Angle Milling

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805moparkid

805moparkid

Slant and AFX Guy
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Ok so i have some questions in reference to angle milling heads. Lets go back to a time when all these aftermarket heads were not available with extra meat and new valve angles over stock. What was to gain by angle milling heads vs just a straight cut? What work was involved after the cut and was it work it for what was available? Lastly on our wedges what is a good valve angle, is it a less than kinda number (closer to 0* the better) or is there a range?

thanks!
 
Angle milling was originally a chebbie thing. Since the combustion chamber is on the outside portion of the head, more can be removed from it be angle milling. You cannot really angle mill a head enough to change the valve angles for any appreciable benefit. The only benefit is being able to remove more from the combustion chamber than with a straight cut. Honestly, there's probably not a whole hell of a lot of benefit to be had at all. Somebody just thought it was cool and tried it and lots of people have copied them since. That's my opinion anyway.
 
It was more of a chevy thing considering there valve angle was 23 degrees. Older heads could not be angle milled as far, the iron eagle will go far enough to get them down to 21+ degree. But the intake has to be done along with them heads and the heads have to have the bolt holes spot faced to straighten them up also. Then when your done you throw them away lol. More for heads up all out type racing.

The La dodge is 18 degree factory, less is better.
 
1970 La said:
It was more of a chevy thing considering there valve angle was 23 degrees. Older heads could not be angle milled as far, the iron eagle will go far enough to get them down to 21+ degree. But the intake has to be done along with them heads and the heads have to have the bolt holes spot faced to straighten them up also. Then when your done you throw them away lol. More for heads up all out type racing.

The La dodge is 18 degree factory, less is better.
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ok lets throw the "its a chevy thing" aside and think about it this way. whats to gain by changing your LA from 18 to 16? on a street build and a race build what would be gained?
 
An assload of metal would have to be LOST to change the angle 2*.
 
I would not recomend it for street use at all. If your going to do it your going to have to go as far as material will allow you to see the gain. It changes the intake port angle by standing the valve up straighter and making more power. Mostly this is done for small cubic inch engines in heads up classes to get as much hp/ci. Another downfall is when you angle mill .200 your rolling the head over towards the exhaust side and your headers have to be modified if you dont have room for them to roll with the head.
 
I dont think you could get 2 degrees out of a stock mopar head, although you can buy a 15 degree race head. I cant remember what the clevland head is but it is down around 12 degrees I think factory. You dont want them running in your factory head class or your going to get your a-- kicked. They make some awsome power.
 
RustyRatRod said:
An assload of metal would have to be LOST to change the angle 2*.
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depends on how wide the head is, but for the SMC its .133 for 1*

1970 La said:
I would not recomend it for street use at all. If your going to do it your going to have to go as far as material will allow you to see the gain. It changes the intake port angle by standing the valve up straighter and making more power. Mostly this is done for small cubic inch engines in heads up classes to get as much hp/ci. Another downfall is when you angle mill .200 your rolling the head over towards the intake side and your headers have to be modified if you dont have room for them to roll with the head.
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Ok let me rephrase, take all the other items out of the equation (header clearance, intake hight, etc) what would be gained by getting a better valve angle?
 
1970 La said:
I dont think you could get 2 degrees out of a stock mopar head, although you can buy a 15 degree race head. I cant remember what the clevland head is but it is down around 12 degrees I think factory. You dont want them running in your factory head class or your going to get your a-- kicked. They make some awsome power.
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interesting as a slant stock is 12*
 
Its been awhile but i am sure the claimed it raised the intake runner also. So If you could have a durable head with a lesser valve angle its supposed to make more power and last. I never did it myself, left it to the chevy guys and believe me on the drag strip it worked.
 
It sure did work. My older friend used to run a 67 Camaro with a 283 in it. Dual quad tunnel ram and a set of angle milled heads. He is a crack machinist and did all the right stuff to make everything fit just perfect. Anyhow, this thing was making 600HP, N/A some 40 years ago. They were untouchable in his ring of racing for over 20 years with that car. He always claimed it was the milling and port work, and the 8500+rpm top end LOL
 
People have been racing with this (LA) engine for 50 years. If there was enough to be gained by doing this to offset the expense, it would be common practice. Sometimes when something isn't a popular modification, it's because there is no reason to do it.

