Classic cars forum & vehicle restoration.

[daglocks]

Hi
I am restoring a Rochdale GT with an E93A engine. I just got it running for the first time in 50 years. The oil pressure reads 140 psi, rising off the clock, so I assume i have a problem and the seals will "Pop" excuse the pun.
The oil relief valve is adjustable, could this be the problem, if so, how do you set it?
Cheers
Andrew

[peter scott]

Hi Andrew,

Welcome to the forum.

I don't think the pressure relief valve is adjustable but it sounds like it is stuck closed. The pressure should be 30 psi. It's located on the top at the front of the engine.

Peter
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

[daglocks]

Hi Peter
it looks like the standard item he's been removed, and an adjustable valve fitted.
It has a slotted head and a locking nut on top of the standard size body.
Regards
Andrew

[daglocks]

Hi Peter
it looks like the standard item he's been removed, and an adjustable valve fitted.
It has a slotted head and a locking nut on top of the standard size body.
Regards
Andrew

[ka]

140psi is stunning, but I think there are two factors adrift here. I think your pressure gauge is a bit 'optimistic', and the release valve is stuck. Look next to the oil filler spout and when removed there will be the nut, a spring, the plunger with an unusual washer on the plunger. For me, do not use any device limiting the movement of the plunger, I have seen the big nut tapped and a screw/locknut assembly fitted to stop the movement of the plunger, but why? Anything over 30-40psi will blow not just the front string seal, but more importantly the gasket between the gallery and the valve chest, which is a guaranteed way of ruining your engine.
Check the plunger moves freely on the spring, it is not gummed into the block, and refit a standard nut. The standard spring length is around 40mm, but I will measure my spare if you require an exact length. New ones were available via small ford, if you feel you need more pressure, stretch the spring slightly, this will make a small difference to oil pressure when cold, but not when hot. The absolutely critical thing is oil pressure when running. The M6 signaled the end of white metal bearings due to the combined affect of speed and engine temperature that reduced oil pressure to next to nothing, melting the white metal in situ. When the engine is hot, and if you choose to either push it on back roads/track, or go for a run to the Lake District, keep an eye on the oil pressure, and adjust your speed to suit.
There are multiple ways to keep oil pressure if you lose it when the engine is hot, the camshaft journals, particularly the centre one, will be worn, and of course big ends and mains. Best way to keep decent oil pressure for the longer term (remember when Ford knocked the engines together, they were designed for around 30,000 miles, then swop for a recon. unit, there are hundreds of blocks with the RC stamped on them) is to do as much additional work as you can along the following lines.
1) Always use a good oil, preferably 20/50, and change it regularly. Not all oil is the same, there is a section in the standards that the oils are made to, that show the oil has 'shear' capability to resist the incredibly high pressures exerted between the cam and follower. I will put a follow up with this standard to look for.
2) Use an oil filter, the E93 standard oil filter gauze is just not good enough. Try fitting the 100e filter arrangement, or even better use the by-pass system detailed in the 'Cooper' book.
3) fit an oil cooler in tandem with the filter,
4) try upgrading the oil pump, the 100e pump rotors are a third longer which will give more flow, the easiest way is to use the readily available adaption from small-ford, they use the standard pump, with the longer 100e rotors and a sandwich plate at the bottom of the pump, all will fit inside the metal sleeve.
5) if nothing else, use a small magnet fitted into the sump plug!

Best of luck!
_________________
KA

Better three than four.

[daglocks]

I just found the answer to this problem, the car has an Aquaplane high capacity oil pump and adjuster.
The instruction sheet says to adjust the pressure to 100psi, then reset it to 60/70 psi at 4000rpm. when cold, this means the pressure may rise to 120 PSI!

the Answer was in the cars history file all along!


regards
Andrew

[ka]

My original advice stands, anything more than 40psi will blow out seals, and end up with more oil outside the engine, than in it.
_________________
KA

Better three than four.

[alapimba]

can you post photos of that relief valve?
i have a friend with a 100e and he don't have oil pressure when hot.

Regards

[daglocks]

If you look at img_2122 in this photo set:

https://www.flickr.com/photos/22719913@N04/sets/72157641153018995/

It is shown to the left of the oil filler funnel. You may have to zoom in.

