New Project Stuart Turner P6M + gearbox

Looks like this one's being dragged back out again. I've just sourced a donor engine for it. So, once the Ruston's done this one should fill in any gaps in the Lister project quite nicely.

I'll take some pics tonight of this donor lump, almost seems a shame to break it, but it's got a bent crank shaft, so really only any good for parts.

Well, here she is....







It almost seems a shame to break this one, but it has a bent crank shaft (could possibly be a bent flywheel, but much more likely to be the shaft, as they are quite weak on these, the book forbids the engine to be rested on it's flywheel when not installed in a boat, but you still see people do it when listing them on eBay).

The shaft could possibly be straightened with a big hammer & a dial gauge, but then I would be left with a P5 which needs restoring (including missing parts) & I would still have a P6 which needs a barrel. Also, on closer inspection, the big end has play on this one, so really it's a donor engine. Let's face it, none of us like to break an engine which looks repairable, but the original project engine (the P6 that this thread is based on) was bought very cheap & was really a gamble, this one can be considered very similarly, it was even cheaper & had different problems, now at least I can make one good engine out of the 2.

So a fight ensued. This was a fight between me & some more Red Hermatite! (God how I hate that stuff ). It has been plastered all over the mating faces of the exhaust outlet casting to barrel joint, the water inlet plate on top of that & the exhaust expansion chamber cover plate, all of which were a fight to the death to get off! Funnily the head & barrel came off really easily.

Still, soon enough it looked like this....



It all appears to be in good order. I found a tiny little brass plate on the side of the barrel which said [Oversize .010"] which means this barrel too has been re-bored!

But at least I have a piston to go with this one, although it's a cast iron piston & the P6 should really have an aluminium one, but I just happen to know someone who has a +.010" ally piston for one of these. Not sure it'll make that much difference, but the gearbox which goes with this engine is a reduction box to take into account the extra engine speed of the P6, so it would be nice to be able to say it has the correct piston to go with the engine number.

Anyway, this will give me something to do when I'm waiting for paint to dry on the Lister. Also it will give me some Stuart Turner spares to flog & hopefully put something back into the engine fund (which is in the red right now to the "bank of dad").

You never know, one day I might actually finish this damned project & have myself a running Stuart Turner marine engine!

Nuts it's always a problem when faced with the decision of breaking an engine that could passably run again but you just have to bite the bullet and get the original up and running as it's a little rarer and the spares of the P5 should sell easy enough as Stuart parts do tend to make good money on ebay.

Stu.

I've done a bit more with this one in the past couple of days as well (as well as the Lister & the Ruston 6PB).

Basically I've cleaned up a few bits & got the primer out again. Much of this engine has been prepared, primed & painted quite a long time ago now, but there was a few bits left to sort.

I had to get all the old paint off the other half of the crank case & clean that out properly, so there wouldn't be any foreign matter in the crank case when it was all back together. I've now done this. The outside of the crank case is especially difficult to strip, & as I can't get the crank shaft out I didn't want to use paint stripper, so I used what's left of my drill powered wire brush, then had to get in there with the dremmel using different sized sanding drums in the awkward places, but it's now completely cleaned out (which has finished off my brake & clutch cleaner) & has been primed....





Yesterday I wanted to remove the water jacket cover plates from the barrel, well I tried to remove the brass screws, but they weren't coming out, so I decided to try drilling the heads off, but that was proving a bit difficult, so I was just giving one of the screws a slight tap with a hammer, when....

Well, I got it off....



But if you look a little closer....



Oh well, I've got spares (thankfully). Now at least I can be sure the water jacket is clear. these little engines have a strange water system. Many people connect it up the wrong way round, but the cool water from the pump is supposed to enter over the top of the exhaust outlet, it then forces it's way over the exhaust expansion chamber cover plate from top to bottom. From here (right at the bottom) there is just 2 small holes where it enters the bottom of the barrel casting (still around the exhaust expansion chamber), but from here it goes all around the barrel, flowing upwards (same direction as the heat) towards the top of the head & exiting out of the top of the head.

