Spitfire engine out. Safe landing. Lax maintenance to blame.

[Neil_S]

Hi All,

 

I watched a video on Youtube last night of the recent 2025 Duxford UK airshow. At the end of the show they had a flypast of 15 Spitfires and 7 Hurricanes (an eighth had returned to the Czech Republic), which was rather more airworthy examples of each than I thought there were.....

 

Cheers, Neil

[BrendAn]

How do they keep all those Merlin's running. So they have a large supply of war surplus parts

 

[facthunter]

Merlins were fitted to a large number of Aircraft and some Made By Packard. Nev

[facthunter]

 A version was fitted to Centurion Tanks. Nev

[Neil_S]

3 hours ago, facthunter said:

Merlins were fitted to a large number of Aircraft ...... Nev

....including a few Buchons, of course!

[kgwilson]

It's been called "The engine that won WW2" which is rubbish of course but it does say a lot about the fact that it was used in many different aircraft and other vehicles and had a legendary service life. The Mustang which was originally built to a British RAF specification performed poorly with its original Allison engine, but once powered by the RR Merlin became legendary itself.

It began producing around 1000 HP & was steadily improved during the war outputting 2000 HP by the end of the war.

 

 

[BrendAn]

All true , but what about parts availability. Is there a huge stock of war surplus parts about or does someone manufacture new gaskets,valves etc for them.

[danny_galaga]

35 minutes ago, BrendAn said:

All true , but what about parts availability. Is there a huge stock of war surplus parts about or does someone manufacture new gaskets,valves etc for them.

 

https://roushaviation.com/parts-inventory/

 

 

[onetrack]

No-one manufactures new Merlin parts - but because there were so many built, and so many spares produced during WW2, there's still enough new parts, components, and reconditionable parts around, to keep the Merlins that are still running, going for many more years.

 

Rolls-Royce reportedly built around 150,000 Merlins. Final, carefully collated production figures, makes that 168,000 Merlins. 

Packard built 55,000 Packard-Merlins.

Continental built 3000 Packard-Merlins.

Ford of England built around 30,000 Merlins under licence.

Even CAC in Australia manufactured more than 100 Merlins.

No-one has recorded the amount of Merlin parts manufactured, it would run into at least the equivalent in parts to put together around 10% more engines than the above production figures. It could even be double that.

 

The Allies produced lots and lots of parts for their war machines - it was a factor that helped the Allies win the War.

The Nazis put all their manufacturing production into producing fully built aircraft, and failed to keep a decent supply of parts on hand. When a Luftwaffe aircraft broke down, other Luftwaffe aircraft were cannibalised for parts.

This soon reduced the amount of operational aircraft available to the Nazis, and it cost them dearly.

 

Some good info below, but neither article gives the full story of the Merlin.

 

https://www.key.aero/article/many-factories-built-merlin

 

https://www.jrcengineering.com/wp-content/uploads/2020/10/Packard-Merlin.pdf

 

[BrendAn]

4 hours ago, danny_galaga said:

 

https://roushaviation.com/parts-inventory/

 

 

Thanks Danny. Interesting that roush stock the parts. They are well known for vehicle performance 

 

[skippydiesel]

11 hours ago, kgwilson said:

"The Mustang which was originally built to a British RAF specification performed poorly with its original Allison engine, but once powered by the RR Merlin became legendary itself."

 

I stand to be corrected - The Mustang was built to USA specifications by the British. The rest is correct😈

 

 

[danny_galaga]

11 hours ago, onetrack said:

No-one manufactures new Merlin parts - but because there were so many built, and so many spares produced during WW2, there's still enough new parts, components, and reconditionable parts around, to keep the Merlins that are still running, going for many more years.

 

Rolls-Royce reportedly built around 150,000 Merlins. Final, carefully collated production figures, makes that 168,000 Merlins. 

Packard built 55,000 Packard-Merlins.

Continental built 3000 Packard-Merlins.

Ford of England built around 30,000 Merlins under licence.

Even CAC in Australia manufactured more than 100 Merlins.

No-one has recorded the amount of Merlin parts manufactured, it would run into at least the equivalent in parts to put together around 10% more engines than the above production figures. It could even be double that.

 

The Allies produced lots and lots of parts for their war machines - it was a factor that helped the Allies win the War.

The Nazis put all their manufacturing production into producing fully built aircraft, and failed to keep a decent supply of parts on hand. When a Luftwaffe aircraft broke down, other Luftwaffe aircraft were cannibalised for parts.

This soon reduced the amount of operational aircraft available to the Nazis, and it cost them dearly.

