griffin versus merlin

[eeyore]

Re: griffin versus merlin

I keep hearing how we are running out of parts. Today custom connecting rods are being machined from billets of 4130 steel and they are the strongest available. Other parts solutions will be found. Not enough demand? there are at least as many racing V-12 as top fuel hemis.

[shadow]

Re: griffin versus merlin

I keep hearing how we are running out of parts. Today custom connecting rods are being machined from billets of 4130 steel and they are the strongest available. Other parts solutions will be found. Not enough demand? there are at least as many racing V-12 as top fuel hemis.

I'm going to go out on a limb and answer this one not knowing fully everything involved.

The size of a merlin/griffon piston is probably the reason why surplus parts are still being sought over newly made pistons. Most custom piston shops, JE, Carrillo, Eagle, are set up for SBC-BBC pistons with appropriately sized tooling. Nothing really larger than 4.5" diameter. Merlin is 5.4", Griffon is 6". That's a big jump in size, probably big enough that they can't use their existing tooling to make the pistons.

So the cost went from materials + man hours to materials+man hours+new equipment+setup+getting it right. When you can't spread that initial capitol cost over tens of thousands of pistons it makes each piston VERY expensive.

That's only for the piston, imagine that for all major components!!

That quickly leads to the decision to back your bags and go to the sahara to recoup that shakelton! Much cheaper. Much Quicker.

Those racing WW2 fighters have their work cut out for them!

I give them a for their efforts!

[David E. Wells]

Re: griffin versus merlin

That same Griffon Spit was The Mk14 that ended up in Tiger's collection, then went to the Museum of Flying. The Mk14 didn't have the laminar flow wing that the Mk 21 had, therefore wasn't an unlimited Gold threat. There was an Excellent article in Air Classics by Michael O'Leary & Bruce Lockwood a few years ago.
...No matter how strong the Rods are, in a Merlin you have to keep the center Main-bearing structure from "Wobbling" at High boost/ rpm levels, THAT's what kills 'em. You saw Merlin's Magic's hole in his 1st Allison Rod motor.
...Shackelton motors don't have the 2-speed-2-stage blowers that make the Merlin 61(and above) so effective. There were so few Griffons and Allisons (read P-82) built with blowers like that that Those parts are in Museum pcs, like Capt. Eddie's Firefly.
...EEYORE, What's a V-12 Top-Fuel Hemi? I don't follow drag-racin', I'm Interested.
...Had Stiletto w/the boil-off and a Mouse Motor, I think History would be Different.
...Say the Same for Tsunami...D.

[W J Pearce]

Re: griffin versus merlin

Didn't Clay Lacy run a 5 blade?... Long time ago, but I think I remember it that way. Purple 64 Mutang..He kept it at Van Nyes.

Not that I know of. The only P-51 around the pylons to have a 5-blade was the P-51H of the Whittingtons. The H was running the 5-blade specially built by Rotol for the XP-51G. Only 2 Gs were made and supposedly, they were unstable with the 5-blade.

The 5-blade for the G, while being extremely rare, is back in the hands of John Morgan, who has the only G (in pieces). This prop would not work on the Griffon because..... the Merlin and Griffon rotate in opposite directions.

[W J Pearce]

Re: griffin versus merlin

Also supposedly, the G achieved 498 mph during NAA testing.

[ignomini]

Re: griffin versus merlin

Not directly related to tuning today, but I always understood the Griffon is not a stablemate of the Merlin, but rather developed from the pre-war R engine used in the Schneider Cup racers. Odds are, if it had the parts availability and development of the Merlin, the Griffon could have been a winner today.

[spacegrrrl]

Re: griffin versus merlin

I think the custom parts issue is one of money and demand. Even though on the surface you would think that replicating a lot of these parts is straightforward there are things that come out in testing that never can be expected. These engines were developed in an enviroment where you could repeatedly test to destruction and spares were not an issue. Today you just can't do that. Also, test flying these things when the bugs were being worked out was a risk beyond what what would be reasonable with a racer today. The motor blew up, no big deal, jump out of the plane and someone will have another one.

An example of the challenge is the blower gear set that failed several times on the red baron. Seems pretty straightforward but in practice metalurgy, machining techniques, gear design all were often figured out by trial and error.

Just look at the challenge we still have with the Merlin. Only a couple of people on the planet really know how to put together a wining engine, and maybe the parts you need to do that are now all gone. It may be a while before someone finds the magic again with the parts that are available.

