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MG MGB Technical - OIl bsystem srart up

The adventure continues.....OK, I turned over the engine on the abandoned project today! Hooray! I could not cause the oil pressure guage to budge using the starter motor. Is there a proceedure to fill the oil system without the starter motor? Thie engine has an oil cooler, its hoses and the oil filter to fill. Thanks Tom
Thomas McNamara

Thomas,

i know this from the competition pump in my B only.
Here is the procedure that worked for me:

1. Take off the hose from the oil cooler that runs to the rear of the engine and the hose at the filter housing.
2. With a pump type oil can the cooler is filled, as well as the long hose to the rear of the engine.
3. The long hose must be reconected to the cooler and the one to the filter should be fixed as high as possible for the time of bleeding the pump.
5. With the plugs screwed out take a piece of tube with a fitting and screw it to the oil filter adapter.
6. inset a funnel to this pipe and fill it up with oil.
7. Turn the engine counter clock wise until oil is pumped out of the short (open) line of the cooler (3.).
8. Refit the short hose from the cooler to the oil pump base.
9. Crank the engine by the starter and there should be presure within +/- 20 sec.
10. check the oil level in the sump and correct it as necessary.

Hope this helps

Ralph


Ralph

Thomas,

Did you have the oil pump off of this engine? If so, are you aware of the two different oil pump gaskets involved? If you use the old style (3-main bearing) on the newer engine the oil pressure will be very slow coming, and some have said it will never make any. I had to learn this on the hard way.

Charley
C R Huff

Tom-
It is essential to prime the oil pump. Failure to do this will result in all of your handiwork being destroyed due to a lack of oil flow and oil pressure. Install a magnetic oil sump plug (Moss Motors Part # 328-282) and fill the sump. Next, pour oil down the vertical tube of the oil filter stand in order to fill the high-pressure oil gallery and supply oil to the main bearings, then install the oil filter. Finally, if your engine is not equipped with an oil cooler, disconnect the large external oil line that goes to the back corner of the block at the oil filter stand and pour oil into it in order to supply oil to the oil pump. If the engine is equipped with an oil cooler, before installing the oil filter, disconnect the large external oil line that goes to the back corner of the block from the oil cooler and, holding it above the height of the cylinder head, pour oil into it in order to supply oil to the oil pump, then reattach it to the oil cooler and pour oil down the aperture in the oil filter stand in order to fill the oil cooler as well as down the tube of the oil filter stand in order to supply oil to the main bearings, then install the oil filter. Pour a tablespoon of oil down the pushrod passages in order to lubricate the tappets and another tablespoon of oil into each spark plug hole in order to lubricate both the pistons and the rings, and then oil the valve stems. Remove the threaded plug in the forward end of the rocker shaft, and then tilt the engine so that the threaded end of the rocker shaft is higher than its opposite end. Pour oil into the rocker shaft in order to lubricate the bushings of rocker arms and allow time for the oil to run down through the oil passage in both the rear rocker shaft pedestal and cylinder head casting to the bushing at the rear end of the camshaft (Now you know why the engineers decided to have a threaded plug instead of a press-fitted plug as at the other end of the rocker shaft). Replace the threaded plug into the forward end of the rocker shaft, then level the engine. Rotate the engine backwards (counterclockwise / anticlockwise) in order to draw the oil into the oil pump. Once the pump is primed, disconnect the power supply to the fuel pump and turn the engine until your oil pressure gauge gives a reading. The oil cannot drain out of the pump once it is primed because the oil pump draws oil from the sump into the top of the pump and also pumps it out of the top on the other side of the rotor.
Upon first turning over the engine, observe to see if all of the pushrods are rotating. If one or more of the pushrods are not rotating, then the tappets in which they are seated are not spinning in their bores and must be freed or both the tappet and the camshaft lobes will quickly be ruined. This may be corrected by switching tappets into alternate bores. Now you may install the rocker arm cover and its gasket, reconnect the electrical power to the fuel pump, and then start the engine.
Steve S.

Hi Charley

Your comment on 3 and 5 bearing oil pump gaskets is interesting. I've recently dropped the sump to check the oil pump is OK on my 2000 cc 5 bearing engine ('professional' rebuild last year/4000 miles ago - Moss/Ivor Searle supplied engine). I'm 95% sure the correct gasket was fitted, looking at diagrams in the parts book.

