etekberg

I've got an L92 to LS3 conversion I'm doing. It will be an E85 street car going in a C5. Thinking I'd want 13:1 to 13.5:1 compression. This will be my first LS build, so no experience; meaning don't assume I know my as* from a hole in the wall. Mainly doing it as just a fun project.

Is there an inexpensive way to get there? Custom pistons my only option?

I'm interested in cheap, because if it gets too expensive, I figure I'll just bite the bullet and go with an ERL dry sleeve 440ci.

Mavn

iTrader: (3)

Why on eearth would you want that much compression in a street car?

pantera_efi

iTrader: (1)

OK, I have used RaceTec pistons @ 16:1 for "drift" cars.
To supply the 13:1 - X:X is no problem for my service.

A note, you should be careful of pump E-85.

The camshaft should be specified with WIDE L/C's, good for the Hendrick head you have stated.

Will you keep the L-92 VVT ?

Lance

clint195

iTrader: (5)

Im at 14:1 on my street car.

hellbents10

iTrader: (10)

Why wouldn't you want that much compression, my street car is 13.7:1. My only regret is not going closer to 14.5:1. Good batt and starter are a must though haha.

You could weld the chambers and angle mill the heads. With the stock bottom end it will be tough to get a real cam in it though with out cutting valve pockets in the pistons.

MuhThugga

You'll spend more in machine work trying to avoid buying pistons than you will just buying pistons.

lsx68firstgen

iTrader: (22)

I ran a l92 with ls3 heads milled to get the compression to 11.1. I then ran a off the shelf comp lsr281 with full valetrain upgrade, Victor Jr intake with a aed 850 carb backed by a 4l80e with a 3200 converter, and 12 bolt with 4.11s. This was in a 3000lb 68 camaro and ran 10.80s driven to the track and back on 93 premium.

Not sure how fast your wanting to go but that type of compression for what it seems like your doing (street toy) I don't think you would need that much compression. To each their own just thought I'd share my experience with a pretty similar setup.

etekberg

Should I go higher? I picked 13 because that is what I read would be good for E85.

CAMSTER

iTrader: (10)

I did this you want to do and is very simple I'm using a solid roller on e85 stock block rods pistons crank save for fly cutting the pistons .125

I flat milled the Trick flow 255cc GenX heads .150 new off the box had Patrick G spec a cam.

Still on ls3 intake manifold and throttle body my ls3 runs consistent 10.5 the first time to the track with only a 3,400 stall.

Combustion chambers are @ 45 cc compression 14.1 to one using Power Master 9509 starter with a 17lbs Braille battery.

OP here's a Christmas present for you enjoy it.

http://www.corvetteforum.com/forums/...track-day.html

Merry Christmas every one!

etekberg

Sweet! That's the kind of info I was looking for. Thanks a bunch. I'm going to look into duplicating that... well except for the solid roller. Not looking for high revs.

pantera_efi

iTrader: (1)

Yes, I agree AND would like to add a comment.
The L-92, LS-3, LS-7, 2006+ year LS engine uses my 60-2 (58x) TW.

THAT VERY ART allows for a static C.R. increase of .5 due to a more accurate Spark Instant.

Thus, that too would be a safety factor, yours as fitted by the OEM.

Lance

dogsballs

Go as high as you can. This is my 15.0:1 alloy 6.0 with ls3 heads we dynoed the other day. 721hp @8000rpm, shoukd be more but vac pump wasnt working

https://m.facebook.com/story.php?story_fbid=10155629637439126&id=66406912 5

CAMSTER

iTrader: (10)

Wow Dale you must have some high compression pistons in the mix there I suppose that's a lot of rpms congrats for those numbers!

dogsballs

Mix of 12.5cc wiseco solid domes and 125thou off the heads. Pistons were hand sculpted to fit chamber.

CAMSTER

iTrader: (10)

Nice thanks for sharing do you do any street driving with it? and what transmission behind it.

You where the motivator for me going to the machine shop to have .050 removed from my heads then went back and asked for another .050 about 3 days later return with the heads for another .050 they thought I was kidding I said no go for it by then we were like 5 thous from the accessory bolts holes threads but made it all work glad you inspired me thanks.

dogsballs

100% street/strip car,!hence why it is on pump e85. Got a mikes pglide. Just plumbing it up atm and waiting for convertor, on the road soon

CAMSTER

iTrader: (10)

Looks awesome and light weight never seen that body style before what diff gears for the glide?

dogsballs

Not sure on gears till we see how 6800 convertor goes. Maybe 4.11 with 255 radial or 3.7/3.9 with 26x8 drag radial

Car is a holden vc commodore

Dyno Junkie

Had 0.075" machined off of our stock LS3 heads.

Flycut the pistons 0.100".

Still running the same CompCam 231 239 .617" .624" 113

CAMSTER

iTrader: (10)

Looks so innocent is the ultimate sleeper with a glide I would be thinking 5.14 diff.

How much slippage would you see with a stall that tall do you know anybody using it on the street? I would love to have a hard hit 4000 and thinking too much in terms of slippage and traction requirements.