Tech Talk => Engine Mechanical / Electrical => Topic started by: KonaGuy on May 26, 2010, 09:09:48 PM
Title: what intake manifold to run with quadrajet?
Post by: KonaGuy on May 26, 2010, 09:09:48 PM
I just removed a GM performance iron intake manifold from my boat and want to replace it with an aluminum. I am planning on running the q jet for now, what are the best options. The motor is a stock 454 with logs and high rise through transom exhaust manifolds. Thanks!
Title: Re: what intake manifold to run with quadrajet?
Post by: IRRebel on May 26, 2010, 09:30:58 PM
Install the carb in your hands, ride in a buddies boat, when you hit the middle of the lake, throw the Q-Jet as far and as hard as you can................ ;D
The best manifold for a Q-jet on a jet boat is the one at the Hydro plant attached to the Dam making the lake....... >:D
That out of the way, personally, and someone will chime in here far more knowledgeable than me, I would put that intake back and invest in a good Holley, Barry Grant, or some square bore carb first and an adaptor if needed. Then when you DO go for a better intake, you're better prepared, for one, but I think you'll get more bang for the buck this way initially. Just thinking out loud.......again......
Ray
Title: Re: what intake manifold to run with quadrajet?
Post by: 88CARRERA on May 26, 2010, 09:39:48 PM
i have a holley 600 you can have if you donate 50.00 to challegers fund, pulling it off this weekend
Title: Re: what intake manifold to run with quadrajet?
Post by: crewchief22 on May 27, 2010, 06:16:10 AM
The Q-jet can be a good carburetor, but I will agree that a Holley can give you better performance with the right combination of parts.
You are limited to the mild upgrade (stock replacement) manifolds to keep the spread bore design... Edelbrock Performer.
Or get a manifold for a square bore design and use an adapter.
Good luck
Title: Re: what intake manifold to run with quadrajet?
Post by: Brendella Pickle on May 27, 2010, 07:19:05 AM
I'll trade you a pair of wooden oars for that Q-Jet...
Title: Re: what intake manifold to run with quadrajet?
Post by: KonaGuy on May 27, 2010, 08:01:57 PM
haha, ya Ive been looking around and after its all said and done Im gunna go with a holley 750 double pumper, instead. Im still curious on the manifold though. With a mild 454, wouldnt I need one with a power range of idle to wot? I have oval port heads, and am gunna go with the dui hei dizzy. I was looking at the summit stage one manifold, or hardin marine and also the edelbrock performer. what you guys think?
Title: Re: what intake manifold to run with quadrajet?
Post by: IRRebel on May 28, 2010, 12:06:01 AM
Been my experience with mine that I really only operate just off idle in the NWZ, WOT to get it goin then either keep it there or lift to around 3000 rpm or so to cruise. Just the nature of the beasts. You have to be under power to even steer the things, not quite like a prop boat.
Personally, I think you need your power from the 2500-3000 rpm range up to the upper limit your engine can/will operate at. 5000-6000 rpm seems to be the norm. Single plane intakes are the ticket, but good results can be had from the dual planes. Really depends on your cam selection as well. I know a lot of boaters run and swear by the Performers, don't know about the others you mentioned. You can pick up used ones around here all the time though pretty reasonable for the BBC.
Ray
Title:
Post by: beerjet on May 28, 2010, 06:09:47 AM
Weiand Stealth Dual Plane intake. I ran one on 049 ported heads , and a 304 solid lifter Clay Smith cam and a Holley 750 vacuum secondary carb . Ran to just over 5K and ran smooth as silk at all RPM's. I will forever swear by that combo.
-beerjet-
Title: Re: what intake manifold to run with quadrajet?
Post by: KonaGuy on June 02, 2010, 08:45:28 PM
thanks for the input guys
Title: Re: what intake manifold to run with quadrajet?
Post by: KonaGuy on June 07, 2010, 11:04:43 PM
thanks for all the help guys, I just found a demon 750 mech secondarys for a hell of a price. So hopefully it works out nice