This system ensures you do not pump fresh cold water over the cylinder head, which not only could cause thermal shock, but would also over cool the engine & it would never run right (fine at a rally with tank cooling, as it will warm up anyway, but in a boat it would be useless if it went straight into the head). Also this system helps to keep the exhaust system cool (always an issue on boats) as well as pre-heating the cooling water for the engine. The mistake people make is to feed the water from the pump straight into the top of the head, so it's going the wrong way around the engine & probably has a few air pockets in the system where no water will be cooling the metal.

The only trouble with this system is there are several restrictions in it to stop the water moving too fast (which again would over cool the engine), the main restriction is the one I mentioned, at the bottom of the expansion chamber, there is also one at the bottom of the exhaust outlet/top of the expansion chamber cover & another at the top of the cylinder head. On the original barrel for my engine the restriction at the bottom of the expansion chamber cover (actually inside the cover itself) was completely blocked, & despite several soakings in battery acid I still haven't managed to clear this blockage of scale, it really is like rock in there, & you can't get a tool in to clear it. Fortunately the donor engine's water passages are remarkably clear, probably because it's not been cooled with sea water.

Anyway, I have also re-assembled the water pump, ready to go back on....



& I've started to clean the magneto, but that's now all in bits & the only pics are ones I took so I would know how it goes back together.

I'm hoping to get this one back together this week, but I need brake & clutch cleaner to carry on. I ordered some today, so hopefully it will be here tomorrow or Thursday.

Coming along nicely Nuts, I can see this up n running before much longer.

Stu.

stationary stu wrote:Coming along nicely Nuts, I can see this up n running before much longer.

Stu.

Cheers Stu. I've given the crank case it's first top coat this morning & put the magneto drive cog & shaft back in. Just waiting for the paint to dry now then I can prepare the gasket faces & start to build it up.

I've also got fed up waiting for brake & clutch cleaner to arrive, so got a big bucket of hot soapy water & my big bottle of "Cif" Cream Cleaner & washed the last few bits, ready for priming & painting (namely the barrel & the exhaust chamber cover plate).

Once it's all back together I will give the whole thing it's 2nd top coat, whilst that's drying I plan to complete the cleaning of the magneto & put that back together.

It will still need a trolley & some tanks, & I need to clean & paint the gearbox & mounting tray.

I'm expecting this one to just fire up & run like a Swiss watch as well.

Here's some pics....

Barrel & exhaust chamber cover with their first coat of red oxide....



First top coat on the crank case....





Coming along nicely.

Well, the paint dried very quickly, so this evening I decided to start cleaning up the mating faces, cut some gaskets, smear on the Wellseal & start building this one up.

I started with the magneto bracket, which also involves the magneto chain drive sprocket, which also has a gear cut on the same shaft to drive the water pump.

Anyway, on it went....



Then it was the turn of the water pump....





I slid the other half of the crank case onto it's studs, but I haven't fitted it yet. Once again the mating faces need cleaning up, & it's a bit more involved with this one. It also needs to be put on carefully, there's a bearing & a seal to sort out, but I put it almost on & put an old magneto on there to see what it looks like....



I will crack on with this tomorrow. Tonight I also put a 2nd coat of red oxide primer on the barrel & exhaust chamber cover, so tomorrow I will give them their first top coat, then when that's dry I can see about getting the barrel on.

Which reminds me, I need to order some Tesnit to make up a head gasket.

OK, a quick recap on what I got up to yesterday with this little project....

I gave the barrel & exhaust cover plate their first top coat....



Then I had a few other things to do while that dried. When I got back I decided to start building up the crank case. The barrel & head are needed for this bit though, as they need to be tightened on before the crank case halves are tightened together to make sure everything pulls together properly & that the face where the bottom of the barrel sits on the top of the crank case is nice & flat. Fortunately the barrel was dry enough by this time to do this. So on it went & so did the other half of the crank case....





