For what it's worth, Al-bronze wouldn't be my first choice for this purpose. Although it has better specifications than SAE 660 for high loads, high speeds, and high temperatures, none of those conditions will found in your gearbox. Despite its specifications, arguing against it are the fact it is ...

As an aside, when I rebuilt my 1928 Ariel (documented in my book 'The Ariel Chronicles') I added copies to my bespoke shop manual of the specifications of ever material I used. These ranged from various bronzes, steels, cast iron, Stellite, etc., to oils, greases, Hondabond, Loctite, etc. Having ...

This bush lives inside the kickstart shaft and is grease lubricated. Can somebody help me with a recommendation for a suitable bronze For what it's worth, I used 544 (also known as C54400) phosphor bronze for the three bushes in the grease-lubricated Burman gearbox in my 1928 Ariel. Depending on ...

Just assemble the cases and do the rest in the frame. I don't like releasing tension on the case bolts/nuts after I've used sealant on the Joint. nev
Assembling an engine in the frame is fine for the agile young men reading this but, personally, I much prefer assembling an engine at a comfortable ...

Damien Towning wrote: Mon Nov 24, 2025 8:02 pmCame across this today so I am a bit late. The answer is yes!

Late, but not too late, since in the meantime I wrote the book:

https://www.amazon.com/Ariel-Chronicles ... uage=en_US

nevhunter wrote: Sun Jul 20, 2025 2:31 amwhen I mentioned finish it was ... where the needle runs and where the Metering is done

Ah, sorry I misunderstood. Oh well, at least it prompted a calculation that someone might find useful or interesting.

I still don't get the need for the middle bore. As a possibly-relevant aside, I already noted in a previous post that Mikuni's needle jets are spaced every 0.0002", indicating that changes at a level of ~0.0001" have a measurable effect. Motivated by that, plus having assembled an instrumentation ...

The surface finish will certainly affect the flow rate. The annular area between the 2.50 mm (0.0984") needle and the rough walls of the 0.125" hole is nearly 4× larger than between the needle and smooth walls of the 0.106" metering-portion of the jet, so the effect of those rough walls on the flow ...

If you've ever been curious what the inside of a pre-Monobloc needle jet looks like (and who among us hasn't spent many sleepless nights thinking about this?), feast your eyes on the two photographs below.

As the first one shows, the annual area between the jet and needle that determines the flow ...

if an old jet orifice/needle can be accurately measured I don't see much of an issue. There's no issue at all with old needles and needle jets, since the flow depends only on the annual area between them. If measurements show they have the as-new OD and ID, they'll work just as well as ones that ...