Twins with Twins, Anyone?

kidturbo

Piston Tester
Jul 20, 2010
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Somewhere On The Ohio
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I missed out on pair of trans I wanted to use with 1.5 first and 1.0 second. Next choice is these COAN XMT units based off a powerglide.



I've been helping get a friends boat running with a 6sp Allison, it's been a pain. Getting one to shift correctly and hold gears in a boat has proven harder than I imagined. So trying to get 2 of them to shift at exact same time, and play nice together is more than I wish to tackle this month.
 

kidturbo

Piston Tester
Jul 20, 2010
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Somewhere On The Ohio
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12 weeks to have it rigged and be on the water. At least in time to make the Cumberland poker run and maybe go to LOTO if the client wants. Then she gets shipped home to Australia, just in time for summer boating season over there..
 

2004LB7

Active member
Dec 15, 2010
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Two questions,

how large of a fuel tank is on this boat? two engines running near 1000 hp for potentially hours, how much fuel is it going to drink in that time?

2nd, would a Gear Vendors unit be of any help for gearing?
 

SmokeShow

Active member
Nov 30, 2006
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Lawrenceburg, KY
cumberland poker run... as in Lake Cumberland in KY???


Are there any billet blocks available so they might be repairable/salvageable if/when engine internals let go?


Given the short time period to achieve this... I imagine you have a game plan in place for the engines by now... So whats the plan?!?! :woott:
 

kidturbo

Piston Tester
Jul 20, 2010
1,170
0
36
Somewhere On The Ohio
www.marinemods.us
Two questions,

how large of a fuel tank is on this boat? two engines running near 1000 hp for potentially hours, how much fuel is it going to drink in that time?

2nd, would a Gear Vendors unit be of any help for gearing?
300 gallons of fuel. Est range is 900miles or more at cruise. I've wanted to build a boat with a gear vendors unit for a while. But with these WMD drives I can overdrive them if I want. So if second gear in trans is 1:1, then final could be .80 if we need. For now I'm planning 1:1 final with like 34 pitch 17.5" dia prop. I can also go clear up to 20" diameter if needed.


cumberland poker run... as in Lake Cumberland in KY???

Are there any billet blocks available so they might be repairable/salvageable if/when engine internals let go?

Given the short time period to achieve this... I imagine you have a game plan in place for the engines by now... So whats the plan?!?! :woott:
Yes the 9th.

I purchased 2 nice LML short blocks from DHD yesterday. Could have left them alone, but going +.20 just to insure zero run out.

The plan is get Callies the bob weights by next Wednesday and cranks be here within 10 days. Which means getting the rods by Monday and having them shaved down to fit the crank. I'll trust Fingers can do up 16 pistons that all weight the same.

So in 16 days I expect to have the bottom ends ready to assemble. After that we start rigging work while waiting on pumps, injectors and such.

Now I need to find another set of good LMM heads this week..
 

2004LB7

Active member
Dec 15, 2010
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in this application, would continuous water injection be beneficial to the life of the engine?

in one's right mind, would sea/salt water work? do any damage? filtered of course.
 

04LB7yz

New member
Aug 16, 2013
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Way North Minnesota
I previously had a wrecked complete 04 LB7 and a 24ft Baja outlaw that needed more power... I wanted in the worst way to put the LB7 in it but i could not figure out an inexpensive way to cool the exhaust and turbo. So I ended up building the stock 454 and going the gasser route. But i still kick myself for not making the duramax happen! From my experiences the EGT's on the duramax are very hot and i didnt think a standard turbo would even be feasible. I thought a water cooled turbo would be an absolute must. How are you going to run the exhaust/turbo on this boat?
 

2004LB7

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Dec 15, 2010
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that's what i thought.

what about injecting it into the exhaust manifolds pre turbo? just to keep the turbo cooler.

set it up with a temp probe so it only starts injecting when the temp exceeds xx amount. i wonder if you would still get salt deposits.
 

04LB7yz

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Aug 16, 2013
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Way North Minnesota
Most of the offshore boats run straight fresh or salt water through them. If they have been in salt they deteriorate incredibly fast.. It wasn't until recently that closed cooling systems started being used on offshore performance boats. Its always been big with cruisers and things like that. Most people have a fresh water flush and use "salt away" in order to keep corrosion down.
 

2004LB7

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Dec 15, 2010
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you're talking about the cooling system correct?

we are talking about injecting it into the intake/exhaust. which as we know is much more sensitive to the purity of the water
 

04LB7yz

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Aug 16, 2013
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Way North Minnesota
We had a Hustler 388 Slingshot with twin 555 big blocks with m-4 pro chargers running roughly 10lbs of boost at 1,200hp a piece, that were 50% water 50% meth injected at 7lbs of boost or so. You could run 10-15 minutes wide open and when you opened the hatch the intake charge pipe would have a thick layer of ice on it. The pro charger itself would be so hot you couldn't get near it. I don't have any experience with water meth on a diesel but it worked wonders on those motors... It made the motors much safer to run with added timing also! We had a 7 gallon tank for it and you would be surprised how long it would last.
 

04LB7yz

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Aug 16, 2013
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Way North Minnesota
Multiple oil to water coolers would definitely be a must. Oil temps would sky rocket without them especially on a diesel running at 4k with high oil pressure.

This would probably be a great application to run dry sumps and possibly some sort of vacuum pump for excessive blow by.