But, seeing this, I couldn't resist getting some of the other bits out & having a play around.

Now, let's see what it looks like if I just....



Oooh, nice. Now what about....



Well, by now I had built up the flywheel (it has 2 ratchet bits on the back of it, which engage on the starter cog thingy). It's looking quite good & giving me an idea as to how it will look when built up....









Anyway, all those extra bits will have to come off again, but it has helped me get some enthusiasm for this project again. I've done so many of the little bits & so much work on this one. There's still some annoying little jobs to do, & the paint is running out, but I should be able to finish it reasonably soon. It will have to go on a temporary trolley for now though, as I am completely out of cash for the next week or two. So unfortunately I doubt it will be getting that nice copper petrol tank or water tank. I've got a new-old-stock Villiers petrol tank all primed up & ready to go which will do, & I'm sure I can find something to use as a water tank. It also needs some control cables for the throttle & choke (I'm going to leave the Amal Concentric carb on there I think, & sell the brass Stuart carb with the spares. It would look nice with the Stuart carb, but it doesn't have the throttle linkages to go with it).

Anyway, I'm putting my efforts into this one now in the hope of finishing it before the rally at the end of the month.

But even when it's gone I will still have plenty to do, especially as I've only gone & done it again! Yes, I've gone & "accidentally" bought another engine off eBay. I won't say too much, just that it begins with "B" & has 2 flywheels. It was very much the same situation as the JAP Model 3 I bought, I bid up to a certain amount, thinking it would easily go higher, but it didn't, so I won it. At least I got a good price on this one (I think).

The Stuarts coming together nice, and looking good, can't wait to see it finished and all the copper and brass polished up.

Stu.

So does that mean the Ali piston isn't required now?

You will need some more wheels before long!

Stamford24 wrote:So does that mean the Ali piston isn't required now?

You will need some more wheels before long!

I would still like to put the ally piston in there, but if I can't get my hands on it in time I will just use the iron one.

I've still got the gearbox & mounting tray to strip, prime & paint....



& I've got to remove the snapped off screws from the water jacket side plate mounting blocks, re-tap the holes & find something else to go in there. & I've got a snapped off stud to sort out on the exhaust expansion chamber cover (as you may have seen in the photos, there was a stud & nut missing from the round cover plate). All that's got to be done before I put it all together properly, so there's a chance we might get the lighter piston in there (would be nice, then it would still be a proper P6, although I'm told they also made a P5A which was a faster & more powerful version of the P5, much like the P6 but, I think, with an iron piston).

Not the end of the world if it doesn't make it in there.

I'm also not sure what to do about a trolley. I've been looking at the one it was on (the one I've been using for just about every other engine) & I reckon, with some modifications, I could re-use it. But, ideally it would need another set of wheels, & I would have to go for plastic, like I used on the Kohler.

Still need to find a water tank & sort out where to mount the petrol tank. Although it's a pumped cooling system, so the tank could be pretty much anything. Could even go for screen cooling, like some of the Listers used.


I think Stu might've missed my comment about getting another engine. I was expecting a load of questions. Oh well, I haven't even got it yet, so I'm not counting any chickens.

I got a little further with this one this afternoon/evening as well. I didn't get far with the paint stripping, as it was too hot out there in the sun. I will continue it tomorrow.

But I did get that pesky broken stud out on the exhaust expansion chamber. I tightened the cover plate on with the 3 available nuts, found a drill bit that fitted the hole in the cover plate exactly (just happened to be the M10 tapping drill size, which is 8.6mm). This gave me an accurate centre dimple on the snapped off stud. then I took it all apart, swung the bench-top pillar drill round, so I could get the barrel under, set it all up nice & straight & drilled a tight tapping drill in there, the correct size for the 5/16 BSF thread, then tapped the hole. I think it all worked out perfectly & I got the original thread, as I can't see any trace oh a double thread in there & it all goes together very nicely....



Now I just need to do something similar with these (the lines of weld are to build them up where they've corroded, I'll get to that in another post)....



