TurboLark

iTrader: (3)

I have here only a short time, and have been studying cylinder heads and cams most of the time while on this board.
Question I have is this :
there is a popular LS1 head out there that has 215cc ports and 2.04 valve and has near identicle flow numbers to the 260cc L92 stock head with a 2.16 vlave. What would the reasons be to use the L92 head over the other one? Price is the only reason i can see.
I am interested in building a 402-408ci motor.
Am I missing anything else?

Thanks.
Phil

Mikey 97Z M6

iTrader: (37)

The L92's flow real well as-cast (320cfm stock) and are very affordable. This leaves some serious room for potential porting (growth) later. Some conservative ported flow numbers are hitting 350+cfm from the L92's, and I believe this is just the tip of the iceburg for ported L92 numbers, plus, ported prices will still be less than a comparable LS1 style aftermarket head. If FAST ever designs/builds/markets an intake manifold for the L92's,,,,, watch out!! I'll be down at the SEMA show in Vegas this year, and I'm going to quiz the FAST booth about an intake for the L92's. I have a sneaking suspicion that they already have one in the works, and might even have a proto-type at SEMA.

One of the drawbacks of the L92's is that because they are so new, they're requiring some significantly different/new cam designs. Some of them are working, others are not so it's still in a "trial/error" stage so to speak.

Mike

NemeSS

iTrader: (127)

What he said, but imo i think a single plane with a proper elbow plenum will yield the best results manifolds wise, but its still too soon to come to a conclusion, im talking about 400ci+ engines with hi flow heads, and stout cams and hi compression, or forced induction.

njc.corp

look at some of the vendors-afr-tfs-etp-wch

there sure be something for your needs-

but what are u looking for?-low-mid-top end-

flow is okay-but where they flow best is the name of the game imo-also depernds on combo of engine+cam etc etc

do a search on heads vs heads(afr-vs tfs )etc etc -their is always something every week and most of the topics show flow figures-

White_Hawk

iTrader: (3)

Cheaper is the reason to do them. You can save big bucks on the intake too. They won't make as much power, but if you are on a budget they are the way to go. Heads and intake can make the difference between a $5000 long block and an $7000 one.

So maybe if you were just redoing your shortblock before, you can do the whole long block for a little more.

-Geoff

TurboLark

iTrader: (3)

Thats exactly what I was thinking, and the reason I made this post. The L92's will be an awesome head for a max effort, larger cube motor, but I think the large port CC's would hurt the torque on most motors.
Guess I need to search a bit more to compare the results between the L92 combos and the LS1/2/6 head based combos.

thanks everyone for the info, and any more would be greatly appreciated.

njc.corp

What is it for- streeter-weekend car-or for the track

what power output u want-

Stang's Bane

iTrader: (22)

Gm puts these heads on 6.0 truck motors. I don't think TQ production will be a problem..

Mikey 97Z M6

iTrader: (37)

Yes, these L92 heads seem to take convential wisdom about port sizing, and throws it out the window....

89Formulaws6

iTrader: (52)

i'm still learning about heads and everthing

but maybe this question is ok to post in here

i am looking at a set of l92's that have been milled to 65cc's

would i run into any problems putting them on my 408 with flattop pistons with just valve reliefs?

also what kind of c/r would i be looking at with stock headgaskets?

ChevyThunder17

iTrader: (48)

Depends on the cam you pick. Need to definitely check your piston to valve clearance. It's rough having a 2.16 intake valve.

TurboLark

iTrader: (3)

I'm looking to do a low(er) budget 408 . Looking at a $600.00 6.0 iron shortblock to work off of. I would like to get up to the 600fwhp range with 525fwtq if I can. It will be going into a 3400lb 65 Buick Skylark Pro Touring car, so will be a weekend cruiser/occasional drag car, with some open track events(if I learn to turn corners).

SUTTERERMAN85

iTrader: (42)

there is still much to learn cam wise on L92 headed engines, IMO. awesome bang for the buck for sure, but depending on what you are trying to do they might not be the best choice for ya.

RGKSR

iTrader: (9)

I've got L92's with 65cc chambers, 6cc dished pistons and .041 head gaskets. SCR is 11.37. With .053 gaskets it would be 11.06.

I would check PTV clearance on any setup. Duration, not lift could cause problems.

I'm a little down on power (451/414) with my 402, but it drives very nice.

Bob K.

WKMCD

iTrader: (2)

This guy built a very nice small cam 403 L92/L76 setup. Makes an honest 501 RWHP with cats, 3.90's, heavy clutch and wheels and still drives like stock. Great low-end RWT to boot.

Lots of good info here.

https://ls1tech.com/forums/generation-iv-internal-engine/662314-l92-dynojet-numbers-plus-plan-b-c-d-e-f.html

TurboLark

iTrader: (3)

Yea, but I hear that guy is a tool.
I have rear your thread a number of times. Nice work. Goes to show that there is not much need to port these L92's.