mgs
[Top] [All Lists]

Re: Fram Filter for Moss MGA Oil Filter Conversion

To: fold@mail.bcpl.lib.md.us
Subject: Re: Fram Filter for Moss MGA Oil Filter Conversion
From: dmeadow@juno.com
Date: Tue, 15 Apr 1997 12:44:29 EDT
Thanks, Chip, for your help.  Barney posted a  thorough discussion, as
well.  For years I have been justifying the use of the PH 3614 with the
thought "well, whatever it is, it has GOT to be better than that old
canister/cotton setup".

I'm pretty sure that the filter head still has a pressure relief valve in
it, at least there is a spring thingy that looks the part.

I haven't noticed a pressure drop as you describe in your TR, so I think
I'm OK there.

I would like to continue to use the PH 3614 as opposed to the others,
merely because it is much smaller.

Thanks again,

David Littlefield
Houston, TX
On Mon, 14 Apr 1997 21:51:57 -0400 (EDT) Chip Old
<fold@mail.bcpl.lib.md.us> writes:
>If the filter hangs vertically below the adapter, then there is 
>probably
>no need for an anti-drainback valve.  Note the "probably".  Filter
>position isn't the only deciding factor here.  On some engines, the
>position of the filter relative to the oil galleries can cause oil to 
>be
>siphoned out of the filter even if it hangs vertically.  I don't know 
>the
>BMC engine used in the MGA well enough to say if that's an issue in 
>your
>case.  Generally speaking, though, and anti-drainback valve is 
>necessary
>only if the filter is off-vertical.
> 
>I didn't say that a pressure relief valve is necessary in this
>application. I said only that some seemingly identical filters have 
>filter
>bypass valves, others do not. The filter heads used on our cannister
>filtered BritCars already have filter bypass valves built in, so none 
>is
>needed in the filter itself unless the one in the filter head is 
>removed
>when the adapter is installed. 
>
>For your MGA application, it sounds like a plain filter (no 
>anti-drainback
>valve, no bypass valve) will do.  On my TR4, where the filter body 
>mounts
>horizontally, I need an anti-drainback valve but no bypass valve.
>
>You won't find these things specified on the filter box.  Instead, 
>you'll
>need to find the manufacturer's specification book.  Somewhere around 
>here
>(can't find it at the moment) I have a huge thick old book from Fram 
>that
>provides detailed specs for all of their filters (well, all of their
>filters as of about 1975 - it's an old book).  You can cross-reference
>filters by body size, thread size & pitch, relief valve (yes/no),
>anti-drainback valve (yes/no), and other useful features.
> 
>If your friendly local filter dealer doesn't have a detailed specs 
>book
>(he probably won't), you may be able to get one from the local 
>wholesale
>distributor or directly from Fram, AC, Purolator, or whoever.  If 
>worse
>comes to worse, contact the manufacturer's customer service or tech
>service department.  Tell them the thread size & pitch, the gasket
>diameter, and the approximate body size, and indicate whether or not 
>you
>need an anti-drainback and/or bypass valve.  They should be able to 
>give
>you the appropriate filter number.
> 
>In your case, where the filter is vertical and the filter head 
>probably
>still has its original bypass valve, which filter you use probably 
>isn't
>critical as long as it fits.  Having an anti-drainback valve when it 
>isn't
>necessary won't hurt anything.  Having a bypass valve when you don't 
>need
>one is probably okay, but watch the behavior of your oil pressure 
>gauge to
>make sure.  I once put a filter with a bypass valve on my TR4 and saw 
>some
>really odd gauge readings before I realized the bypass valve in the 
>filter
>was the cause.  The pressure would rise to a certain point with engine
>revs, then drop back suddenly about 10 psi, apparently when the bypass
>valve in the filter opened up.
>
>Now, even with that 10 psi drop the pressure was more than adequate, 
>but
>what bothered me was that this meant the oil was no loger getting full
>filtration.  The filter bypass valve, whether in the filter head or in 
>the
>filter itself, is designed to allow unfiltered oil to get to the oil
>galleries in the event that the filter clogs up.  In my case, however, 
>the
>bypass valve in the filter opened up at pressures that are normal for 
>a TR
>four banger.  Not good! 
> 
>On Mon, 14 Apr 1997 dmeadow@juno.com wrote:
>
>> So we come full circle on the original question as to which is the 
>proper
>> replacement filter for the spin-off conversion kit for the MGA.  
>Using
>> only Fram numbers for simplicity, we have the following candidates:
>> 
>> PH 3600
>> PH 43
>> PH 3614
>> 
>> I looked at all of these over the weekend, since I have this same 
>problem
>> that I solved unscientifically by using the one that *looked* like 
>the
>> one that came with the kit (which is the PH 3614).  How do we know 
>which
>> is right?  The PH 43 says it is for MG's, but I'm sure that refers 
>to MGB
>> applications.  In the MGA the filter hangs "properly" so 
>anti-drainback
>> wouldn't seem to be an issue.  An internal pressure relief valve is
>> required?  Why?  Surely the cotton filter / canister stock setup has 
>no
>> pressure relief valve.  If it is required, how does one know the 
>proper
>> pressure, then how do you know if your filter has it?  I looked at 
>the
>> boxes and found no specifications, beyond recommended applications.
>> 
>> As often happens, the more answers we get the more muddied the 
>subject. 
>> What is the definitive answer?  Where did the recommendations come 
>from
>> (Barney, I recall the PH 43 was yours)?  Science, or (as in my case)
>> ignorance?
> 
>-----------------------------------------------------------------------
>Chip Old                      1948 M.G. TC  TC6710  NEMGTR #2271
>Cub Hill, Maryland            1962 Triumph TR4  CT3154LO (daily 
>driver)
>fold@mail.bcpl.lib.md.us
> 
>If cars had evolved as fast as computers have, by now they'd cost a
>quarter, run for a year on a half-gallon of gas, and explode once a 
>day. 
>
>
>

<Prev in Thread] Current Thread [Next in Thread>