They go in here....



& hold these on....



But I also need to find some countersunk brass or stainless screws to go in there, so they will probably end up being re-tapped metric, depending on what I can get my hands on.

I also started cutting some gaskets for this one, before coming in to go to bed. I will finish the gaskets in the morning I suppose.

Nice going Nut,
One man's broken engine is another man's new project, it's not like you are destroying anything by pilfering from a downed engine to make another work again.

Take a break will you? No wonder you caught that cold! to busy to rest lol.
I'm the same way when it comes to working my job, can't stand it and love it! I'm even to dumb to stop for food sometimes, my mate says "don't worry..it's ADD/DS"
Good excuse though.

I sure wish I had a good reason to pack up my bits and move to the UK lol.
There doesn't seem to be a shortage of "interesting" engines there.

God speed Nut, I'll be watching,

Regards, John.

nutgone wrote:

I think Stu might've missed my comment about getting another engine. I was expecting a load of questions. Oh well, I haven't even got it yet, so I'm not counting any chickens.

Yes I did but I've not missed this one If you want to play your cards close to your chest till you get it then that's fine or you could spill the beans now and keep your fingers crossed you still get it.

I see your doing all the pain in the ass jobs Nuts, there ackward, time consuming but they have to be done at some time.

Stu.

Yeah, I was cutting gasket until about 10:15pm last night. Still, I reckon it'll all be worth it, she'll look lovely when finished.

That's good to hear that theres going to be another well presented engine your going to be doing soon (fingers crossed you get it). You sure are working late to get other jobs finished so you can clear some space for it and maybe making a few quid by selling something. If I was in your shoes I'd sell the Ruston and either buy a new phone or change your number.

Stu.

Too late Stu, he knows where I live.

nutgone wrote:Too late Stu, he knows where I live.

Well we learn by our mistakes :stick lol: :stick lol: :stick lol: :stick lol: :stick lol: :stick lol:

Stu.

OK, I've been working hard on this one as well as the Ruston Hornsby 6PB (which is now out the way). So between jobs on that I've kept busy to keep this project moving on.

I managed to drill the old brass screws out of those blocks which hold the water jacket plates on, & re-tapped them M6. it wasn't the best drilling-out & re-tapping job in the world, but it was good enough for these. I also welded a few lines along the top & bottom edges of each one as they were a bit short due to corrosion on both sides....



I later ground the weld down & re-shaped it so they would fit in nice & square & clamp up tight. I ordered some M6 countersunk screws to put them on (they're supposed to be raised countersunk, but I could only get them in stainless & I wanted to remain as aithful as possible, so went for brass). plenty of sealant & some nice 0,8mm gaskets & they're back on (took 2 attempts to get it absolutely right though )....





I also put the magneto back together after giving it a really good clean up & service & putting in a new condenser....





Not bad considering it came from a batch which all looked like this....



(GT85 made the top cover shine again )

I also ordered some Tesnit & made myself a new head gasket....



Today I got a visit from Mark, who just happened to have an aluminium piston which is a +.010" size, which is perfect for this engine. We came to an agreement to do a straight swap for my cast iron one so now this engine is back to the full P6 spec (apart for some very minor differences with the exhaust porting, but the actual port area is the same, just the later barrel has one port whereas the earlier one has 2 close together, but like I say, the area is the same, if not more on this earlier barrel)....



This piston appears to be brand new. If it isn't new then it's been very well cleaned. Anyway I cleaned it up & checked the rings. they each needed a tiny bit filed off to be correctly gapped, then I heated it up & put it on....



I've also been doing some painting. It took some doing but I managed to strip the gearbox & the last few mounting pieces back to bare metal (I had thought about just sanding it all down, priming over the top & painting like that, but as I had taken such care with the rest of the engine I thought I should continue this right the way through)....

So off came the horrible green....



All back to bare metal....



& a good coat of some quality red oxide primer....



That was last night. Tonight I have given them a good top coat with the same green as the engine. I will pick out some of the parts in black later on....



