Griffon Aero V Griffon Marine

The RR Spit also has the ex Shac Griffon modification, so there should be no difference in flight to the BBMF aircraft.

I seem to remember that the BBMF can’t run there engines faster because the conversation from contraprop on the Griffon 58’s necessitated a completely new reduction gear arrangement built by Rolls Royce and they are loathed to push them!

They are using engines from a batch of G58s converted by Rolls-Royce to single-shaft.
I don`t know if it was acheived with original casings or new manufactured ones. I know that R-R have made new ones in recent years.
BBMF are certainly more limited on how they use their aircraft, and rightly so, especially in view of the high number of flying hours they do.
I would be interested to know what engine settings they keep to, both for the Merlin and Griffon.

Pete

I seem to remember that the BBMF can’t run there engines faster because the conversation from contraprop on the Griffon 58’s necessitated a completely new reduction gear arrangement built by Rolls Royce and they are loathed to push them!

I’d have to disagree – I’d say 4 Griffons going flat out on a Shackleton sounds much better…. pity it’s also a far rarer occurence now….

One man’s floor is another man’s ceiling and all that! :diablo:

Regards
Scotty

Sure, just my opinion of course!
A Shackleton taking off is truly stunning I have to agree. You don`t get that same effect when they ground run them now unfortunately. The 25lb boost has something to do with that!

Pete

BTW, The only time a Griffon sounds good is a high-RPM / high speed pass by the Rolls-Royce SpitfirePete

I’d have to disagree – I’d say 4 Griffons going flat out on a Shackleton sounds much better…. pity it’s also a far rarer occurence now….

One man’s floor is another man’s ceiling and all that! :diablo:

Regards
Scotty

These beasties also had a “sea going” finish of enamel to stop that ‘orrible sea water playing havoc with the ally components of the engine.
I’ve seen ’em in cream enamel finish.
The Griffon’s a horrible looking engine anyway and the marine version is even uglier (sorry Griffon lovers).
Mind you, I bet it sounds pretty good though.

The cream enamel was covered with a yellow lacquer, same stuff that was put on Shack engines and other post-war hardware.
The one in the photo looks suspiciously like it has been painted yellow to me, either that or it`s like one of those cars that is “better” than when it left the factory!

BTW, The only time a Griffon sounds good is a high-RPM / high speed pass by the Rolls-Royce Spitfire, BBMF don`t push theirs hard enough in my opinion, can`t say I blame them either.
Pete

Sea Griffons

These beasties also had a “sea going” finish of enamel to stop that ‘orrible sea water playing havoc with the ally components of the engine.
I’ve seen ’em in cream enamel finish.
The Griffon’s a horrible looking engine anyway and the marine version is even uglier (sorry Griffon lovers).
Mind you, I bet it sounds pretty good though.

One of the ‘boats’ at Hendon is RTTL 2757, a 68 foot Rescue and Target Towing Launch, built by Vosper in 1957. It (she) was indeed powered by two Sea Griffon engines and was capable of 39 knots.

Interesting that the gearbox only provides a 1:1 ratio (ahead and astern)…..presumably direct from the crankshaft then?

Merlin Pete,
The closest I can get to confirming (or denying) the Hendon ASR launch engine fit, came from a friend of mine in the early ’90’s. We were visiting in order to collect some AP’s from the library and my friend commented on the ASR launch, IIRC undergoing strip and repainting. Knowing of my personal interest and professional involvement with Rolls Royce’s finest, he cheerfully advised me that it was originally fitted with Sea Griffon 101’s.

I have no reason to think otherwise, especially as my friend served his career on the RAF Air Sea Rescue fleet.

camlobe

Thanks, makes sense, or as much as it can to someone like me who knows nothing about boats!
I do, however, know about engines.
So, it shows a single speed centrifugal clutch in my manual, but it is not impossible that some were made with a Mk 58 clutch perhaps? Paul Nixon has been involved in working on them I think. It is very much like the Shack engine because it was in production at the same time.

There is no speed reduction. The gearbox is 1:1 straight through ahead and 1:1 reverse (astern!). It contains a pair of huge multi-plate clutches and a differential to provide reversing.

Pete

Merlin Pete,
The closest I can get to confirming (or denying) the Hendon ASR launch engine fit, came from a friend of mine in the early ’90’s. We were visiting in order to collect some AP’s from the library and my friend commented on the ASR launch, IIRC undergoing strip and repainting. Knowing of my personal interest and professional involvement with Rolls Royce’s finest, he cheerfully advised me that it was originally fitted with Sea Griffon 101’s.

I have no reason to think otherwise, especially as my friend served his career on the RAF Air Sea Rescue fleet.

camlobe

The coupling to the vessel’s propeller is to the right of the picture so does that mean the front (or is it the back) of the engine? :confused:

The ‘big box of tricks’ has to be a gearbox to bring the crankshaft RPM down to something more appropriate for a marine propeller (and to provide a reverse gear for going astern). It looks like the crankcase itself retains the housing for the reduction gear so the original reduction gear is possibly used as the first ‘step’ in the gearbox gearing (why change such major components for a very small production run).

Oh, and if we are going to discuss unknown components let us a least use the correct technical terminology…

…and refer to the component as a ‘box of gubbins’! 😀

I was given to understand by paul Nixon (?) that the sea Griffon has the two speed unit inside, but it is not connected; it appears to be a downraught carb on the one in the pic, and I wonder whether the reduction is retained up front, or does the drive come straight from the crank, into that big box of tricks (technical term).

hehe 21 foot carbon hulled Racing boat sounds like a start 😉

I have a feeling that the launch outside the RAF Museum was fitted with Sea-Griffons.
Can anyone confirm this?

Pete

I’d never even heard of a Sea Griffon.

Me neither. :confused:

What were they used in…..an RAF Rescue Launch?

You learn something new everyday. I’d never even heard of a Sea Griffon.

The Sea-Griffon 101 was virtually the same basic engine as the 57 / 58 in the Shackleton but with a single-speed supercharger, so the nearest spec aero version was the Griffon 37.
Sea-Griffons were derated by both RPM and boost to 2500 RPM and +12lb boost which gives an emergency rating of 1450 bhp. Continuous cruising power was 1100 bhp at 2200 RPM and +8lb

Even in cruise it still used more than one gallon of 100/130 grade fuel per minute!:eek:

Pete

In terms of the basic powerplant there isn’t too much that is different but because the Sea Griffon is a marine engine it comes with a lot more added bits.

See the photo I took at Hendon of their Sea Griffon.