turnnburn

My Feedback: (49)

There will be a 424 and 426 race in my area in a couple weeks. I have a Great Planes Viper that I have raced with an OS .25 engine on it in a local Quickee25 2 pole class but Im thinking I would like to slap a 424 Thunder Tiger Engine on it but Im told they are no longer available. Would like to buy a new in box or gently used one if possible. Thanks

fizzwater2

My Feedback: (61)

one option - the Evolution .46, with the one piece muffler which is currently provided, is legal in AMA 424 racing. Horizon shows it in stock:
http://www.horizonhobby.com/evolutio...ffler-evoe0461

They've been tested, and with the APC 9/6 prop, have been found to have performance similar to the TTpro .40

Otherwise, I probably have a nice used TTpro I could part with. I have several, and haven't been racing that much 424. I'd have to double check at home to be sure any of them are actually worth selling..

So far with the Evo, I haven't heard of needing to do things like replace rear bearings, etc. the Thunder Tigers, at least the earlier ones, had a bad habit of the rear bearing retainer cage coming apart and ruining an engine - most folks changed the bearings to one with a plastic ball retainer in them.

GREG DOE

Turnnburn, If you don't find a better deal, I'll loan you a TT Pro if you like. PM me with your phone number. I've got an Evolution, and so far I'm not too excited about it. I've seen one Evo that was competitive with a good TT. Eventually we will have to figure the Evo out. All you have to do is cover the shipping. If something happens to the TT I'll save it for parts. Greg

turnnburn

My Feedback: (49)

fizzwater2. Let me know if you have one worth selling and your price. Also, do you have a back plate motor mount to go with it ?

jaka

Hi!
Have you tried the Kyosho version of the ASP .40 engine?
This engine is as "fast" as the TT.40 PRO.
Turns a Graupner G-Sonic or RAM 10x6 prop at around 15000rpm on 80/20 fuel at sea level using a Nova Rossi 4 glow plug.

fizzwater2

My Feedback: (61)

Jan - your race rules must be different than ours - for 424 racing, there are two approved engines - the TTpro40, and the new Evolution .46 with the one piece muffler. We only use the APC 9/6 sport prop, 15% nitro fuel. A good TTpro would turn that prop around 16.8+K, sometimes just over 17K. I can't comment on the Evo, as I don't own any. With the 1-piece muffler and 9/6 prop, they appear to be on a par with the TTpro .40

sahartman21

I've used the Evo and it works fine. Some folks have added another head shim to improve the needling. As with any new engine there will be a learning curve to get the best performance.