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End of Nov. 2021

68Chevele

68Chevele

Veteran Member
Senior Member
Look like on the last Sat. of Nov. there will be some cyl head flow testing. The following heads will be tested.
BBC ported 360 heads that ran low 11's this year 2.19 1.88 valves 2 ports.
SBC large port Vortec Bowtie heads 2.00 and 1.55 valves mild porting and valve job
and the new Dart 200 cc with the 49cc chambers 2.02 and 1.6 exhaust valves

That's the word I got from my NHRA friend so there will be a peanut port shootout test with his ported heads vs. mine. Should make for a fun day and this kid knows his stuff as he worked under the legendary Joe Mondello.
 
Well it looks like the brakes just got put on this deal, guy now thinks he's a premier porter in the city and to flow 3 heads will be over $350! Yikes, not from me, that money will be spent on the rear end of my car rather than a piece of paper for me to look at. I guess I will take the SBC stuff to the one local shop that flows 2 ports for $40.
 
I found a new guy that flowed 2 of my BBC heads for $50 each.
The 781's went 308cfm on the bad port @ .600 lift and he said had the surface been smoother (I do the burr finish) the head would have gone 315 cfm
The Exhaust flowed max of 240cfm @ .700 lift and when we added the 2" pipe it went 260 wow. Best part with these oval ports was that I had them flowed prior in 1989 with less work and the intake to exhaust was 66% of the intake, now it's 70 to 75% so the extra work paid off and I'm not done with these.

The 360 Peanut port heads flowed, bad port
291@ .550 lift and styed there until .650 lift than dropped like a rock

Exhaust went 240@ .650 lift so I was very happy with those heads

Looks like the 781's will get a better valve job and I need to remove the stud hump for improved flow on the good port he was saying. He used the little ball in the port floor and the port picked up but with these types of BBC heads he says the always do that.
 
I noticed the stud hump on my Brodix Race Rite 294 R port that are 115CC & CNC chamber when I was putting Permatex thread sealant on the rocker studs, other than giving the stud more meat to hold into the head does the hump help or hurt air flow? Hurt makes sense to me
 
Shovelrick said:
I noticed the stud hump on my Brodix Race Rite 294 R port that are 115CC & CNC chamber when I was putting Permatex thread sealant on the rocker studs, other than giving the stud more meat to hold into the head does the hump help or hurt air flow? Hurt makes sense to me
Click to expand...

The stud hump can be ground out of an oval port head but I sure would not try it on a sq. port as I think it would make the rocker stud hole unstable and the lift would pull the stud out of the head, not good. I always try to just massage around it on those big port heads. It will hurt flow a little as I found out adding epoxy to my Vortec SBC helped in closing up the stud hole indentation in the intake port on those heads, was worth 10 cfm just doing that mod.
 
68Chevele said:
The stud hump can be ground out of an oval port head but I sure would not try it on a sq. port as I think it would make the rocker stud hole unstable and the lift would pull the stud out of the head, not good. I always try to just massage around it on those big port heads. It will hurt flow a little as I found out adding epoxy to my Vortec SBC helped in closing up the stud hole indentation in the intake port on those heads, was worth 10 cfm just doing that mod.
Click to expand...
When I was doing the rocker arm geometry after watching Foxwells vid I bought longer ARP studs (No idea why Brodix bothers with studs) and the first set stuck out in the ports IIRC about 1/4" to 3/8" so I flat cut them but still wasn't happy so bought another set with .850 into the head, I'm at .600 lift both sides so probably should've went with stock length valves, I think? Either way seems like there'd be a better design on the Brodix BBC heads but maybe it's just the Race Rite series heads like that?
 
Had a buddy just flow his 990's, the intake was only slightly better than my 781's but my exhaust blew his 990's away. He was not very happy.
 
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