FAST or L76 Intake?
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 848
Likes: 8
From: St. Louis Mo.
Originally Posted by SpinMonster
They arent interchangable. The FAST is for catherdral ports and the L76 only fits the L92 heads.
Le Mans Master
Joined: Dec 2005
Posts: 8,475
Likes: 332
From: Port Arthur, Texas 77642
Originally Posted by RWSjr
My Bad.. I know that, should have elaborated. If your gonna do heads and cam mod - L92/L76 or AFR 225/FAST? Just wondering, for future mod madness
Scotty
Tech Contributor
Joined: Mar 2003
Posts: 12,094
Likes: 197
From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Originally Posted by black05c6z51
heads and intake are about the same price as fast and flow WAY more!!!
The next issue is that even though they are good at first glance, they arent intended for our small 4" bore motor. The 6.2 has a 4.065 bore and these heads will likey be shrouded by the smaller bore.
I've seen great numbers with etp's and the FAST. I'll beleive the hype when I see the results.
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Burning Brakes
Joined: Dec 1999
Posts: 1,088
Likes: 0
From: Silver Spring, Md.
Originally Posted by SpinMonster
I have been watching for flow tests and havent seen any. Did you hear of any? The other issue here is that even with good peak numbers these heads are 265cc runners which is way huge compared to 205 afr's or 215+ ETP's. I would wait to see some results before jumping on this one.
I've seen great numbers with etp's and the FAST. I'll beleive the hype when I see the results.
I've seen great numbers with etp's and the FAST. I'll beleive the hype when I see the results.
L92 flow results with manifold.
So we did some touching up on some L92 heads. We opened up the exhaust and just barley touched the bowl area on the intake side. The radius to the seat on the intake needs some attention to it, but thats all. These results were done on a superflow 600 bench, 4.100 bore, 28" water.
No manifold
.100_64 .200_156 .300_230 .400_274 .500_318 .600_349 .700_341
With manifold
.100_67 .200_153 .300_224 .400_268 .500_301 .600_323 .700_323
Exhaust was done with no pipe. So numbers will be lower than if there was a pipe on it.
.100_46 .200_124 .300_162 .400_192 .500_215 .600_227 .700_234
Enjoy. Hope this helps everyone out.
Tech Contributor
Joined: Mar 2003
Posts: 12,094
Likes: 197
From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
thanks bud..I guess Im in for a crate motor when they are out. It would be near 500 to the wheels with just a cam change and all the bolt ons. We will see it soon.
A guy in the C5 section is about to have a stroker done with these heads but once again, the flow numbers you have above are done ona 4.1 inch bore and are going to suffer greatly on the 4" bore.
A guy in the C5 section is about to have a stroker done with these heads but once again, the flow numbers you have above are done ona 4.1 inch bore and are going to suffer greatly on the 4" bore.
Burning Brakes
Joined: Dec 1999
Posts: 1,088
Likes: 0
From: Silver Spring, Md.
Spin, apparently GM isn't worried about shrouding with these huge intake valves because the engine only has a 4.06" bore diameter.
6200 6.2L V-8 (L92)
Displacement (cu in / cc):
378 / 6199
Bore & stroke (in / mm):
4.06 x 3.62 / 103.25 x 92
6200 6.2L V-8 (L92)
Displacement (cu in / cc):
378 / 6199
Bore & stroke (in / mm):
4.06 x 3.62 / 103.25 x 92
Burning Brakes
Joined: Dec 1999
Posts: 1,088
Likes: 0
From: Silver Spring, Md.
Originally Posted by SpinMonster
A guy in the C5 section is about to have a stroker done with these heads but once again, the flow numbers you have above are done ona 4.1 inch bore and are going to suffer greatly on the 4" bore.
4.030” test bore
Lift ___.100 _.150_.200_.250_.300 _.350 _.400 _.450 _.500 _.550 _.600 _.650_.700_.750
#1 Int. 74.9 109.4 154.4 193.5 225.3 252.8 274.6 292.7 308.8 321.0 328.7 326.6 310.0 316.6
#1 Exh. 63.6 97.9 126.1 148.7 162.3 178.6 189.6 197.6 205.5 210.7 214.6 217.8 221.2 223.5
The intake was tested with a radius plate and the exhaust was tested with a 2 ½” stub pipe.
Valve dimensions:
Intake = 2.160” X 4.870” X .314”(8mm)
Exhaust = 1.590” X 4.920” X .314”(8mm)
Seat/throat diameters:
Intake = 1.870”
Exhaust = 1.355”
Volumes:
Intake runner = 260.6cc
Exhaust runner = 90.0cc
Chamber = 69.8cc
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 848
Likes: 8
From: St. Louis Mo.
Originally Posted by stinky
Here ya go, Spin:
L92 flow results with manifold.
So we did some touching up on some L92 heads. We opened up the exhaust and just barley touched the bowl area on the intake side. The radius to the seat on the intake needs some attention to it, but thats all. These results were done on a superflow 600 bench, 4.100 bore, 28" water.
No manifold
.100_64 .200_156 .300_230 .400_274 .500_318 .600_349 .700_341
With manifold
.100_67 .200_153 .300_224 .400_268 .500_301 .600_323 .700_323
Exhaust was done with no pipe. So numbers will be lower than if there was a pipe on it.
.100_46 .200_124 .300_162 .400_192 .500_215 .600_227 .700_234
Enjoy. Hope this helps everyone out.
L92 flow results with manifold.
So we did some touching up on some L92 heads. We opened up the exhaust and just barley touched the bowl area on the intake side. The radius to the seat on the intake needs some attention to it, but thats all. These results were done on a superflow 600 bench, 4.100 bore, 28" water.
No manifold
.100_64 .200_156 .300_230 .400_274 .500_318 .600_349 .700_341
With manifold
.100_67 .200_153 .300_224 .400_268 .500_301 .600_323 .700_323
Exhaust was done with no pipe. So numbers will be lower than if there was a pipe on it.
.100_46 .200_124 .300_162 .400_192 .500_215 .600_227 .700_234
Enjoy. Hope this helps everyone out.
Le Mans Master
Joined: Feb 1999
Posts: 7,121
Likes: 0
From: Vilano Beach FL
Nice numbers - I've been following the various L92/L76 threads here and especially over at LS1Tech. Several projects "in process", including some interesting larger displacement L92's.
I'm real interested to see some dynos on the L92 vs. an AFR205 to see how the lower end TQ is effected by the different velocity/flow characteristics.
*If* the L92/76 proves to be a good streetable combo for LS2's, based on the initial pricing I've read, wow, it will be an incredible deal!
I'm real interested to see some dynos on the L92 vs. an AFR205 to see how the lower end TQ is effected by the different velocity/flow characteristics.
*If* the L92/76 proves to be a good streetable combo for LS2's, based on the initial pricing I've read, wow, it will be an incredible deal!
