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Speed,Combat,Scale,Racing => Carrier => Topic started by: Jim Oliver on October 02, 2011, 04:29:24 AM

Title: Talk to me about props for carrier engines, please.
Post by: Jim Oliver on October 02, 2011, 04:29:24 AM

What is a good prop for the TT36 for a Profile class model?  How about the larger (.60ish) engines?

Thanks,
Jim

Title: Re: Talk to me about props for carrier engines, please.
Post by: Randy Bush on October 02, 2011, 08:25:45 AM

Here at sea level, the APC 9x6 seems to give the best times with the TT36 for quite a wide variety of planes.
 
Personally, with a new ABC engine, I do my first test flights with one inch less pitch than I expect to end up with (eg. 9x5).  My thinking is that letting it run free will help with the final break in, and then as I increase pitch, the stopwatch will tell me if in fact there is improvement. 

Randy

Title: Re: Talk to me about props for carrier engines, please.
Post by: john vlna on October 02, 2011, 12:35:57 PM

The APC 9x6 seems to be best for my TT36 with OS 4D carb.

Title: Re: Talk to me about props for carrier engines, please.
Post by: bill bischoff on October 02, 2011, 08:44:22 PM

Here in Dallas we run mostly reverse rotation engines, and mostly on suction. Out prop choices are limited compared to "normal" props, but we are satisfied with the results we get. We use the APC 9x6 pusher for 36, 40, 46 engines. For 60's, it varies by engine. On the OS 65 VRDF, the APC 10x6 pusher is fastest. On the rear intake Webras, the APC 10x7 pusher is fastest. On the front intake MVVS 61, the APC 10x8 pusher is fastest. I have tried Graupner and Zinger pusher props also, but the APC's are decidedly the best.

Title: Re: Talk to me about props for carrier engines, please.
Post by: Wayne J. Buran on October 03, 2011, 04:19:51 AM

So Bill, where do all the reverse cranks come from?
Wayne

Title: Re: Talk to me about props for carrier engines, please.
Post by: Jim Oliver on October 03, 2011, 07:07:12 AM

How does the Webra 32 compare to the TT 36, power wise and carb function?
Thanks,
Jim

Title: Re: Talk to me about props for carrier engines, please.
Post by: bill bischoff on October 03, 2011, 10:43:13 AM

Re: Reverse engines. Any rear intake disc valve engine can be made to run backwards simply by reassembling the parts "wrong". The MVVS 61 was chosen because a factory reverse crank was available. (Same for MVVS 15's)The Fox 36 on my Crusader has a factory reverse crank. All my Wileys were built with reverse cranks because that's what I told him to make. The only engine I have with a non-OEM reverse crank is a Conquest 15.

Title: Re: Talk to me about props for carrier engines, please.
Post by: Wayne J. Buran on October 03, 2011, 04:59:30 PM

thanks
wayne

Title: Re: Talk to me about props for carrier engines, please.
Post by: john vlna on October 03, 2011, 06:40:15 PM

I think the webra 32 and TT36 are about on the same level. The webra carb is pretty good, at least the ones that came with my motors. The TT carb will not work on suction. The fuel nipple feeds into a kind of collector ring that has trouble at fule throttle unless there is some pressure. Muffler pressure is enough, but not allowed in AMA profile. I replace the TT carbs with an OS 4d, it is an exact fit.

Title: Re: Talk to me about props for carrier engines, please.
Post by: bill bischoff on October 04, 2011, 11:23:18 AM

I ran a box stock Webra 36 on 10% with an APC 9x6 and could go 90 mph. Unfortunately, the airplane was a dud so I sold it, and later sold the engine. I don't know how much performance difference you would see between the 32, 35, and 36, but the 36 ran fine with the stock carb, and I think the 32 and 35 probably use the same carb. Alas, more engines they don't make any more.  :'(

Title: Re: Talk to me about props for carrier engines, please.
Post by: Balsa Butcher on October 06, 2011, 11:06:22 AM

The carb on my Webra 32 worked well but it did not have a low idle stop so it was replaced with the OS carb . TT36 got a Perry carb (still being made). This works as well. 8)