Ruston and Hornsby PT

Ok guys. Here's my project so far. First few pics are the of the engine in more or less as found condition.



As you might guess from the pictures, the engine was seized utterly solid and it took many many months of pouring diesel and penetrating oils down the bore to get it moving, when one day it moved a fraction of an inch. From there it was easy to move. What I've never got my head around until today was why the bore was perfect despite being seized solid but more of that later...

Here are some pics of the inside of the engine as I started dismantling.

[url=https://servimg.com/view/20135131/5][img]https://i.servimg.com/u/f48/20/13/51/31/img_201

And a couple more

And partially dismantled

At this point the project got side lined due to other things taking precedence. Recently I had some major surgery and am pretty limited as to what I can do. Luckily I had two days notice that I was getting chopped up and this coincided with the SVTEC autumn crank up. I'm not yet a member but I have a very good friend who is so I headed along with the engine in the back of the land Rover. My friend took the crankshaft and flywheel to press off the flywheel which is absolutely solidly on the crankshaft. No amount of heat or brute Force could shift it for me but my friend has access to a 50 tonne press so that should shift it!

In broke a couple of the piston rings trying to free them up a while back. I picked up a Lister d piston and con rod at the SVTEC farming yesteryear rally (I show the Landy series three there every year) which happily has the same bore so I will swap over the broken rings. Where I had left the R&H piston and con rod in my big workshop wasn't ideal and the gudgeon pin has rusted quite badly. Happily again, the Lister d one appears to be identical!

Now that I'm sufficiently recovered from my surgery I've been playing with the R&H again. So far I've removed the camshaft mag drive gear which I had to drill out. Today I got the valves out. The inlet valve looks quite good but the exhaust valve is a mess. Both sealing faces are badly worn though with concave faces, unless they're meant to be like that? The seats look ok.

Remember when I said I was confused how the engine could be seized solid but still have a perfect bore? Well I suspect that the engine was sitting with the camshaft just rolled over between the valves and it was the tappets that were seized. When I managed to get the thing turning, I think I might have managed to move one of them as they are solid. Absolutely rusted solid!

That's where I'm at so far. The throttle linkage is seized and I can't get it shifted and the tappets are also solid. These are the last components to come out of the engine casting. Once they're out I will pressure wash it to get all the gunk and stinking old oil out and make it less of a chore to work on. The more it cleans up the more original paint becomes visible although I don't have a photo which shows it yet.

The following couple of posts are where I have got to up to now.

Is the amal carb a usual fit? Any other PY I've seen had an all iron carb. Does it suggest what it might have been used for? It's an original fitting as it has the same maroon paint as the rest of the engine (and wooden skids).

That's the camshaft out. The fly weights for the governor and the exhaust valve looking very sorry for itself.

Should the fly weights be sprung? One hangs loose with no resistance but the other one kind of feels like there's a spring there somewhere. I won't be able to see until I have that all cleaned up and unseized.

That's the last photo for tonight. The tappets as I left them soaking in penetrating oil. The adjusted came out really easy, like they'd only just been fitted but both adjuster bolts were bent which kind of supports my theory on how the engine was seized.

I'm not sure how to progress from here. I could keep on trying to rotate the tappets until they are free. There are flats on them. The other thing I've thought of was to leave them in until after I've pressure washed the crank case. There are two plugs, they look like 3/4" or 1" BSP, I didn't look that closely. The plugs are directly beneath the tappets and are presumably there in order to remove them. My thought was to upend the cleaned crank case and use land Rover tool number one and a copper drift on the bottom of the tappets and get them moving that way. Failing that I have hydraulic things that will definitely shift them but they are at work and might break the casting first anyway. Incidentally, the plugs on the bottom don't ever appear to have been removed in the last 79 years as the paint goes right up the threads.

Nice to see someone else working on a Ruston PT, good luck with the restoration. Mine had everything outside seized up but the crank turned and interior looks good. I found most of the nuts were whitworth and moved when heated but I spent days trying to get the sparking plug out which seems to have had mangled threads before it was screwed in.
Most PT's appear painted Hornsby red but mine is also a green one. I know Barclay Ross were builders of threshing machinery, do you know what use they put your engine to?
There is a picture of my PT under the 'Auctions' thread.

Unfortunately I don't know what the engine was used for, although it appears to have had a hard life going by the wear on the valves. It can't have been serviced often. I don't know anything about Barclay, Ross and Hutchinson either although there is still a Barclay Ross on existence I think. The farm buildings were like a time warp when I moved here. The old farmer had died and the farm had been left in limbo for many years.

