Thoughts on the GP-5?

[JoeCook1]

Re: Thoughts on the GP-5?

The GP-5 flew very often the last three days in qualifying togehter with the other super sport racers, I don't understand why there are no qualifying speeds of GP-5 published on RARA homepage?

For the record, the GP-5, flown by Lee Behel, turned a speed of 309 on Tuesday according to an article in the RGJ. http://www.rgj.com/article/20100915/...owers-airplane

[Kegger]

Re: Thoughts on the GP-5?

The latest EAA newsletter said the engine is making metal and she's headed home on a trailer. http://www.eaa.org/news/2010/2010-09-15_reno.asp

[bflynt]

Re: Thoughts on the GP-5?

This morning they appeared to pack it up and trailer it off. The wing was on the top of a truck and the fuselage was on a trailer.

[440_Magnum]

Re: Thoughts on the GP-5?

I've read is that the engine is an "aluminum block Chevy racing engine." Geek moment here- "aluminum block Chevy" could mean any one of a dozen different things- does anyone know if its one of the many aluminum knockoffs of the old Gen-1 smallblock, or is it an LSx derivative?

The day someone makes an LSx into an airplane engine, we just might finally have an automotive based engine that actually works in an airplane.

[Race5]

Re: Thoughts on the GP-5?

I've read is that the engine is an "aluminum block Chevy racing engine." Geek moment here- "aluminum block Chevy" could mean any one of a dozen different things- does anyone know if its one of the many aluminum knockoffs of the old Gen-1 smallblock, or is it an LSx derivative?

The day someone makes an LSx into an airplane engine, we just might finally have an automotive based engine that actually works in an airplane.

From what I have heard it is a large displacement (400+/_ cui) Rodeck built Chevy small block that is not LSX based. It may have the 18 deg. NASCAR heads on it.

[Arctic Cat]

Re: Thoughts on the GP-5?

Pics I have seen indicate it's old style sbc not a new ls type. big striker at 440 plus cubic inches

How bout this for a conversion http://www.motorauthority.com/blog/1...riced-at-21000

630 hp, 24 month warranty. You think running it on a plane would void it?

[stuntflyr]

Re: Thoughts on the GP-5?

It seems that single rpm airplane operation on automobile blocks never works. Is it that the main and rod journals are too small to handle the constant load?

[GeeBeeZ1931]

Re: Thoughts on the GP-5?

Bah Humbug Bummer! 3 days I went down to the pits and the second 2 were to look at the GP-5. High hopes for the future

[Florian]

Re: Thoughts on the GP-5?

I posted a videoclip of thuesdays SS qualifying including some GP-5 passes: http://www.youtube.com/watch?v=vpBdRthG2Po

[440_Magnum]

Re: Thoughts on the GP-5?

It seems that single rpm airplane operation on automobile blocks never works. Is it that the main and rod journals are too small to handle the constant load?

I would guess it has more to do with harmonic vibrations and the reduction mechanism more than things inherent to the engine itself. You read about lots of really annoying little issues with accessory drives and things like that.

But on the other hand, since *most* automotive engine conversions are Chevy based it may be some particular Chevy issues that cause problems more than anything else. Big-inch Chevy smallblocks tend to have really short connecting rods compared to the stroke length (compared to some Fords, Buick, and Mopar for example), and that creates harmonic stresses that are pretty ugly. They also have smaller rod journals and smaller diameter lifters than those other engines, and all engines with stud-mounted rocker arms can develop some ugly valvetrain motions under certain conditions. Not really slamming Chevy, they've got a great history- but just some particular characteristics that may potentially crop up in airplane use more than other designs might see. The LSx series addressed a *lot* of those things, which is one reason I think it might be better suited. But its not as common, not as easy to modify extensively, and certainly not as cheap. Yet. The other reason I like the LSx series is that its been designed for aluminum from the get-go, not an aluminum re-casting of an originally iron block design.

[ChrisAttebery]

Re: Thoughts on the GP-5?

If you've never been to Bonneville, that is what a Blown Gas Lakester or Streamliner sounds like at about 300mph. Sweeeetttttttt!!!!!!

Too bad it had trouble. I'm sure it will be a force to recon with when they get the gremlins worked out.


Chris

I posted a videoclip of thuesdays SS qualifying including some GP-5 passes: http://www.youtube.com/watch?v=vpBdRthG2Po

[MustangScott]

Re: Thoughts on the GP-5?

Florian,
Thanks for video. Was nice to see Relentless briefly healthy-Damn that thing is fast. The GP-5 ,given the care and expertise, will mature and be fast and reliable. How fast? Who knows. If it had a stock ZR-1 engine in it we would know how fast it would go on 638 HP and 604 Ft/lbs. of TQ.
The expertise to setup the computer with aftermarket tuning software
to lock out the "limp-home" features is mature and available. Or go standalone engine management system.
All it takes is money, lol

[spacegrrrl]

Re: Thoughts on the GP-5?

It seems that single rpm airplane operation on automobile blocks never works. Is it that the main and rod journals are too small to handle the constant load?

That just simply isn' true. There are a number of very successfull automotive conversions flying every day. There have even been certified engines based on automotive V-8s.

Problem is this is a new application and anyone trying to race an automotive engine has to figure it all out from scratch. Think about how many airplane engines have been blown to bits getting them reliable when pushed to racing HP.

I think if they keep at it they will get it sorted. An once they do it will open up a whole new source of racing engines for the super sport class.

Spacegrrrl

[Sven42]

Re: Thoughts on the GP-5?

He keeps threatening to put it on a stick. A GPhedron

Let's hope it doesn't come to that! The plane looks too good going around the pylons and he's put so much in to it. I hope he can find a sponsor or something.

BTW, if anyone is interested in seeing what a GP-5 buzzjob looks like, here it is- http://www.rcgroups.com/forums/showthread.php?t=1135098

Steve

[440_Magnum]

Re: Thoughts on the GP-5?

That just simply isn' true. There are a number of very successfull automotive conversions flying every day.

They don't last as long as Continentals and Lycomings even in the most benign usage. Count me in the "car engines don't fly" camp, and I'm a dyed-in-the-wool car engine geek. 40 years of trying and no successful racers with car engines yet. Odds are it'll never happen. The design requirements are completely different. An engine with the qualities suited to an airplane would make a horrible car powerplant and vice-versa.