angle milling bbc heads

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rewguy
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angle milling bbc heads

Post by rewguy »

how much to angle mill a pair of aluminum bbc heads, and how small of a chamber is possible? Starting with a run of the mill 119cc open chamber. Id like a basic "going rate price" and who can do it.........(including correct intake flange)
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Re: angle milling bbc heads

Post by F-BIRD'88 »

by the time you are done you won't have any valve to piston clearance.
get new pistons with the right dome volume to get the desired cr.
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Re: angle milling bbc heads

Post by ProPower engines »

F-BIRD'88 wrote:by the time you are done you won't have any valve to piston clearance.
get new pistons with the right dome volume to get the desired cr.

X2

You did not mention what piston valve angle you are using to start with and while a generic term "run of the mill aluminum head" is not enough detail

Angle milling is tricky and more so on a BBC to do correctly and can be more costly in the end then pistons depending on the build.

Just as an example not only do the intake faces need correction but the head bolt holes and bolt seats need attention as well.
And push rod openings/clearance to port may also be a concern.
This is a final step on a set of heads that have had all the valve seats cut parallel to the heads deck surface and guides are done port or chamber work finished ready for final deck surface machining to a predetermined amount based on final comp. ratio required
But an guess would be $700 to $900 depending on the requirements as it is more time consuming then anything
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Alan Roehrich
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Re: angle milling bbc heads

Post by Alan Roehrich »

For a very specific class application, we take an aluminum open chamber big block head that starts out around 114-116cc nominal, angle mill it 0.00" to 0.140", and then flat mill it approximately 0.040", to get down to approximately 104cc. As stated above in other replies, it requires serious correction to the intake face and the bolt holes. If you use a 7/16" pushrod, as you should, on many applications, it will hit on at least 4 places, 2 on each head. Of course, it also requires rework of the dome and the valve reliefs, unless you are using a custom piston.

Not something I'd advise anyone to do. And the price starts at around $1000.
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Re: angle milling bbc heads

Post by SchmidtMotorWorks »

Alan Roehrich wrote: Tue Dec 16, 2014 11:04 pm For a very specific class application, we take an aluminum open chamber big block head that starts out around 114-116cc nominal, angle mill it 0.00" to 0.140", and then flat mill it approximately 0.040", to get down to approximately 104cc. As stated above in other replies, it requires serious correction to the intake face and the bolt holes. If you use a 7/16" pushrod, as you should, on many applications, it will hit on at least 4 places, 2 on each head. Of course, it also requires rework of the dome and the valve reliefs, unless you are using a custom piston.

Not something I'd advise anyone to do. And the price starts at around $1000.
Does anyone know how far an iron BBC head can be angle milled?
Looking for absolute make before water trouble.
Not worried about head bolt issues etc, I can deal with that.
Only concerned with water jacket or deck sealing issues.
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Re: angle milling bbc heads

Post by ProPower engines »

What iron head are you considering milling??
Some older castings have more meat to them when compared to more current GM offerings from the go leaner years
where overall weight reducing was their goal
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Re: angle milling bbc heads

Post by SchmidtMotorWorks »

ProPower engines wrote: Tue Oct 08, 2019 3:23 pm What iron head are you considering milling??
Some older castings have more meat to them when compared to more current GM offerings from the go leaner years
where overall weight reducing was their goal
60's oval port closed chamber
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Re: angle milling bbc heads

Post by Alan Roehrich »

I have only flat milled those, around 0.060", because we could find the ones that were 96cc nominal, once you added 2.190' intake valves, and put hard exhaust seats in, it took them down a bit, even if you opened the chamber slightly to unshroud the valves. You could get plenty of compression with flat top pistons, a decent overbore, and 0.00" deck clearance.
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