allblowdup

It is a 4.070x4.125
comp 10.38:1
Frankenstein ls3 ported heads
pat g cam 234/238 .604/.604 110 lc
vixtor intake
QF an 950
91 octane 28 deg timing
this is in a play jet boat
Runs great but the tq curve is very flat. wouldn't have mind a little more tq up around 5500 and a closer tq/hp peak. Thoughts?

blk00ss

iTrader: (66)

Low compression, baby cam. Seems about right.

jmilz28

iTrader: (13)

Looks like a reliable way to big fun on the water. That torque down low to get you on plane quick looks pretty awesome. I'm betting PatG spec'd that cam for exactly that purpose.

DavidBoren

Did PatG spec that cam specifically for this? It doesn't seem right for rectangle port heads with only 4* of exhaust bias. But I don't know ****, so don't quote me on that. And as mentioned, raising the compression would definitely help unless fuel quality is dictating static compression. If you can, shoot for ~11.5:1 with ~0.035 quench.

Darth_V8r

iTrader: (4)

Great suggestion.

Also, if you really want to shift the power band up a little, retard the cam two degrees.

allblowdup

Ya only 4 deg split. Went that way because it is carbed.
It runs on 91 octane so ya the comp is low and the cam is small to be very reliable. Retarding the cam is interesting.

musthaveLSx

Based on BSFC (.491) your true HP (indicated) was 504.9 @ 6000 RPM
247.9/.491 = 504.9
Applying J607 (STD) would be 1 % less right at 500 HP.
Weather in Edmonton, Alberta 15 AP 16 was:
30.06 "HG Baro
57% F temp (14 C)
52% humidity
This assumes outside air was supplied to the intake tract.

A 14% correction factor was applied to the raw numbers based upon the fuel flow/BSFC. This would mean the operator would have had to enter 28 "HG baro, and 125 F air temp to get that value on a STD correction.

I doubt that the fuel meter is the cause, because .49 is reasonable number for full power on gasoline. If you watched the operator, Did they enter the weather data and fuel specific gravity values into the software before your test?

jdub38672

iTrader: (4)

I would leave the compression alone if you plan on getting gas at the marina. Purchasing gas at the marina has always been hit or miss.