I've seen a few people taking online about the new TT90 Pro engine -- but can find no information about this engine.

Does it exist -- or are some getting confused with the TT90H (helicopter) engine made by TT?

I love my existing TT engines and would love a 90-sized mill, especially if it's not much heavier than the TT61 engines.

If someone has some specs, prices and sources for these engines then please share!

I saw it first on the box of the Rare Bear ... I think its just a TT61 that is bored out.

My lhs has one, looks like a bored out 61. The casing is similar in size to a 61, but the engine is 1 oz lighter than the 61. I believe its a ringed engine (can verify if you want). Looks like it will be a good performer.

The only thing I did not like about it was the price (similar to os 91).

See the European distributer's site:

PRO-91 509190 14.96 28 24.3 1900~16000 2.75/15000 562.2

http://www.thundertiger-europe.com/flugmotoren.html

The Pro 91 exists. I bought mine from Quantum Models. It's on a Model Tech Delta Fighter 90, with a Performance Specialists muffler and a APC 12x8 prop.
My engine, about 30 days old, had low compression out of the box and proper run-in didn't improve it. It runs well with excellant power but I'm about to send it back to Ace Hobby for repair. It has a ringed piston. Nice looking. OS91FX muffler also fits exactly. I understand this engine was produced to power the Rare Bear pylon plane. Selling price was $199.

$199 for a TT .90pro is no deal at all. Thats the current price of a 91fx. TT's rep on pricing has always been substantially lower. I would pass on it. Especially on these first round of engines.

I agree that $199 is no bargain for a TT91 2c. Quantum doesn't even list it on their site. I was looking for the TT91 2c for a pattern plane I have as I wanted the .61 size case and weight. I wound up ordering a ST 90 from my lhs for $125. Yes I belive in supporting my lhs, as $5 difference is worth the service he provides. He also carries TT but was not able to get the .91 at this time. BTW, I have a .46pro and a .61pro and like them both.

I gotta agree with bdtsr too. $199 is waaaay to much for a TT. I enjoy my TT pro 46's but I also enjoy my ST 75's. I'd go with the ST 90 well before the TT 90.

Regular Tower Catalog

91Fx $219/$199 Sale catalog-------TT90 pro $199

61Fx $169/$160 Sale catalog-------TT61 pro $117

46Ax $125/$115 Sale catalog-------TT46 pro $95

With that price of a Pro 90, that is not a good way to introduce it to the market. I do consider TT and OS to be equal inperformance but it comes right down to cost. If you have a plane that is capable of a 40-60 size, you can get the TT Pro 61 for the same cost as a OS 46AX.

It's an interesting situation.

Although you can buy a TT61 for the price of an OS46, I'd rather have the OS since the TT61 produces only marginally more power but weighs a whole lot more.

In fact, the whole justification for a 61 sized engine is becoming marginal now that you can buy engines like the TigerShark 56 which are only 0.04cubic inches (less than the size of a little Cox babee) smaller than a 61 but weigh the same as an average 40-sized engine.

With a 61 you end up hauling around up to 1/3 more weight with just 1/5th more power -- and you pay more for the privilege.

I've also heard that the OS91 is not their best engine -- and having seen one run this weekend I have to agree. They're not particularly powerful and the one I saw was totally put to shame by an ST90 that was being run-in in the air so was clearly not tuned for anything like max rpms.

The SuperTigre started easy, was very quiet, throttled great and really put out some power -- at just over half the price, that's the engine I'd be buying rather than the Thunder Tiger -- oh hang on -- I did buy one :-)

You got that right.

[quote]ORIGINAL: XJet

It's an interesting situation.

I've also heard that the OS91 is not their best engine -- and having seen one run this weekend I have to agree. They're not particularly powerful and the one I saw was totally put to shame by an ST90 that was being run-in in the air so was clearly not tuned for anything like max rpms.