Replace turbo oil return pipe with hose

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R_p_ryan

Senior Member
Joined
Dec 11, 2014
Messages
171
Location
USA
Vessel Name
Shellbourne
Vessel Make
1978 Mainship 34 Perkins T6.354
I have a rigid steel pipe that bolts to the bottom of the turbo and leads to the crankcase. There's a rubber coupler that connects the bottom of the pipe to a nipple on the crankcase. This is on a 1978 Perkins T6.354. The pipe is about 3 feet long and has several tight bends. I would like to replace the pipe with a section of high quality flexible hose:
  • The current pipe is unwieldy to work around
  • The pipe has deep pitting and corrosion and needs to be replaced
  • The oil pipe currently rubs up against a metal elbow that's part of the heat exchanger. This kind of metal-metal contact is slowly eroding the oil return pipe

The pipe and turbo are currently removed for turbo rebuild. I was thinking about cutting the pipe about 10" away from the turbo, then securing the hose with double hose clamps at each end. I think at some point in the engine's history the heat exchanger was replaced and this is why the pipe rubs against it.

This is the type of hose I was thinking (max temp is 300f):
MegaTech® 250 High-Temp Oil Cooler Hose | Gates Corporation

I really hate this piece of pipe - it routes over the oil pressure switch and is constantly in my way when maintaining the engine. Something flexible would be much easier to work with. But I imagine the original engineers chose to fabricate an expensive steel hose for some reason other than just use a relatively cheaper flexible hose solution for the low pressure oil line.

Thanks,
Robert
 
There's no reason I can see for not doing that. You must make sure there are no kinks or restrictions at all.
When I got my turbo rebuilt which was right as I bought the boat, previous owner paid, I received a set of instructions from the rebuild company.
One of those was if the return AND feed lines were not replaced with new, the turbo was not covered by their warrantee.
So make sure you also replace the feed line. Any hydraulic grade hose will do.
Also make sure you pre-oil the turbo right before start up by squirting your engine oil into the oil feed fitting, then connect that new feed hose.
And follow their break in procedure which as I recall was 15 to 30 minutes running at 1000-1200 rpm. (Those turbochargers (assuming its a Switzer 3LD) have a piston ring type of seal on the shaft and that needs to seat properly)

And make sure the feed hose and return hose is clamped so it cannot chafe. (don't ask how I know this:whistling:)


Actually if you did not send the turbo out yet, you have other options. You can use a Holset H1C (or WH1C) turbo. There are usually several available on ebay, etc. as they are take offs for performance upgrades form the Dodge pickup truck crowd. They will bolt up to the flanges, but you would have to adapt the air inlet and outlets (easy to do).
This would be a slight upgrade to the 3LD turbo and supply more air if required.
 
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Does that engine have electronic fuel control and a mass air sensor or some other way to sense the added air mass?

If not, be careful about installing a turbo that can supply more air.
With out added fuel to compensate for the added air mass you could damage the engine.
 
The turbo has already been sent out - to workbench in my garage. I'm rebuilding it myself with a kit that cost about $100 and includes new bearings, seals, etc. I just noticed this turbo vendor sells a specific oil return line: ATP ATP-OIL-024 Hi Temp Rubber/Silicone Oil Drain Hose - 5/8" (-10 AN equivalent ID)

I've been burning oil and suspected the turbo seal since there was oil dripping out both sides of the turbo. I also checked the play and it was so bad the vanes could touch the housing. I think the only reason it didn't detonate was because there was enough oil to keep everything lubed - although I didn't see any evidence on the housing of any scoring and the vanes all look good. I'll post the results of the DIY rebuild. There's a youtube video of somebody rebuilding a somewhat similar turbo.

While I was in there I also pulled the air charge cooler and the oil cooler. I'm starting another thread on the air charge cooler because that thing was a mess on the inside.

Robert
 
Robert, can you provide a link to the YouTube video. My neighbor tore up his turbo on his wheeler and I suggested we try rebuilding it first.
 
The first thing I always ask myself is "why did the manufacturer do that?". Have you asked a Perkins mechanic or distributor?
 
Glad you are doing it yourself. I rebuilt one of those and sold it. They are pretty simple. Mark the orientation before you remove the nut on the impeller so you can get it back together in balance.
Just because you can flex the impeller into the housing doesn't mean it was hitting while in operation. But it indicates it's time.
Many turbochargers dribble a little out of the intake side. Put a pad under it and boat on
 
Robert, can you provide a link to the YouTube video. My neighbor tore up his turbo on his wheeler and I suggested we try rebuilding it first.

I haven't gotten into mine yet so I don't know how different it is, but from looking at the parts kit they seem similar:

If mine is significantly different I'll post the changes.
 
My Perkins was equipped with the H1C turbocharger from the factory.

Good Luck, RP! It sounds like you have yourself quite a headache with this thing...

J.S.
 
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