Re: How much HP would be gained adding 4bbl to 5.0L Volvo GL Vortec?

[NHGuy]

Re: How much HP would be gained adding 4bbl to 5.0L Volvo GL Vortec?

Re: How much HP would be gained adding 4bbl to 5.0L Volvo GL Vortec?

BTW OP, the 4 barrel carb, and a prevortec head 5.7 in my boat goes 59 MPH. So I say the 4 barrel, which supposedly gets 260 HP, is a good choice.
And the Vortec heads are good too, but that's another step. When you have that money, do them.

 

[deafwish]

Re: How much HP would be gained adding 4bbl to 5.0L Volvo GL Vortec?

Re: How much HP would be gained adding 4bbl to 5.0L Volvo GL Vortec?

Thanks NHGuy, but I assume your Baja hull is designed more for top end speed than my Four Winns!
Did the 260HP pre-vortec version use the same camshaft as my 215HP 2BBL setup?
Walt - Keep at it, champ! ;-)

 

[Walt T]

Re: How much HP would be gained adding 4bbl to 5.0L Volvo GL Vortec?

Re: How much HP would be gained adding 4bbl to 5.0L Volvo GL Vortec?

Cams vary year to year. You are right, the Four Winns hull is a deeper V than the Baja, and the Baja has a pretty good 'pad' in the back for speed where the Four Winns, not so much. However the Four Winns gets a better ride in chop. It's all a trade off. That's why I say you're doing pretty good at 53 mph.

Huh? whatja say?

 

[deafwish]

Just a little update that the 4BBL manifold and 600CFM carb gave me an additional 200RPM!
Yet to get water flat enough to do a proper speed run, but i'm already faster by 1-2 MPH in chop.

 

[Bondo]

Ayuh,.... Not bad,.... I figure ya get 'bout 20 hp for the swap,....

 

[Watermann]

Dang you could serve up dinner on that spotless chunk of iron! Very nice! :thumb:

 

[deafwish]

Thanks once again for the advice & the compliments on my OCD release subject!

 

[gm280]

Nice professional work there. I like how meticulous you do things. I always said, it is in the details every time. :thumb: :thumb:

 

[deafwish]

The boat seems to fall flat on it's face when the secondaries first open & from reading my Holley manual, the secondaries are opening too fast.
It has the 'natural' colored spring in there and no check ball (no brass restrictor either).
I've just fitted the 'brown' spring (next stiffness up) and fitted a check ball to the venturi recess area.

Is this ball meant to make the plunger really difficult to depress by hand?!
It's almost as if the ball has sealed the air from escaping out from the diaphragm, but is perfect when upside down (ball is off the seat)?
Any help?!

 

[deafwish]

Update:

I've replaced the cast iron spreadbore intake and adaptor with an Edelbrock Marine RPM Manifold.
with some jet changes, I've now almost cracked 50 knots.
I'm guessing this package that was originally 215HP is now around the 260 odd...

 

[MBAKER]

that's a good lookin setup...

I did a similar swap on a Mercruiser a few years ago when we put in a new engine (5.7 Vortec). I went with edelbrock intake and carb because all of the bracketry was available off the shelf. Unless you are running wide open all the time a bigger carb isn't going to make much difference, and at normal cruise speeds a smaller carb could be more efficient and the edelbrock primaries are smaller than the 2 barrel mercarb I replaced. While I don't really feel like it helped my max HP that much it idled so much better and ran off idle better than the Mercarb it replaced...... BUT I didn't have aftermarket exhaust either. I think exhaust could help all around but its pretty spendy for a family runabout so I opted against it.

 

[deafwish]

My Holley 4160's primaries are smaller than the old Holley 2300's, so out of the hole torque is drastically improved.
At what point will the stock flame arrestor pose a restriction?
I'd sure love an excuse to upgrade to a nice K&N marine item!

 

[MBAKER]

I don't know the exact answer to the flame arrestor question, but again unless you are running at WOT I don't think the typical 7" (+/-) arrestor is going to be an issue on a 5.0L. Even at WOT it may not be an issue, if we were talking big blocks then things might change.. If you wanted to check, make a couple of controlled passes with the arrester, then remove the arrester and duplicate those passes and see if you notice anything in the way of an rpm or speed increase. My bet is there would be no difference, assuming you keep the arrester clean to start with.