& the tray it all sits on....



I would like to know if the tray & mounting blocks are genuine Stuart Turner parts or if they've been made by whichever marine engineer originally installed the engine? I've had to chop the corner off the tray as it was so rotten. I haven't got any arc rods thin enough to repair it & I don't possess a MIG welder, so it will have to be left off as a "drain corner" for now, as there are no drain holes in the tray whatsoever.

OK, I think that's about it for now. A massive thanks to Mark for doing the piston swap. it wasn't necessary to get the engine running, but he knows what I'm like when I get a bee in my bonnet about these things. When this engine goes back together I would like it to be up to the correct standard so that if someone did want to put it in a boat they could. I will be advertising it in the boat engine section when time comes to sell it, but I might try to sneakily hang onto this one, as I've always liked the looks of the Stuart marine engines.

I'm not going to rebuild the gearbox though. Even the Stuart manual tells you not to take them apart unless it's absolutely necessary. It all seems operational anyway & there is meat left on the forward clutch, dunno about the reverse clutch as I can't see that one, but I guess it's fine. There's certainly no signs of any problems in there anyway.

Should be ready for a test run when I can get my hands on a magneto drive coupling.

matt
the set up is coming allong well again i see there mate
ive still not found a coupling for you matt ,raymond and me had a clean out in there yesterday ,theres only a few more boxes weve not been trough yet
as weve not found the wico a mags and parts either yet should be geting them out in the next few days so fingers crossed i may find one for you when that tub of wico misc comes to light ,as i remembered buying 2 or 3 this winter of a add on here
kev

Stuarts are nice engines but they go for a fair bit

Lewis, how are you? I think your PM inbox might be full, I found a few old messages to you stuck in my outbox (they should've gone over to "Sent Items" if you had received them).

Hope you don't think I was ignoring you. Did I send you that photo of a racing NSU Quickly? (Yes, you heard me right, a racing one ) let's see if I can find it....

Here it is....



I seem to remember you saying you had one that was left to you in your Granddad's old collection.


BTW, what you say about Stuart Turner engines fetching good money. If I told you how much I paid for this one you probably wouldn't believe me, it was very cheap. But I've had more then my fair share of problems with it .

Done a load more work on it today, I will report on that in a minute though.

OK, so today I thought I would finish off painting the gearbox & sort the trolley out. I also had a bit of metal fabrication to do, but I will get to that. First the trolley.

I haven't really got the money to splash out on a new one, & my carpentry skills leave a little to be desired, so I thought I would try & make the best of the one it came on.

First problem to sort out; it was badly balanced. As a barrow trolley, if you lifted the handles the weight distribution was such that the whole thing could easily up-end itself, so I moved the wheels further away from the feet, which should sort the problem out. I haven't moved them far, but it should be enough. There will also be some added weight at the other end eventually, as that's where the tanks are going to go.

With this done I decided to get the engine bearers put in the right place (one was fine, but I had added another for the Kohler, which needed removing, & moved one of the original ones which needed moving elsewhere (not back where it came from though, as that wasn't quite right). I also did what I could with the wooden handles, but I think they may well end up coming off & being replaced with something else (not quite sure what yet). To hide a lot of rubbish old varnish & paint marks I decided to paint it black with the same "Bituminous Paint" I used on the Kohler trolley (it's excellent stuff for wood, much better than using gloss paint as it shouldn't ever flake off)....



I also finished off painting the gearbox....



Picking out a couple of bits in black (gloss this time) to break up the green a bit (& I'm running out of the green paint). I also did something which is becoming a trade-mark of my work, I picked out the oil drain plug in red. I did this with the Briggs & the Ruston (not sure if Mark spotted that or not) & I was going to do it with the Kohler (& now I think I will). I quite like it, & I notice a few of us have our little marks we like to put on these things, like Abes with his gun-metal black finish he likes to give his engines (which is a look I really like too)....



