Reply With QuoteYou old school guys never keep up...
There's the pot calling the kettle....:squiggle:
Cause it was the "trick of the week" in a magazine.
You old school guys never keep up on the "trick of the week."
LMAO!..
You old school guys never keep up...
There's the pot calling the kettle....
Bringing an old thread back to life
Well my problem was solved with lower rpm running. Now i'm just getting fuel pressure loss at near WOT. I'm questioning how well my separator flows, and my fuel line size (3/8) as well as any adjustments on my fuel pump. At least i'm able to move around reliably now.
I have a marine 850 dp with 88 primary and 96 sec. with a 6.5 power valve on each side,30 cc pump on pri. and 50cc pump on sec. J tubes for bowl vents. This is the way it came new. My motor is 463 ci 425 hp app. impeller is a berk B which is small for my motor but it spins to 5500 with #8 fuel lines, holley ele. pump. I tried rejetting leaner but it fell off on top end. It may be a little rich but no black smoke. When I tried 80 jets like a standard 850 it ran like shit! Carb #is 80443
There's the pot calling the kettle....
back in the early 60's...chevy came with a 850 DP with staggered jets on some of there hi-po 427's...the reason being...all cyl do not fire the same...some run leaner than others...so they tried to correct it...it does work...but im not sure about running it on a boat & i'm not sure what the sz's were...as far as i'm concerned...i agree with most of u...just jet the thing with 80's & play around with the power valves...u will be better off..."simple is better"
fastrat
Do all *4 corner* 850 cfm DP's use "square" jetting?
Example...my list/9380 annular comes out of the box with (78) front and back.
PS. lost several hundred RPM with the above carb ^ vs my 715cfm Holley...I'm thinking bigger jetting was need.
The GM stagger jetting was also GM manifold specific and those carbs had little square tangs thet stuck out into the venturi to alter the flow characteristics to work with the jetting and manifold. Basically they were putting a crutch on square port BBC's.
I have a marine 850 dp with 88 primary and 96 sec. with a 6.5 power valve on each side,30 cc pump on pri. and 50cc pump on sec. J tubes for bowl vents. This is the way it came new. My motor is 463 ci 425 hp app. impeller is a berk B which is small for my motor but it spins to 5500 with #8 fuel lines, holley ele. pump. I tried rejetting leaner but it fell off on top end. It may be a little rich but no black smoke. When I tried 80 jets like a standard 850 it ran like shit! Carb #is 80443
Different metering block calibrations...probably the power valve passage sizes. Air bleeds are probably different as well. This is why you can't just arbitrarily throw a jet size at a carb. You need to know the carb's calibration from the factory through it's list no. If you get more than 4 or 5 jet sizes out of the factory setting and you're going to get poor results.
The GM stagger jetting was also GM manifold specific and those carbs had little square tangs thet stuck out into the venturi to alter the flow characteristics to work with the jetting and manifold. Basically they were putting a crutch on square port BBC's.
The staggered jeting was probably only 2 or 3 sizes variation, as well.
Do all *4 corner* 850 cfm DP's use "square" jetting?
Example...my list/9380 annular comes out of the box with (78) front and back.
PS. lost several hundred RPM with the above carb ^ vs my 715cfm Holley...I'm thinking bigger jetting was need.
Bigger carb dosen't necessarily mean richer...in fact can be the opposite, having weaker signal. Given that there was more usable fuel, did you add any timing to help burn the added fuel??
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