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Looks great! Ever plan on installing a 4bbl carb and better cam? 220hp in a 5.7 liter is too american!!

ric wrote:

Looks great! Ever plan on installing a 4bbl carb and better cam? 220hp in a 5.7 liter is too american!!

A Holley 4BBL and GM 'marine' manifold is on the cards for a winter job.
Can you use an automotive 4BBL if you're diligent in keeping it coated with anti-corrosion spray (like WD40)?
Procrastinating on cams, as I hate tearing stuff down that isn't broken!

rpengr - It sounds very similar out of the water.
I will have no performance comparison, as it hasn't seen the water here yet!

260HP+ would be nice! :twisted:

I've just confirmed that I have the 12 bolt inlet manifold (pre Vortec Heads), but have the 2300 series 500CFM Holley Carb' (part # on horn is 80402-1).
Considering we thought my current carb was only 350CFM, am I right in assuming that going to a 600CFM 4BBL & manifold would be a lesser 'bang for buck' than originally thought?

running higher octane and busting air intake would serve you better than yourealize.

Can a 500CFM deliver sufficient fuel for a mild cam upgrade? Can it be re-jetted?
Oh & are you certain my 1997 5.7GL (serial # 572BPLKR) is 220HP? So much conflicting data on-line! :roll:

Maybe I'm wrong but going with a big can change means adding lope to the engine, which isn't desirable in a boat....I had that same engine in my 96 21' bayliner....that was plenty of power and I usually had a boat full....running higher octane and busting air intake would serve you better than yourealize.

Author:	deafwish [ Tue Nov 06, 2012 2:12 am ]
Post subject:	Much Happier!
How much happier does this Volvo Penta sound inhaling Aussie air than American?! http://www.youtube.com/watch?v=kN1kkbW7 ... e=youtu.be

Author:	ric [ Tue Nov 06, 2012 7:30 am ]
Post subject:	Re: Much Happier!
Looks great! Ever plan on installing a 4bbl carb and better cam? 220hp in a 5.7 liter is too american!!

Author:	rpengr [ Tue Nov 06, 2012 1:15 pm ]
Post subject:	Re: Much Happier!
Those look GREAT! Those are on my wishlist. I had talked to Hi-Tek about a week ago, and the price including shipping to USA is $2500/set (although it sounded like he would reduce to $2200). Please let us know how they sound while running on the water, and if you have any increase in performance. Your 250HP engine may have just gone up to 265-270HP. On an H180, you must really fly!

Author:	deafwish [ Tue Nov 06, 2012 3:01 pm ]
Post subject:	Re: Much Happier!
ric wrote: Looks great! Ever plan on installing a 4bbl carb and better cam? 220hp in a 5.7 liter is too american!! A Holley 4BBL and GM 'marine' manifold is on the cards for a winter job. Can you use an automotive 4BBL if you're diligent in keeping it coated with anti-corrosion spray (like WD40)? Procrastinating on cams, as I hate tearing stuff down that isn't broken! rpengr - It sounds very similar out of the water. I will have no performance comparison, as it hasn't seen the water here yet! 260HP+ would be nice!

Author:	Walt [ Tue Nov 06, 2012 3:20 pm ]
Post subject:	Re: Much Happier!
At least get a bigger air cleaner on it (K&N marine). Mine has about 3x the surface area as factory, and made one heckuva difference for very little $$.

www.iFourWinns.com https://www.smwebhead.com/phpBB3/

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Author:	ric [ Tue Nov 06, 2012 3:22 pm ]
Post subject:	Re: Much Happier!
deafwish wrote: ric wrote: Looks great! Ever plan on installing a 4bbl carb and better cam? 220hp in a 5.7 liter is too american!! A Holley 4BBL and GM 'marine' manifold is on the cards for a winter job. Can you use an automotive 4BBL if you're diligent in keeping it coated with anti-corrosion spray (like WD40)? Procrastinating on cams, as I hate tearing stuff down that isn't broken! rpengr - It sounds very similar out of the water. I will have no performance comparison, as it hasn't seen the water here yet! 260HP+ would be nice! There's a few differences in the marine carbs. They use the J style vent tube, sealed throttle shafts, and an extra spring on the float to prevent accidents. All GOOD stuff you want on a boat and shouldn't ride without. A nice holley marine 600cfm 4bbl vacuum secondary is what you'd want. http://www.holley.com/0-80551.asp http://www.ebay.com/itm/Holley-0-80551- ... 0d&vxp=mtr Also is your engine Vortec? It might be. Check the had casting. If so, just get the GM Performance RamJet 350 crankshaft. It's the "hot" mercruiser marine cam. The carb and cam will set that engine (if it's vortec) right around the 320hp mark. http://paceperformance.com/i-6255412-14 ... t-350.html Intake: http://www.summitracing.com/parts/EDL-27164/ If not, get vortec heads. You can get a set of reconditioned ones for a few hundred bucks. Even if you need to buy heads, you should be able to do it all yourself for under $1000.

