[C320-list] Perkins fuel consumption

[Rick Sulewski]

If experiencing what appears to be higher than normal fuel consumption of more than a gallon per hour higher than normal, I would look for a fuel tank or hose leaking with a large amount of fuel ending up below the liner (though hard to miss that diesel odor) and next,  double check the fuel dock pump/sale numbers before and after filling up.....making sure the pump gallons and dollars clear to $000.00 before the pump starts.

-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Jeff Hare
Sent: Thursday, September 03, 2015 12:39 PM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Perkins fuel consumption

Hmm.  That really doesn't seem right.  We've motored for a solid 14 hours with our 3GM30F at 3000 rpm and only were able to fit about 10 or 11 gallons in when refueling.

The Yanmar has a lot of high frequency ping sounds that the sound proofing cuts down on dramatically.  But the lower frequency droning is only slightly muted by sound proofing, so it's still loud.  Closing the aft cabin door while motoring seems to cut down some of the noise also.

For any of these 3 cylinder engines, it's hard to imagine them using much more than 1 gallon an hour unless the prop is substantially over pitched or dirty.  In that case, the engine would only run as fast as it has HP to run but the speed governor would still be dumping excess fuel into the cylinders trying to get it up to the RPM you've chosen with the throttle lever.  So I think that'll waste some fuel and may or may not produce black smoke.  Remember that these engines don't have a throttle like a car instead they have an RPM governor.  Which is evident because when a wave or something loads the propeller, the RPM stays constant but you hear the engine strain and work harder.

-Jeff

-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of John Meyers
Sent: Thursday, September 3, 2015 7:56 AM
To: C320-List at catalina320.com
Subject: Re: [C320-list] Perkins fuel consumption

My Yanmar  3GM30F gets anywhere between 2 and 2.5 hours per gallon and I usually run between 2800 and 3000

On the noise thing...   This year I replaced the air "filter"  which really
wasn't much left of it. The noise reduction is very noticeable as the cone shaped foam filter really cuts down on the noise coming from that part of the engine. I also have sound insulation on both covers which I put on a few years back and that helped a lot too back then.

John Meyers
Wind Chime #406
Muskegon, MI

On Thu, Sep 3, 2015 at 7:22 AM, bruceheyman <bruceheyman at cox.net> wrote:

>
>
> Have you ever had the injectors serviced or valves adjusted?  I did 
> both and the low rpm knocking improved.
>
>
> Bruce Heyman(949) 289-8400
>
> -------- Original message --------
> From: Louis spitz <aronella at gmail.com>
> Date: 09/03/2015  1:56 AM  (GMT-08:00)
> To: c320-list at lists.catalina320.com
> Subject: [C320-list] Perkins  fuel consumption
>
> Hi all,
> My 1995 Perkins 29 hp with 875 hours uses about 2.6 gals. of diesel 
> per hour. The manual says fuel consumption at 2700 rpm should be about 1.6 gph.
> The exhaust is clean (not smoking). The engine knocks very badly at 
> low rpms, say below 1000, but I don't think that's related. Also, the 
> engine is VERY loud. I added insulation to the cover in the main 
> cabin, but not yet in the aft cabin.
> Any thoughts on these issues would be much appreciated.
> Lou Spitz
> #195, 1995 Merry Chase