Angle Milling V/S Flat Milling

[stroker1]

I have been in limbo for awhile over some heads. I almost had a deal on Vic. Jrs, then I was going to buy some Profilers. A few nights ago I bought a set of Track1 heads with 76cc chambers in a package deal with alot of other stuff. I bought an complete disassembled turbo motor. I really need to get it to at least 12:1, gonna spray 250-300 on it.

Question is, what's the best way to jack up the compression in addition to adding domed pistons? I think if I angle mill the heads .060" it should yeild maybe another 7-8cc from the chamber. If I flat mill them, I assume I can't cut that much. What are the pros and cons of angle milling v/s flat milling? I've never dealt with a whole lot of cutting the chambers down. I know I will have to have the intake side of the head remachined if they are angle milled, and spot face the head bolt holes, but what does it do to the valve angles and piston to valve clearances?

[coony278]

If you flat mill them you wont be able to cut much off.

On the other hand if you angle mill wich will get expensive if you cut alot , but you can cut them all the way to the intake valve .250ths ( about that) also it will make the engine more like a 20deg instead of a 23 deg.

intake side of heads will have to be redone and the intake itself will have to be cut down to fit again. And the bolt holes in head will have to be redrilled.

I had a set done like this once ended up with about 350.00 labor in machine work.

[stroker1]

Sounds like this is going to get expensive. What about the dowel holes? Angle milling is going to make them not square to the deck anymore. So what do you do for dowels?

[wikd69]

Sounds like this is going to get expensive. What about the dowel holes? Angle milling is going to make them not square to the deck anymore. So what do you do for dowels?

Wouldn't the same be true for the longer head bolt holes ?

[stroker1]

Sounds like this is going to get expensive. What about the dowel holes? Angle milling is going to make them not square to the deck anymore. So what do you do for dowels?

Wouldn't the same be true for the longer head bolt holes ?

Oh, yeah. The bolt holes I have figured in already. But don't know what to do exactly about the dowel holes. Can't just drill the oversize or redrill perpendicular to the deck. So I don't know what the standard is. Plug and remachine dowel holes in heads? Offset ground dowel pins?

[coony278]

The machine shop will fix the dowel pins also.

[vegaracer]

Plug and remachine dowel holes in heads? Offset ground dowel pins?

You could weld them if the heads are auminum and re-drill them

[stroker1]

I was looking at the heads more closely today and my feelings are kinda hurt. The edge of the intake valve is already beginning to come out the edge of the combustion chamber. What in the heck? Does this mean I can't mill them?

[wikd69]

I was looking at the heads more closely today and my feelings are kinda hurt. The edge of the intake valve is already beginning to come out the edge of the combustion chamber. What in the heck? Does this mean I can't mill them?

Got pix ?

[stroker1]

I was looking at the heads more closely today and my feelings are kinda hurt. The edge of the intake valve is already beginning to come out the edge of the combustion chamber. What in the heck? Does this mean I can't mill them?

Got pix ?

Nope. No pics, camera is broke. I talked to Brodix and they told me it's pretty hard to screw up a set of their heads by angle milling too much. They said the valve can stick out past the deck with no problems until you get near the valve seat. But I tell ya what, looks to me like by the time I have them cut enough to drop the volume of the chamber where I need it, the surfacing machine is going to be cutting real close to the valve seats. Beats me, I quess I'll let the head gurus make that decision.

[stroker1]

Good News, Good News!!! For me anyway. I was talking to a local performance shop and the guy convinced me if the edge of the intake valve was protruding out of the chamber just a tad, they had to be pretty small. So I take them to him and he CCed the heads. Turned out to be 58cc. But he had a little extra grease in the chamber, so he said they're probably around 60cc. He's going to do them again tomorrow. It was closing time. So with the KB flat tops the guy had in his turbo motor (he thought he had Manley flat tops) and a 60cc chamber, and no boost gage, no damn wonder he burned holes in 5 pistons.

[vegaracer]

Thats good news for you