Carb question

[89 VIP Valiant]

Hello all, I'm new to the forum, and just purchased an 89 VIP Valiant 19 foot with a 4.3L OMC. I'm pulling the engine, and when doing so noticed that it was equipped with a 2 bbl Rochester carb; a buddy owned a 91 model 4.3L that was equipped with a QuadraJet, and I guess that is what I was expecting. His boat topped out at around 51 running a 19 pitch prop, and sipped fuel until he opened it up, and could then watch the fuel gauge drop. I was curious if anyone else had a similar setup as mine, and what type of performance you get; or if most rip off the 2 bbl for a 4 bbl setup, and if so, what is popular (Q-jet, Edelbrock, ect.) Thanks for any sort of feeback or advice any can offer, I appreciate it!

 

[blueoval1]

Re: Carb question

Your motor/carb combo is the same as mine. It is the 175 HP version. Your buddies 4bbl setup is the 190 HP version.
My 17' Vision runs 53 mph @ a elevation of 6600 ft. However , it takes it a while to get past the 47-48 mph mark. That is with Smart Tab SX trim tabs also. They alone gave me 3 mph on the topend.
With a little tuning and proper prop you should be able to run with him easily unless your boat is 19-20 ft. Plus you can run all day long with no worry of running out of fuel.

 

[matt.benson]

Re: Carb question

I have a 1989 VIP Vantage 18.5 and I also have the same engine/carg set-up as you do. I have read under other links in this forum that someone tried to do just an intake and carb swap to a 4 bbl and had some pretty bad reaction (i.e loss of throttle response, etc.). My boat is used primarily for wakeboarding so I am not going top speed very much of my time on the water, however the 4.3 and 2bbl carb will let me be out on the lake for an entire weekend and I am only using about 20 gallons.

 

[89 VIP Valiant]

Re: Carb question

Hey thanks for the info, it sounds pretty unanimous from all that I have spoken with that I should keep the setup that I have. My engine just got done being rebuilt this week, so hopefully I will have an idea how it does pretty soon.

 

[89 VIP Valiant]

Re: Carb question

Well, BlueOval, you were correct, I can run with the 91 model with a QuadraJet; my 19 footer ran 51 MPH (52 on the GPS). I was very impressed, I didn't expect to get to that speed with a 19 pitch prop; I would have been happy with 42 or so. So, if anyone has the same question as me, 2BBL Rochester or 4BBL QuadraJet, I highly recommend you stick with the smaller set up!

 

[blueoval1]

Re: Carb question

Just curious , but at what altitude and at what RPM were you running?