However, your problem won't be solved by adjusting the oil bypass pressure, probably the engine is knackered!, if it smokes, then its the valve guides or piston rings, if knocks, then the main/big end bearings.
Hope you get to the bottom of it
regards
Andrew

[alapimba]

ok i saw it. i thought on the 100E engine was the same but theres no valve in that place.

the things that you mentioned all were replaced on his engine. valve guides, piston rings, main/big end bearings and oil pump, oil valve..
with all that done he still has a pressure of about 5 when hot and the light goes on...
no ideas anymore on what should be checked

[daglocks]

If the light comes on there is a serious mechanical wear issue somewhere unless oil is pouring out from engine.
did he use the cheapest 20/50 oil he could find in it?
Modern oil gets too thin.
I buy mine from Lidl when available, or the cheapest 20/50 I can get.
Regards
Andrew

[ka]

There are again two ways to look at this.
5 psi at tick over is not fatal, but it depends on the engine, some engines were designed to have low pressure at tick over, and only 30-40 psi when hot, any pressure at tick over could be enough to lube the bearings, and prevent oil wash where the excessive oil pressure just flows through.
White metal is particularly sensitive to low pressure, that is why they all died when the M6/M1 opened, but whilst 5psi is far from ideal, some engines have oil warning lights that operated at 2psi, so their manufacturers were even less optimistic.
The critical bit is the oil pressure when the engine is under load, 5 psi at 2000rpm will destroy the bearings as the engine will be under load, and the pressure is not adequate to provide the oil film required to keep the surfaces apart.
I would suggest you strip the engine, and check everything for wear, but before you do this, check the relief valve is not sticking open, and remove the side cover to the valve chest and ensure the gasket has not blown between the oil gallery and the valve area, any leak here will allow the oil to bypass and give poor pressure.
I am also intrigued as to your use of an oil warning light, where is the sensor plumbed in? The standard drilling for the e93 was just behind the timing chain bulge, but the 100e side cover had a threaded drilling in the cover itself. Before you do anything too radical, it would be worth checking pressure with a quality pressure gauge, and then start looking.
Best of luck, keep us informed how it is going.
_________________
KA

Better three than four.

[alapimba]

hello

the 100E don't have any relieve valve.. so that point seems out of question (unless the valve is on the pump but the oil pump is new).

I was wondering if it's possible to loose pression trhought the valve tappets?

[Old Wrench]

A few thoughts on this.

In the days when the E93A was designed (1938) it was a direct successor to the earlier sidevalve "flathead" Fords going back to the Y Type.

Machining tolerances in those days were basic. To say the least!

Babbitt (White Metal) bearings were designed to be sacrificial and were the direct descendent of splash feed crankshafts, which enjoyed little "paddles" to scoop up oil from the sump and splash it over the working parts. The main difference being the oil galleries drilled in the crankshaft to actually feed oil direct; under pressure.

Oil too then was simple: one lighter grade for Winter and a heavier grade for Summer.

Oil serves two disparate purposes in an engine: it lubricates the bearing and conducts away heat.

With modern "thinwall" bearings (i.e. Shells; hat tip to Tony Vandervall and others), the fit up is much more precise; and to retain bearing condition the aim is to maintain a thin oil "Cushion" on which the component actually bears. Modern developments in lubricating oils were revolutionised by what are called "Long Chain Molecules" or Polymers.

The addition of polymers to lubricating oil, prevents the oil cushion from being squeezed out.

However, Babbitt bearings were made by melting the white metal into the big end (con rod and cap) and the main (and cap) and then hand reaming using Engineers Blue when the crank was loosely fitted up, to show "High Spots".

(P.S. I still have my set of Moore and Wright scrapers and no I won't do any!! ).

Babbitt bearings relied on an oil "flood", rather than an oil cushion.

Thus volume tends to be more critical than pressure. Flow and pressure are directly proportional to each other. However, flow (volume) much more critical than pressure.

At a guess probably 40 PSI is about correct.

Some useful stuff here for you?

https://www.smallfordspares.co.uk/categories/small-ford-spares-engine-oil-and-sump?vehicle=prefect-model-e93a-1939

[alapimba]

my friend is now running his engine with sae 30.

When the engine is cold on the road the oil stays betwen 15/20lbs, when hot on the road ( 80/90 km's/h) he have 10/15 lbs.

When hot at idle the pressure is 3/4 lbs, is that ok? with 3/4 lbs if i accelerate then the oil pressure goes to 9/10 lbs...

What do you think about this?

if this is too low, Can it be in the parts that link oil pump/camshaft/distributor?
The parts at the right side of the diagram:
http://www.smallfordspares.co.uk/plates/32-100e-engine-interior

Can it be the valve tappets?
He is so tired of the car! Everything else was replaced. pistons bearings oil pump...