There were loads of old grain elevators and threshing machines etc which were driven by a massive and ancient electric motor, which was obviously mounted on an old engine base that was big enough that it could have had a horizontal engine on it at some point. I assume the PT was utilised for driving some of this equipment. There were old stables etc which were just stacked to the roof with ancient farming equipment, all the collars and straps etc that attached horses to various implements, plus the implements themselves. Amongst all this right at the back was a big vertical stationary engine with twin flywheels. Totally wrapped up in oiled Hessian. I never did get far enough back in that shed to extricate that engine and find out what it was.

Unfortunately the farm was bought by the local Laird who set about emptying everything indiscriminately and burned the lot. There was so much stuff parts were holding the roof up, which subsequently collapsed and a digger went in and dumped everything else straight into skips. I have no idea if the big engine survived and I haven't had an opportunity to have a nosy but it would be a nice find if it had. There was a tattie dresser dumped out under a dutch barn with a petter AA1 mounted on it fairly recently Soni have hope.

Some more progress today. The seized throttle linkage dropped out quite easily after soaking overnight in innotec deblock penetrating oil (magnificent stuff, if a little pricey). The tappets were still pretty solid though. I turned a bit of copper bar down to a mm or so smaller diameter to the tappets. I had some stainless steel round bar that was almost exactly the same diameter as the valves so cute a piece to a length that let me knock right through. I took out the plugs and then the tappets hammered through fairly easily. Surprisingly,they were actually in quite good condition, it just seemed to be rust at the tops and bottoms that were keeping them stuck. Anything I've taken off has been dumped in a tub of turps to degrease until I get round to cleaning them properly.

With the engine now stripped to a completely empty casting it was time to pressure wash it. 20 minutes trying to dig out the pressure washer resulted in me finding out it was knackered. So a stiff brush and some fairy liquid were put into use. I'll let the pictures speak for themselves! I knew there was original paint left but I didn't imagine it would be so good.



I dried the engine off and liberally oiled up the bore, camshaft bearing faces, valve guides, tappet guides and all the machined faces to prevent rust.

The inside of the engine is still black and manky. It's thick with oily deposit which I'll have to scrape off I think. I'll maybe use turps but I don't want to damage the paint. The sludge that came out of the sump was thick and stinking and my wee elderly cat decided she wanted to walk through it so I spent the next couple of hours trying to clean her paws. She still hasn't forgiven me!

I suspect that the hopper and fuel tank aren't going to clean up as nice, I think they're maybe just a bit too rusty but then I haven't paid eyes on them for a couple of years so they might yet. I'll need to get the rest of the parts up from my big workshop and keep it all together and get it all cleaned up together. Comparing the engine from the "as found" pics to now, im still surprised at how it looks!

Interestingly, the exhaust muffler thing had a 6PB part number. I wonder if it was changed at some point or if that was just what the factory fitted. I know they're both basically the same engine. When I took the end off, the exhaust pipe was virtually blocked with soot!

Progress report for today. Cleaned up the various components that have been removed. Noticed the exhaust valve spring is a larger diameter and lower rate than the inlet. Is this normal? Exhaust valve definitely for the bin. Ned to see about making or buying a new one.



Managed to get the governor weights off fairly easily but had to turn new retaining pins on the lathe. Used some nice stainless steel for those. The sliding pin that operates the brass governor arm was seized solid and needed some effort to remove. The ends were quite pitted but it was a loose fit and to my mind doesn't really take much loading so a clean up and file off of high spots and reuse was the order of the day. Spent a long time cleaning up the camshaft/gear/governor then oiled it up ready for reassembling.

The cam loves are a bit pitted but a careful file to remove high spots will have to do I think

Doing a hell of a fine job there fella! That crankcase looks unremarkable condition considering how you found it...

Thanks, encouragement is always good. I was really surprised how well the crankcase paintwork has come out. I knew there was paint on it, you could see little spots here and there but I didn't think it would ever look that good. That's just the first scrub as well. I'll give it a good going over when it's all bolted back together. I'll nip down to my big workshop later on today and pick up the rest of the engine and see how they'll clean up. I don't have too much hope for the hopper or fuel tank as far as paintwork goes, going by the photos at least. The date stamps on the as found pics is 2013, I didn't realise I'd had it that long. Explains why I don't remember the condition of the parts! I do have a vague recollection of their being traces of an R&H transfer on the tank so maybe!

A fantastic job.  

Can't believe the later pictures are the same engine as the first set. Very well done - keep up the good work.

