classic motorcycle forum

Very nice. Could I have the frame number please? It is likely on the right side of the seat lug.

Re engine: depends a bit on the frame number. The early version of this frame was usually fitted with the overhead-inlet-valve Fafnir single, thus the very narrow lugs. When Healing gained access to Precision engines, they fitted 500s to this frame using aluminium spaces between the frame lug and the engine plates. Some of Healing's customers - maybe even Healing themselves - fitted the 4 1/4 hp Precision (600cc) to this frame, but to do so the front down tube had to be bent forwards because of the bigger crankcase. It would seem wrong to do this now. If a 600 Precision were fitted to this frame it would have had Precision on the magneto chain case. PRECISION BIG FOUR was a Healing trade name that was only used on the "new" bikes (in new frames) that came out around August 1913.

Anyway, I can guess engine based on frame number, as Fafnir engines in this frame stopped when the new Peerless frame came out in August 1912, but Precisions continued. It's such a nice frame - many have been cut down to lower the seat - that it would be a pity to put the wrong engine in it. Missing petrol tank is Davison and hubs were Chater Lea.

Leon

Any idea which Villiers engine this is?

Well update on the nuts. I could not find the correct sized bar at any of the local steel merchants, so even looking at internet sellers gave no joy. The price of a tap to use once or twice was prohibitive so I just counted up the number I needed and added then to my Hiscocks order. Still not cheap but will be the right size and should fit with no dramas.

Thanks folks.  You have to love the vintage motorcycle community.  No matter how unusual the bike is or how strange the problem, somebody out there has ideas and tips they are willing to share.
I'm off pursuing some of these now.
Thanks.

If you want a really good picture of an original manifold, 'The Vintage Motorcyclists' Workshop" by Radco contains a full double page photo of his restoration of the same model. Pages 180 and 181 to be precise. Its a photo of the timing side so gives you a good view of the manifold.
Radco also wrote a fairly extensive article on restoring the engine for the Vintage Motor Cycle Club Journal. This would be back in the late 70's. early 80's as his book was published in 1986 and was mainly a compendium of all the restoration articles he had written for the Journal over the years.
He wasn't complimentary about the engine but I think anyone trying to beat Villiers at their own game back in the early 30's would have had a tough job. In the end Cov Eagle came back to the Villiers fold. They made a better and cheaper product.
All that aside I think looking at 3D printing is the way to go. I've made one batch of inlet manifolds. Made the patterns, got them cast and then machined the result. It is not as simple as it looks. Making a pattern the foundry was happy with was a learning curve in itself but the big pain was making a range of jigs and fixtures to hold the castings so I could machine them afterwards. Not as simple as it looks. I realised early on that making a batch was no harder nor dearer than making one so a batch it was. No one was interested in my efforts nor wished to help nor put money in until I appeared with the completed batch when desperate owners needing one just appeared out of the woodwork. All the extras went amazingly quickly.
It's 3D printing for me nowadays and that is more involved than you expect.
Have fun.