Working Merlin Engine Questions

Thank you for all posts so far. MerlinPete – I was hoping you might pop by 🙂 At least it means you don’t get waylaid for too long by me when I next see you on an engine run. I’m surprised about your comment about early mark Merlins out there. I’d have assumed most of them vanished years ago.

Cheers!

You can backward modify Merlins to a degree, yes. It was done with the Merlin III to make it Merlin II spec with later standard blocks after overhaul during the war, but there are still quite a few early engines around for the time being. The MkI at Duxford has a Merlin III, as does the Shuttleworth Sea Hurricane, and, I think, Peter Vacher`s Hurricane. The other recent Spitfire MkI, at Biggin Hill has a post-war Merlin 35 and Hydromatic propeller. There is a good argument for using late manufacture Merlins, but it does go against originality, it`s the owner`s choice at the end of the day.

168,000 Merlins were built, along with a load of spare parts. Engines and parts are still widely available, with a few exceptions, so although some parts are now being remanufactured, such as camshafts, the likelihood of complete engines ever being built is slim. There are 11,000 parts in a Merlin, and the demand would not, in my opinion, be high enough to justify the costs, which would be immense.

Reconditioning is fine. The Merlin doesn`t have any “lifed” components, so parts are subjected to condition, dimension and non-destructive testing examination, and if suitable, refitted.

The failure of the engines on RR299 was aggravated by a tolerance issue between the carburettor floats and the top of the float chamber. I haven`t read the report lately, but it is on the AAIB website, I think.

Pete

I just read the accident report after seeing the last post, what a ****-up! they didn’t say who last did the flow checks on the carbs was anything done to find out or at least check all other operators carbs?

I believe RR299 was due to faulty maintenance/ignorance.