Crankcase ventilation and filtration for 3208nat

[Bud]

Any recommendations for installation of crankcase filtration for 3208 cat naturals?

 

[Pete Meisinger]

There was a link about this recently. Several home done ideas. I will search it out myself because I want to implement one of them. If I find it this morning I will provide a link.

pete

 

[Comodave]

We made a system for a previous boat with Detroit Diesels. Ran a hose from each airbox vent into a fuel filter. Didn’t put the filter element in the fuel filter. Drilled a vent hole to let the air out of the filter housing. The oily air would enter the filter housing and the oil would stick to the housing sides and drain down to the bottom. The air would exit the housing with much less oil in it. Then drain the housing every once in a while.

In out RV we had a lot of blowby from our 6BT so we put in the Racor CCV system. It filters the oil and recirculates it back to the engine. It was relatively reasonable in price compared to the Walker Airsep.

 

[Portage_Bay]

+1 For the Racor CCV

 

[gsholz]

What is wrong with the standard crank case ventilation/filtration on the 3208NA? That big can on top of the stbd valve cover is your CCV/filter. Most oil mist collects on a metal mesh and drains back into the valve cover, the rest gets sucked into the intake. If you have pressure build up the mesh in the canister needs to be cleaned.

These engines have only two piston rings, i.e. only one compression ring. They will always smoke a bit when cold.

 

[Comodave]

The reason for a CCV is to stop the blowby from becoming airborne in the engine room. I don’t know about 3208s but my DDs blew oil all over the engine room. There was an oily film everywhere. I made the system I spoke about in my previous post and gradually as I cleaned the engine room the oily film stopped and got cleaned up. Before you could clean it up and it would come back when you ran it.

On our Cummins in our motorhome there is a “slobber tube” that would direct the blowby down to the road. Problem was if we towed our center console or our car, they would get covered in oil from the blowby. We put in the Racor CCV system and no more blowby.

 

[gsholz]

The 3208NA in the marine application does not vent blow-by. See above.

 

[Bud]

The 3208NA in the marine application does not vent blow-by. See above.

I did not realize that those were crankcase filters. I will clean them. I assume you just take the front cover off?

 

[Capitaine R]

From my 3208t manual

 

[gsholz]

The round canister is the crankcase ventilation valve. It should open and recycle the blow-by as long as crankcase pressure is higher than intake pressure. It could gum up and get stuck I suppose. Cleaning and making sure all the parts are in good shape is probably a good idea every few thousand hours.

 

[oscar]

One thing to consider is the fact that diesels are direct injection, ie the fuel goes directly into the combustion chamber and not into the intake manifold ahead of the intake valve. (Like it does on many, but not all, DI gas engines.)

What this means is that on engines that vent their crank case into the intake side the oil mist makes it into the intake manifold and blows by the intake valve, over time leaving a carbon buildup. In time the valve will need cleaning.

On non turbo engines this can be done by introducing a cleaner into the intake air stream on a regular basis. On engines with turbos this can be unhealthy for your turbo.

Bottom line is that in some engines it behoves one to keep the intake air as pure as possible. Although Airseps may not be cheap, consider the job of pulling the head to clean, or replace, intake valves.....

 

[ghost]

I was going to put a racor ccv on my Volvo’s as they always coated the aftercoolers, but sold the boat before I had a chance to put them on, still sitting on a shelf somewhere.

On my 3208 na’s I’ve never had them make a mess or leave a film anywhere. Clean up the canisters before you decide if you have a problem needing solved.