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[Archibald H.]

Fascinated by steam since quite some time I decided it was time for some real experience instead of reading about the subject. I must say actually building such an engine makes you understand things a lot better. The exchange rate of the US$ made buying an engine an easier decission. I have no metal-working experience, no lathe or drillpress so I chose the PM Research '#8 Marine Steam Engine'.


It arrived, well packaged, with a simple but clear manual. As I said no fancy machinery needed, a screwdriver, small file en a small pare of pliers suffice.
Casting and materials are of good quality, no mentionable flush, everything ready to assemble



The main block comes ready assembled.



One servo only can control speed ahead and reverse and full stop.


Crank and shaft are installed.


Bottom of one of the cylinders is installed, on the right there's the top. Cylinders are made from anodised alluminum, apparantly solid and very wear-resistant, it seems to be used a lot in aviation.


The piston is beeing fitted in the cylinder. Perfect fit!


This is how the cylinders are mounted on the main block. Before they're closed there are some adjustments to be made.


The pistons must stay 2 mm under the top of the cylinder when in their highest position..


Nice cover for each cylinder.

I've run this engine shortly on compressed air and I was surprised by the power and response. However I don't dare to run it anymore untill I have the right kind of oil. Is steam oil necesary? Advice anyone?
When I can run it on the right oil, I'll post a small film here.

All in all I'm very pleased with this engine. Hopefully I can install it in a nice boat in the near future with a suitable boiler (maybe this one: http://www.maccsteam.com/Horizontal_Marine_boilers/3_and_half_inch/3_and_half_inch.html ?).
Cheers, A!H.

[Martin (Admin)]

Nice job!

What was the hardest thing to do?

[Archibald H.]

Hey thanks, Martin,

the hardest part was getting Belgian Customs to release my package after it's been staying with them for more than 3 weeks.

As far as building the engine, I must say there are no hard things I can think of . . .

[Bunkerbarge]

Very nice job there and many thanks for showing us the assembly.  I would be tempted to paint the rough cast parts and polish the brass parts to really give it some presence and I might be tempted to lag the cylinders with wood but a nice model anyway and it looks like it would be quite powerfull, although requiring quite a lot of steam to run it.

I would always advise a long period of running in with compressed air but I notice the engine is fitted with what look like nylon piston rings so it is not quite as critical with this one.  I would though set it up on compressed air after dismantling and thoroughly oiling all parts before reassembly again.  I use normal car engine oil for running in because steam oil is a lot more viscous and offers better protection but for running in you don't want the highest levels of protection, you actually want the parts to "bed" in together.  I would run the engine for about four hours in total, oiling regularly the external components and adding oil to the cylinder internals every 15 minutes or so.  The easiest way to do this is to shut the air off and inject a couple of drops of oil through a hyperdermic syringe into the rubber air supply hose.  This process is always a bit messy but it will give you a more reliable engine.

You might find that the control valve leaks from the face as well and the locating plate looks like it might be a weak part of this assembly.  Make sure that you do not overtighten the plate because if you do it will deform the plate and the face could leak steam badly.  Don't be tempted to tighten further if it leaks because it will almost certainly make it worse.  You may have to gently lap the faces on a flat surface such as ground glass or a surface plate to ensure an even matt finish across the entire surface.  I would use a 1000 grade grinding paste to give you a surface texture that will hold oil as well as ensuring a flat finish.  Use of the valve will once again bed the faces in so a part of your running in process should be to operate this valve regularly.  See how the running in goes first as you might find the valve works fine and does not leak.

Do not be tempted to run it again with no oil.

Once the engine has run in for the four hours you should notice that it has freed up and spins that bit easier.  I would then dismantle it, clean all the parts thoroughly and re-oil with proper steam oil.

Then you need to connect it to a boiler and run it on steam with a proper displacement lubricator in line.  You will need to know the bore and stroke to quote to the boiler manufacturer who should then be able to supply you with a boiler that will do the job.

[Proteus]

there 1/2 inch bore and 3/4 stroke..  there has been a few posts  about them on the American sites of late


Fredy

[Archibald H.]

Hey thanks very much Bunkerbarge, those certainly are usefull tips for a 'steam-rookie'. Specially the one about the control valve
I was wondering: if I add oil in the air supply hose, won't this soil the internals of the block to much so that the air will have difficulty passing? Or did I miss something?
Anyway for the time being I'll only run it on air, I'm saving up for a good boiler and I 'd like to finish up the ship I'm building at the moment (a ship from one of the Tintin-adventures) first.

@ Proteus, what is the unit of stroke? Do you know more tech-specs from this engine? There's not much to be found on those . . .

Cheers, A!H.

[Bunkerbarge]

I agree, be carefull when you put the oil in.  A couple of drops is enough and then you might have to turn it over a few times with your fingers to push it through.  As long as you are carefull and are aware you shouldn't have any hydraulic lock problems.  It won't "soil" anything any more than when you run the engine on steam and use a displacement lubricator, that simply admits small quantities of oil with the inlet steam.