 

Some good info below, but neither article gives the full story of the Merlin.

 

https://www.key.aero/article/many-factories-built-merlin

 

https://www.jrcengineering.com/wp-content/uploads/2020/10/Packard-Merlin.pdf

 

There are some newly manufactured parts. If you look at the link I posted, you'll see that pistons, rings and even three differently profiled camshafts are being manufactured.

 

But clearly not fuel pumps as per my original post 😄

[facthunter]

Merlins don't have a Lot of gaskets. A lot is metal to metal. That's where RR gasket cement came from. Cam follower scuffing is common. Most such engines have roller followers. Merlins don't..  Nev

[danny_galaga]

47 minutes ago, facthunter said:

Merlins don't have a Lot of gaskets. A lot is metal to metal. That's where RR gasket cement came from. Cam follower scuffing is common. Most such engines have roller followers. Merlins don't..  Nev

Wouldn't be surprised if some of those racing guys have made roller followers or equivalent for their engines 

Edited Tuesday at 01:43 AM by danny_galaga

[kgwilson]

6 hours ago, skippydiesel said:

 

No it was designed and built by North American Aviation to the original specification provided by the RAF to the British Purchasing Commission. The commission was established in November 1939 to co-ordinate the purchase of war supplies in the USA. https://en.wikipedia.org/wiki/British_Purchasing_Commission

[facthunter]

I doubt there's enough room to do that (Fit rollers)  It's' A known PROBLEM. THAT and the Magneto drive skew gear set up..  Nev

[BrendAn]

4 hours ago, facthunter said:

Merlins don't have a Lot of gaskets. A lot is metal to metal. That's where RR gasket cement came from. Cam follower scuffing is common. Most such engines have roller followers. Merlins don't..  Nev

Don't think I ever worked on a petrol motor with roller cam followers.

Yella terra roller rockers were a flash add on when doing up a Holden red motor.

[danny_galaga]

1 hour ago, BrendAn said:

Don't think I ever worked on a petrol motor with roller cam followers.

Yella terra roller rockers were a flash add on when doing up a Holden red motor.

This is what went through my head when he said it. But those are rockers pushing on the valve stems. I haven't looked at the Merlin, whether it has overhead cams driving rockers or cams on valves.

 

Unlimited hydroplanes used Merlin's and Packard's until the 1970s as well. Would be interesting to see what they did to boost performance. Miss Bardahl for instance ran at 3000 hp 😲

[BrendAn]

28 minutes ago, danny_galaga said:

This is what went through my head when he said it. But those are rockers pushing on the valve stems. I haven't looked at the Merlin, whether it has overhead cams driving rockers or cams on valves.

 

Unlimited hydroplanes used Merlin's and Packard's until the 1970s as well. Would be interesting to see what they did to boost performance. Miss Bardahl for instance ran at 3000 hp 😲

They sounded unreal. I remember them racing at Paynesville in Victoria. Miss bud was the one I recall.

[facthunter]

Just Pour boost into them . Four valve Head and overhead cams.  Lot's of engines these days use roller cam followers. Most American bikes since about 1913 Speedway JAPs since 1932. Nev

[Thruster88]

Single cam with 3rd order lever rockers. 4 valves per cylinder, one lobe per valve. The rocker pivot shaft rotates? Not sure why.  

[tillmanr]

That carries the gear driving the camshaft’s. 

[facthunter]

. The whole set up is not very impressive, Valves are near Vertical . The shafts  each side are for the Rocker Pivots. Apparently the Hydroplane Boys blew up Lot's of them. There's a piece been out of the end of that head casting for a while too. Nev

[Siso]

Not bad for the early to mid 30's though

[onetrack]

I've always been amused at the story (perhaps apocryphal) that reputedly occurred between the RR engineers and the Packard engineers, when the discussions were taking place with regards to manufacture of the Merlin by Packard.

The story goes, the Packard engineers asked for details of the engineering stress and strain calculations on the Merlin components by RR engineers.

 

It's reported the RR engineers replied, "Oh, we never bothered with those type of calculations, we just ran the engine under huge loads until something broke - and then we made that part stronger!"

This news apparently horrified the Packard engineers who normally went into great detail regarding calculations of stresses and strains, and who never considered testing engine components to destruction.

 

I think the best comment I've seen regarding the Merlin, is one that said, "if RR had ever known they were going to have to produce 150,000+ engines for aircraft during the War, they would've designed a different engine".

If it wasn't for WW2, we would possibly only have ever seen a few hundred Merlins manufactured, before a new improved design was produced.