The reason for the inspection is that my oil pressure rises slowly on starting from cold (5-10 secs? to reach 40-50 psi)and then struggles to reach 60 psi until the engine is up to normal temperature/2-5 miles on clear roads. I've checked the oil pressure relief valve in case that was sticking open. There were some slight score marks on the plunger/thimble which I've carefully sanded off; and packed out the spring with a couple of washers inside the thimble. (I don't want to fit a higher pressure spring because if I'm getting 60 psi with normal running, that's enough?)

This work has made no difference, even with trying some 10W-40 semi synthetic oil which my son's very experienced 'A' series race engine builder suggested.

Hopefully, this is not a serious problem. Tickover pressure warm/hot is fine at 40-50 psi.

P W L STAIT

Charley, can't help you other than to say that my oil pressure gets to 40 psi within 2 to 3 seconds, but then behaves exactly like yours. It takes 2 or 3 miles before the pressure reaches 60 psi. My engine has not been rebuilt so maybe it is just the way it is.

I, and Charley no doubt, would appreciate any comments on this behaviour.

Tony
Tony Oliver

On 20/50 my car takes about 1 second to register oil pressure (seems like longer when you are watching the dial :-) ) It idles at about 40 lbs and only comes up to 60 PSI when it is warm and you start to get over 2000 RPM. I have no idea what it would show at over 2000 rpm before the water comes up to temp as I never use more than a very light throttle opening and moderate RPM before it is warmed up. It holds that pressure all day regardless of traffic and outside air temp. On semi synthetic it used to register pressure instantly. Hope this helps.
Stan Best

My 73 roadster takes 2 or 3 secs to show oil pressure if left overnight, considerably more if not used for a couple of weeks (see below). It goes straight up to idle cold at 60, runs at 60, and only idles at 40 when fully warm. On a very warm day, if stuck in traffic for a long time, it will gradually come down to about 30. They are all different, as long as you stay within the Workshop manual figures of 50 to 80 hot running and 10 to 25 hot idle you should be fine. Remember the gauge can vary, as well as well as the pump, relief valve and bearings in the engine.

Over the years I've been doing some one-off comparisons of oil filters. For years I used Champion and Halfords and never had cause for concern, although I never noticed how long it took to get pressure either. Then I started seeing adverts from a well known club for Unipart GFE121F filters with an 'improved' anti drain-back valve which are actually Fram PH2857A. I bought some, and immediately noticed these were taking much longer to get pressure, so much so that I wouldn't use them on the roadster anymore but kept them for the V8 with its hanging filter. Whilst this oil filter survey http://people.msoe.edu/~yoderw/oilfilterstudy/oilfilterstudy.html does say that *some* Fram filter types are good, it indicates this type is pretty poor. Then I started reading about Volvo/Mann filters as having good valves, so tried one of those last year and it was much better, albeit at twice the price of the Champion etc. from Halfords. Even after a year it only took 2 or 3 secs to get oil pressure after 2 weeks standing. I've also read about K&N Gold filters and after much digging found out which one and where I could get them in the UK. They are difficult to find, twice the price of the Volvo, but no better than the Fram! I'll be sticking to the Volvo filter in future - 3517857-3 or Mann W917 widely used in Volvos over many years and so readily available.
Paul Hunt

I got a new oil pump from Moss some time ago
and it was manufactured in of those Far East
places. Of course, this requires a bit of
double-checking.

Upon opening the pump, one of the ports had loose casting flash. When I checked the rotor-to-cover clearance it was BARELY
within specs.

A few minutes of fine-sanding the end of the pump
body on a flat steel surface brought the clearace to
spot-on new specifications.

Now when I fire up my car it immediately goes
to 60psi, and it drops to about 50-55psi on
especially hot days (using 10W-40).
Daniel Wong

Tony, Stan, Paul, Daniel

Many thanks for all your comments. Most reassuring. What a great website this is, especially for technical queries.

Paul
P W L STAIT

This thread was discussed between 18/05/2008 and 27/05/2008

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