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Angle Milled Head
https://slantsix.org/forum/viewtopic.php?t=68417		 Page 2 of 3
Author:  Dart270 [ Fri Nov 14, 2025 5:16 am ]
Post subject:  Re: Angle Milled Head
Good to know, Mark. I had a phone call with Stan yesterday and laid out my thoughts and possible advantages... Glad you guys got together in Tulsa.

Best,
Lou
Author:  hyper_pak [ Mon Nov 17, 2025 7:14 am ]
Post subject:  Re: Angle Milled Head
Quote:
We did.
Care to spill any speed secrets?
Did you think it was worth the effort?
Is it on the lump of cast iron in my garage?
Author:  Rick Covalt [ Mon Nov 17, 2025 8:41 am ]
Post subject:  Re: Angle Milled Head
Quote:
Care to spill any speed secrets?
Did you think it was worth the effort?
Enquiring minds want to know! :D :D
Author:  Dart270 [ Mon Nov 17, 2025 11:39 am ]
Post subject:  Re: Angle Milled Head
You can tell if a head has been angle milled by measuring with a caliper from deck surface to valve cover machined mounting surface, for the manifold side and then the spark plug side. The measurements will be within a few thou if it has been flat milled, but different if angle milled.

Lou
Author:  Team Green [ Sat Nov 22, 2025 11:23 am ]
Post subject:  Re: Angle Milled Head
We looked at the evolution of the MoPar W heads and the valve angles were decreased so if it was good for the V8 it should be good for the slant.
I know we cut enough of an angle that the top of the head bolt holes had to be surfaced. We also went to 1/2" studs at this time.
I have no proof of an improvement as we changed other things that I would have to check with Pops to see if I can disclose anymore information.

Jr.
Author:  slantzilla [ Tue Nov 25, 2025 9:56 pm ]
Post subject:  Re: Angle Milled Head
:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:
Author:  drgonzo [ Fri Dec 12, 2025 8:57 am ]
Post subject:  Re: Angle Milled Head
Mine is angle.milled but I can't recall the measurements. Pretty small chambers.
Author:  Rick Covalt [ Fri Dec 12, 2025 10:40 am ]
Post subject:  Re: Angle Milled Head
Drgonzo, are you racing your engine?
Author:  Dart270 [ Fri Dec 12, 2025 11:09 am ]
Post subject:  Re: Angle Milled Head
I forgot about the valve angles relative to the deck (or cylinder axis). Thanks Mark for that juicy nugget. If you have 0.2" of angle mill across the deck (like 0 on the manifold side and 0.200" on the plug side), then you will have right around a 3.5 degree change in valve angle (more towards "straight up"). Pretty significant difference! Mine are 1.7 deg different than stock (0.1" on one side and 0.2" on the other). On mine, I did nothing to the bolt bosses, but IIRC Meril said they did face theirs at the new angle.

I believe the factory Slant has the same 18 deg valve angle as the LA and Magnum smallblock V8 engines. If you take 3.5 deg off of that, you are at 14.5 deg, which is essentially the same as a W2 smallblock head at 15 deg.

Lou
Author:  hyper_pak [ Fri Dec 12, 2025 11:19 am ]
Post subject:  Re: Angle Milled Head
Good to know.
Author:  drgonzo [ Fri Dec 12, 2025 4:19 pm ]
Post subject:  Re: Angle Milled Head
Quote:
Drgonzo, are you racing your engine?
Rick, I was a few years ago, but it hasn't moved in a while now.
Author:  Rick Covalt [ Fri Dec 12, 2025 4:29 pm ]
Post subject:  Re: Angle Milled Head
Quote:
then you will have right around a 3.5 degree change
I wonder if that makes any measurable difference?
Author:  Dart270 [ Fri Dec 12, 2025 5:01 pm ]
Post subject:  Re: Angle Milled Head
Well, I doubt Mopar would have made the W2 heads with 3 deg smaller valve angle if it didn't. OTOH, it would be really hard to do a convincing back-to-back test on a Slant...

Lou
Author:  slantzilla [ Sat Dec 13, 2025 11:56 am ]
Post subject:  Re: Angle Milled Head
W-2's also have longer valves, but the biggest change was the exhaust ports.

As far as does it help on a Slant, Junior will be more the expert there. I'm just a hack with a hammer and screwdrivers. :oops:
Author:  hyper_pak [ Sun Dec 14, 2025 1:04 pm ]
Post subject:  Re: Angle Milled Head
Quote:
As far as does it help on a Slant, Junior will be more the expert there. I'm just a hack with a hammer and screwdrivers. :oops:
Jr is waiting on permission from you to release more speed secrets.
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