FWIW I believe the reason it's not needed on an LA Mopar is that the valves already open "on center". That is, the centerline of the valves is the centerline of the bore, so they are at the widest point. The small Chevy (production) heads have the valves offset from the bore center. Angle milling moves them closer to bore center which provides some unshrouding benefit. Then again, I might be full of sh*t.
 
Unless you need the maximum from your combo, meaning a certain class where it's allowable, and while the narrow valve angle does help, i'd probably not worry about it.
 
MRL Performance said:
It sure did work. My older friend used to run a 67 Camaro with a 283 in it. Dual quad tunnel ram and a set of angle milled heads. He is a crack machinist and did all the right stuff to make everything fit just perfect. Anyhow, this thing was making 600HP, N/A some 40 years ago. They were untouchable in his ring of racing for over 20 years with that car. He always claimed it was the milling and port work, and the 8500+rpm top end LOL
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those chevy guys sure like to rev the piss out of them huh! i have a friend with a de-stroked 327 and i watched it drop off 10 grand tachs... thanks for the info

C130 Chief said:
People have been racing with this (LA) engine for 50 years. If there was enough to be gained by doing this to offset the expense, it would be common practice. Sometimes when something isn't a popular modification, it's because there is no reason to do it.

well lets look at that, how many people are willing to really look for gains for the amount of work that would take? i mean if you were serious for 2 degree's, say .260" (just a number) the work to get all the holes to line up properly, etc etc etc. i would be curious if eliminator motors are angle milled (if legal)

FWIW I believe the reason it's not needed on an LA Mopar is that the valves already open "on center". That is, the centerline of the valves is the centerline of the bore, so they are at the widest point. The small Chevy (production) heads have the valves offset from the bore center. Angle milling moves them closer to bore center which provides some unshrouding benefit. Then again, I might be full of sh*t.
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Now this is make sense. I can see where the gains would be more on the chevy. But there are still the benefits of valve and port angle.

ntsqd said:
And here I was just thinking that angle milling the / head might be a way to give it a better squish zone.
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well its certainly a way to gain that. For my purpose it would be to gain pushrod clearance, improve chamber shape, and improve port/valve angle. I just like to know options before i move on things.
 
/6 Matt said:
I've often wondered if angle milling a slant couldnt create a quench zone.
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would be milling the wrong way as the "pad" is on the port side. What im looking into is maximizing the slant head in a number of ways, hence reading about this. IMO getting quench requires correct custom pistons, not chamber work, but not that you couldn't go that way.
 
Sure you can go that way. Get one of them Argentina heads.
 
I know. Rest assured, it's not one of a kind either.

The biggest thing I would think with angle milling the slant head would be you would end up needing to enlarge the ad bolt holes due to interference and the fact that the bolts will not tighten down flush against the head.
 
RustyRatRod said:
I know. Rest assured, it's not one of a kind either.

The biggest thing I would think with angle milling the slant head would be you would end up needing to enlarge the ad bolt holes due to interference and the fact that the bolts will not tighten down flush against the head.
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well correct, that would need to be corrected. Im more interested on whats to gain or lose, fitment/adjustments/etc are not my concern at this point, i need to figure if its worth what i'll get.
 
Like has been said, you aint the first to think of it. This stuff is ancient. It's all been thought of and probably tired already. If it worked, it'd be front page news. It ain't cause it don't.
 
Where do I find one of those Argentine heads? If what I had were aluminum it'd already have that chamber.
 
RustyRatRod said:
Like has been said, you aint the first to think of it. This stuff is ancient. It's all been thought of and probably tired already. If it worked, it'd be front page news. It ain't cause it don't.
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never said i did

ntsqd said:
Where do I find one of those Argentine heads? If what I had were aluminum it'd already have that chamber.
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there is only 5 heads, stock American heads, in aluminum produced from what i understand, though only one has been seen. the arg heads only come in iron as well...
 

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And the mystery head Doug's holdin up might be painted up cardboard fakery. It may as well be. We'll never know.
 
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