The dimensions are both in inches which relate to about 12.5mm bore by 19.1mm stroke.  That's actually quite a substantial size for this type of engine and although powerfull will use a lot of steam with the throttle opened up.

Let us know how you get on with it.

[Timo2]

Hi All
 Great little engine .order my one late Dec 07 post time 10 Days to Glasgow.  :) Very easy to build ( 40min ) to first turn over by hand, .
 Running in I ref. you to http://www.paddleducks.co.uk/smf/index.php?topic=3303.0 
A thread started by me , clifforddward  replies were very helpful. 
Will run at low pressure ( wet steam ) from  a Wilseco boiler ,  start-up to   2=3 rpm up to 800 rpm ( LP about 18psi )  back to Stop . Run time 14min. on 1 gas fill.  Freeing  off nicely.  Couple of drops of light steam oil  ( V460 Light ) ever  4-5 min. plus light machine oil for crankshaft  & oscillator block.

Look a good one

Timo2

PS  Not a Steam Expert just ABOY

[Archibald H.]

Hi all,
here is the movie I promised to post.
http://nl.youtube.com/watch?v=r6Mblfv_hEc

When this clip was made, the engine was run in for about a 1/2 hour.
I followed your tips about running it in, Bunkerbarge, thanks again. It's running like a dream, the power is impressive. I'm almost affraid of running it at full throttle
Next step: a good (and big enough) boiler.

Cheers everyone, A!H.

[tigertiger]

Hi Archibald

Do you have a website for the supplier, and how much did the engine cost?

[gribeauval]

Here they are:

http://www.pmresearchinc.com/store/home.php

Mike

[Bunkerbarge]

Glad I could be of assistance and glad the engine is up and running.  It is actually a very smart looking unit and certainly seems to run nice and freely.  When you first get it on steam you might find a couple of leaks open up but, hopefully, continuing to run it in carefullt on steam will bed it all in further and it will settle down.

By the way Tiger, I looked, it's $159.00, so for 80 quid you get a double acting twin cylinder oscilator with built in control valve.  Not a bad deal at all.

[oldiron]

I've run this engine shortly on compressed air and I was surprised by the power and response. However I don't dare to run it anymore until I have the right kind of oil. Is steam oil necessary? Advice anyone?
When I can run it on the right oil, I'll post a small film here.

All in all I'm very pleased with this engine. Hopefully I can install it in a nice boat in the near future with a suitable boiler (maybe this one: http://www.maccsteam.com/Horizontal_Marine_boilers/3_and_half_inch/3_and_half_inch.html ?).
Cheers, A!H.

  Very nice engine you've got there. I'm impressed how well it runs.
  For running on air a lite machine oil will suffice. However, a lite steam oil should be used for running with steam The difference between the two is steam oil, although being more viscous to handle the heat, is also water soluble. Most oils, including the lite machine oil aren't water soluble. In the presence of steam (hence water condensate) the non soluble oil is displaced and the running surface only end up with water for lubrication. In the case of water soluble oil (steam oil) the water can;t displace the oil, but mixes with it and ensures all running surfaces are lubricated.
  When lapping in brass or bronze and similar metals, be careful what you use for a lapping compound. Traditional valve lapping compounds have a hard grit that will embed itself in the soft metal. Although it may not appear to be there visual, tiny microns impbed in the wearing surfaces and eventually wear them out prematurely. I've used a course tooth paste such as "Gleem" with success. Its hard on the teeth, hence the bright white smile, but good for lapping in soft metal parts. It also washes off with water.
 If you can lap the two mating surfaces against each other you'll end up with a better job than doing them separately. I'd use separate lapping as an option if you can't lap the two parts together.

[tigertiger]

By the way Tiger, I looked, it's $159.00, so for 80 quid you get a double acting twin cylinder oscilator with built in control valve.  Not a bad deal at all.

very reasonable.

[Proteus]

tigertiger
they must be the cheapest about for the quality , I think the corrugated cover put me off when I first saw it

Also I may have made a mistake when I said it was 1/2 bore as they now have it as 8 mm unless they do two engines , they do say "new" by it  and I have seen engine  on sale for some time.

fredy

[Archibald H.]

The ebayshop Eclectorsdevices has them on offer sometimes, last time they sold them (buy now) for 147 $.
I bought mine at www.theengineshop.net  but it seems they're no longer active . . . a shame because they were realy kind and helpfull people.

[Proteus]

   8m is the model number , my mistake

fredy

[Bernhard]

Hi.......yes they are closed....i will miss them ...reale nice to deal with here is the email from  the Engine ship


 Hello Bernhard
   I am too old   too tired  and I want to lay back and enjoy life
and build some of the models for myself now   I will miss all of my friends from all over the world ,  I am happy to have known you and what a nice person you are   Thank You very much Bernhard  live well
 
Best Regards
Roger