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MG MGB Technical - 73-74 Hanging Oil Head Valve

I have got the 73-74 Hanging oil head on my 68 B's. It uses the smaller filter as on the midget.
The head has a ball-valve built into it and I assume it is for bypass if the pressure builds up too much in the filter for all the oil to get thru. Which means unfiltered oil is getting to the engine. When you push on the spring-loaded ball it doesn't have a lot of resistance. Is this all true or is this nothing to be concerned with. Both engines are new rebuilds so I want all the junk in the oil to be trapped. Any experience/opinions?
Sam Sullivan

Use a bigger filter! There are many that will fit. See the thread "IMPORTANT! Filtering oil, air, and morons" below." ***Do it now*** Who says it uses the "Midget" filter, and just what Midget filter are we talking about? The bypass valve is only supposed to deal with pressure drop across the element, which needs to be low. Most filters have a bypass built in, and the specs can be found with considerable difficulty from the filter manufacturers. Having two bypass reliefs is not a problem, but it will bypass at the lower of the two settings. Anti drain-back is not an issue with the pendant filter as it is with the uprights, but the presence of an anti drain-back valve won't hurt either.
FR Millmore

I have some information on that type filter adapter but I cannot get my response to post.

Clifton Gordon

When my 74 was purchased it had one of those filter heads on it.
According to Clausager sometime in Dec 73 an alternative oil filter of spin on type was introduced for Roadsters and GT's. See Clausager Page 148. In Feb 74. "Inverted oil filter re-introduced" So it was used for only about 3 months.

As for using a bigger filter there isn't enough space to install a bigger filter. A longer filter may fit.

Same as a Midget? Moss Midget plate;
Item 52 Filter 950-045 Filter cartridge spin on Crossland.
950-545. Filter cartridge spin on various brands.

Moss MGB plate
Item 76 950-045 Filter cartridge spin on Crossland
950-545 Filter cartridge spin on, various brands. Note "hanging down filter"

Purolator. 1974 - MG - Midget Mk III application L10028
Purolator 1974 - MG - MGB application L10028 Models with bottom mounted filter

I used the Purolator L10028 on my car from purchase in 1998 to 2006 and always had good oil pressure and no oil related problems.

The head does have a ball type bypass valve. The Purolator L10028 doesn't have a bypass valve.


Clifton Gordon

Well the Purolator link didn't work as I thought it would. If you look up a 74 Midget and a 74 MGB you will see that the L10028 is listed as the application for the Midget and 74 MGB with bottom filter.

Clifton Gordon

I'll bow to Clifton here; the hanging filters are indeed rare and it is sometimes difficult to recall how much clearance there was. By my old Fram catalog, the small filter PH966B fits some MGB to 79, but I sure never saw one that late like that, and that may be the reason for the standpipe/short filter debacle. I don't have Clausager, does he say anything about the earlier form of inverted filter - specifically, when did they get the standpipe?
FR Millmore

Thanks for the info. Just wanted to make sure all the oil was getting filtered. I change oil frequently so not too worried about the filter size. I use the Purolator L10028 and also the Napa gold that crosses over to that number.

Fletcher. I cannot find any information about the standpipe. Clausager engine changes they say in March 70 "New oil filter of cartridge type with inverted canister was introduced" They go on to memntion the model numbers and engiine serial numbers the change applied to. In the MGB Experience there was a thread a few days ago about K & N filters. In the K & N filter lookup they list a HP 1002 for 75 and later MGB. The 1002 is a small filter that fits many Toyota's including most Tacoma's
The HP 2004, a bigger filter is listed for earlier MGB's.

Clifton Gordon

Thanks, Clifton, as they say, now we're gettin' nowhere! I worked mostly in exclusively British shops before '69, except for a Volvo dealer stint, then not on cars till 72, when I opened my first shop, with lots of Britcars but more Volvo and mixed imports. So, I missed the constant MG experience in the transition period for the filters. I certainly recall the no standpipe ones, as it seemed really stupid to have the engine rattle before oil pressure, and as I said in the other thread, I built a standpipe. The pendant was a noted improvement, and when the inverted became standard over the pendant, I thought they were daft, but the standpipe had arrived. That must have been a result of the trouble with the no standpipe design, and likely the pendant variety was too. I never did figure out the order of these changes, but now think that the sequence must have gone this way, given Clausager's wording. The K&N listing sounds too much like the little one I found on the car with no oil pressure! Certainly there seems to be no reason for a break at '75. Such a break would make sense if there is confusion with the Midget transition from A series to Triumph engine.
FR Millmore

This thread was discussed between 21/03/2007 and 22/03/2007

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