DSM's in a 30' Scarab!!!

[SUPERBOAT]

Hi everyone! I have a 30' Wellcraft Scarab boat w/ warmed over 330hp Mercruiser big blocks (two). I was wondering if two modified turbo DSM's would be reliable and torquee enough to make @450-500hp and be able to live at 75% power for long periods of time on pump gas. I know thats a lot to ask but the gains in fuel efficiency and huge weight savings would be incredible. I am an experienced fabricator and would have no problem making mounts, heat exchangers, exhaust, wiring harnesses, etc. What do you think!! Thanks! Big Block Chevys??

 

[GloriousDSM]

You might wanna stick with what's proven. But if you have lots of money to blow and want to be diffrent go for it- sounds sweet.

-gold

 

[luvmygst]

The biggest problem I would see is the reliabilty. Its asking alot of the 4 cylinder to run full boost and make the power you are going to need to push a boat for extended periods of time. It might make a good drag boat. but I dont think it would make a reliable cruiser. Just my .02

 

[DSM90AWD]

I get goosebumps when I hear the lopey idle of a twin or trip V8 engined offshore boat.. worth the extra gas IMO

I know it's been done before with the 4G63, just cant' find the post.

 

[inspector-111]

Are you looking to get 450-500hp total? Or do you want that from each engine?

 

[Rob10_99]

if you have the room and the need for power,
go with two cummins twincharged diesels, now thats proven!
with gas boat engines, they dont like full speed runs for hours on end,
my roomies dad has rebuilt his 565's about 4 times now because of that.

 

[DSM90AWD]

Found what I was thinking of, though a bit different that what you are asking about.

GT42 Boosted Methanol consuming 4G64 race boat FTW

 

[Locke]

You would want Crane or Crower or somebody to cut you some custom cams to a marine specification. Use a larger water cooled turbo, (more cfm, less turbine rpm) and don't go nuts with the boost.

I don't see why that couldn't be a reliable marine engine. I still favour the V8.

 

[SUPERBOAT]

Cool pics of the tunnel boat! I love the sound of two big blocks also but all day of it gets tiring. I would run the exhaust through 4" marine mufflers then into the water to be quiet. I would need 450-500hp out of each engine.

 

[SUPERBOAT]

I was thinking instead of the single speed trans to use a Powerglide or TH350 to get the thing on plane since I would have a lot more room in the bilge. That would make up for the lack of low end torque.

 

[housegsx]

Although I like the idea and would love to see it done, I'd probably stick with the torquey V8s.

I personally want one of these. http://www.gas-turbines.com/squirt_2.htm

 

[underradar92]

Gotta like the idea of water to air lake warmers (intercoolers) though...

 

[SUPERBOAT]

Thats a BAD boat! I was at Turbine Marine in Miami a couple months ago, million dollar 50' cats with two 1800hp turbine engines- cool stuff. Back to pistons- A seawater cooled intercooler would be a must, and maybe might make the engine live better? The weak link in most marine engines is the exhaust valves. Does anyone make an extreme duty inconel valve for 4G63's? I would also have to make water jackets for the headers to keep them legal and from melting. what else might be a problem with these engines?

 

[kambonate]

with twin 4g63, the horsepower is going to be thier, but one thing is missing that you might miss in the big block.. thats torque, thats what going to get you out of the hole. you can have twin 450 hp dsm motors in their but you are going to be killing them by putting an incredable amounts of load on them.(pushing a 30foot boat).. my sis has a 43 foot lighting w/ triple 575's and, i am totally addicted to the 4g63 engine and when they get on it, im totally lost.. im a dizzum at heart, but when im on the river thats whole different story.. big block forever baby.. if you have the money to run a boat like yours their is no replacement for displacement.. i cant wait till i can have toyz like you...

 

[kambonate]

i would also look at putting a cummin diesel in that.. a single that is.. you can punch some serious power and crazy torque with that thing.. i think you might be able to snag a 6.0 cummins out of a 95-99 dodge pickup.. anything newer has all of the electronic controls.. the 95-99 has all mechanical fuel pumps and injectors.. so crank up the fuel pressure and weldup the wastegate and hammerdown. i have a buddy that runs the same engine on his modified pulling tractor.. four turbo's and 250lbs of boost and 3000 horsepower.go about 10 stages below that and you'll be haulin some serious ass and probley getting too.. the only problem is finding a prop for the rpm's.. just my two cent.. take it easy and good luck!! give us an update if you do anything..

 

[dieseltech]

i would also look at putting a cummin diesel in that.. a single that is.. you can punch some serious power and crazy torque with that thing.. i think you might be able to snag a 6.0 cummins out of a 95-99 dodge pickup.. anything newer has all of the electronic controls.. the 95-99 has all mechanical fuel pumps and injectors.. so crank up the fuel pressure and weldup the wastegate and hammerdown. i have a buddy that runs the same engine on his modified pulling tractor.. four turbo's and 250lbs of boost and 3000 horsepower.go about 10 stages below that and you'll be haulin some serious ass and probley getting too.. the only problem is finding a prop for the rpm's.. just my two cent.. take it easy and good luck!! give us an update if you do anything..

It's very early 90-98 that has the mechanical injection pump. 98.5-02 has the vp44 injection system and 03 and up has the common rail injection.
I'm not exactly sure how much room there is on a 30' cruiser for and engine. If there is enough, I would say go for it. Personally I like the vp44 system. Besides if your a good fabricator with wiring and such, it would be no problem. You could even put a performance module on it to get even more power, not to mention performance injectors. You'd want to get a 245hp engine with the 028 injection pump. That, injectors and a module would get you over 400 hp easily and relatively cheap. Diesels run much cooler temps as well. Make sure to mount that sucker good, coz if you didn't.........well lets not even consider if you didn't

 

[SUPERBOAT]

The diesel engines would be the most logical choice. I got the idea of 4g63's while I was at my Bud's machine shop, a guy stopped in that has a 700Whp Mitsu. I figured if I detuned two of those they might work in the boat, but after talking to a lot of people it would probably be asking too much from such a small engine for long periods of time. The weight savings would be one of the biggest plusses. I'll probably stick with the big blocks, I already have them, they are both fresh, reliable, and bolt right in. I do have a tube chassis '62 Nova with a 377ci. small block that might benefit from an 800hp 4g63!!

 

[SUPERBOAT]

250 PSI of boost WOW!!

 

[1g_tsi_awd]

Crazy ideas!

 

[SnowBird]

I would not rely on 4g63's to keep me from being stranded at sea, unless they were tuned super pretty, even then I would be worried. But...a good possibly reliable setup would be two engines with E3 16G's, with some wicked exhaust they would spool pretty damn quick and together put you well over the 500HP mark .

 

[EclipseTrbo420A]

I would not rely on 4g63's to keep me from being stranded at sea, unless they were tuned super pretty, even then I would be worried. But...a good possibly reliable setup would be two engines with E3 16G's, with some wicked exhaust they would spool pretty damn quick and together put you well over the 500HP mark .

Yea, 2 of those could mage upwards of 700 together... never seen a boat with a 6 bolt swap(s)