SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: 87hardin on June 09, 2015, 12:23:41 PM

Title: Carb and manifold set up
Post by: 87hardin on June 09, 2015, 12:23:41 PM

For a cruiser boat bbc what is the better set up square  flange  or spread bore and what manifold are guys using. Thanks

Title: Re: Carb and manifold set up
Post by: mash on it on June 09, 2015, 12:59:24 PM

Quote from: 87hardin on June 09, 2015, 12:23:41 PM

For a cruiser boat bbc what is the better set up square  flange  or spread bore and what manifold are guys using. Thanks

Victor Jr and 750 Holley VS, 1" spacer, 36* timing, w/GM HEI, and a K&N

stay away from edelbrock and Q-jets carbs

Dan'l

Title: Re: Carb and manifold set up
Post by: 87hardin on June 09, 2015, 01:01:26 PM

Cool deal ignition now is msd so i would have to think that is ok

Title: Re: Carb and manifold set up
Post by: mash on it on June 09, 2015, 01:26:05 PM

Have never used MSD, But I guess so.

Dan'l

Title: Re: Carb and manifold set up
Post by: Roadrunner on June 09, 2015, 02:14:35 PM

On my 21' cruiser I have a BBC with a Torker II (square flange), Holley 750, timing @ 34*


SCJB iPhone

Title: Re: Carb and manifold set up
Post by: 87hardin on June 09, 2015, 09:20:41 PM

What is the difference between a square flange and a spread bore in the butterflies in the secondary is larger but in performance what is the difference.

Title: Re: Carb and manifold set up
Post by: mash on it on June 10, 2015, 06:44:07 AM

Primaries are smaller, secondaries are larger.

Holley's are easier to tune, but Q-jets can be tuned, just takes more time to get them right.

Leave the Q-jets for work duty on motorhomes and tow trucks.

Dan'l

Title: Re: Carb and manifold set up
Post by: 87hardin on June 10, 2015, 11:44:09 AM

Thanks again I'll start working on mine.

Title: Re: Carb and manifold set up
Post by: 86caribbean on June 10, 2015, 01:04:18 PM

I'm one of the yo yo's that chose a tunnel ram intake for my BBC. It's the Edelbrock street version that I have port matched to my iron oval port Chevrolet heads. On top are two Holley #4160's 600cfm vac. secondaries that I have modified and dialed them in on an engine dyno with O2 sensors in every exhaust tube so I could see what the air/fuel ratio is leaving each cylinder. Between the carbs. and manifold are Magna Fuel's reversion plates to control the reversion pulses in the plenum. The vacuum canisters are linked together with a light spring to ensure opening rates are in sync. Jetting is all staggered per what the engine wanted and O2 sensors told us during the dyno pulls. Opened up the (PVCR) orifices .010 with 6.5 power valves and opened up a few of the high speed air bleeds. Quick Fuel Technology's billet metering plates replace Holley's factory stamped plate so I can use Holley jets on the secondary side. Along with Quick Fuel's floats that are tunneled for jet extensions on the secondary side. This set up took some time, but the result is flawless through all transitions of load and throttle position, you will never hear me shooting any ducks...LOL

Title: Re: Carb and manifold set up
Post by: 87hardin on June 10, 2015, 10:46:45 PM

That is sweet