BajaRunner

My boats ready to go. Heres what we (bobl) did to the carb'd hp500's

Bowl Blend heads, port exhaust side
crane 731
Raise rev limiters to 5600
mill heads .020 with cometic .027's

I am hoping for ~575hp. Should the jets go up a size or 2 or is the motor rich enough stock to support this?

jryan26

Good question. Are you going to dyno them?

BajaRunner

no, they are already back in the boat ready to go-

stevesxm

no way to know about jets because no one knows if you where correct in what you had in the first place.... need to do egt's to know for sure or spend a long time trying to read plugs....

dyno should have been on your list of things to do before installation...

Nordicflame

iTrader: (4)

BobL has a nice LM-1 O2 setup. Bung(s) in the exhaust would be very helpful here and get you where you want.
Bob will get her right
Dave

baja36ft

IF YOU REV IT TO 5600 THE STOCK 800 CARB IS TO SMALL
I WOULD GO WITH A 850 OR JET THE 800 UP SOME
YOU SHOULD HAVE 81,75,93,89 I WOULD GO 85,79,97,93
HOPE THIS HELP. ARE YOU USING A CARB SPACER?

BajaRunner

Havent done the spacers yet. we were going to see what it does first.

baja36ft

If You Go With A Spacer Some Times It Leans The Carb Out And Need To Go Bigger

axapowell

Still using the 800 cfm Holley on my HP500's Changed the heads to AFR CNC'd 315cc, Crane 741 and Dart 6200 intake 1" HVH SS plate and had to jet down to get the correct A/F an BSFC on the dyno. Made the jets :

Primary: Starboard 71, Port 77
Secondary: Starboard 83, Port 87

Hope this helps,
Dave

Nova 26

I need an education, why do you recommend 4 different size jets in a carb? I have a 625 hp n/a 540 with a 950 quick fuel carb, jetted 86/86 front, 90/90 rear. How do you determine what jets to use? I think that I am lean at part throttle, before the secondaries come open= engine will start to miss at times at cruise on primaries.