Home port LS6 head ideas
09-21-2006, 11:22 AM
#1
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Home port LS6 head ideas Any suggestions for where LS6 heads pickup a lot? I was thinking I'd remove the rocker bolt hump, and take down the swirl ramp. Worth the trouble?
T
T
09-21-2006, 01:04 PM
#2
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Originally Posted by Terry Burger
Any suggestions for where LS6 heads pickup a lot? I was thinking I'd remove the rocker bolt hump, and take down the swirl ramp. Worth the trouble?
T
T
racer7088, SStrokerAce and airflowdevelopment have some good information in this thread:
https://ls1tech.com/forums/advanced-engineering-tech/575861-good-flow-numbers-small-runners-only-keys-home-porting-success.html
09-21-2006, 05:47 PM
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Terry,
The best thing you can do is have a good valve job performed on the heads.
When I say good valve job, I would use the following cuts.
Intake
38-.050
45-.041
60-.060
75-Balance to generate a throat that is 91% of valve size
Finish with a 90.
Cut the bowl out .100 in total diameter approx .275 down from the bottom of the 75, making a nice soft radius on the throat. (if you are well trained with a die grinder, you can use a high-helix or fine single cut, and knock the bottom of the 75 off into the 90).
If you have access to Radius cutters, the exhaust will benefit from anything R-9/11. Keep your 45 atleast .050 wide. A 35 top cut will work also.
If you feel energetic, you can easily take .100 out of the long wall from the end of the pushrod pinch into the base of the bowl.
At this point, on a home port head, I would not worry with the total port size or SSR, unless you have access to a way to verify airspeed and flow.
Dennis
The best thing you can do is have a good valve job performed on the heads.
When I say good valve job, I would use the following cuts.
Intake
38-.050
45-.041
60-.060
75-Balance to generate a throat that is 91% of valve size
Finish with a 90.
Cut the bowl out .100 in total diameter approx .275 down from the bottom of the 75, making a nice soft radius on the throat. (if you are well trained with a die grinder, you can use a high-helix or fine single cut, and knock the bottom of the 75 off into the 90).
If you have access to Radius cutters, the exhaust will benefit from anything R-9/11. Keep your 45 atleast .050 wide. A 35 top cut will work also.
If you feel energetic, you can easily take .100 out of the long wall from the end of the pushrod pinch into the base of the bowl.
At this point, on a home port head, I would not worry with the total port size or SSR, unless you have access to a way to verify airspeed and flow.
Dennis
09-21-2006, 07:33 PM
#5
So long as you dont go crazy, and follow the advice that can be found on the board, youll do fine with some home ports. I had teriffic results.
For what its worth, I have a 232/234 cam and home ported LS1 heads, milled .040, and I pulled 35 HP more than my friend with stock LS6 heads and a 227/230 cam (back to back pulls). Good results can be had by a first timer, if youre so inclined...
For what its worth, I have a 232/234 cam and home ported LS1 heads, milled .040, and I pulled 35 HP more than my friend with stock LS6 heads and a 227/230 cam (back to back pulls). Good results can be had by a first timer, if youre so inclined...
09-22-2006, 03:04 PM
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Interesting on the valve job, I didn't really think of that. I'll see what one would run.
I've done this a couple times with regular LS1 heads, but never with LS6 heads, so I wondered if they benefited from the same changes. On the 853/241 heads I grind down the ramp, remove a little material in the intake bowl, and grind down the intake port hump. Do LS6 heads pickup with those same changes?
I've done this a couple times with regular LS1 heads, but never with LS6 heads, so I wondered if they benefited from the same changes. On the 853/241 heads I grind down the ramp, remove a little material in the intake bowl, and grind down the intake port hump. Do LS6 heads pickup with those same changes?
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10-10-2006, 07:59 PM
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I Know for a fact do not take out that swirl ramp it mades the engine real lazy on the dyno. Its realy bad on the LS-7 engine. It Shows real good flow numbers might be great for drag racing.
10-20-2006, 01:30 AM
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Terry,
The 243 flow #'s are easier to pick up than the others. Remove the rocker boss up front and do all the porting on the straight wall, mostly near the valve guide (swirl ramp area) just before the valve. And you can get alot of flow without a new valve job. I wouldn't remove the ramp because it can get thin there, but pull it back a ways. Narrow the guide boss but don't worry about the section toward the bottom of the port, I would rather keep the tail so to speak on it. And of course open the bowl up some.
The 243 flow #'s are easier to pick up than the others. Remove the rocker boss up front and do all the porting on the straight wall, mostly near the valve guide (swirl ramp area) just before the valve. And you can get alot of flow without a new valve job. I wouldn't remove the ramp because it can get thin there, but pull it back a ways. Narrow the guide boss but don't worry about the section toward the bottom of the port, I would rather keep the tail so to speak on it. And of course open the bowl up some.
