Got the heads back, flow numbers post
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From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Got the heads back, flow numbers post
I got the heads back today. I was hoping for a little more peak flow #s, but am more than impressed with the low and mid lift areas.
These are Edelbrock ovals tested at 28in
Intake: cfm
.200 / 148
.300 / 242
.400 / 282
.500 / 305
.600 / 313
.650 / 318
.700 / 322.5
Exhaust cfm
.200 / 130
.300 / 155
.400 / 179
.500 / 210
.600 / 220
.650 / 222
.700 / 227
Looking at the heads it is obvious there was a lot of work done to them. The chambers have been laid back a lot and looking down the ports on intake and exhaust sides shows almost no untouched area. The Victor jr. was also matched to the intakes. The work on the Victor jr. goes all the way up the the plenum area.
The heads were also flat milled .035 to raise the compression to almost 11 to 1. The chambers are 110 cc stock they are now 108.
The porter assured me the milling would not weaken the heads enough to worry about running NOS
Does anyone see any problems, i.e valve train geometry, etc.
Any thoughts are appreciated
These are Edelbrock ovals tested at 28in
Intake: cfm
.200 / 148
.300 / 242
.400 / 282
.500 / 305
.600 / 313
.650 / 318
.700 / 322.5
Exhaust cfm
.200 / 130
.300 / 155
.400 / 179
.500 / 210
.600 / 220
.650 / 222
.700 / 227
Looking at the heads it is obvious there was a lot of work done to them. The chambers have been laid back a lot and looking down the ports on intake and exhaust sides shows almost no untouched area. The Victor jr. was also matched to the intakes. The work on the Victor jr. goes all the way up the the plenum area.
The heads were also flat milled .035 to raise the compression to almost 11 to 1. The chambers are 110 cc stock they are now 108.
The porter assured me the milling would not weaken the heads enough to worry about running NOS
Does anyone see any problems, i.e valve train geometry, etc.
Any thoughts are appreciated
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From: Corsicana, Tx
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Re: Got the heads back, flow numbers post (69 N.O.X. RATT)
Great numbers. You can feed 600 HP with those with enough cam. Which you have!
Were the exhaust numbers done with a test pipe?
How long before it's running?
JIM
Were the exhaust numbers done with a test pipe?
How long before it's running?
JIM
Thread Starter
Safety Car
Joined: Aug 2001
Posts: 3,892
Likes: 13
From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Re: Got the heads back, flow numbers post (427Hotrod)
Glenn,
The heads were flowed before. I will post the numbers when I get the rest of the paperwork back.
Jim,
I should have asked but I do not know if they were done with a pipe or not. I should have it back together in 2-3 weeks.
When is yours going to be done.
[Modified by 69 N.O.X. RATT, 4:31 AM 4/15/2003]
The heads were flowed before. I will post the numbers when I get the rest of the paperwork back.
Jim,
I should have asked but I do not know if they were done with a pipe or not. I should have it back together in 2-3 weeks.
When is yours going to be done.
[Modified by 69 N.O.X. RATT, 4:31 AM 4/15/2003]
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Joined: Jan 2000
Posts: 13,014
Likes: 2,257
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
Re: Got the heads back, flow numbers post (69 N.O.X. RATT)
I'm working on it, but work is been awful busy. Plus I got sidetracked a couple of days this last weekend because the Top Fuel guys were in town and I had to go out and get my annual "nitro fix"!!!
I got new TTII's installed with bigger tires, plumbed line lock last weekend, shortblock is all built. Cam sent out for a little "upgrade". Had a bad rocker, so Comp is rebuilding them under warranty. Had to return a bunch of fuel fittings. Summit decided somehow that along with all that Aeroquip braided line and A/N fittings, I must have wanted half of them to be push-lock type! Hopefully this weekend I'll install the Aeromotive fuel pump, regulator and tank sump possibly.
Still waiting on my heads, so I know what you've been through. Then I gotta port intake etc. Lots to do, but progress is being made.
I really wanted to make the Forum Cruise in...I dunno if I can pull it off. Time is getting tight. But spring is here and it sure hurts to have a convertible sitting in the garage!
Keep us up to date on yours. You're ahead of me!
JIM
I got new TTII's installed with bigger tires, plumbed line lock last weekend, shortblock is all built. Cam sent out for a little "upgrade". Had a bad rocker, so Comp is rebuilding them under warranty. Had to return a bunch of fuel fittings. Summit decided somehow that along with all that Aeroquip braided line and A/N fittings, I must have wanted half of them to be push-lock type! Hopefully this weekend I'll install the Aeromotive fuel pump, regulator and tank sump possibly.
Still waiting on my heads, so I know what you've been through. Then I gotta port intake etc. Lots to do, but progress is being made.
I really wanted to make the Forum Cruise in...I dunno if I can pull it off. Time is getting tight. But spring is here and it sure hurts to have a convertible sitting in the garage!
Keep us up to date on yours. You're ahead of me!
JIM
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From: Waterloo ontario Canada
Re: Got the heads back, flow numbers post (69 N.O.X. RATT)
Good numbers Glenn and with the formula of CFM x .257 x 8 cylinders you get a rough idea of what the heads can support for horsepower.
But this doesn't take into account intake loss. An intake can easily take 20% off the numbers and if it reaches 25% they recommend a different intake.
But this doesn't take into account intake loss. An intake can easily take 20% off the numbers and if it reaches 25% they recommend a different intake.
