Jet Size On 460 ?

[IMPATIENT 1]

HOPE SOME OF YOU FORD BIG BLOCK GUYS CAN GIVE A GM TECH
ALITTLE HELP IN SELECTING JET SIZE. I REBUILT MY 460 AND I CAN'T SEEM
TO GET THE CARB TO THAT "SWEET SPOT"BETWEEN LEAN AND RICH.
THIS IS WHAT'S IN THE MOTOR
.400 DOME TRW FORGED 10.5 TO 1
EAGLE STANDARD STROKE STEEL CRANK
PORTED AND POLISHED 92CC HEADS
2.19 INTAKE 1.71 EXHAUST STAINLESS VALVES
469-595 LIFT WITH 234 244 DURATION
RPM INTAKE
850 DP
EAGLE RODS
200 NITROUS EXPRESS HITMAN
ON THE DESKTOP IT SHOWS TO BE @565HP AND @520 TORQUE
CURRENTLLY RUNNING 85 IN FRONT AND 90 IN THE BACK PLATES
I'M RUNNING AN A IMPELLOR ,SPEED LOADER,PLACE DIVERTOR
ON A TAYLOR SJ.
ANY HELP WOULD BE APPRECIATED
:hammerhea

[Squirtin Thunder]

HOPE SOME OF YOU FORD BIG BLOCK GUYS CAN GIVE A GM TECH
ALITTLE HELP IN SELECTING JET SIZE. I REBUILT MY 460 AND I CAN'T SEEM
TO GET THE CARB TO THAT "SWEET SPOT"BETWEEN LEAN AND RICH.
THIS IS WHAT'S IN THE MOTOR
.400 DOME TRW FORGED 10.5 TO 1
EAGLE STANDARD STROKE STEEL CRANK
PORTED AND POLISHED 92CC HEADS
2.19 INTAKE 1.71 EXHAUST STAINLESS VALVES
469-595 LIFT WITH 234 244 DURATION
RPM INTAKE
850 DP
EAGLE RODS
200 NITROUS EXPRESS HITMAN
ON THE DESKTOP IT SHOWS TO BE @565HP AND @520 TORQUE
CURRENTLLY RUNNING 85 IN FRONT AND 90 IN THE BACK PLATES
I'M RUNNING AN A IMPELLOR ,SPEED LOADER,PLACE DIVERTOR
ON A TAYLOR SJ.
ANY HELP WOULD BE APPRECIATED
:hammerhea
I would go with 80 jets on both sides and 6.5 power valves to start. You may end up with 8.5 or 9.5 PVs in it because of vacume reading.
Read this it may help;
http://www.mortec.com/carbtip1.htm
http://www.mortec.com/carbs.htm

[IMPATIENT 1]

YEAH I THOUGHT IT MIGHT BE ALITTE TO MUCH JET. I'M FROM THE
FUEL INJECTION GENERATION AND CARBS ARE STILL A MYSTERIOUS
TO SOMEONE WHO NEVER WORKS ON THEM!YOU RUN A 460 TOO?
I'VE ONLY TOOK THE BOAT OUT ONCE SINCE THE REDO AND PLUGS
WERE BLACK. I'VE GOT ALL MSD IGNITION SO IT JUST BURNS IT
@4200 IT'S DOING 58 ON GPS ,JUST CAN'T WAIT TO STICK MY
FOOT OF IN IT!!!! :clover:

[Squirtin Thunder]

YEAH I THOUGHT IT MIGHT BE ALITTE TO MUCH JET. I'M FROM THE
FUEL INJECTION GENERATION AND CARBS ARE STILL A MYSTERIOUS
TO SOMEONE WHO NEVER WORKS ON THEM!YOU RUN A 460 TOO?
I'VE ONLY TOOK THE BOAT OUT ONCE SINCE THE REDO AND PLUGS
WERE BLACK. I'VE GOT ALL MSD IGNITION SO IT JUST BURNS IT
@4200 IT'S DOING 58 ON GPS ,JUST CAN'T WAIT TO STICK MY
FOOT OF IN IT!!!! :clover:
81 is a big jump and 79 is a big jump the other way.
Read that info a few times so you understand it.
It makes thing much easier.

[dave186]

i have a 460, same pistons as you, big chamber heads (ported exhausts only), but the rest is different. i only have a 750 vac sec. carb for now and im running 75 in the front and 80 in the rear. its not perfect but i dont have a jet kit, just a collection of them and thats what i had. i started with 80/84 and it was waaaaaaay rich, it would load up on the top end.

[Squirtin Thunder]

i have a 460, same pistons as you, big chamber heads (ported exhausts only), but the rest is different. i only have a 750 vac sec. carb for now and im running 75 in the front and 80 in the rear. its not perfect but i dont have a jet kit, just a collection of them and thats what i had. i started with 80/84 and it was waaaaaaay rich, it would load up on the top end.
Dave I bet it would run better with 72s in it and a 8.5 PV !!!!

[dave186]

i have some 72s! i just need to try them. i think the pv is a 6.5? eventually what i am going to do is get one of the pro form main bodies for the 650 DP i have, the vacs arent snappy enough.

[bakerjet]

if you have to go up or down more than 4 jet sizes you need a differn't carb......just my 2cents.

[Squirtin Thunder]

i have some 72s! i just need to try them. i think the pv is a 6.5? eventually what i am going to do is get one of the pro form main bodies for the 650 DP i have, the vacs arent snappy enough.
if you have to go up or down more than 4 jet sizes you need a differn't carb......just my 2cents.
72 jets are stock in that carb !!!
Dave READ the Mortec info !!!!
I think it will help you !!!

[bakerjet]

yep, yep. just some info!!!

[Blown 472]

I take it we all know how to read plugs? if not this might help.
http://cochise.uia.net/pkelley2/sparkplugreading.html

[IMPATIENT 1]

You Guys Are Probally Right.i Was Just Scared Of Burning Windows
Into The Pistons.took Me All Spring To Save To Build It.first Nitrous System I've Ever Owned And Still Get The Willys When I
Mash That Button.i Live In An Area Were There's No Filling Stations
For No2 And Alot Of Blown Boats.so Every Trip To Lake To Tune Gets Expensive After The Trip To Fill Bottles($45.00 For 10lbs.and 50 Miles To Filling Station).thanks For The Suggestions.i'm Learning
Alot Reading The Boards!!