Perkins T6.354 Best Practice

Brooksie said:

Here is a good intercooler complete for $250. and in nice shape too only 1600 hrs 161884129580 ebay item #

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Maybe best to think marine age and not hours, especially if parked in salt water.

sunchaser said:

Maybe best to think marine age and not hours, especially if parked in salt water.

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I can't speak to where it was "parked" but from the pictures the tube stack looks great. Mine drains itself when moored maybe this one did too.

I couldn't see bypassing the air charge cooler. The ebay unit is similar to mine - but you'd have to see the inside of it, up close, to know if it's any good. Mine had heavy corrosion and you'd have to know how thin the cast iron sleeve is. Seems like plastic would be a much better housing for the unit.

R_p_ryan said:

I couldn't see bypassing the air charge cooler. The ebay unit is similar to mine - but you'd have to see the inside of it, up close, to know if it's any good. Mine had heavy corrosion and you'd have to know how thin the cast iron sleeve is. Seems like plastic would be a much better housing for the unit.

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I know of someone who made an intercooler housing out of plastic. It looked like a nice option.
I also know of more than one who bypassed their intercooler. As long as you keep cruising rpm under about 2200 you'll be fine that way according to the data I saw. They were both more "northern" boaters with somewhat cooler air temps. Short bursts at WOT would be ok, but I wouldn't do 20 minutes that way.

R_p_ryan said:

I couldn't see bypassing the air charge cooler. The ebay unit is similar to mine - but you'd have to see the inside of it, up close, to know if it's any good. Mine had heavy corrosion and you'd have to know how thin the cast iron sleeve is. Seems like plastic would be a much better housing for the unit.

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So drop him an email and ask for more pictures. The tube stack alone is worth 2X what he is asking.

My air charge cooler had heavy scale on the inside. I cleaned it all out with a wire wheel, even the nipples, one of which lost about 3/16" on one side. It's all solid iron and despite the corrosion, it's structurally sound. I added epoxy to the inside of the casing and I'm adding a zinc to help address the steel breaking down. I don't know if those will save it for four more decades, or just until the next season. But it's due for de-assembly next year. It the casings show wear problems next year then I'll have to consider the plastic housing option.

Thanks,
RR

From my experience, if you keep the rpm down, you're keeping the horsepower WAY down (remember the propeller law?) so if you monitor the manifold air temp and keep it conservatively low (say 200 - 220 F) you'll be fine bypassing the intercooler.

In my Prairie, the cruising speed of 7-ish knots only uses around 25 horsepower, the engine could use a charge air HEATER. I am more concerned with running too low a power setting, so occasional sprints to keep everything clean and loose is called for.

GOOD LUCK!

JS

R_p_ryan said:

My air charge cooler had heavy scale on the inside.
Thanks,
RR

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What do you think RP, was it even acting as a charge air cooler for all these years? How would one know on a low HP demand Perkins?

The site that seems to discuss not performing air coolers is boat diesel. Discussions there center on trying to get the last few hundred RPM or so out of the engine and not able to do it safely due to a plugged air cooler.

sunchaser said:

What do you think RP, was it even acting as a charge air cooler for all these years? How would one know on a low HP demand Perkins?

The site that seems to discuss not performing air coolers is boat diesel. Discussions there center on trying to get the last few hundred RPM or so out of the engine and not able to do it safely due to a plugged air cooler.

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I tested the temp on each side of the cooler. Air entering the cooler was 80F and exiting was 70F, however that was at a low power setting.

smitty477 said:

"Are all the 34 Mainship and Mainship IIs powered with Perkins? All T6.354?"


My 1978 Mainship 34 was a Perkins T6 - 354 at 165 hp and all of the ones I had seen up here on the East coast were the same - but there could be other versions I am not aware of although the power increases on that engine typically came much later on in years.


"Is the Perkins a 200-hp turbocharged engine? "
Mine was a 165 Turbocharged engine - I believe the turbo was a 'switzer'.


"Are parts really hard to get?"
As mentioned above the exhaust manifold for mine had to come form England and was expensive as boat parts go - most other things were not so bad as aftermarket or common parts were still available.


