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M11 Oil Bypass Filter return

March 22, 2011, 11:35:07 am

I am installing an AMSOIL bypass filter in my 1996 Foretravel with the Cummins M11.
I will replace the quarter inch "T" for the oil pressure sender with a four way "T" as the source of oil.

The most convenient oil return location is a fitting on the top of the head. Does anyone know if returning one gallon per minute to the top of the head will cause problems? At first glance it would appear that the extra oil into the valve train area would be a benefit, however, I worry that perhaps the oil passages between the top of the head and the pan may not be large enough to handle a gallon per minute. AMSOIL recommends returning oil to the pan. A phone call to Cummins has not been reponded to. 

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Re: M11 Oil Bypass Filter return

Reply #1 – March 22, 2011, 09:37:57 pm

Wyatt,

I don't think you'll ever get a comment from Cummins on an aftermarket system.  I use that port for my Centinel oil replacement system, but that is very low flow.  I'd call Bruce Mallinson at Pittsburgh Power (724) 360-4080.  He specializes in enhancing diesel engines to wild levels.  If Bruce doesn't know, only Cummins Engineering does.  Mention my name.

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Re: M11 Oil Bypass Filter return

Reply #2 – March 23, 2011, 10:37:07 am

I have the same year & same engine, What is the advantage to installing that set up? And what does the bypass do?

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Re: M11 Oil Bypass Filter return

Reply #3 – March 23, 2011, 11:00:18 am

A bypass oil filter system allows finer filtration due to a low flow rate. It will filter down to 2 microns or less. Used in conjunction with an extended life engine oil filter and in this case, Amsoil synthetic oil, you can expect to utilize the oil indefinitely based upon periodic testing. I have had this setup in our coach for two years and thus far have changed the engine oil filter twice and bypass filter once.

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