www.iFourWinns.com

I have the 320 horse 5.7 GXi's and have always liked these with the 328 except for the noise level at cruise. I understand that among other things, VP removed the exhaust bellows to attain the horsepower level. I would be more than willing to give up for example 20 HP per engine to get a quiet cruise. Would installing these do any damage or increase the load on the engines? They currently have ~250 hrs.

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2014 Vista V435
2011 Glastron GT180
2013 Sea Doo RXT-260

I have that motor and have run without and now with. I don't recall noticing a difference in noise or performance.

Probably nothing noticeable.

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1981 Columbia 8.7
2015 Yamaha FZR - 87mph - sold
2006 Yamaha GP1300R - sold
2003 Chaparral 215 SSI - sold
2009 Stingray 195CS - sold
2000 Four Winns H180 - sold
1976 O'day Daysailer II - sold
Rick's Four Winns H180 Mods/Upgrade Thread

They did not remove the bellows, if its not there it fell off or someone else removed it. big block engines have a tube that does not attach to the drive but mates to it when the drive is down all the way. they use these on big engines because the regular bellows acts like a potatoe in the tailpipe and restricts the exhaust flow.

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Brian Borchik
The Winds of Cold Springs Harbor Marina
Baldwinsville, NY

Isn't the 5.7L Gxi just a beefed up small block 350?

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One of 4 Previous (Sold) Boats:
2000 Four Winns 268 Vista

Current Boat: 2004 Chaparral 235 ssi cuddy

It's a full power un-molested vortec 350 from chevy. Not beefed up at all. It's actually stock. Any other 5.7 from Mercruiser/VP in the last 15 years is actually beefed down so it's not 320 +/- hp by removing GM's stock vortec crate engine cam and installing a milder one. Also by restricting the air intakes (crappy manifolds and 2bbl carbs).

If you want the full power "marine" cam... AKA the mercruiser hot cam...
http://paceperformance.com/i-6255412-14 ... t-350.html

_________________
1981 Columbia 8.7
2015 Yamaha FZR - 87mph - sold
2006 Yamaha GP1300R - sold
2003 Chaparral 215 SSI - sold
2009 Stingray 195CS - sold
2000 Four Winns H180 - sold
1976 O'day Daysailer II - sold
Rick's Four Winns H180 Mods/Upgrade Thread

Now I get it. Our last boat a '03 268, had the 5.7 volvo duo prop 280 hp, and I never noticed it as being loud. A friend of ours has a '00 268 with the 5.7 merc 320 hp, and we went on a trip with them, he said he couldn't hear his marine radio over the noise of the motor.

They must be doing something different with the exhaust.

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Jeff

'14 Cruisers 380 Express "Simon Sez"
Merc 8.2 Mag MPI 380
DTS B3X, (x2) Axius Premier


(SOLD)
'08 V318
Merc 350 Mag MPI 300
DTS Seacore, B3 (x2)

You guys gave me a great idea how to squeeze a few ponies out of my 4.3

_________________
1981 Columbia 8.7
2015 Yamaha FZR - 87mph - sold
2006 Yamaha GP1300R - sold
2003 Chaparral 215 SSI - sold
2009 Stingray 195CS - sold
2000 Four Winns H180 - sold
1976 O'day Daysailer II - sold
Rick's Four Winns H180 Mods/Upgrade Thread

I got hacked off with the exhaust noise from my 5.7GXi with the "high flow" exhaust straight stub pipe and MHP transom shield, the noise made even worse due to reverberation of the swim platform.

I fitted the complete exhaust bellows version for last season. It's noticeably quieter and, sorry Ric, it doesn't appear to have reduced the power, there's no difference in WOT RPM or general performance compared to previous years. Maybe the stub exhaust brings something for the big blocks: it's not going back on my boat though ! The only problem is that I can now hear other noises that I worry about !

As it was put on as an experiment, I used an aftermarket one as it was about half the VP price. The internal circlip that came with it that retains the bellows to the tilt housing wouldn't fit inside the bellows, so I didn't use one. The bellows stayed in place.

Not sure you can do that with an SX drive

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One of 4 Previous (Sold) Boats:
2000 Four Winns 268 Vista

Current Boat: 2004 Chaparral 235 ssi cuddy

Not so much the SX drive affecting HP (or DPS for that matter, the upper units are the same), but there are 2 distinct transom shields. The standard has a single anode, the MHP ( = minimum hydrostatic pressure, I believe) has 2 anodes which do not impede exhaust flow, more mounting studs plus different setup of the lower and upper steering pivots. I don't kmow if there are any other differences that result in increased exhaust flow; the single exhaust stub ( plus of course the standard bellows) can be fitted to both..

Graham, can you share the part numbers for items you installed? Or what you would recommend since the circlip is not compatible?

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2014 Vista V435
2011 Glastron GT180
2013 Sea Doo RXT-260

The VP circlip is compatible with the VP bellows, the previous boat I had was fitted with one and it always fitted in place easily ( it fits inside the bellows at the tilt housing end). I've no idea why the aftermarket one wouldn't fit, maybe the rubber was thicker; it proved unnecessary to use one with that item as it turned out. The OEM one is bronze, the aftermarket one stainless steel.

The part numbers for the MHP tilt housing is the same as for the standard of the same year. so there shouldn't be any compatability issues

Bellows: 3850426

Retainer (circlip): 3852665

There might be "kit " available containing both the bellows and retainer; If I was using the VP bellows, I would also use the retainer.
ps: The bellows has drain holes in it.

Graham

http://www.marinepartsexpress.com/VP_Schematics/MARINE%20DRIVE%20&%20TRANSMISSION/SX-M_DP-SM/TRANSMISSIONS/Gimbal%20Ring%20and%20Pivot%20Housing0.pdf

I assume item 23 clamp is required as well? Can this be installed without removing the drives? I may attempt doing this in the water.

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2014 Vista V435
2011 Glastron GT180
2013 Sea Doo RXT-260

The clamp is the same as on the exhaust hose you already have. A new one might come with the "kit" ( it did with the aftermarket one)

You should certainly be able to remove the old hose in the water, with the drive tilted up fully. The outdrive end of the bellows has to be pushed through into the pivot housing. There's a lip on it's end on it that sits inside the housing, you might be able to do it by pushing a little of that lip through at a time and then rotating it, repeating the process until all the lip is through. It's probably easier doing it that way than attaching the forward clamp and continuity wire first. A lot depends on how warm the water is/ how soft the rubber is. You won't be able to insert the retainer/ circlip at the outdrive end without removing the drive though.

Graham