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MG MGB Technical - Oil Filters and Oil Pressure

I have just completed a winter oil change and service on my 76 roadster and when I removed the oil filter to my horror no residual oil came out. I have been using K&N filters for quite a few years now, thinking that they were the best, but now I'm not so sure. I can only assume the filter I was using (HP-1002) had a faulty anti drain back valve.

The car has always taken a little time to build up oil pressure (can seem like an age, but really only a few seconds), when it hasn't been run for a while and I have taken that for the norm. So it begs the question are K&N anti drain back valves up to the job?

After reading a few threads from this forum, I decided to fit a MANN W916/1 filter and the difference has been amazing. I now have instant oil pressure after the car has stood for a week! Not only are the MANN filters cheaper, they seem to work much better too.

Andy
Andy Robinson

I use Mann 916/1 by choice as well, because of their reputation. However whilst over night the pressure rise is instant, after a week or more it takes a second or so. I've used Unipart, Volvo, Champion, Halfords, K&N Gold as well as Mann over 26 years of annual oil and filter changes and only found relatively small differences between them - except in price! Up to £15 for the K&N, which was double the price of the Volvo, which was double the price of the Halfords/Champion. The Mann is really good value at about £3, and can be ordered from Halfords at the moment. Insist on Mann, the last time I got one Mann and one something else which was one of the many 'plug compatible' makes, but I insisted they supply what I had ordered.
paulh4

Hi Andy, can you see the anti drain device if you look at the olf filter? usually a rubber ring which acts as a one way valve.
Peter
Peter Burgess Tuning

Hi Peter, yes it did have a rubber ring at the bottom of the filter (red I think), but it has now been binned and recycled. Obviously this one didn't work too well. As I said above, I have used K&N for quite a few years now, but have always had a delay in building oil pressure, the MANN filter appears to be much better for oil pressure response. The two filters are no different in height, but do differ in circumference.

Andy
Andy Robinson

Interesting observation Andy, I will file it away for future recommendations when choosing oil filter!
Peter
Peter Burgess Tuning

I can also recommend the Mann filters from when I had 1800's. In fact i still use them for my V8's, even though the anti drain down valve is not essential, on the grounds that if Mann can take the trouble to get that right, they probably also do the filtration right too.
Allan Reeling

I had exactly the same problem with a K&N oil filter,if parked up for a week or two slow to gain oil pressure, switched to a Mann almost instant oil pressure,
Andy Tilney

There are two parts to anti drain-back with the inverted filter - one is the rubber ring inside the filter and the other is the tube that is part of the filter adapter that projects up inside the filter. This about 2" long, and you can get some shorter filters that screw down onto the end of that tube and block the oil flow altogether! The Volvo filters I have used are shorter than the others, but still had enough clearance at 2.57". The internal space on the other filters I mentioned ranges from 2.785" on the Champion to 3.02" on the Unipart GFE422/121, with the Mann 916/1 at 2.93". The shorter Mann 917/1 is also OK at 2.75".
paulh4

Never had any problem with the Unipart GFE422 - never use anything else.
Chris at Octarine Services

Agree on choice of Unipart filter, Chris. And were very affordable from my local Unipart outlet until Unipart (or that part of same) went under. It then became a Europarts outlet, funnily enough where I bought a Mann filter (but not quite so affordably)!
net.com

I worked in the Parts Division of Volvo Cars of N.A., from 1975-1982. The Volvo oil filter at that time was part nbr. 3517857- (forgot the check digit after the -). Volvo replacement filtration products at that time were made by Wix, Inc.

Wix marketed their own brand also, and I would venture a guess there were other filter companies that used Wix manufactured products with their logo printed in the boxes as Volvo did.

I use the NAPA 1068 oil filter in my 79-B. I doubt if NAPA has a manufacturing facility for oil filters.

On the topic of anti drain valves, I can understand the concern on an inverted and side mounted filter application but not on top filling filters. Is there a concern with the top filler filter?

Cheers

Gary
79 MGB
gary hansen

Another little thing to look for when selecting your oil filter - is to look inside through the centre hole and make sure the filter you have decided on has a blowoff / bypass valve in it
If you are doing any fast / angry driving it pays to have a filter with a blowoff, specially if the filter is a bit smaller or finer than original or you don't get a chance to get the oil nice and hot before your run
Or your oil cooler is too efficient
Ask me how I know-----------
I ran a smaller filter on my B series powered midget and ruined a crank finding out the hard way
And as Paul mentioned above, make sure you have good clearance between the end of the standup pipe and the inside end of the filter----- 10mm plus I would reckon is what's needed there for proper flow

willy
William Revit

The Volvo filter I used to use was 3517857-3. I thought it was made by Mann, but in any case it was quite a bit shorter than any of the others which was one of the reasons I stopped using it.

