Injector identification

[johnd]

A couple of months ago i picked up a quantity of 31/2” loco bits,chassis boiler etc, whilst sorting out a couple of boxes i found a quantity of new boiler fittings including the unused injector shown.
Would be interested if anyone can identify it, might be useful on my Maise.

[uuu]

There's a similar one on ebay at the moment, described as a John Cashmore injector. Ebay link

I've not handled one, but they have a good reputation: modeleng.proboards.com/thread/10988/injector-design-musings

If it's 22oz, it might be too large for a 3 1/2" loco.

Wilf

[millman]

Definitely a John Cashmore injector, I have a smaller one fitted on a 3.5 gauge loco, they had a good reputation as Wilf says. At 22oz it’s more suited to five inch locos.

[dhamblin]

Following the principles in D.A.G. Brown's book I've got a 12oz injector on Britannia, which is sized to suit the pipe bore dia. as specified by LBSC. Seems to be a good feed rate for the boiler size.

Regards,

Dan

[johnd]

Wilf, Millman & Dan thankyou all for your replies, as this injector seems a bit big for my Maise i will put it to one side and use it on my Minx that is in work and about 85% complete.
All the best
John

[simon6200]

Maisie boilers are a good size. I don’t see a problem with a larger injector, you simply leave it on for less time. I’ve run my Simplex with one 26 oz injector (no pumps) for many years. I am more likely to forget a slower feeding small injector is on until water is bubbling out the safety valves.

[johnd]

Thanks Simon for your reply, from your info it seem there is more than one way to actually run a loco with an injector.
My experience in using injectors is very limited. The only loco i have with an injector is a large freelance with an equally large injector that works every time, no idea of the maker.
I cant remember seeing a quick calculation to choose a suitable injector for a loco? Just in 31/2” gauge you have so many size locos from Titch to Caribou.

[jma1009]

Hi John,

The JC (John Cashmore) injectors have a very good reputation.

I certainly ran a 3.5"g 'Maisee' for many years with a standard medium injector of Arthur Grimmett make - 26 oz per min.

Cheers,

Julian

[andyhigham]

Aug 12, 2024 8:02:59 GMT johnd said:

Thanks Simon for your reply, from your info it seem there is more than one way to actually run a loco with an injector.
My experience in using injectors is very limited. The only loco i have with an injector is a large freelance with an equally large injector that works every time, no idea of the maker.
I cant remember seeing a quick calculation to choose a suitable injector for a loco? Just in 31/2” gauge you have so many size locos from Titch to Caribou.

I would say "Tich to Lucky 7"
The lucky 7 is massive with 2" cylinders and a 7" x 23" boiler

The full size loco is about the same size as a Fowler 4F but riding on 2ft rails