need before/after head flow #'s
Thread Starter
Melting Slicks
Joined: Jan 2001
Posts: 2,635
Likes: 2
From: Aloha, Oregon
need before/after head flow #'s
i just got my LS6 heads back from the machine shop after having my hand porting flow checked. Hello!!! below are my #'s. i'm particularly interested in both I/E across the entire lift range of others that have ported LS6 heads. I was a bit disappointed with the flows. Here they are:
lift ... INTAKE.... Exhaust
0.1...... 66........ 54
0.2...... 133...... 117
0.3...... 196...... 176
0.4...... 246...... 213
0.5 ...... 275...... 235
0.6...... 287....... 246
let me know what you think. these #'s are with a 4.08" bore, 2.02" intake/ 1.575" exhaust valves, not back cut. the cam will be 236/236 .601/.601 on 112lca. in a 389 (4.08 x 3.72 stroke). I was thinking of opening the intakes more. i could also pick up more low flow #'s if i get the valves back cut.
Robert Judd
2001 C5 coupe- 389 stroker.
[Modified by rwj383, 1:50 AM 9/20/2002]
lift ... INTAKE.... Exhaust
0.1...... 66........ 54
0.2...... 133...... 117
0.3...... 196...... 176
0.4...... 246...... 213
0.5 ...... 275...... 235
0.6...... 287....... 246
let me know what you think. these #'s are with a 4.08" bore, 2.02" intake/ 1.575" exhaust valves, not back cut. the cam will be 236/236 .601/.601 on 112lca. in a 389 (4.08 x 3.72 stroke). I was thinking of opening the intakes more. i could also pick up more low flow #'s if i get the valves back cut.
Robert Judd
2001 C5 coupe- 389 stroker.
[Modified by rwj383, 1:50 AM 9/20/2002]
Burning Brakes
Joined: May 2000
Posts: 827
Likes: 78
From: Tennessee
Cruise-In II Veteran
Re: need before/after head flow #'s (rwj383)
This is not really what you asked for but maybe it will help. My LS1 heads were flowed with a 3.90 bore and the at .600 lift they flowed:
295 intake
220 exhaust
Of course the 3.90 bore vs the 4.08 bore makes it really hard to compare the flow numbers of my heads vs yours.
295 intake
220 exhaust
Of course the 3.90 bore vs the 4.08 bore makes it really hard to compare the flow numbers of my heads vs yours.
Thread Starter
Melting Slicks
Joined: Jan 2001
Posts: 2,635
Likes: 2
From: Aloha, Oregon
Re: need before/after head flow #'s (2001C5)
This is not really what you asked for but maybe it will help. My LS1 heads were flowed with a 3.90 bore and the at .600 lift they flowed:
295 intake
220 exhaust
Of course the 3.90 bore vs the 4.08 bore makes it really hard to compare the flow numbers of my heads vs yours.
295 intake
220 exhaust
Of course the 3.90 bore vs the 4.08 bore makes it really hard to compare the flow numbers of my heads vs yours.
Drifting
Joined: May 2002
Posts: 1,607
Likes: 1
From: San Francisco CA
Re: need before/after head flow #'s (rwj383)
This is not really what you asked for but maybe it will help. My LS1 heads were flowed with a 3.90 bore and the at .600 lift they flowed:
295 intake
220 exhaust
Of course the 3.90 bore vs the 4.08 bore makes it really hard to compare the flow numbers of my heads vs yours.
295 intake
220 exhaust
Of course the 3.90 bore vs the 4.08 bore makes it really hard to compare the flow numbers of my heads vs yours.
Scoggin-Dickey sells some GM CNC ported LS6 heads with stock valves that flow .200 at .300 and 290+ at .500. They don't say but I assume that's intake flow with a stock bore.
Here's a link to some ported LS1 heads that are being sold by LPE on ebay. Included in the description are the flow numbers at various lifts: http://cgi.ebay.com/ebaymotors/ws/eB...tem=1862234433
[Modified by SFVetteman, 12:03 AM 9/23/2002]
Thread Starter
Melting Slicks
Joined: Jan 2001
Posts: 2,635
Likes: 2
From: Aloha, Oregon
Re: need before/after head flow #'s (SFVetteman)
Thanks, SFVetteman. the lower lift #'s is what i'm looking for, too. I seem to be determining that my intake is lacking at the lower lifts particularly. especially for bigger bore flowing on the bench. but my #'s above were right after cutting the seats, prior to tuning the seat throats and short turns. My numbers are way up, but still slow in the lower lifts. I'm going to have the intake valves back cut. that should do the trick at the lower flows.
