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MG MGB Technical - no oil pressure yet

I had an 1800 rebuilt by a very competent machine shop with lots of mg experience. I have left the oil pressure guage unconnected at the guage. I have an oil cooler on it and an upright oil filter adapter with a tall fram oil filter. So far I've added 4 qts of castrol 10w-50.

As I crank it over with the plugs out, I'm not getting any oil out of the end of the oil pressure tube at the guage. I expected it to squirt out. Now, it's only 18 degrees f in my garage and she cranks pretty slow which I think is compounded by the fact that the engine is new and tight.

I didn't put vasoline or anything else in the oil pump b4 assy. I have probably cranked it over of about 2 minutes total, probably about 30 seconds at one time.

What should I be doing to be sure I have oil pressure? Is this normal for a new engine?


fritz
Fred Horstmeyer

Fred - You don't say which 1800 engine, but if it is a later, 5 main bearing engine, you may have gotten the wrong oil pump gasket on it (one for the earlier engines). I made that mistake when assembling my 18V enging and could not get any oil pressure. Changing out the gasket resulted in almost instant oil pressure. Good luck - Dave
David DuBois

Fred

david is correct but before you take the sump off, try priming the galleries and oil pump

next to the pressure gauge take off is a large bolt head (if you have no oil cooler) or the oil cooler feed if you have a cooler.Disconnect this and squirt with an oil can into the hole.It will probably take about 1/2 pint over a period, thus filling the gallery and from that the oil pump

Some people advocate turning the engine over backwards whilst doint this to create suction , but I have never bothered

replace all you have disconnected and try again with plugs out, say 15 secs at a time - in normal climate conditions you should get pressure within about 30- 40 secs of cranking, but in extreme cold it may take longer

Chris
chris

I filled the oil cooler and both lines with hot oil. I poured hot oil down the rear block oil fitting. She's cranking pretty slow now, so I'm off to gregs' place to fetch his booster. (drat, now I'll probably have to return his welder)

Thanks for the replies. I'll report back later.
Fred Horstmeyer

Fred-
Here's the complete drill for those starting a freshly rebuilt engine for the first time:

Pour a tablespoon of oil down the pushrod wells to lubricate the tappets and another tablespoon of oil into each spark plug hole to lubricate the rings, then oil the rocker arms and valve stems. Next, pour oil into the oil pressure hose connection port on the block. This will fill the main oil gallery and supply oil to the main bearings. You may need to try priming the engine closer to the oil pump. Disconnect the large external oil line at the back corner of the block, fill the port in the block with oil, and then rotate the engine backwards to draw the oil backwards 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. Now you may reconnect the electrical power to the fuel pump and start the engine. At this point it is critical that the camshaft and its tappets be properly bedded in to avoid ruining them. Hold the idle of the engine at 2,500 RPM for twenty minutes, occasionally varying engine speed gently between 2,000 and 2,700 RPM. After this process is completed, change the oil and the engine will be ready to be broken in on the road. Drive for 100 miles and change both the oil and the oil filter again, then again at 500 miles to bed in the new cam and lifters, then let it cool and then retorque the head using the proper sequence pattern. You will find some nuts almost tight, some can take almost a quarter turn. Run the car for 100 miles and retorque the head again. You'll find that this time the studs have not lost quite as much torque. Run an additional 400 miles (or 500 total on new engine) and retorque. During this period do not exceed 4,000 RPM or 45 MPH, operate the engine at full throttle, or allow the engine to labor in any gear. Until the next 500 miles (1,000 miles total) has been completed, limit engine speeds to around 4,500 RPM when shifting gears. Cruising on the highway should be limited to no more than 3,500 RPM. Keep
varying the throttle opening and engine speed. The secret is to constantly vary the speed and load without creating excess heat through full throttle laboring and high engine speed operation. After 1,000 miles of following this procedure, change the oil and oil filter and refill the sump with a quality oil such as Castrol 20W/50. After another 1,000 miles the engine will be properly broken in and ready for service.
Steve S.

OIL OIL it's OIL!! The battery booster did it, along with all the other stuff.

Boy, once the oil started flowing out the oil guage hose, it really started turning over faster. I know the mechanic used assy lube, but the instant I had pressure, it cranked much easier.

thanks to all
Fred Horstmeyer

Steve - at the rate I've been driving it will take me three years to break in my engine!!
Bud G

Bud-
MGs are meant to be driven. Put down that polishing cloth, get behind the wheel, and enjoy!
Steve S.

This thread was discussed on 17/01/2003

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