Twins with Twins, Anyone?

turbo_bu

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Mar 27, 2007
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Talking about lubricity (or the lack there of) in diesel fuel, is there any thought to just adding in 2 cycle oil like those of us still running the old LB7 injectors? I'm not sure where it would stack up against other additives or how much it would help a CP3 pump at high RPM, but I know it makes a difference on the older injectors.
 

kidturbo

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I have some buddies who always run two stroke oil, or quart of transmission fluid as fuel additive. Have also seen a couple LLY trucks with sticky FP regulators that made it a few extra years with a little biodiesel every other tank. Then I quit producing, and they had to finally change it out.. So adding some lubrication certainly doesn't hurt these pumps performance.

I pulled the sending unit to check for metal in the tank from that cp3 failure, and did notice a half cup of water laying in the bottom. Figured you guys would like to see how easily it can grow fungi in diesel fuel..

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THEFERMANATOR

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I have some buddies who always run two stroke oil, or quart of transmission fluid as fuel additive. Have also seen a couple LLY trucks with sticky FP regulators that made it a few extra years with a little biodiesel every other tank. Then I quit producing, and they had to finally change it out.. So adding some lubrication certainly doesn't hurt these pumps performance.

I pulled the sending unit to check for metal in the tank from that cp3 failure, and did notice a half cup of water laying in the bottom. Figured you guys would like to see how easily it can grow fungi in diesel fuel..

cc19b061044476d93f0db4c3ddea3021.jpg


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Unless you're burning through a tank of fuel every few days, I always recommended my customers put biocide in there fuel. My Suburban doesn't get driven much, so I keep biocide in it to prevent this. Biocide is cheap compared to going through 20 racors on a trip because your tank is full of growth.
 

kidturbo

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Yeah I was actually surprised to see it in there. Had sending unit out a couple months ago and it was all good. Only bought fuel at two places here in town. Gonna suck it all out and dump some in there to kill it off. All my years of running biodiesel I never ran into it. Even washed all my biodiesel with pond water.. lol

With a UV light filter on the water feed of course. :)

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kidturbo

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When do you hope/plan to finally send this boat off to its owner?
Once we throw these drives in the junk, but some Merc 6's back on it, and make at least one run to Cuba and back.. Then I'll call it done.

For now, still debugging a few things. Seem to have the CCV resolved, but after setting on the bench for a week, the port turbo is spitting up some oil in compressor. Only thing I see, map ring is almost closed off on this one, so might be sucking it out. Was gonna adjust before the last ride, but didn't get time. Boat back in the shed, I'm rolling thru north Georgia at the moment. Taking a week off to go home and do paperwork.

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kidturbo

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Have one nagging issue holding up progress this week. Once resolved, a trip to Cuba, or at least Key West and back is well within reach. The lower units keep getting water in em. And after full day of running, the synthetic 75w90 looks like CNC cutting oil.

6qrts per unit per day, equals little over half a pale of $130[cheap] gear lube. We've done everything but have them blessed by a priest, and they still make milkshakes every time out. Not shitting any metal yet, but surely not far behind if not flushed every outing. Nor do I trust running them loaded for hundreds of miles straight. Feel the reduction box issues are resolved, but the parts that spins the prop are ticking bombs.

So time to find a fix, which likely means going to a different outdrive setup. That's no straight R&R swap. Angles, heights, gear ratios, and things we sorted out last summer all come into play again. No easy fix, but have considered dipping the drives in Flexseal as a last resort..

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THEFERMANATOR

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Do they have reservoirs inside the boat for the outdrives like 90+ mercruiser's, or are they sealed? Do you have a way to monitor the outdrive temps? Sounds to me like they're running hot, then creating a big vacuum inside of them when they cool off, and sucking in water.
 

kidturbo

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Drives are atmospheric vented into the transom boxes, so no way they can pull a vac. Also pressure tested them two weeks back and can't find any leaks. Gotta be getting in around bellows [also now vented to upper boxes] or rhe case half seals are leaking under heavy loads. Both previous owners were unable to keep water out also, and I was like "Hold my beer..'

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kidturbo

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Is it possible to vacuum test them?
Not easily while on the boat.

I drilled a hole thru the transom box carrier bearing assembly so if the bellows leak, any water could drain into the transom box.

When doing the pressure test, I could hear and feel air coming out the past the input shaft splines or seal, thru the bellows, into the upper transom box. But saw no bubbles around the bellows, or anywhere else..

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kidturbo

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1 of 2 Air Raid track day filters ordered back during the snow storm finally arrived in FL today.

Figured I should put something over the turbos before we suck a rag down the pipes. They also get a bit of sea spray splashed back in that area under rough conditions. So hopefully these don't strain the spooling, but keep out the leaves and occasional minnows..
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2004LB7

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Drives are atmospheric vented into the transom boxes, so no way they can pull a vac. Also pressure tested them two weeks back and can't find any leaks. Gotta be getting in around bellows [also now vented to upper boxes] or rhe case half seals are leaking under heavy loads. Both previous owners were unable to keep water out also, and I was like "Hold my beer..'

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Plumb those vents onto the PCV or turbo of the engine to pressurize the cases and keep the water out of any leaks 😁
 

036.6turbo

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keep out the leaves and occasional minnows..
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When I read that it made me think of those "asian carp", aren't they the ones that frickin jump out of the water? I pretty sure they're fresh water and your offshore, but I guess I need more coffee.

Outdrives taking on water almost makes you wonder if the cases are expanding under load and breaking a seal somewhere? I know nothing about their physical configuration, but there has to be some explanation as to why your "bench" testing doesn't show the leak, but it happens everytime out.