Mig/ Griffon

[Leo]

Re: Mig/ Griffon

Unless you wanted a Griffon powered weed-whacker first time you try to fly it...

[hm66sk]

Re: Mig/ Griffon

Bury it in the fuse with an extension shaft...

With that wing-sweep, the engine would HAVE to be located behind the pilot for weight-and-balance reasons, P-39 style.

If you look at the drawings, that's exactly what he did.

mid engine, fair off the exhaust.

How about grouping all the stacks together in a "header" and pipe it straight out the rear where the jet exhaust was for some additional thrust maybe?

[BellCobraIV]

Re: Mig/ Griffon

Where are the radiators?

[Leo]

Re: Mig/ Griffon

Could the little triangles on the side be NACA intakes? Bury it in the fuse bhind the engine maybe?

[RichH]

Re: Mig/ Griffon

Needs a tail cone too...

[Flyer57]

Re: Mig/ Griffon

Believe it or not guys we have doen a lot of headbanging but it worked because we have a definate thought process on the engine configuration and the Mig 17 empty weight is less than 10,000, so CG and HP and power to weight is in the realm of a 347 MPH airframe. That will get us into the bronze easy.

[tjyak50]

Re: Mig/ Griffon

Just put a 5hp Briggs and Stratton and call it a prop airplane.

With centrifugal supercharger that happens to make substantial thrust.

No different from what Will Mathews had...

[hm66sk]

Re: Mig/ Griffon

Believe it or not guys we have doen a lot of headbanging but it worked because we have a definate thought process on the engine configuration and the Mig 17 empty weight is less than 10,000, so CG and HP and power to weight is in the realm of a 347 MPH airframe. That will get us into the bronze easy.

Seems like an awful lot of engineering, time, work, money, etc. to go for just a bronze.

[spacegrrrl]

Re: Mig/ Griffon

After Reno this year I got interested in what could be a jet converted to racer project. I was thinking R2800 or Gryphon. I was pretty quickly discouraged when I looked at the weight of most of the likely candidates. Most of the older jets you could actually get your hands on weigh far to much. I finally decided maybe a Folland Gnat, Seata, or an Iskra Spark. Prop clearance seems problematic whatever you choose.

Still, would be great to find a path to a racer that is built with less "rare" pieces.

Michele

[bluffman]

Re: Mig/ Griffon

A lot of you are getting the idea. Mig 17 has a longer fuselage than the 15, more stable. Weight of a 17 is just under 9,000 pounds, but I reckon we could get rid of some of that. Mid engine, shaft drive, and the exhausts on the drawing was just to show the engine location, The NACA ducts were just a "how about this". They would be located different than that in reality. My posting this was so I could get some constructive criticisim, as well as negative, both add to my thought process, and are appreciated. Together maybe we can make this happen! Roger mentioned the "Bronze", but that is not what I am shooting for. I will have to talk to him about this tomorrow.

Thanks for your responses, I will address them all in time, one way or the other.

Larry

[bluffman]

Re: Mig/ Griffon

Michele, Regarding "rare pieces", everything racing in Unlimited class is in that catagory, Merlins, Griffons, 3350s, P-51s, Sea Furies, Bearcats, and all. As far as the Mig, there are a lot of them, so I don't consider them all that rare. I don't know where we go from here, but we would all like to see Unlimited Air Racing continue, preferably with "War Birds".

Larry

[B52Hfan]

Re: Mig/ Griffon

Mr. Burton, with your experiences, limiting your choices to 'Warbird' airframes may not be a good thing! Composite technologies may be another avenue. You could, literally, mold whatever you needed. Scaled
Composites, Inc. does that ALL the time. I'm not suggest a 'Rutan
Racer', just the possibilties are only limited by, I really hate to say it,
money! Even a 'Tsunami' like airframe would be great! Really give your metal mashing skills a run!

Whatever you and the team decide, it'll be great for racing! Good fortunes to you, Sir!

[JET1]

I dismissed the same thought...its TOOOOO HEAVY

but it is an interesting exercise in futility!

[spacegrrrl]

Re: Mig/ Griffon

Michele, Regarding "rare pieces", everything racing in Unlimited class is in that catagory, Merlins, Griffons, 3350s, P-51s, Sea Furies, Bearcats, and all. As far as the Mig, there are a lot of them, so I don't consider them all that rare. I don't know where we go from here, but we would all like to see Unlimited Air Racing continue, preferably with "War Birds".

Larry

I don't discount the MIG because it is rare, I discount it because it is too heavy. My point was when you start looking at the candidate jets most of the available ex military jets are considerably heavier than a Mustang. Empty weight of a stock P-51D is 7300 pounds. We know racers have dropped a lot of that. A MIG 17 is 8600 pounds of which the engine is approximately 1400 pounds. So a gryphon even before cooling, driveshaft and prop is a net increase in weight of 400 pounds.

The F-86 which is where I started my exercise is 11,000 pounds. The L-29 which was another thought I had is maybe a better start at 5000 pounds. Those are also very available. The Folland Gnat is interesting at 4800 pounds. Those I expect are harder to come by.

Even if you get past the weight you need to figure out the driveline issues. The engine is probably going to have to go back in the fuselage somewhere and then you need a drive shaft and some sort of nose mounted gear box. Add the issues around controlling the prop and you have a ton of engineering to do, not to mention the cost.

Finally, prop clearance. Its a fun thought project but...

I expect this is why the couple of racers we know about at this time that use jet parts harvested wings and other parts but built their own fuselages.

Seems like you are better off buying a nice Yak-9 and basing a project on that. I's still love to see a seriously developed inline engine Yak racer.

There is one part of this discussion I'd love to know more about. Just what engines are still commonly available? I have heard gryphons can be found although that was some time ago, R3350's were supposed to be easy to find back when they started the "Blind Man's Bluff" project but we hear the "best pieces for one of those engines if you want to race it are all spoken for. What about R2800s? How rare are they? or R4360s? At one time I was told certain dash numbers of merlins were easy to get. Is that (or was that ever) true?

Would picking one of the less common engines really save you anything in the end?


Michele

[hm66sk]

Re: Mig/ Griffon

Even if you get past the weight you need to figure out the driveline issues. The engine is probably going to have to go back in the fuselage somewhere and then you need a drive shaft and some sort of nose mounted gear box. Add the issues around controlling the prop and you have a ton of engineering to do, not to mention the cost.

Why not whack the whole front of the fuselage off, mount the engine conventionally and, move the cockpit back ala Gee Bee?

Finally, prop clearance.

Make it a taildragger!