ajensen383

Well, after a long time, the new motor is finally done and was put on the dyno on Friday. Heres the short list of the motor

383 Chevy,
11.1:1 CR
SRP Pro series flat top pistons
Scat 4130 crank
Oliver 6" rods
UD Harold Solid roller... 255/263 @.050 .640"in/exh ..106/102icl
Crower HIPPO lifters
Lunati Roller Rockers- 1.65int/1.6exh
Pro-Filer 210s done by Chad Speier ( 2.08/1.60 "econo" ported")
Holley 300-25 Strip Dominator intake ( gasket matched)
JDR performance carb (820-840cfm) 1.455" venturi x 1.75" baseplate
2" HVH Super Sucker spacer

Keep in mind, this is a pump gas street/strip motor. The dyno test was run on 93 octane. .

588hp @ 6500-6900 (varied by 1-hp(587) through 6900)
514ft/lb @ 5000

I do think there is more in this combination with more tuning, but I was only at the dyno for 3 hours, and made 10 pulls. I am REALLY happy with the results for a pump gas motor with no intake porting or real head porting ( just Chad's "econo" porting).

This was dyno'd on a conservative Stuska dyno, so its not a "happy" dyno by any means.

The test sweep was 4,000 - 7,000 rpm , and was making 489hp @ 5,000 , 525@5500 and 568hp @6,000

Torque was 496@ 4900, 514ft/lb@5000 and stayed over 500 ft/lb until 6,000.

I know Joe Sherman made 615hp with a 383 a few years ago on pump gas, with 195cc AFR's, but I still think this is pretty good for a non-professional like me to build on the cheap.

I'm sure it would also make more with a rippier cam, but Harold told me that this "24 hour" grind cam of his will be gentle on the valve springs and make no less than 575hp.. He was right on the money. I'm not looking to change springs alot, so I will sacrifice a few HP for durability.

A huge thanks to Andy Jensen at Jensens Engine Tech, Chad Speier from Speier Racing Heads, Harold Brookshire (UDHarold), and John Dunn at JDR Performance Carbs

brandoz28

iTrader: (3)

sweet man, i've been hearing a lot of really good things about those heads lately.

SS MPSTR

iTrader: (1)

Great job.

N2OBaby

Great Job.

ZONES89RS

iTrader: (25)

Sounds like a winner!

kenSS

iTrader: (1)

congrats. Jensen is the man.

SS MPSTR

iTrader: (1)

...so is Harold Brookshire. He knows a little bit about camshafts.

Oldsmobility85

iTrader: (1)

Wow this is awesome dude. I am actually waiting on my profiler 210's in the mail right now. Mine is very similar to yours except going with a hyd roller and it is a 406. I don't know what you paid for your heads but I got mine for 1299 and I think that is a heck of a deal for such a nice cylinder head. Congratulations I hope mine runs as well as yours.

gosch383z

Very nice results

SpeedDensityZ

iTrader: (5)

Great results!! I've been waiting to see some results on these heads.

riplt1

those are outstanding numbers. what kind of timing were you running?

ajensen383

Thanks, the numbers are a touch low, as the carb was running REALLY rich at the top end, but the timing was set at 36 degrees, we didnt want to push it much more on crappy pump gas. We felt it wasnt worth a hole in the piston for a couple of HP

riplt1

yea. i understand that. with that kind of compression i wouldn't think you could run a whole lot more advanced.

are you gonna try for a race gas pull and see what she does?

h0t

Nice numbers especially on straight 93 pump gas. Easy 600+ on race.

Just curious as to the flow numbers INT/EXH on those heads as ported?

ajensen383

These were taken from Chad's site..www.speierracingheads.com He said they flow a bit more ,around 304cfm, but he said this was a safe number that would be realized on all flow benches due to all flow benches being different

Lift/Inch Press INT EXH
0.200 28 144 101
0.300 28 206 144
0.400 28 253 175
0.500 28 287 194
0.600 28 293 205
0.700 28 296 213
0.800 28 298 219