Now if I could just win one of these huge lotteries I could toss multiple millions at a project and see what could be done.

Right now I think you either build a new Tsunami and search for the magic merlin or start with the FW-190 airframe they are building new in Germany and build a program around RW-2800s.

Or maybe you buy Bill Rogers Seaf Furry and see what happens when you throw a lot of money at a 4360! :-)

Hmm, where did I put that lottery ticket.

Michele

[eeyore]

Re: griffin versus merlin

Drag race hemis are v-8 in the the late 70s people were declaring top fuel dead. No parts. Along came Kieth Black and others. True those are big pistons but ever see the pistons out of construction equipment. My big point is we live in an age were anything can be fabricated. I never said it was easy or cheap

[kiwiracefan]

Re: griffin versus merlin

That was the big problems with the griffon's, all the good 5 blade units are currently flying on griffon spitfires, there were some late model Seafires that were fitted with a late model 2 speed, 2 stage griffon 87/88 and contra props, check out the Seafire 47 restoration that Nelson Ezell this machine is beautiful. only the late Seafire 46 & 47 used contra props operationally, and the differences between the two were minor.
But alas, the fact that the majority of the Griffons around today are ex shakleton bomber cells, the props are the Contra and the supercharger set up is more toward the cruising side. That is why the POF mk XIX spitfire has the contraprop, because the powerplant is an old shackleton unit, and not a fighter variant with the 5 blade unit.
Also of note, most of the 5 blade spitfires use a laminated wood propeller blade and not a metal blade. The hubs themselves maybe Rotol, but the blades tend to be manufactured by Hoffman in Germany.

[wyhdah]

Re: griffin versus merlin

I'm going to go out on a limb and answer this one not knowing fully everything involved.

The size of a merlin/griffon piston is probably the reason why surplus parts are still being sought over newly made pistons. Most custom piston shops, JE, Carrillo, Eagle, are set up for SBC-BBC pistons with appropriately sized tooling. Nothing really larger than 4.5" diameter. Merlin is 5.4", Griffon is 6". That's a big jump in size, probably big enough that they can't use their existing tooling to make the pistons.

So the cost went from materials + man hours to materials+man hours+new equipment+setup+getting it right. When you can't spread that initial capitol cost over tens of thousands of pistons it makes each piston VERY expensive.

That's only for the piston, imagine that for all major components!!

That quickly leads to the decision to back your bags and go to the sahara to recoup that shakelton! Much cheaper. Much Quicker.

Those racing WW2 fighters have their work cut out for them!

I give them a for their efforts!

The mountain motors now running in Pro Mod and some of the Outlaw cars are 5 inch bore motors. In an 870ci motor the piston is 4.800 so I think it would be possible to make pistons for these motors. I think the bigger problem is demand or lack thereof as you eluded to. I know the guy building these huge motors is a Nitrous guy and he probably uses more pistons in one year than all the pistons used at by Reno Racers this year.

I would love to see a Fw-190 rounding the pylons with any motor in it.

[hm66sk]

Re: griffin versus merlin

By the way, there is an intact (well, it was when they left it) Shackleton out in the middle of the Sahara desert. It was forced down out there by a sand storm. There are 4 Griffons right there! ;-)

Michele

Let's go get 'em! Really bitchin' coffee table anyone?

[mustang5151]

Re: griffin versus merlin

FW-190 with a R-2800!!!!! I love this forum. What a great discussion we've got going here. That's where great ideas come from. I wish I knew some people around here I could sit down with and have this kind of discussion. I have a picture of a race Merlin on my toolbox at work, and people either think its weird or wonder what the H__L it is. Not much interest in Air Racing in these parts. That's why i'm HERE!!!! Thanks to all, keep the posts coming.

[ebutner]

Re: griffin versus merlin

Not much interest in Air Racing in these parts. That's why i'm HERE!!!! Thanks to all, keep the posts coming.

I know that one all too well. Small town and no one around with the same "bug." Thats why we end up here.

[David E. Wells]

Re: griffin versus merlin

I would love to see a Fw-190 rounding the pylons with any motor in it. [/QUOTE]


YES! A Good Reason for a "Heritage" Racing Class, there's Also a Fw-190D13 with a Running Engine ...D.

[hm66sk]

Re: griffin versus merlin

Are there just no non-contra rotating gearboxes available? The contra props are cool but, as others have stated, they're set up more for cruising rather than high MP settings. Couldn't a four blade be adapted with standard reduction gears? Other than rotation, is it a spline issue?