"Any significant problem areas with that engine?"
Exhaust, turbo rebuild, heat exchanger, and the rotary fuel pump that liked to 'hunt' until it was refitted with "O" rings that were unaffected by low sulfer fuels.


FWIW - My engine had a "U" in the code indicating a 'reverse' rotation engine.

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Re.perkins 6.356 diesel: Are parts hard to get? Perkins 6.356 and Caterpilar 3056, same engine,(Since Cat. bougth Perkins back in 1998.)
maybe the Caterpilar people are more alert in the US. concerning for part service, for US. Citizen.
According to Wikipedia; The Perkins 6.litre diesel are described;
"as a higthly succesful engine"

Gadenors

When Perkins went to Sabre to marinize the new design 6 liter engine about 15 years ago the similarities to the older Perkins designs were few. Even the paint is different. The Perkins Sabre 225TI and its variants are a current engine and when painting yellow began about a decade ago the Cat 3056 was born. Parts for either are easy to come by in the US, Canada or flown in from England.

The most common parts like filters are off the shelf in most locations and the raw water pump a Jabsco. Water pumps are gear driven and exhaust manifold coolant cooled.

sunchaser said:

Gadenors

When Perkins went to Sabre to marinize the new design 6 liter engine about 15 years ago the similarities to the older Perkins designs were few. Even the paint is different. The Perkins Sabre 225TI and its variants are a current engine and when painting yellow began about a decade ago the Cat 3056 was born. Parts for either are easy to come by in the US, Canada or flown in from England.

The most common parts like filters are off the shelf in most locations and the raw water pump a Jabsco. Water pumps are gear driven and exhaust manifold coolant cooled.

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I wonder if I could swap the heat exchanger for the one from a Cat 3056 and put the exhaust manifold into the freshwater circuit. My existing exchanger is in excellent shape and I just disassembled and cleaned it out.

About which engine, make and color.
Europe we have Mitsubish

R_p_ryan said:

I wonder if I could swap the heat exchanger for the one from a Cat 3056 and put the exhaust manifold into the freshwater circuit. My existing exchanger is in excellent shape and I just disassembled and cleaned it out.

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Get the engine drawings from boatdiesel, Cat or PS to see what fits. The marine specific parts are pricey and likely don't compete with some alternatives you are considering.

What I bought vs what I own

I'm just finishing up a major service:
Rebuilt turbo
Rebuilt air charge cooler
Disassemble and acid clean heat exchanger
Acid clean oil cooler
36 hour cycle of Evapo-Rust through exhaust manifold
Remove, clean and paint all plumbing
Replace hose couplings
Replace oil drain hose
Clean and paint motor
Oil and filter
New oil pressure switch
Two new batteries
Flush coolant from block and hot water heater

Attached are two pictures. One is the boat I bought, the other is the boat I own as I'm finishing up the maintenance.

A few things I learned:
Open the coolant drain valve on the low side of the block. Connect a hot water hose to the front of the block where the hose to water heater attaches. Turn on the hose and watch for several minutes while brown junk exits the valve. This was after draining all the coolant and it all was nice and clear green. So there was a bunch of brown slime coating the water passages in the block and head.

There is long, 1" diameter copper pipe that carries raw water from the heat exchanger to the exhaust manifold. It's about four feet long with several bends. The inside had hard black scale that looked like stalactites, crossing the inside of the tube.

The air charge cooler had a massive amount of scale on the raw water side and I believe this massively restricted the raw water flow.

The motor never overheated but the amount of scale that came out of the raw water circuit was several pounds. Makes me think that any flushing technique that doesn't involve disassembly is a waste of time.

R_p_ryan said:

There is long, 1" diameter copper pipe that carries raw water from the heat exchanger to the exhaust manifold. It's about four feet long with several bends. The inside had hard black scale that looked like stalactites, crossing the inside of the tube

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Mine didn't overheat either. But while running the engine after an oil change I noticed that all the raw water hoses between the raw water pump and that crossover pipe were swollen up like sausages and felt very hard to the touch. I pulled that pipe off and found the same buildup as you and a water passage about the diameter of a pencil.