Kermits Napier.

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Profile picture for user 1batfastard

Member for

11 years 2 months

Posts: 3,652

Hi All,
Just thought I would post the pictures of Kemit Weeks Napier engine god it looks clean (All descriptions and images Courtesy of:-https://www.facebook.com/KermitWeeks Please click link for comments by others and other features from Kermit...:cool:

Here's a shot of it sitting in Andy's shop!
https://scontent-lht6-1.xx.fbcdn.net/v/t1.0-9/26238986_1650600378342368_7860698724729371914_n.jpg?oh=190f2f0beaf3b40f691dc16ade3ac50f&oe=5AF67EAF
Here's a side view of half of the twenty-four cylinders! You will notice the clean cylinder design because there are no intake or exhaust valves. This is a SLEEVE-VALVE engine where there is not only a piston going up and down in each cylinder but a sleeve valve as well that goes up and down at half the piston rate and outside the piston with inlet and exhaust ports cut into each sleeve.
https://scontent-lht6-1.xx.fbcdn.net/v/t1.0-9/26239380_1650600381675701_7295276804947753064_n.jpg?oh=c68e398e62499ff47aa1f0b4cab191ca&oe=5AE8BAD2
Here's the back end showing the induction system with the carburetor located on the bottom. All the levers on the port side are for the engine controls including prop control, supercharger/boost, mixture and throttle.
https://scontent-lht6-1.xx.fbcdn.net/v/t1.0-9/26231631_1650600368342369_8820358940235142402_n.jpg?oh=ef03fa645a7d909cc6491fc79d2c0e20&oe=5AF60C85
Here's the front end showing both round silver distributors with the square silver mags behind them on either side with the vacuum pump on the front port side and the air compressor with fins behind the port mag. The two braided lines crossing up front house all the spark plug leads.
https://scontent-lht6-1.xx.fbcdn.net/v/t1.0-9/26220055_1650600468342359_7472511997148458578_n.jpg?oh=1a0c964ac312ed834003ac85b9236bf0&oe=5AE153FF
Here's a closer shot of the starboard mag and distributor with the air compressor in the rear of the shot.
https://scontent-lht6-1.xx.fbcdn.net/v/t1.0-9/26230215_1650600488342357_6767460718794473865_n.jpg?oh=710a2f8799fd41251d24dea4b9f7bf03&oe=5AFC84D9
And last but not least is the original Coffman cartridge starter that basically holds five shot-gun shell-type cartridges that release expanding gases into a worm-shaft that rotates the engine for starting. There are additional cartridges stowed in the cockpit should the pilot forget to turn on the fuel or the mags!
https://scontent-lht6-1.xx.fbcdn.net/v/t1.0-9/26195579_1650600375009035_3349982210171671071_n.jpg?oh=3e6c43ae62efdca0342282480922fec1&oe=5AF1FADB

Geoff.

Original post

Member for

20 years 1 month

Posts: 1,587

A work of art. A very ingenious design but so complex.

Member for

24 years 3 months

Posts: 3,185

Presumably they also built special mechanics who could work on it, with eight fingers with six joints each on each hand?

Adrian

Member for

8 years 8 months

Posts: 427

I think he's just brought it back from.Vintage V12s as it was either taking up valuable space or left outside I cant remember. Either way it's a lump of an engine! I took a look at Hawker Typhoon RB396s engine at Duxford and my word it's complex!

Member for

13 years 8 months

Posts: 56

Presumably they also built special mechanics who could work on it, with eight fingers with six joints each on each hand?

Adrian


Amongst those of us from outside the UK working on British cars, bikes or aircraft the assumption is that over there all mechanics must be born that way. :-)

Member for

24 years 3 months

Posts: 1,777

Double-jointed with thin fingers was par for the course for those of us trained to work on big piston engines!

Member for

12 years

Posts: 149

Has anybody a rough idea when there was a Sabre running for the last time? I am shure, because of their highly complex maintenance and spare parts situation those engines have not been used for racing boats or tractor pulling after the war.

Member for

19 years 2 months

Posts: 6,044

Probably not too long after the RAF stopped flying the Tempest TT5 (1955)
Nobody in their right mind is ever going to fly behind a Sabre again ; )

Member for

12 years

Posts: 149

I think so, too. I also think, that there will never be a Sabre pulling an aircraft. But 10 years ago I also had the same opinion about the BMW 501. Obviously I was wrong.

Member for

13 years 7 months

Posts: 722

NICE pics!
(saw a cut-away at Duxford)

I think so, too. I also think, that there will never be a Sabre pulling an aircraft. But 10 years ago I also had the same opinion about the BMW 501. Obviously I was wrong.

BMW 801.

But the 801 is nothing unusual compared to run-of-mill radials.
The fan at front is pretty simple too.

Sleeve valves are the big hurdle, but there is sleeve valve radials still flying, so...

Member for

12 years

Posts: 149

The problem of restoring an 801 to reliable running conditions was not the basic engine, which is not too complicate if you have the spares or you are able to produce what you need. The problem is the highly complicate mechanical "Steuergerät", which enables to control the engine and propeller functions with only one lever. In the common aircraft there were three of them necessary. So everybody was wondering how they were able to restore or repoduce this mechanical nightmare.

Member for

17 years 11 months

Posts: 2,605

At the time it was finding a good one to rebuild off memory.That plus documentation.

Member for

16 years 3 months

Posts: 2,841

The Sabre is remembered mainly for one bad reason - it's original propensity to fail catastrophically and kill the poor chap behind it in the ensuing crash.

What is forgotten or not known is that the Sabre, with technical input from Bristol Aeroplane Co on how to make robust enough sleeves, became a reliable engine. It is unlikely that they would have continued to use it in the Tempest TT's until the mid-fifties if it had the reliability it displayed during its early years.

What is a pity is that the stock of engines they surely must have had to keep the TT's flying (Sabres weren't THAT reliable) were completely disposed of so soon after they went out of service, possibly because there was such a small batch of aircraft and powerplants they went to a single scrap contractor. There seems to be a fair number of just about all the late-war/post-war piston engines about even today but the Sabre - hen's teeth :-(

It would be very nice to have a ground runner to tour the air shows but much better, though considerably more unlikely, to have one in the air over here again.

Anon.

Member for

8 years 8 months

Posts: 427

Don't the guys at Typhoon RB396 plan on using a sabre in their project?

Or am I thinking of a completely different engine?

Member for

24 years 3 months

Posts: 9,780

Yes they are -the engine is ex Cranfield

Member for

20 years 7 months

Posts: 504

Currently there are 3 viable Sabre to the air projects, Kermits Tempest, the UK's Typhoon & Canada's Typhoon