Hi All,

That’s steam cars for you…

After nearly 3000 wonderful and reliable miles with my 740 Roadster, on return from a brilliant one-week tour of the Cotswolds (huge thanks to Les and Pat for setting this up), unfortunately the car suffered an oil line fracture near the inlet to the engine. As I was driving in very hilly territory, the damage came quickly and irreversibly.

I spent Sunday removing the engine and trying to assess how the failure occurred un-noticed until too late. On the 740, the oil delivery is indicated on a pressure gauge helpfully calibrated with ‘Off’ and ‘On’ sections, no actual pressures; there is no winker (although this would not have helped either). The pressure gauge pulses with each shot of oil and is a fair indicator that the lubricator is working well.

The oil is fed via a chassis mounted, spring-loaded check valve into a flexible, coiled section which then connects to the steam inlet elbow. I tested the check yesterday and it opens at about 140 psi. Most of the time in the steady cruise the steam chest pressure is around 120-130 psi, which means that the oil pressure gauge still indicated a good healthy pulse because the lubricator was still having to overcome the spring loaded check. I’m going to put in a much weaker spring in the check to lift at around 10 psi, in the hope that a sudden fall in oil pressure will indicate a problem. I’m also going to take a closer look at what can be done to ensure a more reliable flexible pipe to the steam elbow to avoid another fatigue fracture.

I’m telling you all about my woes in the hope that I may save someone else from a similar fate. Please regularly check your oil lines for integrity, preferably a pressure test. If you have a pressure gauge as oil indicator then make sure that the check valve spring is only just strong enough to close the check in the thick oil; any stronger and it could mask a problem.

Sadly the cylinder block is unrecoverable - during the restoration I had machined the last of the ‘meat’ from the port faces, with no further opportunity for another go; I know that I could probably add new port faces, but I’m not sure that I can face (ha ha) the effort!

So, if anyone has a 20hp cylinder block in usable condition and surplus to requirements and preferably with valves, then I’m very interested! Please let me know right away, private message would be best, the Club tour at Frensham is only 3 weeks away – so there’s a challenge…

Happy steaming everyone,

Mark

Rotten luck Mark - hope you get fixed up in time. I trust you will come anyway!
I had a pressure gauge on the oil pipe and it showed me the steam line/valve chest pressure - if the pipe had broken I would have been able to see (despite the check valve spring effect) as the pressure would not have varied with the throttle opening/load as it so clearly did.

I can't recall exactly how it attached to the winker unit but it must have been after the check valve formed by the winker glass as it didn't pulsate with the oil pump. The non condensing cars feed the oil soon after the superheater which may be bad for the oil but at least prevents too much fatigue inducing twisting of the pipe.

Mike

Change out your 5/16" copper oil line to 1/4" steel brake lines and your future oil line problems will be much reduced. At the point where the steel brake line attaches to your steam line, it should also have a coil in the oil line to allow for steam line vibration. From fatigue and vibration, I have lost the original 5/16" copper oil line in both our 1914 model 606 and in our 1922 model 735B. I caught the 606 in time because of its oil mess gave it away. On our 735 B it gave me lots of grief. The slide valves became scrap iron but the cylinder block required very little machine work, and it still lives on today.

What a crying shame for such a thing to happen to such a beautifully restored car - a car that we all aspirer to. I know how much you were looking forward to your first official tour; perhaps you will push the 735 into service.

As you know I too have a steam chest pressure gauge fitted to my 10hp Stanley, this is “T”ed into the oil line just after the winker and there is no check valve further down the line, therefore if I suffer an oil line fracture the pressure gauge will immediately drop to zero irrespective of the regulator opening, I keep an eye on this gauge a lot more than the winker. Perhaps a high temperature flexible brake hose as a connection could be the answer?

Good luck

Don

Hi All,

My heart-felt gratitude to you all.

It is only a few days since I started this thread and I wanted to say a massive THANK YOU! to everyone that has offered support, help and advice. I may still be some way off being able to get my engine back in working order, but already there are a few good offers which possibly may bear fruit.

In particular I would like to thank: Steve B, Nigel H, Les N, Basil C, Dudley W, George H, Grant & Justin G, Steve T, Mike M for their patience, offers and help; and all you good folk that have left posts and supportive private messages.

I may or may not have the car repaired in time, but we will certainly attend for a day at the beginning of the week of the Club Tour. I am very lucky and humbled to have the acquaintance of such good people.

Thanks!

Mark

Sad news, I know that you and everyone else will be pleased when that beautiful car gets back on the road.

My car has a box lubricator, and a pressure gauge between checks, and it feeds into a tee right where the steam line enters the valve chest. I haven't yet upgraded to a steel line, and the copper line broke at the flare, due to engine movement. But for me it was really obvious - the loss of that line meant that the steam exited its port on the tee rather than driving the pistons, making quite a racket and bringing the car to a halt.

Kelly

Hi Everyone,

Great News - I'm back on the road and she's purring like a mountain cat once more! I have a new block and valves from Justin Goold which assembled with ease and I have to say that I'm very pleased with the outcome - shame it's just in time to put the car away for the winter!

I've significantly altered the oil feed arrangement: I now have a dedicated flexible section made from PTFE / stainless braided hose which is firmly anchored at both the fixed and moving end, with the hot end isolated from the steam line with a length of 1/4" steel tube. I'll probably change the hose every few years as they're cheap enough to have made up. The oil check valve now has a much weaker spring so that a leak will be much more evident at the dashboard oil pressure gauge.

I've only done about 20 miles, but the system appears to be functioning well, oil is appearing at the oil separator as it should and the engine sounds very happy.

Already looking forward to the Cotswold Tour 2014....

Oh, and a Happy Christmas everyone!

Mark

Well done = a quick repair - changing the block is a load of work!
Mike

Hi Mark, glad to hear that you are back on the road and that all is well. A lesson for us all! hope to see you at the AGM or the Cotswolds.

Harold Bell

Hi Mark,

Congratulations on the fix and the improvement. Is the composite high-pressure line you described visible on a supplier website anywhere? It sounds like a good upgrade for my car.

Kelly