I have too many engines I want to put on the stand and run. Now, I have another one. Anyone here own one of these? The Hobbico instructions say to use an 11x7 running in the mid-11,000's:

http://manuals.hobbico.com/osm/pre-2...structions.pdf

I guess it's not intended to be a screamer?

BTW, the venturi is huge on this #46 carb, hence the use of the pump.

David

No I don't have one of those but I have one of these. Runs an 11X6 prop to mid 13s. Without the pump.

Dave, I have 2 of the OS46 SF's - both being ABC versions (they were marketed as ABC but I understand they were really ABN) but with the normal carb. I bought my first one in 1989. Well made solid engines with good power but these days they are outpowered by the OS46 FX & AX, also the TT46. Having said that, I love my OS46SF & will never part with it [8D]

To date I've only ever seen pics of the larger bore carb & the pump.

Well done on the purchase !

I really like engines with round cylinders. The Aviastar is a good looking engine. I would maybe buy one if I didn't already have plenty of .45's and .46's. I like my AX .46, but, I like the looks of the SF a lot better.

Anyway, I guess I'll have to run this engine with an 11x6 just to see how it compares.

David

Thanks Bone. I also have an SF .40 "ABC" that I bought new in 1990. It's always been a great running engine, too.

I've wanted one of these pumped engines since back then. Patience pays off.

David

I just had to mess with ya Dave.

What is the muffler bolt spacing on the Aviastar?

Speaking of mufflers, I'm still keeping my eyes peeled for a Fox .15X muffler. I'll let you know if I find one... since I already have mine.

David

Dave, looks like 38mm. Oh you just had to bring up the muffler . [:@]

I have a couple of these engines , a 46SF with the PD04 pump and a 46VF also with the PD04 pump. Mounting the pump can be a hassle, instructions are still available on the net! The carb is a type 7L for the OS 61 but with a smaller bore. You'll be able to see 46 stamped on the carb.The engine works best with a pipe. Power was extremely good. In those days you could buy the pump and carb combo to upgrade your engine. I haven't checked but if I remember, the carb bore and the hanno carb bore was very close.This engine was designed for the Japanese F3A for 40 sized planes. Ahhh memories!

Thanks togatoga. Do you recall what prop it likes best? I have a 40-46 pipe and a new header; maybe I'll set it up.

David

Age is catching up on me I'm afraid. I think I went for an apc 11x8~11x9. The japanese were going for higher pitches like 11x10 because it was the era where everyone was sensitive to noise pollution,but I never had any success probably because i was running 10%nitro.
These engines were designed for 10~20% nitro. It was known as the PA104 pump system and they recommended mounting the pump such that the pump centerline is level with the carb inlet.
The diaphragm pump wasn't very hardy though and occasionally tuning the engine could be a problem.Hope this helps.

Mine Likes the 12X5 a lot! But it's an Aviastar.

Hi Dave.