T6.354 (mgt) Air Filter install

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RMK818

Member
Joined
Sep 7, 2021
Messages
20
Vessel Name
Fleur de Lis
Vessel Make
1979 California Marshal 42
Looking for guidance. My mechanic suggested I install air filters on my Perkins T6.354 (MGT) motors. The only place I can see to install them is at the turbo inlet screens. Has anyone added air filters on their boat? How and what did you use?

1979 43 California Marshal.

Thank you
 
Following. I have the same engines and would like to have filters too.
 
The intake size for the stock turbo is 2.75", you can spent as much or as little as you would like installing a filter on this from an eBay special to a closed crankcase breather setup like an airsep brand. Before you go through too much trouble on this, I would inspect the condition of your exhaust side V-band coupling from the turbo to the "can" which connects to the riser/mixer. The rust away and can leak exhaust into the boat eventually. You can dress it up with a file but eventually the lip for the v band clamp gets pretty thin and can rust apart.

I retrofitted mine to a eBay knockoff of the Holster H1C, the exhaust side is 3" nominal v band versus the 2.5" stock turbo so an adapter is needed. The intake side is 3", same as the 210 hp spec Cummins 6bt (non-aftercooled), there are plenty of intake filter options for these. This is why I suggest checking the computer condition of your stock turbo first. You can get a direct replacement turbo but it is about $800-1000 more than what I used.

For the crankcase breather, you can get a filter with a hole and plastic elbow for the breather hose to attach to, just run the hose to a catch jug. Rig up a ventilated catch can or get a walker airsep or SBmar setup. I just ran mine into a old antifreeze jug, doesn't have much blowby at all, especially at the low rpms most of us run at.

I covered the turbo swap in this thread:
https://www.trawlerforum.com/forums/s11/spring-2022-my-old-mainship-projects-62169.html

Attached is a pic of the stock intake.
 

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No room in my boat for the large Donaldson type filter canister. Instead, used standard house hold air conditioning filter material cut in round shape and fitted in turbo inlet screen housing. The original Perkins philosophy was that boat engine room not a dusty place, so no filter required. I figure that air conditioning filter material will provide added protection for the application.
 
Thank you for the information. I just replaced the clamps and exhaust elbows for both of my engines. They were both very corroded and one elbow had a leak. If you have any pics, I would deeply appreciate it. These motors are starting to cost me more than what I paid for the boat....
 
I had those engines on my 1977 42' Californian. They had the stock (barely) flyscreen air filters with a pattern of somewhat large holes in piece of sheet metal. Both my mechanic, who is now retired but was a career Perkins specialist who worked for a time for the factory in Britian, and the local legacy Perkins dealer who has sold and serviced those engines since the early 1980s, told me that there was no need to upgrade the air filter unless I wanted to go with something like a Walker airsep for a cleaner and (very slightly) quieter engine room. They felt there was no benefit to a better air filter for that model of engine, some of which were running for decades with just the factory filter.

They also expressed some concern that a poorly maintained modern filter, whether a very fine media or an oiled filter, woukd lead to a restriction that would never occur with the factory filter and could starve the engine of air leading to less power and more black smoke, etc.

They almost laughed that one (me) would think adding an air filter that was never there to an engine that had been in reliable service for 40+ years would measurably extend it's life or improve its performance.
 
STB, Thanks for expressing my reasons for not for addng air filters. I was curious and asked the folks @ Transatlantic Diesel who remarked something like ... if Perkins came with them or needed addition filters we would have them.
 
T6.354 (mgt) Air Filter instal

Thanks everyone for the info. Sounds like, "If it aint broke, don't fix it". I will keep it the way it is with the stock screens.
 
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