Stuart S50

[Ilyessa]

I just bought this S50. It has a Gunmetal cylinder. Is the normal as I have a couple of other S50s that have
cast cylinders. Also the big ends have been drilled off set is this normal? And just for fun the oil holes do not go all the way to the crankshaft. The last picture is the base, any suggestions for filling the holes so I re drill them.
The crankshaft is bent and the lobe is loose, I can fix that,the fly wheel is not drilled in the center either. Also the piston ring was gland packing. I paid like 150. I was looking for a project and I guess I got one. Any advice would be greatly appreciated.
Thanks in Advance.

 

[Jake M]

I've never seen one first hand. I just googled pictures of the engine, got many in various states of assembly, and of course the ones from the Stuart page.... So my opinion is what it is.....

It looks to me like the whole base plate didn't align with the rest of the model from the beginning, and most of the project was a battle to make everything in the rest of the engine line up properly. The offset holes might just be an attempt to bring things into alignment? Same with the crankshaft bearings... Those appear to be cast in one piece with the base on the original? They may have been remade to allow more room to offset the crankshaft bore for some other dimension that's way off.

The cylinder looks to be cast... That's kind of a big deal to be doing at home. Where else would you get one?

And the screw holes that need filling... I'd make a "bolt" or threaded rod to screw into them, from as similar of a material as you can find, or possibly even just a mild steel, and thread them as far as they'll go, locked in with a retaining compound (as opposed to a threadlocker). That would allow a center cutting end mill (not a drill bit) to remake an overlapping hole.

It does look like a heckuva project. Just the kind of "impossible" crap that I like to take on, taking a basket case and making something nice out of it.

 

[ErichKeane]

I've never built a Stuart, but I've watched quite a bit of Kieth Appleton on youtube I suspect you did just get yourself a heck of a project. I see they missed on the base casting on the cross-head guides as well. From the looks of it, the builder didn't do a great job or pay much attention. The big-ends being that far off are either a mistake, or to make up for a too-short/long piston rod.

Jake's suggestion on threading those holes, filling with a bolt, is a good one, but you don't necessarily need an endmill. You can file it flat enough, then use a center drill.

ALSO, rings being gland-packing (assuming it is the teflon stuff) is not uncommon, that is a really typical material these days.

If it were me, I'd re-make the crank, piston rod, and big-ends from stock at least. TBH, I'd probably start remaking/plugging holes on a LOT of those parts...

As far as the cylinder, according to this site: http://stuartturnersteam.com/Horizon/S50/S50.html The S50 has a gunmetal cylinder casting, So I suspect that was actually the case at one point.

 

[Chewy]

Go check Keith Appleton. You may have to go through a lot of videos, but at times he talks about older models vs newer ones. Some had gun metal parts and some cast iron. Unfortunately I don't know which ones. You might want to contact him or Stuart directly for the answer. He also shows how to fix holes. You need to fill the hole with comparable metal. That way when you drill correctly, the bit doesn't move to the softer material. Everything you show, he has done in a video, but it may take a while to find correct one. Condsidering what a new S50 kit sells for, and you still have to make it, you probably came out OK. Please document your repairs. We would like to see them.

 

[Jim Dobson]

I much prefer the gunmetal cylinders on the older S50s as they don't rust like the cast iron ones.

 

[Janderso]

You got a fair price on this unit.
I have a lot of respect for Stuart engines.
I sold a 5A for almost $2,000.
I may work on my little steam engine this winter. They are fun for sure.

 

[Ilyessa]

Thanks every one for your thoughts and advice.
I think I will start with the base and work my way up.
Chewy. I will do my best to document the repairs.
I have some parts coming from Stuart models and a set of Drawings.
So it could be a few days before I have an update.
I will also need to spend some more time with Keith, Girlfriend jokes and all

 

[Ilyessa]

Hi all.
Just a quick up date on the S50.
Been doing a lot of cleaning and sanding. I do not think there is a drilled hole on the entire model that is straight or in the right place.
Just waiting on drawings from Stuart Models before I get serious.

 

[Jim Dobson]

Look forward to following this rebuild.

 

[tomc938]

Looks like a challenging project! Filling everything and starting from scratch seems like a good idea. I'm a beginner, and even my screw ups aren't that bad. But give me time, I've just started my first engine.