The Steamboating Forum

Hi All,

I ran the Jackie Lee for about three hours yesterday and overall it went well. I am still haveing some issues though, so I thought I would seek your sage council. (Parsley, Rosemary and Thyme council can be had at Scarborough Fair).

I am running a watertube boiler feeding a 3x4 double acting single with a stephenson reverse gear.

My plan heretofore has been to build a fire while the boat is still on the trailer and get things warmed through before I put it in the water. That way I dont occupy space at an active ramp/dock any longer than I have to.

Yesterday I put the boat in, parked the trailer,and by the time I got back down to the dock I was at about 100 psi. I set the stephenson gear to reverse, and when I opened the steam valve the flywheel just rocked back and forth. I tried forward with the same result. I tried encouraging it by hand but it was impossible to turn.

I finally opened the to petcocks for venting the top and bottom of the cylinder and was able to get it going, but it was not pretty. Is there a way to deal with this ? I thought I had my timing set pretty well,. but perhaps I was wrong. I had an opportunity to run the engine for about 5 hours at a steam show last weekend with no load on it, and at lower pressures, and had not problem then.

Any help would be appreciated.

jon

Could this have been water in the cylinders? Warmup with the cylinder drain cocks open, with steam in the steam chest, will normally warm the cylinders and eliminate the water. Turning the engine over by hand works OK, and even slight leakage past your steam valves is often enough to warm the engine without any need for manual turnover. Water in the cylinder can lead to serious engine damage, so proper warmup with a small steam flow is prudent.

A 1/4 inch compression copper steam line (going arount the main throttle valve) can warm up the engine, but it will not pass enough steam to rev the engine, which could be a problem if the boat is on the trailer.

Engine valve timing should be checked, how well does forward/reverse work once the engine is warmed up and the boat underway in the water?

Hi Fred,

I was pretty sure I had all of the water out of it before I put it in the water. I guess it is possible that some water condensed while I was launching it an parking the trailer.

Should I open those petcocks again before I try to leave the dock to make sure all the water is out of the engine ?

The timing was workjing really well when I had the boat at a steam show last weekend. I had the coupling disconnected, so there was no load, and it seemed to work great. Of course I was running at lower pressures that yesterday. Will the pressure make a difference if the timing is off slightly ?

I was having more issues yesterday in getting it to go into reverse. I pretty much had to stop the engine, throw the lever and then restart it.

jon

Check your valve setting (timing).

The best way is to use the flywheel (if you don't have one, fix a circular disc to the shaft coupling at the engine and divide it into 360 degrees) with a pointer firmly attached to the engine bedplate and pointing at TDC with the piston on TDC. Don't use the shaft as most settings are critical within a degree or two - like admission starting at 3 to 5 degrees before TDC. Note this is not 3 to 5 percent linear travel before TDC. This is also why one does not use the pretty little pointer afixed to the crosshead sliding along the scale mounted on the crosshead guide. This is due to the difference between linear and rotary motion. Because of the tolerances within the linkages of the engine, always rotate the crankshaft in the same direction when timing. To check when the valve opens for have both cylinder drain cocks open and use about 5lbs air pressure (not enough to move the piston). Slowly turn the engine over by hand and when you hear the hiss of air coming out the drain cock that is the valve opening. Look at your degree point on the calibration disc.

Is the valve free on the valve rod so that the valve can "float" on the valve face.

Out of the water the engine is running free; in the water there is substantial difference due to resistance.

Hi Ron,

Do I need to check the timing going both directions ?

jon

If this engine has a slide valve, they can get quite 'sticky' while under steam pressure. Just barely crack the throttle and turn the engine over by hand.... w/o much steam applied, the engine should turn over readily. You can also turn the engine to not be at TDC or BDC and then crack the throttle....

- Bart

I think you are all over analyzing this. My does boat just exactly the same thing if I let it sit for more than a few minutes. My engine is a single with a piston valve.

I warm it up on the trailer first. Then launch. Then run around getting the rig parked. Then trot back to the boat and find it hydrolocked.

I just routinely open both cylinder cocks whenever I start up after a pause of any significance. I know pretty well just what I can get away with now.

What helps sometimes is to warm it up a bit more than would seem sensible just before I launch. I run the engine enough that the condenser gets so hot that it is passing steam into the hot well.

Mike

Thanks Guys !

I think I have a combination of hydrolock and timing. Is there any reason for me to open the petcock on the steam chest when the engin has been stopped for a bit ?

I will open the petcocks on the cylinder, and I also like the idea of just turning the flywhell before I tryo to start. to get it off TDC/BDC. I am assuming that a quarter turn is what I am lokking for. Is that right ?

jon

I would make a habit of opening the cylinder cocks whenever you have been stopped for a bit. You will get a feel for how long it takes for any condensation to collect in there. I don't have a petcock on my steam chest. Actually I don't have a steam chest, per se. My engine has a piston valve.

Big marine engine are warmed up and tend to be run at constant speeds for long periods of time. My experience has been that I spend a surprising amount of time fiddling about in close quarters. If I had to place the engine in any particular position before opening the throttle I would also spend a fair amount of time banging into docks. I crack the throttle, give the flywheel an almighty kick and away we go. Helps to wear tennis shoes and keep the flywheel dry and clean!

If I ever change from a single to a multi cylinder engine it will be mostly to get good starting.

Also, you can fit relief valves at each end of the stroke to prevent possible damage from condensation. Mine are on their own tapped holes but I see no reason why they couldn't share the condensate holes.

As far as setting the engine at any particular position before opening the throttle, I just plan on giving the flywheel a kick any time I am starting or reversing at low speeds. If The engine is turning at 100-150 rpm or above, it always reverses but at lower speeds, not so reliably.

I suspect that your engine timing is fine. Just do a bunch more steaming to get to know your power plant.

Hey Mike,

What type of relief valve would I put on the cylinder ? How do I know what size they should be ?

jon