Engines > Restoration of Model Engines

A messed up Stuart no.8 Mk I

(1/5) > >>

Sanjay F:
I took a break from the Clarkson restoration as quite frankly it was driving me bonkers!  ;)
 
This is an MkI no.8 which means it doesn't have a trunk guide, just a single sided crosshead. The original pictures make it look like its done, painted, mounted nicely and someone has even gone to the trouble of labelling it with transfers.

I guessed that wasn't the full story when I got it as it was cheap, so eyes wide open! The engine doesn't run, the valve has been remade and there was an actual nut holding the valve rod tightly in position. The valve also scraped along the port face and the valve chest. The holes from the ports to the cylinder are slots rather then drilled holes and one is particularly wonky. There is also no valve gland and rod goes straight into the valve chest.

So far ......

Machined the valve so it fits without catching
Made a new valve nut to give the valve some float
Drilled out the valve boss and made a valve gland to fit
Drilled/tapped cylinder exhaust to take 5/16" union
Drilled/tapped cylinder so inlet flange can be fixed
Drilled/tapped cylinder for drain cocks
Stripped off paint and repainted base, soleplate, flywheel and valve chest
Drilled oilway in eccentric

The painted items are now in my 'drying' room which is where the boiler is, so nice warm and I can shut the door to stop dust getting onto new paintwork.

Here's the valve after the above changes, made from Ali as opposed to brass, that's clearly a modern modifcation. I also rounded off the valve guide boss on the valve chest

https://www.youtube.com/shorts/7PtdT8y4b2M

Sanjay F:
More pictures and also I have now detected there's a mix of metric and Imperial ::)

vtsteam:
Really great what you're doing! That port angle really surprised me. So much so that I thought maybe it was an intended  feature for some reason I didn't understand. Since it's square cornered it must have been cast in place, or was chipped out with a chisel. Probably cast in place with a core.

I've seen good illustrations of those rectangular section steam cylinder port cores and core boxes to make them -- Terry Aspin's drawings. I guess that one must have floated out of position during the iron pour, or partially broken inside the casting and twisted.

What do the ports look like at the steam chest end? Are they aligned there?

Sanjay F:
That's a good point, I never looked at the steam chest end! The slots continue all the way through to the ports, you can see them on the photos.

This old advert mentions the ports are cast in, I presumed someone had taken an end mill to the casting and it had gone a bit skew!

Sanjay F:
Made the lagging using Titanium foil to make a template and then drilled through it some copper sheet - it came out okay, a splash of paint and it'll look just like the Stuart lagging  ;D

Navigation

[0] Message Index

[#] Next page