Anyway, onto this bit of metal fabrication. I'm using a barrel from an earlier engine on this one, a P5 to be precise. Here's a pic of Abes' P5, take a look at the starting handle shaft (the starting handle operates the flywheel by a chain BTW)....



Now, my later design has a different starting shaft, much shorter & with 2 mounting points on the side of the barrel....



Here's a pic of a P5 barrel (in red) next to the P6 barrel to see what I'm up against....



& from above....



The earlier one had the longer shaft with the 2nd mounting point on the gearbox.

I had originally intended to cut the shaft short & just have the single mounting, but as I put it together I could see this wouldn't work. These engines have a lot of compression for a 2-stroke, & if the next owner was to be heavy handed with it, that small casting which holds the shaft onto the side of the barrel wouldn't last long.

So it was on with the thinking cap. I decided to utilise a few inches of a piece of old angle iron Ian left round here for me to fabricate some tank mountings on the Briggs (still not done!). I marked the shape of the curvature of the barrel onto it by using the spare cylinder head I have & after a lot of "sculpting" with an angle grinder (don't try that at home kids) & some drilling & tapping I finally had the other shaft support mounted & lined up. I quickly painted it & took some pictures....





The hole I used to bolt it on is not used on this engine. this was used on the earlier brass Stuart carbs as part of the throttle linkage, but this is a later engine, so the hole was going spare. it took a lot of lining up though, but I'm much happier it's on there now.

After dinner this evening I went back out there & painted the underside of the trolley with the bituminous paint, then I took the masking off the gearbox to reveal the drive side (looks very technical, I was dying to take the gearbox apart but even the manual says not to. Maybe I will dismantle the one of the donor engine :chin: )....



& I made up a new gasket for the joint....



Hopefully tomorrow I can start to mount the under-tray to the trolley & then start to mount the engine to that & the gearbox to that.

It really won't be long before I can give her a test run. I just need to source some cables for the throttle & choke on the carb & some levers to operate them. They're the kind of thing you'd get off a scrap lawnmower. I did have one cable with the engine, but I pulled the nipple off (ouch! ) trying to get the stuck throttle slide out. I will try my local lawnmower man, he's very old school, so might have a few old ones knocking about I can have. Otherwise I will have to source or make new ones (I haven't made a control cable since my early teens).

I just remembered, there was a cable & lever on that Vincent 2-stroke engine of Ian's. I'm sure he wouldn't miss them.

Great work as normal Nuts, not long before it's finished, is there anymore problems you know of that need sorting or have they all been solved now?

Stu.

Cheers Stu. The only problems to overcome now really is plumbing. I've got to plumb in a petrol tank & a water coolant tank (although the water could be run into & out of a bucket using some old garden hose for now). I think I've got a Villiers tank I can use for now for petrol, until I can find something better (or it may just end up with the Villiers tank or good). Not sure about a water tank, but I'm sure I will find something.

I also need to make an exhaust, but the outlet is just a straight forward BSP male thread, so I can get an adaptor fitting & make something from copper tube or steel/iron barrel (I would prefer barrel, but for ease of fitting it will probably have to be copper, as I don't know anyone who can thread barrel pipe for me). I may wrap the exhaust with heat proof lagging tape, like you have to on boats these days, just to give it that maritime feel .

I did a bit more work on it today, I started off by getting the tray & engine mounted to the trolley....



Then I added the gearbox (after a LOT of faffing about)....



Then I added the flywheel, put the mag back on (that had to come off to get the gearbox on) & put a few other bits & bobs back on, so it's slowly taking shape....





Now it's just the plumbing & cables to sort out & a mag coupling (which may be sorted now, but I'm not sure, so if anyone still has one then let me know, as I may still need one).

I'm going to try the mower shop tomorrow for the throttle & air-slide (choke) cables, if he's no good I will try a bike shop, as I will also need a lever of some sort & an old gear lever off a push-bike will be ideal if I can't find anything else suitable.

I'm happy to report that the gearbox is in good working order, as far as I can tell. No rumbling bearings & both forward & reverse gears engage & work as they should.