"blowoff / bypass valve in it"

Exactly. Without one cold starts can blow holes in the filtration medium, and then you effectively have no filter, like here https://www.youtube.com/watch?v=tqsn7CH0a8Q
paulh4

The better can filters these days have a silicone rubber anti-drainback "valve" which is really just a flapper sort of affair. Even then it is just asking for trouble when your spin on filter is inverted, or, with the threaded part down. With such a backwards setup I would re-locate the filter somewhere else completely, to allow for a bigger filter in the summer, and one oriented the proper way. Fill with oil when installing new prior to screwing it on and you will always have immediate oil flow on start up.
S Cole

The V8 has a hanging filter and pressure rise is a lot slower than inverted on an MGB. There's a lot of unnecessary worry about oil pressure and engine wear. Bearings remain slathered in oil for days after a hot switch-off. The shells on my V8 had done pretty-well 100k and were still at or just inside the tolerance for new shells.
paulh4

Thing to remember Paul is that most oil additives are still inert at startup temp's and remain so until good and hot. Quicker startup oil pressure in any engine is better than slower. Only multi-grade oils remain on engine surfaces days and weeks after shut-down, while single weight does not. "Slathered" is an over statement, but yes an engine will run for hours even with all the oil drained out of the sump.
S Cole

""Slathered" is an over statement"

Not when I removed the shells after standing for three days following a 'fully up to temp' switch off it isn't!

And who uses single-weight?
paulh4

Maybe you should have used single weight? Change the oil now and then and the bearings should last longer on those V8's. Oil sheer in multi weight oil is real. If you insist on 100,000 mile oil change interval's you should try some single weight.
Confused about "slathered" as bearing clearances are not quite a gaping gap. ie only a small amount of oil in between there. Shut down hot and oil is thinner and more will drip off than if shut down just warm.
S Cole

"100,000 mile intervals??" Paul isn't talking about oil change intervals, rather the appearance of his shells after that mileage. He, I would assume, like most of us with Rover/Buick V8's, change oil at 3-4 thousand mile intervals.
Allan Reeling

There is a difference in the quality of oil filters. I too use NAPA/WIX filters as they have been OEM along with MANN for Volvo. I found that the Volvo B20, B21 and B200 engines would knock unless OEM filters were used. Fram and Baldwin filters elicited a momentary rod knock upon start up but with OEM filters, this was no longer an issue on the Volvos. On the B, the WIX/NAPA 1068 filters have prevented rod knock from drainback.

My last batch of NAPA 1068 filters has had threading problems. The filters from the previous purchase thread on perfectly but the aluminum base on the B is particularly sensitive to filter thread integrity. Apparently WIX has not been rolling or checking its threads consistently.

I don't have a source for Unipart filters in the U.S. but used them without incident on the Midget when it was new and the filters could be purchased from the dealer.
Glenn Mallory

" rather the appearance of his shells after that mileage."

Correct, typically 3k oil change interval. Two occasions the crankcase gasket had been removed the innards were golden brown. Given the clearance of the bearings, and the fact that both shells and journals were fully coated with oil after standing three days from switch-off fully hot, that counts as 'slathered' in my book.

And I still don't see why I, or anyone, should use use a single-weight oil for every-day running. Running-in maybe.
paulh4

""And I still don't see why I, or anyone, should use use a single-weight oil for every-day running. Running-in maybe""

As I stated above a single weight would be good for some dope who never changes the oil.

Multi weight is to allow good oil flow on startup, while "slathering" in oil the bearing interfaces at running temps. If you have an engine with close bearing tolerances you need a less thick oil than one with larger tolerances. 20 weight oil is good for starting (thin enough) to easily accomodate down to 35F. 30 weight good down to 40F. So if you have a "tight" tolerance engine and you told to use 20 weight (for instance) and you live in a place where the garage is heated, no need to use 20W20 just use straight 20 weight.

You could use 0w20 or something like that and run the risk of not properly "slathering" bearings etc in thick enough oil to lubricate properly at startup/warmup.
S Cole

S Cole- says

", but yes an engine will run for hours even with all the oil drained out of the sump"



William Revit

"As I stated above a single weight would be good for some dope who never changes the oil. "

So which dope would that be, then?
paulh4

There should really be some way of doing age identification for sites like this. All the 10 year olds cutting school and pretending putting the chain back on their schwinn bike makes them knowledgeable about cars is not entertaining. Or are there really adult people so stupid as william and paul?
S Cole

Well, it would seem that we're all that stupid, according to your judgement. RAY
rjm RAY

Who cares what you think rjmray? Try taking your tongue out of the gutter and learning something new you little creep.
S Cole

Pathetic.
paulh4

Very. RAY
rjm RAY

This thread was discussed between 22/11/2016 and 30/12/2016

MG MGB Technical index

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