6-3544M Perkins

Hi all, the PT-41 has twin Perkins 6-3544 M diesels. I don't know a thing about them. Except the smoke a fair bit cold! A Seatte broker said they are trouble. I would appreciate input. These have about 3200 hrs. Tracy

Hi Tracey, Couldnt be farther than the truth. They are great engines. Properly maintained and they will last a life time.

This horizontal version had 20,000hrs on it when this photo was taken.

Most parts can be purchased through farm equipment dealers for a fraction of "marine" prices.

Ditto. My trawler has twin 6.354 Perkins circa 1985 that continue to work well without trouble. Naturally aspirated Perkins were very reliable while the later model Turbo design was prone to overheat problems. That may be what your dealer was thinking about, so check to see if they are naturally aspirated. I think the turbos numbers have "T" in the suffix, like 6.354T. Other TFs can correct me if I am wrong.....

boatpoker said:

This horizontal version had 20,000hrs on it when this photo was taken.

Most parts can be purchased through farm equipment dealers for a fraction of "marine" prices.

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BP
On most of our marine engines, the parts most used, abused and sometimes hard to find are the marinization parts. These cannot be found at farm equipment dealers.

A Perkins engine that has the manicooler design should cause a prospective buyer pause. The manicooler itself is pricey and hard to find. Leaky manicoolers can severely damage an engine.

So when boat shopping, being leery of a Perkins with a 30+ year old manicooler is wise. There are plenty of Perkins engines out there that have a better heat exchanger design, I suggest the OP focus on those.

"So when boat shopping, being leery of a Perkins with a 30+ year old manicooler is wise." There are plenty of Perkins engines out there that have a better heat exchanger design, I suggest the OP focus on those."
The above is the position we took when shopping for our boat. Our Perkins
T6.354 has the heat exchanger and tank on the port side, not the manicooler. . The heat exchanger end caps are easily removed to inspect and clean if needed. The Perkins smokes VERY little at start up and goes away within a couple minutes. Our Perkins has been a reliable economical power choice with no complaints for 6 years.

Our Perkey has the Multi-Cooler which it the more rectangular of the Perkins HX's. See attached. No issues in 36 years.

Can you tell from these pics if these are manicooler? These look like manipulated to the untrained eye.

Is there a difference between the mani-cooler and multi-cooler?
I've always referred to mine (coolant and exhaust manifold) as a mani-cooler.

I have the same as the perks in above pic, which also look super clean for 3,200 hrs

The entire engine room is beyond immaculate. Lets hope mechanically is is as good as it looks. I do however recognize its a 35 year old boat.

Max Simmons said:

Is there a difference between the mani-cooler and multi-cooler?
I've always referred to mine (coolant and exhaust manifold) as a mani-cooler.

I have the same as the perks in above pic, which also look super clean for 3,200 hrs

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Max
Do you have a separate transmission cooler? Do you have an after cooler or turbo?

sunchaser said:

Max
Do you have a separate transmission cooler? Do you have an after cooler or turbo?

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Yes, separate transmission cooler, no turbo.

I’m not in bed w either Perkins or Ford/Lehman but I’d go for a Perkins even though I know of a Perkins that suffered a broken crankshaft running in Chatham Strait.

Also in the past Perkins engines have found favor in our US Navy.

Also I may favor them as when I worked in a mine in Alaska I snagged a job in the diesel electric powerhouse. On graveyard shift I read magazines that the chief engineer subscribed to. I remember a lengthly article about a “new” 4cyl diesel that featured a pre-chamber (combustion chamber) and a compression ratio of 23-1. I was very impressed as an impressionable young man. Some of that awe probably lingers.

As for Perkins engines being trouble ..... I submit that that Seattle broker may be the trouble. I’ve not heard of Perkins engines being even as troublesome as the average old marine engine.

tdoriot said:

Can you tell from these pics if these are manicooler? These look like manipulated to the untrained eye.

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Yes, that is the Multi-Cooler, same as I have. The Mani-Cooler has rubber end-caps for tube clean out.
OK, from the Perkins manual, the top two are the Multi-Cooler with and without a turbo.
The bottom is the Mani-Cooler.

Mani-Cooler

Yeah, I don't think I have any of those. I think the Seattle broker either had a bad experience with perhaps the turbo version, or just doesn't want me to by this boat since it isn't thiers!

tdoriot said:

Yeah, I don't think I have any of those. I think the Seattle broker either had a bad experience with perhaps the turbo version, or just doesn't want me to by this boat since it isn't thiers!

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It's a Multi-cooler.

Can the Multi cooler be switched out with the mani-cooler if need be?

FWIW, pulled my 36 y/o Multi coolers and had them cleaned, reinstalled and no problems at all. I will say that I do think the elbows are on borrowed time though