New engine combination-anyone tried this

**krazysandman** · 04-26-2009, 04:55 PM

I'm finishing up on putting this new engine combination together for one of my latest projects, not your typical thing on this forum, I'm curious if anyone has tried and or seen this combination or anything close to it, how it performed and any other thoughts about it. It is going into a 2200 pound sand rail, 2500 rpm stalled 3 speed automatic, no vacuum accessories, map sensor only. All engine control is done with the FAST XFI engine management system, 36 lbs injectors working at 58 psi (will flow like a 41 lbs). Base engine is an LS1 346 inches, 10.25:1 compression, heads are GM Performance CNC ported LS2 units rate to flow 307 cfm intake and 218 cfm exhaust at .600" lift with 65 cc combustion chambers, Comp Cams new grind shaft 235 degrees intake 243 exhaust at 050, lift is .621 intake and .624 exhaust on a 113 degree center line, running Comp Camp Pro Magnum 1.7 ratio rockers, matching springs, push rods and lifters rated to spin 7200 rpm. Intake manifold is FAST LSX composite with matching 92 mm big mouth throttle body, exhaust is tuned tubular headers with race mufflers (pretty much open)-any thoughts?

**mark21742** · 04-26-2009, 11:51 PM

sounds like a wicked ride man! the only thing I think is off is your stall, I'd be looking at somewhere around 3,600+ stall for that cam

**krazysandman** · 04-27-2009, 07:11 AM

Raising the stall speed is something of an enemy in this application, we have to rememeber we are dealing with a vehicle that weighs in at 2200 pounds, the traction conditions in sand are very slippery until you get the wheel speed up, thus the engine will almost immediatley start to RPM under hard accelleration, the high stall convertor will also produce more heat in the transmission, we have been running a good cooler with twin fans and have seen no heat issues even with our other supercharged engine combos in the past and don't want to create one now.
I'm really curious to see if any of you have seen the potential power of this combination as this vehicle will never fit on a wheel dyno, and there is no straight engine dyno within reasonable distance.

**mark21742** · 04-27-2009, 03:45 PM

i see your point on the wheel rpm vs. traction, might want to try contacting an expert in sand rails (most of us on the street want a hard hit and max traction right off the launch) i'm not sure if maybe someone offers a type of slipper clutch.
with a cooler for the tranny a higher stall wont give you any heat issues.
the problem with a lower stall with that size cam is your motor will want to fall on its face before it gets into the powerband

**Dr.Crash** · 04-27-2009, 04:10 PM

sounds like an awesome project

**c5z28** · 04-27-2009, 06:50 PM

Can I see pics of what your vehicles look like? Sounds fricken awesome

**Marc 85Z28** · 04-28-2009, 06:40 AM

That engine should be good for around 525HP. With your driveline, probably 420 or so at the wheels.

I would recommend at little more compression. Another point would make it happy

**mark21742** · 04-28-2009, 08:13 AM

Originally Posted by Marc 85Z28

That engine should be good for around 525HP. With your driveline, probably 420 or so at the wheels.

I would recommend at little more compression. Another point would make it happy

good point, with that cam dynamic compression will be way down......maybe mill a hair off the heads, I'd check to be sure on PTV clearance.....maybe drop as far as a 60-58cc chamber

**Firebirdjones** · 04-28-2009, 12:02 PM

You ask if anyone has seen this combo before. Actually LS motors in sandrails is very popular and been done many times.

Down in southwestern AZ in the dunes,,,,you see sandrails all the time with LS swaps.

My neighbor currently runs an LS2 with twin turbo's in his 4 seater rail.

And ya it's street legal too.

**mark21742** · 04-28-2009, 04:19 PM

Originally Posted by Firebirdjones

You ask if anyone has seen this combo before. Actually LS motors in sandrails is very popular and been done many times.

Down in southwestern AZ in the dunes,,,,you see sandrails all the time with LS swaps.

My neighbor currently runs an LS2 with twin turbo's in his 4 seater rail.

And ya it's street legal too.

that is so sick.....id love to have that for a dd

**Firebirdjones** · 04-28-2009, 05:09 PM

Originally Posted by mark21742

that is so sick.....id love to have that for a dd

I thought it was a little crazy myself, it's really an overboard sandrail for sure. Everything about it is high tech and big dollar. It's a 100K investment sandrail easily.

To the original poster,,,I have no clue what he did for a transmission in that thing, I'd have to look at it again. Maybe snap a pic of it and post it on here.

**mark21742** · 04-28-2009, 05:31 PM

I'd look into mating the ls1 to a 4 speed manual porche tranny

**krazysandman** · 04-28-2009, 08:11 PM

This sand rail is not our first attempt at warp speed across the dunes, I have multiple other LS1 powered vehicles including other dune set ups. We are currently running a Jeff Fields automatic transaxle, he claims and I have seen over 600 horse motors run thru them, these are even used in the Baja series
buggies. Mine runs a manual valve body modified Audi Quatro box,NASCAR quick change gears and a heavy duty transaxle case. And yes the LS1 platform is used regularly in sand rails, it is by far the power plant of choice for any of us doing this type of thing. My real intention on this thread was to see if any one had run this cam grind and head package on their motor, the stall convertor, weight of the car etc. is not of concern to me as it has all been calculated by engineers way smarter than me for this package- what I want to know is how did it really run?, did it have any tuning issues?,did you cut the heads after initial blueprinting? if so how much? and what did it do on the dyno in your vehicle. This is what I really want to know if you have any answers.
Thanks