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E93A Engine Oil pressure
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AlexMG



Joined: 30 Oct 2012
Posts: 13

PostPosted: Tue Oct 30, 2012 11:48 am    Post subject: E93A Engine Oil pressure Reply with quote

Hi. new to any forums and hope someone can help me in this restoration. I am restoring a 1933 MGJ2 with a Ford E93A engine installed. I have had this vehicle stored for the last 40 years and now restoringand replacing items. Now the engine runs although not smoothly at low revs however oil is spitting out of the dipstick pipe, and pooring out of the 'breather' hole at the back of the sump casing when running. I have put in a 20W50 oil. The pressure guage reads around 30psi. Is this because the oil pressure is too high, a blocked pipe, or the oil is too viscus. What are my options. Thinner oil, flushing the engine or takinf the sump off and cleaning. Your help anyone?
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colwyn500



Joined: 21 Oct 2012
Posts: 1745
Location: Nairn, Scotland

PostPosted: Tue Oct 30, 2012 12:25 pm    Post subject: Reply with quote

Piston rings stuck or broken?
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Rick
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Joined: 27 Apr 2005
Posts: 22429
Location: UK

PostPosted: Tue Oct 30, 2012 2:13 pm    Post subject: Reply with quote

Welcome to the forum.

According to the factory manual, the non-adjustable oil pressure relief valve kicks in at ~ 30psi, the recommended pressure quoted in the same book. It mentions that a copper gasket of the correct thickness should be fitted between the cover nut and the cylinder block face, incorrect thickness will affect the blow-off pressure.

20/50 should be fine, I always used that in my E83W pickup. It does sound like the crankcase is pressurising.

RJ
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AlexMG



Joined: 30 Oct 2012
Posts: 13

PostPosted: Tue Oct 30, 2012 4:23 pm    Post subject: Reply with quote

Thanks guys. Wow this is quick. Piston rings see OK although I have not taken the pistons out. Did have the head off though for regrind of the valves. So this is due to the crankcase pressure and the relief valve kicking in. But why?
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colwyn500



Joined: 21 Oct 2012
Posts: 1745
Location: Nairn, Scotland

PostPosted: Tue Oct 30, 2012 5:54 pm    Post subject: Reply with quote

AlexMG wrote:
Thanks guys. Wow this is quick. Piston rings see OK although I have not taken the pistons out. Did have the head off though for regrind of the valves. So this is due to the crankcase pressure and the relief valve kicking in. But why?


The problem is that without removing pistons it is impossible to know the state of the pistons or rings which could be stuck in their grooves. The valve guides, if really worn, could conceivably give these symptoms.

I think that after 40 years out of use it would be wise not to assume anything about the state of the engine. From what Rick says, the valve being not adjustable is actually doing its job and keeping pressure below 30 pounds. I doubt that that sort of pressure, which is similar to what is expected on my 1935 Austin 10, would give the symptoms you describe.

Perhaps you could test the compression on each cylinder to be sure that they are all good and reasonably similar to each other.

I am not saying that the oil itself isn't the problem; it just seems unlikely. the engine will have been designed to run on an oil which at starting temperature at least, would be "thicker" than 20-50. Any surplus pressure would normally be released back into the sump and shouldn't manifest as a spray or by pressurising the crankcase.
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exbmc



Joined: 18 Jun 2009
Posts: 236
Location: Derby East Midlands

PostPosted: Tue Oct 30, 2012 8:18 pm    Post subject: oil spray Reply with quote

According to the old handbook i have, the recommended oil when the engine was new, was monograde 20, or 20w/20, so 20w/50 should be fine. You have excess crankcase pressure. If i recall correctly, and it's many years since i worked on one, the oil filler cap is the main breather. If this has become dried up and rusted while standing, it may be the cause, of pressure finding it's way out through the dipstick tube etc. If it's not a breather cap, then you need to identify the crankcase breather, and ensure it is clear. On the 100E type side valves,i think there was some sort of breather pipe low down under the manifolds.Yours may be similar? If you can confirm the crankcase breather(s) are clear, then i am afraid you are back to piston rings being stuck or broken, allowing combustion pressure past the piston into the crankcase.
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V8 Nutter



Joined: 27 Aug 2012
Posts: 587

PostPosted: Tue Oct 30, 2012 9:15 pm    Post subject: Reply with quote

I would suggest seized rings. Try removing the plugs and filling the bores with something like Red Ex. Leave it to stand for a few days it may free the rings off.Be sure to turn the engine over to blow out excess fluid before re-fitting the plugs. An alternative is to dribble Red Ex straight down the carb with the engine on fast idle, but be prepared for lots of smoke
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AlexMG



