Thread:

Small Block Jets - Let's see your combos

I run a Sbc 377 all forged, 11.5 to 1, edelbrock performer Rpm alum heads, solid roller cam .660 .620 lift, rev kit, comp belt drive, roller rockers, single plane high rise intake, BG 850 double pumper. Full msd ignition. Bassett twisty headers dry.

Spinning a SS b, inducer, stuffer 5300 to 5500.

My 17 foot Avenger is a SBC boat.

It is a wore out 350 lowend with a pair of camel hump 202s and a 480/280 monarch grind cam. Erson gear drive, roller rockers, holly strip dominator intake with a 800cfm spreadbore holly and a pair of jethot coated Borlas running dry.

Will run 50-55 with 2-4 people. With no gas and just me on smooth water it will GPS a 60 mph pass.

I used to run a "A" impeller and it would reach the same speed, but was a turd and would hesitate no matter how I tuned things. I switched to a "B" impeller and now it makes great power. Same speed but no more stutter and way more power out of the hole.

Diverter didnt seem to make a difference in speed with my hull.

I'm running an aluminum 550 hp 383 LS1 in my 21' Liberator jet. I've only been on the water a few times since the conversion to EFI, and have no real performance numbers yet with EFI. With a carb, it spun a stainless B impeller to 5800 rpm and had a GPS top speed of 81 mph with just me and light fuel/load. Ran 75-76 mph with 4 people, 20+ gallons of fuel, and cooler.

EFI Setup:
383 LS1
MTI stage 3 ported 853 heads
JE pistons - 11:1 compression
6.2" Lunati rods
4" stroke Lunati crank
238/244 @ .050, .600/.600, 113 LSA Bullet hyd. roller cam
Yella Terra Ultra-Lite rockers
Ported FAST 90 intake/ported 90mm TB
45# injectors
GM "0411" ECU
Closed cooling
Rewarder water injected through transom headers
Lightning rear motor plate with top mount starter


Carb setup:
Same as EFI, but with
Edelbrock Super Victor intake
Demon 850 carb
MSD 6010 ignition

Currently running EFI:






When it was carbed:

Bought with a 350 but blew a head gasket and detonated a piston(had cast pisons and crank with junk heads). Bought another 350 from neighbor with roller rockers and mild cam hes said it is probably 325HP.
old motor

new motor

73 Rogers

'75 Saguaro, 350 chev, '99 'burb motor, roller cam, 650 VS holley, Eddy rpm intake, crappy swirl port heads, stainless sprint car headers, Dominator pump, shoe, rideplate & loader, "A" impeller, 4600 rpm, 55 gps'd w/3 on board, solid 60 in good air, family boat.

Daniel

Originally Posted by Elkidminoltu:1680325

Great info guys.

Weiman, do you have a GPS'd speed at that RPM?

Last time I gps'd it it was 75 in not so good water end of last year. I haven't gps'd it since.

Btw, I also run a shoe, ride plate, top loader, and diverter. My boat is an 18'. I'm still playing with the hardware to find that sweet spot.

This was my previous boat. Again, not a tradition Gen 1 SBC...but it's an SBC nonetheless.

18' Horizon jet

347 LS1 - 435 hp
Stock short block
GTP stage 2 853 heads
210/218 @ .050, .531/.531, 112 LSA VHP cam
Edelbrock Performer RPM intake
Demon 850 carb
MSD 6010
Closed cooling
Doug's 67-69 F-body LS swap headers
Moroso Spiraflow muffler cut in half to make 2 mufflers

Unknown rpm, unknown impeller, 72 mph GPS with just me and 5 gallons fuel.

Cheyenne, Ray Carson, (presumably 450lbs or so) 383sbc zz4block, Procomp heads, $45'to my door' modified HEI. Comp marine roller, Stellings offshore headers (custom watermixing/waterdam collectors) Bushwacker diverter...spins an AT SS B 5500 on 89 5900+on 100shot nitrous. Easily handles 150shot, but i will run 93.

That is 450 'jet pump horsepower' (no nitrous) for you torque fags.

The light weight of the sb makes this boat a real pleasure to drive, and can EASILY keep up with many big blocks. Nothing like waterjacketed headers. 4mpg at 55-60mph, tested for hundreds if not thousands of miles. 15 gallon (12-13 with good airspace) tank mounted center sponson between the seats, tied to the stringers. Took me 4 engines to find that money now or later...only lost one due to worn valve guides. Hundreds of miles of WOT and hundreds of Lbs nitrous on each engine. It would not occur to me to put a big block in one of these and drive it hundreds of miles just for fun. Has been the target of much experiment....like dual holley red pumps (valved for independant service)...plenty of flow, redundancy when 40miles from the ramp, just the right pressure and cheep...or the secret 4deg nitrous retard distributer...no electronics....or the pump bearing thermometer...or the 0-20 oil. The front mounted alternator has gotten many complements as well.

Experimentation is not without it's consequences...the boat AND ME caught fire IN FRONT OF EVERYONE...much to the delight of the challenging Blown Big Block...who would have lost his ass...i wont say his NEW name but his old name was CARBON MONOXIDE.

It has bested 'the enemy' (i wont say his name either, but his initials are FAKETHIS) once...he came back with a vengance. Killed my dreams of EVER being able to make a SB keep up with a PROPERLY ENGINEERED RACE GAS BIG BLOCK.

Shit i got beat by a JETSKI in June (out the hole)...

Dont matter...NO BIG BLOCK FOR ME IN THIS BOAT OR ANY LIKE IT>

a little advice...any boat gets 'slower' (well, i suppose) as you get used to it. Want it to go lots faster? Let your crazy-ass no fear foo wife drive it...you be shittin your drawers and she be texting 'this boat aint shit'

bolebe me, i got vids.

Originally Posted by miketeast

Dont matter...NO BIG BLOCK FOR ME IN THIS BOAT OR ANY LIKE IT

Agreed.

Originally Posted by FormulaZR

Agreed.

i really thought i was alone in this. Closed cooling...i considered it....figured i would blow something else up on the motor before corrosion would be an issue. Jury is out.

Originally Posted by 67weiman

I run a Sbc 377 all forged, 11.5 to 1, edelbrock performer Rpm alum heads, solid roller cam .660 .620 lift, rev kit, comp belt drive, roller rockers, single plane high rise intake, BG 850 double pumper. Full msd ignition. Bassett twisty headers dry.

Spinning a SS b, inducer, stuffer 5300 to 5500.

It would be interesting to see what that thing would run with a "C" or "C/D" impeller what ever it takes to get that engine to 6,500. If the hull would handle the speed. It sounds like that engine is good for 7,000 or so.

S CP