Milling 624 Heads

Chipper Chapman · 02-25-2016, 10:01 PM

To get the 624 sbc head down to the neighborhood of legal (63.3 minimum) I assume they are being angle milled? Can anyone confirm this and if so what how far are you rolling them?

Mike Taylor 3601 · 02-26-2016, 09:58 AM

taking 882's down to 64cc we angle milled .150''
have cut 614's which are light weight casting like the 624 that much also.
624 and 882 style casting can angle mill like that without water jacket on spark plug side giving you a problem,I.E. older castings like 461,462,291 style you had to plug small water jackets by spark plug because gasket wouldn't cover them any longer.
If don't have one, make a square(that won't be square) that matches intake to head surface angle,so when set up to correct intake face of head you can setup from the square from head surface so you can mill intake face back at correct angle.
Mike Taylor 3601

Chipper Chapman · 03-02-2016, 09:31 PM

Tried .150" and it took our dummy head from 76.5 to 57cc. We'll try a little less on another lol.

Mike Taylor 3601 · 03-03-2016, 09:58 AM

Quote:

Originally Posted by Chipper Chapman

Tried .150" and it took our dummy head from 76.5 to 57cc. We'll try a little less on another lol.

if you unshroud around valves you may get back close to where you need,you can unshroud chamber out to the gasket.
I think the 882's may have started off 78-79 cc been a while.

Mike Taylor 3601

Daran Summerton · 03-04-2016, 10:44 AM

Did you stop at the end rails or did you go the entire head?

Mike Taylor 3601 · 03-05-2016, 10:46 AM

I setup to mill the whole head,when setting up check with dial indicator so there is the amount of angle you want, I.E. zero at exhaust side and .125'' at intake side of end rail,that should be right at .125'' angle mill, if still use stones on mill then it will take more than that by the handwheel because stone loss,but it should be .125'' removed from head although handwheel will show more.

You can mill and leave end rails uncut and seal with silicone,but I always try to mill whole head less chance for leaks.

Mike Taylor 3601

02-25-2016, 10:01 PM	#1
Chipper Chapman Member Join Date: Jan 2004 Location: Belmont N.S. Canada Posts: 473 Likes: 246 Liked 166 Times in 71 Posts	Milling 624 Heads To get the 624 sbc head down to the neighborhood of legal (63.3 minimum) I assume they are being angle milled? Can anyone confirm this and if so what how far are you rolling them? __________________ Chris Chapman 1969 Chevelle NHRA F-G/SA 1090

02-26-2016, 09:58 AM	#2
Mike Taylor 3601 VIP Member Join Date: Oct 2008 Location: Somerset,Ky Posts: 1,372 Likes: 357 Liked 308 Times in 103 Posts	Re: Milling 624 Heads taking 882's down to 64cc we angle milled .150'' have cut 614's which are light weight casting like the 624 that much also. 624 and 882 style casting can angle mill like that without water jacket on spark plug side giving you a problem,I.E. older castings like 461,462,291 style you had to plug small water jackets by spark plug because gasket wouldn't cover them any longer. If don't have one, make a square(that won't be square) that matches intake to head surface angle,so when set up to correct intake face of head you can setup from the square from head surface so you can mill intake face back at correct angle. Mike Taylor 3601

03-02-2016, 09:31 PM	#3
Chipper Chapman Member Join Date: Jan 2004 Location: Belmont N.S. Canada Posts: 473 Likes: 246 Liked 166 Times in 71 Posts	Re: Milling 624 Heads Tried .150" and it took our dummy head from 76.5 to 57cc. We'll try a little less on another lol. __________________ Chris Chapman 1969 Chevelle NHRA F-G/SA 1090

03-04-2016, 10:44 AM	#5
Daran Summerton Senior Member Join Date: Jun 2003 Location: Las Vegas nv Posts: 600 Likes: 18 Liked 66 Times in 37 Posts	Re: Milling 624 Heads Did you stop at the end rails or did you go the entire head? __________________ 72 cutlass

03-05-2016, 10:46 AM	#6
Mike Taylor 3601 VIP Member Join Date: Oct 2008 Location: Somerset,Ky Posts: 1,372 Likes: 357 Liked 308 Times in 103 Posts	Re: Milling 624 Heads I setup to mill the whole head,when setting up check with dial indicator so there is the amount of angle you want, I.E. zero at exhaust side and .125'' at intake side of end rail,that should be right at .125'' angle mill, if still use stones on mill then it will take more than that by the handwheel because stone loss,but it should be .125'' removed from head although handwheel will show more. You can mill and leave end rails uncut and seal with silicone,but I always try to mill whole head less chance for leaks. Mike Taylor 3601