Stuart twin launch

[Team ricky]

Hi Chaps,

I’ve wanted to build a Stuart engine for while so picked up a part built one to have a
go !

So far the machining is good in some areas and bad in others…

The bad first is the crankshaft and probably the reason someone stopped, It apparently was turned between centres looking at the ends but assumption is the mother of all cock ups! It looks to be off set end to end so scrap… the big end journals are different sizes…

I usually make one piece between centres but this one I’m trying a little easier in some ways harder in others build up crank, should be interesting.

I’ve normalised some 303 stainless for the job , this makes it a little harder to work with over steel but the end result is what you want for a marine engine.

Pretty much all the valve gear needed making and fitting

Good bits , pretty much everything else you see ! Made very well when checked amend measured, all threads cut really nicely so not a big set back for me.

I tidied up the paint work pretty much straight away .

[Sanjay F]

A nice engine in need of some attention, will be following along 

[tghs]

looking good,, I have some extra Stuart twin castings that I didn't use when making my navy launch engine..

[Team ricky]

Cheers chaps


I’ve fabricated the crank up to completing the silver solder,

All went well, I used 303 precision 8mm, and 2.2mm tapered pins later…

I decided as it was the first soldered crank I’ve made to gently heat everything up below flux melt and held it there for 3-4 mins, then kept a small butane burner on to give background heat , Then used a map gas torch to carry out the soldering, Works well ,

I also pined the webs and journals with copper with the idea if I need to move very slightly any geometry I would have some advantage before soldering! This also worked well and the crank measured well before the heat lol 😂

I fully expect it to move no problem

Next I’m taper pinning the webs via drilling out the copper in each location..

[Sanjay F]

Nice work, looks like a nice solid crankshaft you’ve made there 👍👍

[Team ricky]

Cheers Sanjay ,

Yes it worked out just fine being Silver soldered then pinned….

It all rotates well without slop in the bearings

I’m back to where I started and now working on the valve gear

Cheers Ricky

[Team ricky]

Here’s a quick video just running on one cylinder,

I’m going to the engine for a while just on one eccentric until I make the reverse gear

https://youtube.com/shorts/X27OxDOR1aQ?is=-9aykFO4WOCgOR5j

[Michael S.]

It’s already going really well. The other direction of rotation isn't far off now.

[Team ricky]

Cheers Michael,

I was surprised it ran as fast as it did just on an airbrush compressor!

Hopefully soon I will machine the second eccentric rod ….

Cheers Ricky

[Michael S.]

Hi Ricky

I built the Stuart Compound a while ago and initially experimented with the HP cylinder.

Michael

[Team ricky]

Hi Michael,

Just out of interest as my next engine is the compound version 😁

What did you discover?

Cheers R

[Michael S.]

I wanted to mention that I also tried turning the engine over for the first few revolutions using only one cylinder.
And without the reversing gear, too.
I modified the engin slightly and built it using metric dimensions.

Michael

<a href="https://www.youtube.com/watch?v=WzGeeNbDjPk" target="_blank">http://www.youtube.com/watch?v=WzGeeNbDjPk</a>

[Team ricky]

Here’s the engine running on both cylinders and complete for now

Runs on a whiff of air

https://youtube.com/shorts/pXoTFN-Q7o4?is=LnGpzD_YC21rVkpV

[Sanjay F]

Nice one - makes a great sound! 

[Admiral_dk]

Well worth the effort - nice beat   

Per   

[Chipswitheverything]

Runs very nicely, and is an interesting engine to see in motion.  Nice to display as well ... Dave