383 build.

**GMR-PERFORMANCE** · 11-10-2009, 03:26 AM

I have lurked for a while not much time to post really. I build Harley's for a living and have done many a non ls engine. I did a search and came up with some info but not much, and i know this has been asked before so maybe not searching in the right area?? I have a lS1 in my sand rail. Thus far it has dynod 380 hp and 360 tq. It has a truck intake, and a cam that is of unknown specs. The engine was built 5 years ago by UMI racing in AZ. I am running a MEFI 4 ECm and had ADS tune the car. Runs well makes very usable power in the dunes. Car weighs just over 3000 lbs , running a albins tranny etc.

My goal is 450 hp and tq at the rear wheels. With a broad tq range. The dyno numbers are not a deal breaker but driving what I have now and driven a car very close to mine with more power than mine and that was dyno's at same location makes me want a bit more. Not to mention the engine is due to be rebuilt after this dune season.

Looking for a good 383 package that others have done , pump gas only ( 91) and for the heat we run in most cannot run over 10.5 without running into issues. i also plan on adding a 150 shot for the sand drags for a little extra punch , when I run up against the big guys. Some cars we run with are putting down 1100+ to the ground. Not a chance I can bet them but still fun.

Heads CNC my 241 casting?? buy a new set of 243 and CNC them, or just replaced with AFR, trick flow, etc.

I plan on running callies crank and rods, Not sure on the pistons yet maybe CP, or Mahle.

Fast intake and a F.R.E. 90 T/B

Comp cam not sure which one yet.

open to ideas and to find out what other have done and what the results where.

**KP1** · 11-11-2009, 02:24 AM

I have a 383, AFR 205, Fast 92.UMI 90, 11:1 SCR, Flowtech Induction cam.

Dynoed 467 RWHP and 460RWTQ but had a kock sensor acting up and was only getting 22 degrees of spark advance.

Dollar for dollar, you probably can't beat the 243 heads. I was just looking for something better. TFS 215 might be a good option too.

My StreetSweeper HT cam is a torque monster.

**GMR-PERFORMANCE** · 11-11-2009, 05:01 AM

That is the type of info I am looking for. Do you happen to know what the CCP of your engine is?? or the cam specs sorry not up on all of the cams. I can figure out the CCP. Fuel here is 91 only and guys that have tried to run 11.1 and with a big cam you can bleed off enough compression but the car does not dune as well. I should post up a picture of this car.

Thank you for that info.

**KP1** · 11-11-2009, 05:21 AM

The published specs on my cam are
~~ LSX – STREET SWEEPER-HT ~~
Intake Exhaust
Valve Adjustment: .000” .000”
Lobe Lift: .361” .353”
Gross Valve Lift 1.70 Ratio: .614” .600”

Duration @ .050” Tappet Lift: 228* 232*

Lobe Separation: 111*

You lost me with the ccp question. If you're talking about dynamic compression ratio, when I put the cam specs in a program calculator I think it came out to be 9.5:1. Really seemed high to me, but IDK.

My Static Compression Ratio was achieved with -7 cc pistons and by milling the heads to 62-63 cc combustion chamber and using .041 compressed thickness head gaskets. I could have been closer to oem CR with the standard 65 cc chambers and GM 0.060 head gaskets.

**GMR-PERFORMANCE** · 11-12-2009, 04:49 AM

CCP is cold cranking compression. Say on a harley engine we set up the compression to 10.1 use a cam with a 42 close point on the intake, we will end up inthe 9.0 DCR and 190 CCP.

**KP1** · 11-12-2009, 05:32 AM

I haven't done a compression test on the engine, or even one cylinder. If I can remember, when I pull the plugs to check them, I'll check compression on a few cylinders and post it up. My guess is it will be 200+-. I think at 10.5:1 it was around 185.