2bbl. to 4bbl. conversion

[ramster]

I have a 2004 glastron 195sx, with a 5.0 volvo GL 220 HP, it has a holley 2bbl. but looks like it's mounted on a four bbl. intake. How much power do I stand to gain, and would it kill my economy at cruise speeds switching to say a rochester 4bbl. which has small primaries, but large secondaries.<br />On my trucks they seem to get better economy with the 4bbl. as long as you didnt run wot to much. Most of my boating is done around 2500 to 3000 rpm's for tubing and skiing, but would be nice to have the extra punch when I do go flat out. Any body expirement with this?

 

[tommays]

Re: 2bbl. to 4bbl. conversion

if you try the red search above its covered in many ways that may tell you if you want to try it<br /><br /><br />tommays

 

[beckmanrussell]

Re: 2bbl. to 4bbl. conversion

Am curious to see how this works out should you try it. I have a 2002 Glastron 205GX with the same setup. What prop do you run and how fast WOT. Thanx..Senior B.

 

[vettman]

Re: 2bbl. to 4bbl. conversion

I've got the same setup but an '03 sx 195. Looks to me like the manifold is the performer rpm that edelbrock sells , although it has volvo stamped on it. The picture of it in Jegs magazine looks just like it. I think the 2 barrels are adapted to the 4 barrel manifold. Also, i'm running a 14&3/4 x 21 s.s. volvo prop and g.p.s. at 57 top speed at 4850 w.o.t. When i find out for sure i can swap to a 4 barrel i'll get the 650 holley marine carb and hope to hit 60

 

[Bondo]

Re: 2bbl. to 4bbl. conversion

I don't see Volvos,.. So I can't say,......<br /><br />But,.. You Guys have the Boat,........ Go Look under the Carb........<br /><br />The Suspence is Killing Me,.... I Gotta Know.............. <br /><br />Does Volvo adapt a 4bbl. manifold Down to 2,.....<br />Or is it a Dedicated Manifold..?..?..?..?..?..?.<br /><br /><br />Either Way,........ The Up-Grade is Worth It,..... For the Power..................

 

[mikeneal]

Re: 2bbl. to 4bbl. conversion

My 99 5.0GL VP has an adapter plate,, I dunno what the bolt pattern is for the plate but is diffinatly has a adapter.

 

[Boomyal]

Re: 2bbl. to 4bbl. conversion

I find it unlikely that you would find a 4 bbl manifold under a 2 bbl carb, especially from a major manufacturer. Both 2 bbl's and 4 bbl's have spacers if that is what you all are calling adaptor plates.

 

[whywhyzed]

Re: 2bbl. to 4bbl. conversion

is it this? sure looks like it would work with a 4 bbl...<br /> http://www.dougrussell.com/partscatalog/images/omcvolvo/ACF8CF.gif

 

[fseries]

Re: 2bbl. to 4bbl. conversion

i believe you wont gain very much for the simple reason you still have a rev limiter , i would try a new prop first ,,a new 4 bbl carb is not cheap enough to see a worthy gain and also on some 5.0 s you might have to change the cam to for a 4 bbl

 

[Buttanic]

Re: 2bbl. to 4bbl. conversion

The rev limiter would have no effect because the 4 barrel would not increase the RPM range. It would increase performance through out the present RPM range if sized and tuned correctly, if not sized and tuned correctly it may reduce performance. It may also require a prop change to take advantage of a power gain. The $64,000 question is how big an increase and is it worth the cost of the change.

 

[vettman]

Re: 2bbl. to 4bbl. conversion

Hey guys: Bondo's right. The suspense was killing me too. So this morning i proceded to look under the carb and low & behold there she was the two big holes i was looking for. The 2 barrel has the adapter plate attached to it.Going on the edelbrock web site the Performer R.P.M. #7116 is the exact manifold. My '03 has the Vortec motor and requires that manifold with just 8 bolt holes. So it seems a 650 Holley would be a bolt on project since the 2 barrel is Holley. Thanks for the kick in the butt to do something about it Bondo, this should pretty much answer things VETTMAN

 

[vettman]

Re: 2bbl. to 4bbl. conversion

P.S. Need to add this.Have had my boat up to 5000 R.P.M.with the wrong prop, she still wanted to go more. Don't know what a rev limiter is. Must not have one.She now runs 4850 wot Thanks VETTMAN

 

[Boomyal]

Re: 2bbl. to 4bbl. conversion

Originally posted by vettman:<br /> Hey guys: Bondo's right. The suspense was killing me too. So this morning i proceded to look under the carb and low & behold there she was the two big holes i was looking for. The 2 barrel has the adapter plate attached to it.Going on the edelbrock web site the Performer R.P.M. #7116 is the exact manifold. My '03 has the Vortec motor and requires that manifold with just 8 bolt holes. So it seems a 650 Holley would be a bolt on project since the 2 barrel is Holley.

Wow, learn something every day vettman, I'd a never figured. It's sure a no brainer now tho. Go for it.

 

[Bondo]

Re: 2bbl. to 4bbl. conversion

I Can't believe it Either,.........

 

[Boomyal]

Re: 2bbl. to 4bbl. conversion

I am also surprised that any OEM would include an Edelbrock Performer RPM manifold. From all I have learned, that would move the powerband higher than is ideal for a marine engine.

 

[f_inscreenname]

Re: 2bbl. to 4bbl. conversion

<br />A little high for a boat but what am I saying? I run the "air-gap" version and love it.

 

[Boomyal]

Re: 2bbl. to 4bbl. conversion

F'n, can you find a graph for the plain Performer manifold? Be interesting to see the difference.

 

[vettman]

Re: 2bbl. to 4bbl. conversion

Hey guys; Got the volvo number off the intake '3856270' Like i said it doesn't say edelbroc but volvo may have bought some rights to put their name on it.Maybe someone can verify the number. It definitley is a high rise ,dual plane squarebore that my 2 barrel sittin on!

 

[f_inscreenname]

Re: 2bbl. to 4bbl. conversion

Your wish is my command. <br /><br />

<br /><br />

<br /><br />Ford 260-289-302 V8 <br />PERFORMER 289 (idle-5500 rpm)<br />Designed for street 260-289-302 c.i.d. Ford V8s without EGR. #2121 is stock replacement/street legal part for 289 and 302 V8s with OEM 4V carb.; 1966-72 (1973 non-CA); except stock equipped EGR. Will not fit Boss 302 or 255 c.i.d. V8s. Aftermarket 4-bbl carbs are not compatible with Ford Auto Overdrive Transmission (AOD) unless used with Lokar bracket SRK-4000. Available with standard finish, polished or with PermaStar or new EnduraShine finish for a look you've got to see to believe, see Optional Finishes

 

[f_inscreenname]

Re: 2bbl. to 4bbl. conversion

Maybe he was talking about something like this.<br />

<br /><br />Ford 351 Windsor V8 <br />PERFORMER 351-W EGR (idle-5500 rpm)<br />Designed for street Ford 351-Windsors with EGR. #3781 is stock replacement/street legal part for 351-W 2V V8s; 1972-87 and works with either the OEM 2V carb or an aftermarket EGR 4V carb for off-road by using Edelbrock #8053 4V EGR plate and compatible EGR valve and gasket. #3783 is stock replacement/street legal part for 351-W 4V H.O. V8s; 1984-86. Performer 351-W #3783 includes provision for EFE valve on H.O. engines. Aftermarket 4-bbl carbs are not compatible with Ford Auto Overdrive Transmission (AOD) unless used with Lokar bracket SRK-4000.