In everything I have read, it appears that for my 1999 M-35BC the Fuel Pump has a 60 micro filter screen, the Primary Racor 200 Series Fuel/Water Separator has a 30 micron Filter (R15P or R20P) and the Secondary Fuel Filter attached to the engine has a 10 micron filter.
Can someone please confirm my assessment?
Thanks, Bob B.
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Bob & Maggie B. Hobby Time 1999 C36 MK II TM/Wing Hull #1796 Warwick, RI
My M-35, 1990, Racor primary filter/water separator has a 2 micron and the filter on the engine is 10 micron. I don't know what the pump filter is rated at and I don't understand why the Racor needs a 2 micron.
__/)__/)__/)__Capt Mike__/)__/)__/)__
Punta Gorda Florida
1990 Std WK M35 Hull #1050
Mike,
I don't think the Racor should have a 2 micron filter element. Everything I've read says that a 30 micron in the Racor and a 10 micron on the engine is what's called for. Hope this helps.
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT
Well here is an update.. What should be so very simple, isn't! I tracked down at the Universal Westerbeke Headquarters Mr. Joe Joyce (508-823-7677 x 234) one of the (very) senior designers at the company who designed the system. This is what he told me,
The M-35B Engine fuel system was “designed” for a flow rate of 30 gallons per hour, the Primary Racor Fuel Filter should have a 10 micron filter R20T and the Secondary Universal Fuel Filter has a 25 micron filter. He could not explain why the 25 micron on the engine didn’t make sense to me or why it was designed using a 30 gallon flow rate rather than a 15 gallon flow rate, only that the fuel system design is in synch and works for this engine. I am not a fluids engineer, so I am at a loss to common sense.
Help! Your thoughts and experiences???
Thanks, Bob B.
Bob & Maggie B. Hobby Time 1999 C36 MK II TM/Wing Hull #1796 Warwick, RI
Clear as mud! :-)
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT
From what I can gather, the factory setup of a Catalina 36 fuel delivery system is Racor = 10 micron, engine spin-on = 25 micron, and flow rate = 15gph. This setup does not follow most industry best practices. Most industry best practices are that when you have a dual-filter set up and one filter is coarser than the other, when the fuel leaves the tank the first filter it should encounter is the coarser of the two filters.
The terminology for primary and secondary are sometimes swapped, so just view the enclosed Racor diagram in the context of filter placement.
Nick Caballero
Retired C36/375IA Mk II Technical Editor
Mike, If the fuel pump you are using is a Facet 'Gold Flo' their filter inside the pump is rated at 74 microns.
Bill Dolan 1990 Catalina C-36 MKI - Hull #1041 'Williwaw'
Std. Rig, Walk Through, Wing Keel
M35, Oberdorfer Conversion,
Home Waters; Charlotte Harbor & The Gulf Islands of Florida
'You are never out of work if you own a boat'
Mike, If the fuel pump you are using is a Facet 'Gold Flo' their filter inside the pump is rated at 74 microns.
Bill Dolan 1990 Catalina C-36 MKI - Hull #1041 'Williwaw'
Std. Rig, Walk Through, Wing Keel
M35, Oberdorfer Conversion,
Home Waters; Charlotte Harbor & The Gulf Islands of Florida
'You are never out of work if you own a boat'
rbbrooks,
Bob, do you think that this could have anything to due with fuel pressures ? I agree with you that it doesn't make too much sense, but it probably takes a higher fuel line pressure to filter to 10 microns than at 60. Just a guess on my part.
Bill
Bill Dolan 1990 Catalina C-36 MKI - Hull #1041 'Williwaw'
Std. Rig, Walk Through, Wing Keel
M35, Oberdorfer Conversion,
Home Waters; Charlotte Harbor & The Gulf Islands of Florida
'You are never out of work if you own a boat'
FWIW;
In the 'For What It's Worth Column' on this subject : I was talking to an Engineer who formerly worked for Westerbeake and asked about the logic using the finest filter first in fuel line and the more course filter nearest the engine. His response was; ' But of course !
His two cents worth went like this; 'The Racor filter is the easiest filter to change underway and you want that filter to be the one that filters out almost everything. Imagine trying to change the spin - on engine filter while in a seaway' You can change the Racor underway but doubtful that you would manage to change the spin-on'
In his logic, the Racor is the filter you want to catch everything and it should be changed often. The 'engine spin-on' is only there should something catastrophic happen between the Racor and the engine. Adding that the spin -on filter seldom needs to be changed.
So maybe that was the logic in use when Universal was talking about using the finest filter first ?
Bill Dolan 1990 Catalina C-36 MKI - Hull #1041 'Williwaw'
Std. Rig, Walk Through, Wing Keel
M35, Oberdorfer Conversion,
Home Waters; Charlotte Harbor & The Gulf Islands of Florida
'You are never out of work if you own a boat'