@woodsman:. Thanks, neither can I really haha. This being my first engine as well makes it that much better. I'm no stranger to building engines but it's always been modern engines and in a short timescale for getting to work again! The project I have just now that I've been putting off for nearly a year is the 4.2TDI out of my A8 which threw one of it's four timing chains. Now that is a seriously complex engine and requires lifting the whole car off the front subframe/engine/transmission!

Anyway, back on topic:. Today's jobs consisted of scrubbing at the thick black coating inside the engine with turps and a toothbrush. Not s pleasant job and I lost interest fairly quickly and turned my attention to the carburettor. I don't think I have a before pic but it was another lump of rusty metal. It all stripped apart quite nicely and was actually in pretty good nick. I can't tell if it's an Amal carb or just the float chamber as the jet appears to be identical to the R&H ones I've seen elsewhere. It's a similar set up to the Amal carb on a little BSA engine that's on a vintage ransomed lawnmower I was given a few years ago. With the exception of the slide throttle on the sloper. After giving the rusty metal a good scrub with a stiff brush and fairy liquid there was evidence of original paint again which was nice.



The choke/throttle lever was removed, cleaned up and replaced with a good oil, as was the spring and plunger that keeps it in position. The float bowl was full of crud that was dug out then everything cleaned up. The jet was nice and clean so didn't require any work other than cleaning off the rusty dust that was all over the big brass bit the jet sits in. The bore of the carb also got a good scrub out and rub down with emery to get rid of the surface rust. Then I oiled Up the internals and put it in the ready for rebuilding pile.

It was extremely difficult not to polish up the brass but it would look daft as a working clothes rebuild with shiny bits!

The next thing I looked at was the magneto. I literally just looked at it and decided that was going to be the last job I'd do on this engine.

Turning it over by hand, there does seem to be some magnetism left in it. I don't know how strong it's meant to feel though. I'm going to guess it will need a new condensor but I don't really know enough about mags. There is a guy in the SVTEC who restores mags, so I'll probably give it to him to refurbish. Here are some pictures of it anyway.



As you can see, the mag has the R&H paint on it along with the rest, suggesting it's original, so I'd much rather refurb this one than replace it, even though the paint is only on the engine side and would never actually be seen.

Next job was the piston. I broke a couple of the rings a year or two ago, before I shelved the engine rebuild. The piston has been sat in turps for a week or more now to free off the oil control ring at the bottom. It was held on only by a tiny amount so I gave it a wee pry and predictably broke it!

As I mentioned before, I had bought a Lister D piston for a couple of quid at the farming Yesteryear rally back in September as I knew the rings were the same size. The oil control ring is totally different but I've fitted it anyway. Presumably it does the same thing in the Lister and it fitted the slot nicely. Also fitted the two compression rings that were missing.

The gudgeon pin had rusted up after afew years on the floor of the workshop. Luckily, the Lister one was identical, so I cleaned it up and fitted it. Also cleaned up the con-rod. The big end cap retaining bolts and nuts are badly pitted with corrosion but not enough to lose their strength so I will re-usr them. I'm keen to keep the history of the engine as much as possible. The shims and bearings were in good condition so didn't need any attention. Gave it all s good oil up and set it aside in the rebuild pile.

I'm pretty much ready to start assembly now. I'll need to get hold of my pal and see if he's managed to get my crank and flywheel separated. He's a very busy man now he's retired so hopefully I'll be able to get it fairly soon. Meanwhile I've got afew more bits to clean up down in my other workshop and I can always spend time scrubbing the inside with a toothbrush!

One final thing. It's not important I'm just curious. There is/was writing on the piston crown. Does anyone know what the significance is? Probably just abatch number or something but it could be an oversized piston I thought maybe although they're strange markings if it is, plus it doesn't look like the engine had much,if any maintenance during it's life.

The large ST is fairly obvious and there could be a subscript 2 just after it.b below this is a smaller S followed by possible an E.

It strokes me as odd that it seems printed on rather than stamped.

Another day scrubbing parts...



I'm having to be careful. There is a lot of thick oily mud on the crankcase. If I scrub too hard the paint comes off with the mud. It would probably come off anyway but there are still little bits of crap in the books and crannies that I didn't want to scrub too hard at.

And the cylinder head

Now, I really didn't have much hope for the hopper and fuel tank. They were both really rusted. Also, the fuel tank still has the remains of the original transfer on it so I couldn't scrub it. There is a bit of paint on the hopper but not much. Does anyone have any hints and tips on how brighten up and protect the paint that's left, and dull down the rust.

I believe the paint would be linseed oil based and there's something I can rub on that will make it nicer. I have linseed oil in my head but that might just rub it all off!