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gettinthere · 23-10-2008, 03:06

I have a Perkins 4.154 200 (1985) Mazda version.
The alternator was mounted poorly and generated a LOT of belt dust. Fixed that. Then pulled the air intake cover to find it packed with the belt dust. Cleaned it out and cleaned out much belt dust from the manifold without letting it go further in. I used a shop vac to pull out loose stuff.

My question is regarding the stainless steel screen as an air filter. Seems primative to me. Should I upgrade it? K & N wouldn't advise me bacause it's marine use and they are worried about CG approval. But it's diesel so I'm considering fitting one. I'll need to deal with the oil breather line that goes there too.

Anyone upgrade their air intake system on their Perkins 4.154 from the simple perforated metal screen?

never monday · 23-10-2008, 03:59

K&N won't because of potential liability. I would get their catalog and find a filter in their generic listing that meets your dimensions. You can drill a hole in the base and insert a barb to connect the oil vapor hose to.

Baring that, look into Walker AirSep.

gettinthere · 23-10-2008, 04:23

Would I have survey/insurance problems? The K & N guy was worried about spark/flame arrestor but being deisel I don't think that is an issue.

gettinthere · 23-10-2008, 04:26

Engine rooms get hot. How much benefit would there be to plumbing the air intake outside the engine room? I would not plumb directly outside because of salt air but was thinking just through a wall to the interior space. I have choices of pulling from the galley passageway or perhaps into the genset space.
Worth it?

never monday · 23-10-2008, 04:29

Quote:

Originally Posted by gettinthere

Would I have survey/insurance problems? The K & N guy was worried about spark/flame arrestor but being deisel I don't think that is an issue.

not an issue with diesel boats

Quote:

Originally Posted by gettinthere

Engine rooms get hot. How much benefit would there be to plumbing the air intake outside the engine room? I would not plumb directly outside because of salt air but was thinking just through a wall to the interior space. I have choices of pulling from the galley passageway or perhaps into the genset space.
Worth it?

Engine rooms are designed to be 120*F. Did you have a performance problem with the old set up? I wouldn't worry about cold air induction.

**GordMay** · 23-10-2008, 05:16

Engine room Ventilation:

The maximum temperature of the engine room should never exceed 60 degrees C (140 F) within 20mm (3/4") of any electrical equipment, and 45 C (113 F) at the air intake.

Ventilation Requirements for Yanmar Diesel Engines:
Duct Sizes (2 Required - 1 Supply In & 1 Exhaust Out)
Engine Square inch = Diameter
1GM10 3.02 sq. in = 50mm = 2" ∅
2GM20 6.0 sq. in. = 75mm = 3" ∅

100mm inside diameter tube duct area is 78.54 cm2
50mm inside diameter tube duct area is 19.7 cm2
4 inch inside diameter tube duct area is 12.57 inches2
2 inch inside diameter tube duct area is 3.15 inches2

Note: TWO ducts the same size are required, one inlet and one outlet.

gettinthere · 23-10-2008, 07:06

Gord
I was thinking of plumbing an external feed directly to the air intake of the engine, not to the engine room. The engine room is hot but not unacceptably so.

I'm thinking any engine runs better with cool air ducted to the intake.

never monday · 23-10-2008, 08:02

go for. I doubt you will notice any quantifiable difference for the expenditure.

gettinthere · 23-10-2008, 08:57

Quote:

Originally Posted by never monday

go for. I doubt you will notice any quantifiable difference for the expenditure.

Well, I'd rather not "go for" if it doesn't result in a quantifiable difference. That's why I'm asking.

never monday · 23-10-2008, 12:36

Unlike your gas car engine. The old mechanically injected Perkins meters fuel by engine RPM.

In newer injected gas engines the air is measured for volume, temp and density. This is then put in an algorithm to adjust the fuel amount. Then it's burnt, The O2 sensor sniffs the exhaust to confirm and adjust the mixture.
In a mechanically injected diesel. The fuel is controlled by the governor. The governor is adjusted by the rotational speed of the crankshaft*. As load increases the engine can't make enough power to maintain that RPM. The crank then slows down. This causes the gov to increase the fuel to the engine. Causing the power output and RPM to go back up

*=For the fact checkers, yes the gov can be on the cam. I'm trying for the simplest explanation.

**Inlet Marine Services** · 27-10-2008, 12:30

Becareful oft the perkins system because of the intake heater. Some of the early intake heater systems start a small fire in the intake to warm it up.

gettinthere · 28-10-2008, 09:21

Quote:

Originally Posted by Inlet Marine Services

Becareful oft the perkins system because of the intake heater. Some of the early intake heater systems start a small fire in the intake to warm it up.

What do you mean by "early"?

I have a 1985 perkins 4.154 200.

Is there an easy way to identify if there is an intake heater system?

Thanks