perkins 6.354T comments and questions

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jamespaulca

Member
Joined
Nov 11, 2012
Messages
9
Location
USA
Information and 2 questions.

Have twin Perkins 6.354T in my 42LRC Californian. Owned for 10 yrs, PO ran hard for 2 yrs before that. My strategy to date is preventing costly engine repairs. Run slow maybe 175 RPM; 7-8 knots. That has worked fine; don’t really need top end performance since fuel efficient minded. So worked well for 10 yrs, don’t operate that much. Converted to J/W cooling to both breadbox intercooler and exhaust manifold to preserve those two expensive weak links. Recently discovered (on cold engine) on one engine the exhaust piping after turbo exhaust can (before going down to wet elbow) had corroded through. No obvious signs in operation, visit engine room frequently underway. Corroded joint was a v-clamp design, but welded solid by PO. No problem though I can fix. As usual one issue leads to another, turbos (first time examined) looked bad. Going for H1C conversion from 3LD in this first engine. Still no problem, it will happen. Engine not instrumented with boost or EGT, so will add them too. Of course turbo studs/nuts were frozen corroded and PIA problem to get off. Cut some, sheared others. But it is now out and can recover, from all issues. The two problems I write about are oil/gummed up surfaces on compressor side. The exhaust side was bad too with soot/carbon but more expected. I always suspected high EGT at higher RPM (above 1750), but without instrumentation you run kind of run blind and just go by smoke signals in exhaust. Q1: this question concerns breadbox air cooler, I don’t want to expand current project by removal and disassembly for cleaning. Is there a way to flush/clean air side only in place? Then suck out liquid solvents/cleaners used (using my oil change pump) and dry out. Q2: From reading internet sources see oil source in air side was from failed turbo oil seals and/or crankcase breather hose. Oil seals will be solved with new H1C, anything to be done or worry about crankcase breather? No filter on inlet air just wire screen.
 
The gunk on the compressor side points fingers at the aftercooler, I’d remove it and make sure it is properly cleaned and tested.
Blowby should be checked too, as that often contributes to an oily aftercooler/turbo.
You are doing the right thing in running that motor conservatively.
Once the exhaust manifold and aftercooler are added to the coolant circuit, it’s cooling abilities are stretched pretty thin, not capable of extended hard running.
Don’t fail to install that EGT gauge, the exhaust color is a poor temp indicator!
 
James, I have a t6.354 too. Had the same joint failure.
Tell me more about the turbo conversion. I have a Holset H1B. Almost impossible to get parts for.
Do they make a H1C with a water cooled housing ?? Where to get one and price ??
 
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