Javelin engine oil pressure

[Moises]

This is what my Javelin engine sounds like when it's hot. Can you give me a diagnosis?

Engine hot.mp4

[Keith Clements]

There seems to be a high pitched noise that I suggest may be coming from the generator or possibly distributor. I cannot hear any low pitched noises at low revs, or tappet or timing chain or camshaft noises . What do you think you are hearing as reproduction of engine noise is usually not good?

[David Morris]

Hi Moises,

Thanks for the video. To me, she sounds like a typical Javelin, and so beautifully clean! A tribute to you! Perhaps a bit 'clatterly', but with Jowett's never fitting a timing chain tensioner, some clatter from the timing chain is to be expected.

Have you tried altering the camshaft endfloat with the adjustable peg in the front timing cover? This must NEVER be done with the engine running. I believe the correct adjustment is to screw the peg in with the engine off, then back it off by a quarter of a turn? But do check the maintenance manual before making the adjustment.

Also, I see that you have a petrol in-line filter fitted. I enjoy watching some of the US classic car revival YouTube videos. One recommendation they often make is to change your type of in-line filter to one of the plastic types. Apparently, although the chrome and glass ones look nicer, they can come undone with engine vibration and suddenly leak petrol, with dire results! Especially with your hot exhaust manifold just below!

All the best,

David

[PJGD]

I am preparing a technical article on the Jowett oil pump, and I need some first hand practical data.

What I need is to have someone record the oil pressure as read on a/the gauge at 500 rev/min increments. This should be taken with a warm/hot engine after a brisk run with an engine in reasonably good condition and perhaps with "straight" oil rather than a multi-viscosity oil if possible. This test can be run with the car stationary; just gradually increase the engine speed, holding it at each test point for the gauge to stabilize, from idle up to 5,000rpm if you are comfortable doing that.

Thanks

[Moises]

I am preparing a technical article on the Jowett oil pump, and I need some first hand practical data.

What I need is to have someone record the oil pressure as read on a/the gauge at 500 rev/min increments. This should be taken with a warm/hot engine after a brisk run with an engine in reasonably good condition and perhaps with "straight" oil rather than a multi-viscosity oil if possible. This test can be run with the car stationary; just gradually increase the engine speed, holding it at each test point for the gauge to stabilize, from idle up to 5,000rpm if you are comfortable doing that.

Thanks

[Keith Clements]

Philip what a good idea. But getting all the parameters correct for comparison will be an issue.

• Most Javelins do not have a rev counter so will need a timing light with a rev metering.

• Most engines will not have fresh single grade oil, but saying that knowing what different grades and ages of oil give as oil pressure would be useful knowledge.

• Most engines will be worn in one or more places and there will be some with large and small bore oil delivery and early and late oil pumps.

But hey let us see what responses we get.

[Nick Webster]

Sorry if I'm missing something but I have not seen mention of how all the pressure readings are obtained. Are the pressure readings done with a modern calibrated gauge, or the one in the car? Ancient gauges are not much use for proper testing and consistent results are even less likely when comparing with another old gauge.

Nick

[Forumadmin]

Good point. But how inaccurate are the old gauges. Perhaps that is another subject for study.

[PJGD]

At this point, I am not looking for laboratory grade data; I can use pretty much anything. Plus, if we were to get two or three or more reports, we can average the data which might give us a meaningful baseline.

What I am trying to do is to arrive at an orifice size that can be used to represent the flow area of all the bearings and oil consumers in the engine. This can then be used with the oil pump test rig that you may have put together, so that the pressure that you set the regulator to operate at ends up being the same as or close to the pressure on the gauge in the car. Also, the pump speed at which the valve starts to regulate will give an indication of how much the pump is worn. A higher speed for a given blow-off pressure indicates a worn pump. I recognize that this then gives you a problem as to how to measure the pump speed, but it is worth thinking about it and seeing what can be done.

[Keith Clements]

A thought.

This might be a way of comparing the flow of a rebuilt or worn engine or oil pump.
Disconnect the oil delivery pipe from the oil pump to the block. Rig a feed into the block at the disconnection and connect to a tank containing a litre of oil via a large bore tube one metre above the entry to the block. Time how long it takes to drain the oil through the engine.

Do the same but connect the feed from the tank to the oil delivery pipe and measure the time to drain through the pump.

This would be a reasonable comparison between different engines and pumps given a consistent viscosity of oil. It might also show even with just a pair of tests whether it was the pump or engine that was more worn.

The test might even show where the wear was on the block as you might see where it was coming out especially if you used a dyed oil.

Some experimentation may be necessary as 30sae maybe too viscous to flow at all. A further modification to force oil through with a piston driven by a regulated air compressor or inflated tyre might be the ultimate test rig!

We came very close to doing this when trying to find the problem with the race engine which eventually turned out to be the new tappets uncovering the feed gallery. I also did something similar when proving a worn camshaft housing on an otherwise good engine.

[Moises]

Hi David, Philip, Keith and Nick, I am following your interesting comments. I am on holiday at the moment, but when I return to Madrid I will carry out the measurements relating rpm and oil pressure. I will then remove the pump and check its operation with hot oil.
All the best

[David Morris]

Hi Moises,

Many thanks! Enjoy your holiday! If your Javelin was an early one, they only had an oil light on the dashboard and no gauge. This went out at 7psi, so the driver never had any concerns about oil pressure and continued in bliss!

All the best,

David

[Moises]

Hi David: Unfortunately, I installed an oil pressure gauge on my Javelin many years ago. That's why, as you say, I've never been able to travel in peace. Best wishes

1726867467133 (1).jpg

[Moises]

Hi Philip, I'm attaching the file with the oil pump pressure measurements from my Javelin, taken today.
I don't think it will be of much use to you because my engine is not in very good condition and the oil pressure gauge is not very accurate either.
In any case, I will follow with interest the studies you do on this subject.
Best wishes

RPM-OIL PRESSURE.doc

[Forumadmin]

viewtopic.php?p=38533#p38533
Philip suggests spring buckles which maybe why pressure valve does not work properly.