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So our local track finally opened up after renovations and I hit up the Friday night street legals. I put an all stock LY6 in my full interior 81 malibu weighing in at 3520lbs with me in it. First pass out the car ran a 12.28! I was really impressed and just playing with tire pressure I got a 12.20 at 109 with a 1.72 60'. I'm really impressed with these LS engines and who do you guys recommend to spec me a cam? Who are the guys that really understand these rectangle port heads and carb setups, I'm also looking for someone who knows the limitations of the LY6 PTV clearance as I don't want to flycut, thanks for the input guys!!
 

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that's impressive!! what trans, converter, and rear gears are you running now? The more I read about the LS motors, makes me want to drop a 6.0 in my Camaro.
 

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Bret Bauer for an awesome cam.
my Stock LY6 ran 12.59 @ 109 through a sycro'd 5 spd @3425lbs, and ~650ft altitude
with a few tweeks to engine(including flycutting) and a BRE cam, 10.77 @ 130 @ 3505lbs. yes should have et'd better, but that is on my car setup, not the engine
 

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that's impressive!! what trans, converter, and rear gears are you running now? The more I read about the LS motors, makes me want to drop a 6.0 in my Camaro.
It's a th400 with a 3200 stall, and 3:73 gears, all that's done to the engine was remove the VVT and put on a L92 vic jr intake 750dp and Hedman 1 7/8 headers, I had 32degrees of timing in it from 3200-6500 rpm and shifted at 6000, it went thru the top end at 5350 rpm with the 28x9 slick, I think it has an 11.99 in it
 

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Thats crazy thats the same dam motor I have in my GMC 3500
 

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So our local track finally opened up after renovations and I hit up the Friday night street legals. I put an all stock LY6 in my full interior 81 malibu weighing in at 3520lbs with me in it. First pass out the car ran a 12.28! I was really impressed and just playing with tire pressure I got a 12.20 at 109 with a 1.72 60'. I'm really impressed with these LS engines and who do you guys recommend to spec me a cam? Who are the guys that really understand these rectangle port heads and carb setups, I'm also looking for someone who knows the limitations of the LY6 PTV clearance as I don't want to flycut, thanks for the input guys!!
You may find this thread interesting:
http://ls1tech.com/forums/carburete...ane-carbureted-ls-engine-camshaft-thread.html

As for the piston to valve limitations for square ports, as I understand the valve drop in the intake side for stock, un-milled square port heads is .133". Add a .051 head gasket and subtract out the LS positive deck (about .007") and you get about .177" assembled valve drop. With that valve drop measurement that might limit you to about a 6 BTDC @ .050" intake valve open without having to flycut.

That being the case, you would be limited to something like a 227 duration intake lobe on a 108 ICL or a 229 intake lobe on a 109 ICL and still have an IVC that might favor a single plane manifold. With your stall and gear, I would pick the 227 on 108 if it were me. Then, based on the exhaust lobe testing that Brian Tooley shared, you might do well to pick something like a smooth low lift 240 duration exhaust lobe. Maybe something like. 227/240 on 111+3.

With all that said, I am no cam guru, I have just delved into it quite a lot lately writing that thread above. And, SBE LS engines have been the only scenarios I have been looking at. Also, I have an LQ9 6 liter in my car, but with cathedral port heads. I have a small 226/234 cam and it peaks at 6,650 RPM and pushes my #3700+ Buick to 11 ohs on the motor just as I drive it to the track..
 

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Bret Bauer for an awesome cam.
my Stock LY6 ran 12.59 @ 109 through a sycro'd 5 spd @3425lbs, and ~650ft altitude
with a few tweeks to engine(including flycutting) and a BRE cam, 10.77 @ 130 @ 3505lbs. yes should have et'd better, but that is on my car setup, not the engine
^^ Bret is a smart cookie....
 

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I could be wrong but I think the ly6 has more ptv clearance than the lq4/lq9 since they have l92 from factory.
 

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I could be wrong but I think the ly6 has more ptv clearance than the lq4/lq9 since they have l92 from factory.

By more PTV, I guess you mean factory notched ? ;)

There is the valve reliefs on the exhaust side for models equipped with VVT and then there is the dish to consider. The figure that I suggested would be for an LS3 scenario with flat tops. Estimating the extra valve clearance that the dish and the exhaust valve relief provide would be impossible without actually measuring.

We need a few people who have or who would be willing to measure the valve drop on a stock LQ4, LY6 and L92 with square port heads all assembled with head gaskets to share those numbers with us for the record. Then we could predict how much cam might fit.
 

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I had to fly cut on my lq4. I can't remember how much but a lot. I try to block that out of my mind, especially when I spray the shit out of it.
 

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I had to fly cut on my lq4. I can't remember how much but a lot. I try to block that out of my mind, especially when I spray the shit out of it.
That is the ONLY reason I don't flycut mine. How much have you hit it with?
 

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.073 jet but has ported big shot solenoid. I'll let ya know if it survives an .082
 

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Discussion Starter #20
Thanks for the info guys, and thanks for the cam link speedtigger, 3 pedals setup is what really got me excited about these LY6's. Sounds like I'll be giving Brian tooley a call Brian Tooley soon as I was going to use his spring package anyways, you guys have been a great help
 
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