Joined: 30 Oct 2012
Posts: 13

PostPosted: Tue Oct 30, 2012 9:37 pm    Post subject: Reply with quote

These are great responses. Much appreciated. On the strength of this I have ordered a compression tester. Should be here Friday so will test over the weekend. If the compressions differ will try the RedEx idea. Anyone know what the compression should be? Does this also explain the loss of oil through the hole at the rear bottom of the sump (crank case cover).
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Rick
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PostPosted: Tue Oct 30, 2012 10:40 pm    Post subject: Reply with quote

I'd have thought if the compressions were comparable with each other, and in the 90-100psi range, you'd be ok. Wild variations, or significantly less than say 70 on any one pot would lead to more investigation being required I think.

RJ
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exbmc



Joined: 18 Jun 2009
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Location: Derby East Midlands

PostPosted: Wed Oct 31, 2012 8:41 pm    Post subject: compressions Reply with quote

Have the engine warm for compression checks, and throttle wide open during cranking. Note the results, then do them again, but before cranking, put a few squirts of engine oil in each plug hole in turn. Compare the results, and if the oiled compressions are higher, this indicates ring problems being temporarily improved by the sealing effect of the oil.
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AlexMG



Joined: 30 Oct 2012
Posts: 13

PostPosted: Fri Nov 02, 2012 4:16 pm    Post subject: Reply with quote

Compression tester arrived today so had to try it. Did as suggested and didn't get any reading on any pot. Am I using the tester incorrectly or is it faulty? Anyway chucked some redex into the carb and used an oil flush. The oil pressure now sustained at 25psi and NO loss of oil from the hole in the crankcase. Maybe the fault has been cured and the pressure tester is faulty! Anyway will keep an eye on it all.
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colwyn500



Joined: 21 Oct 2012
Posts: 1745
Location: Nairn, Scotland

PostPosted: Fri Nov 02, 2012 6:03 pm    Post subject: Reply with quote

AlexMG wrote:
Compression tester arrived today so had to try it. Did as suggested and didn't get any reading on any pot. Am I using the tester incorrectly or is it faulty? Anyway chucked some redex into the carb and used an oil flush. The oil pressure now sustained at 25psi and NO loss of oil from the hole in the crankcase. Maybe the fault has been cured and the pressure tester is faulty! Anyway will keep an eye on it all.


I think there must have to be some pressure or the engine couldn't run. Presuming you mean that you have drained then flushed and replaced with different oil, I have noticed that the warmed-up pressure can change with different oils.

If the problem is sorted now you just need to hope it doesn't recur. Try to get some use out of it so that things get a chance to settle down.
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Bitumen Boy



Joined: 26 Jan 2012
Posts: 1733
Location: Above the snow line in old Monmouthshire

PostPosted: Sun Nov 04, 2012 2:56 am    Post subject: Reply with quote

Sounds like the compression tester must be faulty - they're pretty well self explanatory in use and if it's running there must be some compression. Refund time, methinks Very Happy
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AlexMG



Joined: 30 Oct 2012
Posts: 13

PostPosted: Tue Nov 06, 2012 4:46 pm    Post subject: Reply with quote

Recieved replacement pressure tester today and still NO measured pressure in any of the pots. When testing does one turn the engine over on the starter motor or under power of three cylinders. To date I have inly turned engine over on the starter. Alternatively will have to see if there is any power in the engine under load. Failing all this I will have to take engine out and rebuild. Stilll there is a long winter commuing up.
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Rick
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Joined: 27 Apr 2005
Posts: 22429
Location: UK

PostPosted: Tue Nov 06, 2012 5:21 pm    Post subject: Reply with quote

AlexMG wrote:
Recieved replacement pressure tester today and still NO measured pressure in any of the pots. When testing does one turn the engine over on the starter motor or under power of three cylinders. To date I have inly turned engine over on the starter. Alternatively will have to see if there is any power in the engine under load. Failing all this I will have to take engine out and rebuild. Stilll there is a long winter commuing up.


Hi, remove all the spark plugs, put the tester in one cylinder's plug hole and spin it over on the starter for a few seconds, with the throttle open. As already mentioned, ideally do it with the engine warmed up, you should get *some* reading, even if quite low, if the engine is a runner.

RJ
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