doubts about this, and also the workshop manual wasn't specific about this.

The reason I'm going to have the manifold milled is that the heads are going to be milled by 0.050
The intake faces then have to be cut by 0.0615 which would mean the helicoils for the intake would be touched by the mill.(aluminium heads)

Frederick

[62 Max]

Why not cut the intake side of the heads, this way you can use any manifold without needing to have it cut. Once you cut the intake it will really only fit on heads that have been milled. To me the 2 have always gone hand in hand, plus any competent machine shop knows this already.

If you read again we were both refering to the head intake surface,not the intake.There is no need to mill an intake.

[Nacho-RT74]

Why not cut the intake side of the heads, this way you can use any manifold without needing to have it cut. Once you cut the intake it will really only fit on heads that have been milled. To me the 2 have always gone hand in hand, plus any competent machine shop knows this already.

If you read again we were both refering to the head intake surface,not the intake.There is no need to mill an intake.

by now I allways have understood mill the intake not the head intake surface. I don't know if head intake surface will have enough to be milled

mill both sides of the intake .012 for every .010 of head surfacing.



Ron

[62 Max]

Read !
You should mill the block,once you mill the intake it is useless on another motor.

[Nacho-RT74]

yeah I know, and all we know the deal on mill the intake, but I'm just meaning allmost every body talks about mill the intake itself, instead mill the head intake surface.

Is there enough material to mill a head intake surface when you mill maybe 040 the cilinder surface ?

[tecmopar]

Theres plenty of meat on the heads for cutting, the manifold rails could become weaker if cut to thin leading to the chance of cracking. I may be old school but we always do the cutting on the heads mainly because you can use any manifold and it will fit, stock or aftermarket. Lets say you cut a manifold and you don't like it and you find a better one, now you have to cut that manifold also plus the first manifold won't fit on another motor unless those heads were milled and the intake side left alone.

[l8rg8r]

I was considering doing this myself but didn't know what the affects would be ie brackets linkage and valley pan what affect would milling the heads and intake have on these

[frederick]

I know I can only use the intake on this when milling it, but it's not a problem, I am never going to fit another one.

Frederick

[Chatt69chgr]

Help me make sure I understand this.  I'am starting out with a used 440 block that will be decked and installing a new 440 Source Stealth aluminum head.  I don't know what the actual deck height is now (engine has never been rebuilt) but will be building the engine for zero deck.  So if I have take, say, 25 thousands off the deck (of the block) to achieve zero deck then I need to take 2.5 X .0123 or .03075 inch off the intake surface of the head.  If I didn't want to mill the head, could I mill the intake manifold .03075 on each side instead?  Reason I ask is I can buy a new intake manifold for a couple hundred dollars or so but a new set of heads costs $1000 plus.  If I milled the head, then I would have trouble using it on another engine later.  I assume that the exhaust manifold surface doesn't matter as there is probably a certain amount of "slop" in the fit of the H-pipe to the cast iron exhaust manifolds.

[frederick]

Help me make sure I understand this. I'am starting out with a used 440 block that will be decked and installing a new 440 Source Stealth aluminum head. I don't know what the actual deck height is now (engine has never been rebuilt) but will be building the engine for zero deck. So if I have take, say, 25 thousands off the deck (of the block) to achieve zero deck then I need to take 2.5 X .0123 or .03075 inch off the intake surface of the head. If I didn't want to mill the head, could I mill the intake manifold .03075 on each side instead? Reason I ask is I can buy a new intake manifold for a couple hundred dollars or so but a new set of heads costs $1000 plus. If I milled the head, then I would have trouble using it on another engine later. I assume that the exhaust manifold surface doesn't matter as there is probably a certain amount of "slop" in the fit of the H-pipe to the cast iron exhaust manifolds.

You are correct with the 0.03075, only I would have calculated it differently: 1.23 x 0.025 = 0.03075.
After reading everything above I thinkit doesn't make a difference if the 0.025 milled comes from the head or the block.
In both cases you would have to mill either the cylinder head intake or the inlet manifold.
The reason I milled the head is not to get squish but to raise the compression.
If you milled the head(intake and block surface) to fit on an unmilled block you can fit it on another unmilled block.
Exhaust side doesn't matter, if you mill your exhaust system will be a couple of thousands lower.

Frederick

[firefighter3931]

I know I can only use the intake on this when milling it, but it's not a problem, I am never going to fit another one.

Frederick

Exactly ! When milling the heads .050 you need to take .062 of the intake side of the head or the intake manifold.    If you take .062 off the intake surface of the head that leaves the valvecover sealing surface awefully thin. 

Intake Manifolds are relatively cheap in the grand scheme of things when compared to the overall build costs of the engine. 



Ron

[Nacho-RT74]

Exactly ! When milling the heads .050 you need to take .062 of the intake side of the head or the intake manifold.    If you take .062 off the intake surface of the head that leaves the valvecover sealing surface awefully thin. 

Intake Manifolds are relatively cheap in the grand scheme of things when compared to the overall build costs of the engine. 



Ron

thats what I suspected, plus I have two stock intakes.

AN JUST IN CASE will be able to fit one of those misterious intake gaskets that Mopar never fit but aftermarket gaskets brands provides