Author:	rpengr [ Tue Nov 06, 2012 5:52 pm ]
Post subject:	Re: Much Happier!
deafwish wrote: A Holley 4BBL and GM 'marine' manifold is on the cards for a winter job. Can you use an automotive 4BBL if you're diligent in keeping it coated with anti-corrosion spray (like WD40)? Procrastinating on cams, as I hate tearing stuff down that isn't broken! No, this is one place you don't want automotive. A marine carburator is designed to prevent any venting or spillage of fuel outside of the throat (which is protected by the flame arrestor and/or ingested by the engine. An automotive carb does not adequately protect against fuel spillage = vapors = boom! The good news is that you can order a marine carburator directly from Holley and save big buck over ordering from Volvo. On the other hand, you might not get much improvement with a 4BBL without a CAM. You probably have the 600 cfm 2BBL, and that is enough cfm for 5000 rpm, so the cam is probably more of the power limiter. But you have 250+ HP in an 18ft boat. Aren't you already getting 55-60mph? If not, maybe you should be looking at your prop first? I have the same engine in a Horizon 240, and I can get 47mph with my SST prop (SX drive).

Author:	deafwish [ Wed Nov 07, 2012 3:17 am ]
Post subject:	Re: Much Happier!
I've just confirmed that I have the 12 bolt inlet manifold (pre Vortec Heads), but have the 2300 series 500CFM Holley Carb' (part # on horn is 80402-1). Considering we thought my current carb was only 350CFM, am I right in assuming that going to a 600CFM 4BBL & manifold would be a lesser 'bang for buck' than originally thought?

Author:	ric [ Wed Nov 07, 2012 7:06 am ]
Post subject:	Re: Much Happier!
deafwish wrote: I've just confirmed that I have the 12 bolt inlet manifold (pre Vortec Heads), but have the 2300 series 500CFM Holley Carb' (part # on horn is 80402-1). Considering we thought my current carb was only 350CFM, am I right in assuming that going to a 600CFM 4BBL & manifold would be a lesser 'bang for buck' than originally thought? yup. you'll go from 220hp to 220hp.

Author:	deafwish [ Wed Nov 07, 2012 3:44 pm ]
Post subject:	Re: Much Happier!
Can a 500CFM deliver sufficient fuel for a mild cam upgrade? Can it be re-jetted? Oh & are you certain my 1997 5.7GL (serial # 572BPLKR) is 220HP? So much conflicting data on-line!

Author:	TX H210SS [ Wed Nov 07, 2012 10:34 pm ]
Post subject:	Re: Much Happier!
Maybe I'm wrong but going with a big can change means adding lope to the engine, which isn't desirable in a boat....I had that same engine in my 96 21' bayliner....that was plenty of power and I usually had a boat full....running higher octane and busting air intake would serve you better than yourealize.

Author:	deafwish [ Wed Nov 07, 2012 11:34 pm ]
Post subject:	Re: Much Happier!
TX H210SS wrote: running higher octane and busting air intake would serve you better than yourealize. Busting air intake? Can you please elaborate?!

Author:	rpengr [ Thu Nov 08, 2012 8:35 am ]
Post subject:	Re: Much Happier!
deafwish wrote: Can a 500CFM deliver sufficient fuel for a mild cam upgrade? Can it be re-jetted? Oh & are you certain my 1997 5.7GL (serial # 572BPLKR) is 220HP? So much conflicting data on-line! I'm not sure of your exact spec, but 220 is probably right for a 1997 5.7GL If there was a GL model and GS model the same year, then the GL had less HP, and the GS had more (GL = "Limited", GS = "Superior" according to Volvo/Penta). My engine is a 2000 GS, has the Vortec head, and is rated at 250HP. (not sure if Carb is 500 or 600 cfm) What is your speed? RPM? Prop?

Author:	ric [ Thu Nov 08, 2012 9:43 am ]
Post subject:	Re: Much Happier!
TX H210SS wrote: Maybe I'm wrong but going with a big can change means adding lope to the engine, which isn't desirable in a boat....I had that same engine in my 96 21' bayliner....that was plenty of power and I usually had a boat full....running higher octane and busting air intake would serve you better than yourealize. The cam in the 5.7GL is as mild as it gets. Going to the 350 Ramjet cam doesn't have lope. It's just a standard full power camshaft. It's the cam that comes installed from the factory in the Mercruiser 350MPI---VP 5.7GXi

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Author:	deafwish [ Thu Nov 08, 2012 5:09 pm ]
Post subject:	Re: Much Happier!
Thanks fellas! Will my 500CFM 2BBL supply sufficient fuel to safely accommodate a mild cam upgrade? If I have to go to a 4BBL & manifold to run a milder cam, the bang for buck will be hard to justify.