, L92 
Small Bore L92 heads for LS1 (article)
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Melting Slicks
Joined: Oct 2006
Posts: 3,447
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From: Los Angeles
Small Bore L92 heads for LS1 (article)
I was dreading back to back 14 hour shifts this weekend so I picked up the April 07 "GM High-Tech Performance" magazine while I was at the gas station. I dont have a scanner but its on the bottom of page 10. I transcribed the short article here:
"SMALL BORE L92 HEADS FOR YOUR LS1?
Is GM Performance Parts modifying the high-flowing L92 heads for the LS1's, 3.98-inche bore? Recent intel reveals that the General hasn't forgotten about the thousands of LS1 owners, many of whom are enamored with the performance and price of the L92 castings but can't use them with the LS1/LS6's smaller bore. Currently the L92's bolt up to a 4-inch-or-larger bore and use a host of tricks (like 2.16 intake/1.69 exhaust valves and raised port design) to make mad power. We saw 44 horsepower over an LS6 head, with the flow numbers of 332-cfm intake, 189-cfm exhaust at .600-inch lift! If GM greenlights this program, is able to retain most of the L92's stellar flow numbers , and can keep a lid on the low pricetag, everyone will win."
From what I can see so far, its just rumor... I'd like to hear something from GMPP. I can definitely say I would be saving for a set if they kept the same price and similar performance. Does anyone have any more information on this? Confirm its validity? It would be great for us LS1/LS6 guys who don't have the 4" bore to use L92s and are on a budget.
"SMALL BORE L92 HEADS FOR YOUR LS1?
Is GM Performance Parts modifying the high-flowing L92 heads for the LS1's, 3.98-inche bore? Recent intel reveals that the General hasn't forgotten about the thousands of LS1 owners, many of whom are enamored with the performance and price of the L92 castings but can't use them with the LS1/LS6's smaller bore. Currently the L92's bolt up to a 4-inch-or-larger bore and use a host of tricks (like 2.16 intake/1.69 exhaust valves and raised port design) to make mad power. We saw 44 horsepower over an LS6 head, with the flow numbers of 332-cfm intake, 189-cfm exhaust at .600-inch lift! If GM greenlights this program, is able to retain most of the L92's stellar flow numbers , and can keep a lid on the low pricetag, everyone will win."
From what I can see so far, its just rumor... I'd like to hear something from GMPP. I can definitely say I would be saving for a set if they kept the same price and similar performance. Does anyone have any more information on this? Confirm its validity? It would be great for us LS1/LS6 guys who don't have the 4" bore to use L92s and are on a budget.
Last edited by DefenderC5; Mar 4, 2007 at 04:32 PM. Reason: speeling
Race Director
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From: Bergen county NJ
www.ls1tech.com has been talking about this for awhile.
It'll probably happen in the not to distant future.
The exhaust flow numbers needed a little work and velocity seems to be off if I remember the discussions but the price is right and could make good power...
44hp over ls6 heads seems kinda high but you never know.
It'll probably happen in the not to distant future.
The exhaust flow numbers needed a little work and velocity seems to be off if I remember the discussions but the price is right and could make good power...
44hp over ls6 heads seems kinda high but you never know.
Thread Starter
Melting Slicks
Joined: Oct 2006
Posts: 3,447
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From: Los Angeles
The L92 head flows much better than a stock LS2 head. They've been putting some pretty good numbers on the LS2. I don't know about 44 hp on an LS6 head swap, but thats probably not too far off for a stock LS1 swap. Perhaps with the right tune. But an L92 for an LS1 bore with the right cam would be a good setup for those looking to save 1500+ bucks over an AFR or similar head.
At any rate, I hope they release this and the price is comparable to the L96 that is available now.
There wasn't much talk on it at LS1tech.com But from what I could find, it said that these heads are upper RPM biased and flow better at the higher rpm range. Can this be complimented by a cam that favors the low end/torque spectrum for a better package altogether? Especially if its a higher flowing head on the smaller bore.
At any rate, I hope they release this and the price is comparable to the L96 that is available now.
There wasn't much talk on it at LS1tech.com But from what I could find, it said that these heads are upper RPM biased and flow better at the higher rpm range. Can this be complimented by a cam that favors the low end/torque spectrum for a better package altogether? Especially if its a higher flowing head on the smaller bore.
Last edited by DefenderC5; Mar 5, 2007 at 03:57 PM. Reason: dee dee dee
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From: Haymarket VA
The L96 head flows much better than a stock LS2 head. They've been putting some pretty good numbers on the LS2. I don't know about 44 hp on an LS6 head swap, but thats probably not too far off for a stock LS1 swap. Perhaps with the right tune. But an L96 for an LS1 bore with the right cam would be a good setup for those looking to save 1500+ bucks over an AFR or similar head.
At any rate, I hope they release this and the price is comparable to the L96 that is available now.
There wasn't much talk on it at LS1tech.com But from what I could find, it said that these heads are upper RPM biased and flow better at the higher rpm range. Can this be complimented by a cam that favors the low end/torque spectrum for a better package altogether? Especially if its a higher flowing head on the smaller bore.
At any rate, I hope they release this and the price is comparable to the L96 that is available now.
There wasn't much talk on it at LS1tech.com But from what I could find, it said that these heads are upper RPM biased and flow better at the higher rpm range. Can this be complimented by a cam that favors the low end/torque spectrum for a better package altogether? Especially if its a higher flowing head on the smaller bore.
Thread Starter
Melting Slicks
Joined: Oct 2006
Posts: 3,447
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From: Los Angeles
For me, as a daily driver that has to be smogged in CA, an inexpensive head swap is far more appealing than the engine swaps you mentioned.
So back to the original topic, any GM people on the forum have any recent information on this?
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I'd bet that the L92 heads will have very large ports, and though the flow #s might be great, on a 346, will result in very poor low-end power, and be high RPM biased. Might be a great combo for road-racers,and big stalled/geared 1/4 milers, though. Total speculation until they're produced/tested.
Safety Car
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I think you may be right. Even if you changed the valve seats out and put in some smaller valves to clear the bores, the intake ports may be too big for low to mid rpm power on a 346 street motor. For drag racing only, it may work great.
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True, the runners are quite big, but didn't someone just post some numbers on a stock LS2 shortblock that were up over 500 at the wheels which a phenomenal tq curve and without the aid of a gargantuan cam??? Something tells me that GM knows what they're doing and if they signed off on a 260cc runner, they did it for a reason.
Safety Car
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From: Hobart, WI
True, the runners are quite big, but didn't someone just post some numbers on a stock LS2 shortblock that were up over 500 at the wheels which a phenomenal tq curve and without the aid of a gargantuan cam??? Something tells me that GM knows what they're doing and if they signed off on a 260cc runner, they did it for a reason.
