Milling 624 Heads

[Chipper Chapman]

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]

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]

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]

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]

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

[Mike Taylor 3601]

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

[Paul Precht]

Originally Posted by Mike Taylor 3601

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

What part of the head is called the end rails.
.

[Rich Biebel]

Beyond the deck area of the head up to the intake. A short section that just seals the head to the block at the valley area.

If your angle milling a lot you don't have to keep milling to finish that area and make the head perfectly flat....

The last couple passes will cut that flat...

I always did ....

I ran an 85-B for years and angle milled plenty of heads....

Big Block Chevy heads....for SS use.....LS-6
Small Block Chevy heads for various uses....

I angle milled a set of 462 heads for an engine I ran down to low 50's CC's
Flat top pistons....383...13-1 compression...

[ron mattson]

Call Matt Steen @ Victory Engines they have
done quite a few of those 624 castings!

[Paul Precht]

Originally Posted by Rich Biebel

Beyond the deck area of the head up to the intake. A short section that just seals the head to the block at the valley area.

If your angle milling a lot you don't have to keep milling to finish that area and make the head perfectly flat....

The last couple passes will cut that flat...

I always did ....

I ran an 85-B for years and angle milled plenty of heads....

Big Block Chevy heads....for SS use.....LS-6
Small Block Chevy heads for various uses....

I angle milled a set of 462 heads for an engine I ran down to low 50's CC's
Flat top pistons....383...13-1 compression...

I'm picking up my 85 B in a few weeks, I left my old one in NH with my former partner when I came to PA. Nothing beats an 85 B for durability and versatility.