a pro told me that removing the slant in the roof will cost you 7-9% of the port velocity and you will gain neglable cfm. so he told me to keep the slant or if i want to remove some of it i can remove safly up to 50% of the slant more than that you will hurt port velocity and gain neglable cfm which i did in my current home ported heads, i didn't remove much from the slant just enough to mtach the bowels. he also told me to make the fast wall straight shot into the bowel seat, work on the bowel, unshroud the valves in the chambers, remove the material around the valve guide boss. he also said to leave the short side radius, pushrod pinsh, slant. when he does that his heads do 116-117 mph with small hydraulic cam in M6 f-bodies. i will see how the real gains are with the TAZZO meter .

 

 

Glad you all like the work!!!!!!
Heres a picture of the man who did that great porting work.
Hes goofing off with my new soild roller cam
hahahaha

http://www.clanulf.com/tazcar/gallery/eddieshaft.JPG

 

Saying that I like the work would be an understatement, that job is beautiful!! I am actually in the process(have been forever it seems like) of homeporting some heads. I've been going slow and taking care not to mess anything up. Those exhaust bowls he did just gave me an idea. My intake runners look almost identical to yours, except I didn't break through any on the pushrod side. I didn't take mine that far, but they are close. I shaped the chambers almost exactly like he did, although I didn't contour as much on the exhaust valve side as he did.

I might try and get my exhaust valve guides flattened down like your heads- anyone have suggestions on this? It will take me all of a half an hour with the die grinder bit I have.

BTW, what did the chamber volume come out to on your heads, and how much did you mill them??

Thanks
John

 

On the intake side you can use an aluminum weld to fix any holes you make. =)

The exhaust ports should not be attempted by an amature. If you are not a pro at this I would not recomend doing this. You can crack a valve guide very easily. Also I doubt you can get thru the steel valve guides without cracking them using a standard die grinder. You need a more powerful makita or air grinder to accomplish this. But good luck

 

Yeah I've been using an air grinder. After hearing that it's probably best not to take my chances. I might see if I can knock it down a hair though.

John

 

i use Makita electric die grinder when i home port LT1 heads. i use dimmer switch with the electric die grinder to control the speed of the die grinder so that should help in porting more accuratly. i can go with this dimmer switch for controling the die grinder speed from very slow speed to wide open .