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MG MGA - Screw on filter adaptor

My A has an MGB engine with an adaptor for spin-on filter. The filter is "upside down" ie the oil comes in from the bottom. THis suggests to me it ought to have an antidrain valve in the filter. I don't know who supplied the adaptor so I can't check. The existing filter is a Mann W712 and I do see it takes a few seconds for the oil pressure to build up, consistent in my mind, to filling the filter first. I thought of trying the W712/80 which has the anti drain valve built in.
Any harm in that?
Graeme Williams

I have just switched from the upside down spin-on filter back to the normally orientated filter for the same reasons.
I asked at Bob Wests about this a few days ago and apparently they have stopped fitting the upside down filters as they are now struggling to get hold of oil filters with the anti-drain valve.

If your new filter has got this valve then I would stick with it as it is much easier to change this type of filter.
Just check to make sure that the threaded hole in the middle of the new filter doesnt project beyond the level of the rubber sealing ring.

If it does then your filter will not seal properly and you will find thay most of your new oil will be pumped out onto your drive!

I found this out when I bought a box of new filters from my local motorists discount shop as they were half the price of my previous supplier. It was an expensive mistake and my drive has never looked the same since!

Cheers

Colyn



Colyn Firth

The Mann filter that has been recommended on the MGB BBS is the 916/1.
Dave O'Neill 2

I have an inverted filter on an MGB, and use a K&N HP-2004 which has an anti-drainback valve. With this filter, it doesn't take any longer to get oil pressure than with the hanging type. It also has a 1" nut on top for easy removal, and painted engine color resembles the original canister type.
Steve Simmons

For the inverted filter I use
WIX 51068,
Napa 1068,
O-Reily's (Wix) 51068.

These do have anti-drain-back valve. Many filters do have it. Look at the inlet ports, the small holes around the circle. If you see only a rubber piece inside covering the holes, that's the anti-drain-back check valve.

Not sure what drain-back you are trying to stop. You can let the car sit for a year and the filter will still be full of oil. The only way to get the oil out is to unscrew it or punch a hole in it to let air in.
Barney Gaylord

Barney:
It has a filter fitted which doesn't have a drain back valve. Even after only a day or so, it seems to take a few seconds for the oil pressure to build up so I wondered (correctly or otherwsie) whether the oil was running back and so the pump having to fill the filter first. My concerns were aroused when I noted that the MGOC filter specified for their adaptor is a type with a drain-back valve.
May all be a red herring of course.
Graeme Williams

There is a very small restrictor orifice in the (original) brass fitting between the small oil flex hose and the small steel pipe going to the pressure gauge (near the starter switch). This serves to damp down sudden fluctuations of the gauge needle. If there is air in the pipe between this fitting and the gauge, it will take some time to compress the air, resulting in slow reaction on the gauge. It may also have similar slow reaction on engine shut down taking a few seconds for the visible pressure decay back to zero.

You can improve the gauge reaction speed by bleeding air out of the pipe at the back of the gauge. Disconnect the pipe at back of gauge, and hold it in a small catch vessel. Start engine and run it until all air is gone and you get a steady slow trickle of oil from the small pipe. Then reconnect the pipe to the gauge. Look to bleed out about one tablespoon of oil after you think there is no more air.

There was (originally) a thin leather washer (sealing gasket) at this flat-faced joint. Some cars (mine included) get away without the gasket here and do not leak. YMMV.

Also be aware that some replacement brass connector fittings have a large bore through, no restrictor orifice, and may pass oil a bit faster up the small pipe.
Barney Gaylord

Went for a Mann W916/1 in the end. I decided, having drained the oil and removed the filter that the length of the inner spout was a bit close to the top in the Mann W712.
The one fitted was a W712 - boy did the oil flow everywhere when I undid it! No non-return valve.
Graeme Williams

Having just changed my "normally oriented" spin on filter for the first time I can attest to the difficulty of removing the filter.

I had the car up on a hoist and I have a goodly selection of filter wrenches but it is really difficult to get purchase on it.

In the end I bashed it off with a piece of timber and a mallet.
A Bowie

I use a strap filter wrench from above with a long socket extension and at bar. Gets them off in two minutes and once they are loose I can then just drop them into the plastic tub sitting under the car
dominic clancy

I have found the style of the upturned filter easier to remove than the ones which screw up from underneath - apart from in my case, the escaping oil.
I always felt that bashing a hole in them to try to tunr them was never a good idea. The metal is so thin it tears rather than helping the filter unscrew and then you have a lethal cannister to try to turn.
Those filters with a nut on the top seem to unscrew easily; otherwise I resort to a strap which tightens up with a socket ratchet.
Graeme Williams

To loosen my oil filter when changing the oil, I can usually loosen it by hand if I use a piece of sandpaper to wrap around the filter. It's amazing how much this helps.

Jim
JL Cheatham

If you use the K&N spin on filter that Moss supply you will see these have 1" AF nut attached to the base of the filter. Next problem is "do you have a 1" socket or spanner to fit? I use a set of vice grip pliers to grab the nut and give it a twist, from then on it is a "hand job"!
Mike
Mike Ellsmore

This thread was discussed between 25/03/2016 and 19/04/2016

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