QSB6.7 HE and AC Maintenance

[Chris Dahl]

QSB6.7 480HP-Turned 3 years/600 hours on my engine just before hauling for winter and thought might as well hit the cooling system for a checkup. The aftercooler weeped a few drips per hour from factory so it was pulled apart and greased up early on, nothing done to the HE. Notes below on findings:

-AC came right apart, could push the core out with a couple thumbs, couple feathers, small eel grass, and a few evergreen needles piled up, not bad. Zincs looked good

-Gear cooler looked good, nothing to service but the zinc.

-HE only has end caps that come off, core does not come out of this model, end caps on HE and AC are plastic with inserts where the bolts and zincs are to maintain continuity to the aluminum housing. Bolts were factory greased quite well and caps came right off. Quite a bit of small eel grass, feathers, and evergreen needles at the return (top), I assume with the turn of the water flow it is prone to trapping items as they change speed and direction. Boat runs in the Puget Sound and there is a lot of topside crap to suck into raw water systems. Zincs looked good

Couple questions:

Does the crud caught up in the cooling components seem normal? I run a Vetus strainer and small epoxy formed scoop on the thru hull (no screen on the thru hull) and routinely clean my strainer/freshwater flush the engine. The thought behind no screen on bottom was that piles of eel grass might get sucked/stuck onto the intake screen, lots of eel grass in the sound, and I figured easier to clean the strainer inside the boat than on the bottom of the hull. I have first hand viewed a friends hull with eel grass half sucked through the hull strainers and it was not something that was just going to fall to the bottom if the engine was turned off.

Anything in the pictures look like I need to do more than clean up, grease and re-assemble with new 0-rings?

Thanks,

Chris

 

 

Topic

[Chris Dahl]

10-4, have a Buck Alonquin screen unit coming for the hull side. I’ll keep the inside of the boat just as is, I like the Vetus for ease of dockwater engine flushing.

Hopefully get the HE and AC greased and back together this weekend.

[Rob Schepis]

Cummins Strainer Spec

Cummins spec is 2.0 mm strainer holes.  A 5/64″ drill bit would suffice for checking hole size

 

[Woo]

I say it’s unacceptable Chris, far too much grass getting there. I’d suggest either install a superior internal strainer or an external.

I personally have the latter, here pictured prior to install. The mesh is sizes to “Cummins spec”.

 

[Chris Dahl]

I’ll take that as a no to my question about acceptable amount of crud that gets by the basket strainer.  I actually thought it didn’t look too bad for 600 hours, but then as mentioned last engine was keel cooled so no basis.

[Tony Athens]

Chris,

 

I am very disappointed………….I cannot believe you, of all the guys that have it “together”,   would not put a decent  strainer type pickup   on the bottom of the boat..

Tony

 

[Chris Dahl]

No hull strainer, just a Vetus standard basket strainer unit inside the boat. The south bay looks like it has smaller holes than my Vetus basket. The basket holes are large enough that a tree needle or small eel grass can find a route given enough time swimming around the strainer. Probably not change a thing. Last engine was keel cooled so a little new to the whole operation.

[Rob Schepis]

Looking good to me, I’d just keep doing what you’re doing and stay on that 3 year/600 hour plan..

What external strainer are you referring to?  Like this?  These are known as squid screens or south bay strainers and the “south bay” name (as far as I know) originated here on the south shore of LI due to all of the eel grass….everyone here runs them without issue and pretty much swear by them (where that saying originated I do not know…)

[Author]

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