OS 29R

Max Bowman..... I just picked up a like new OS 29R. Does anyone know anything about this type of engine. [email protected]

Hi Max

It was basically a control line speed engine, although I have heard of them being used on the odd free flight model. They had a big venturi, and used a pressure tap in the backplate. They also came with a factory spinner assy. They pop up on ebay every now and then, and are fairly rare in original condition.

Les

Hi Max

Les is correct about the intended use for the 29R as a speed engine although my pop used his in a B gas size free flighter (still got the engine with spinner). As for use in a class B T/R, don't waste your time unless you want to build a flying gas tank and refuel every 5 laps

Ployd

Read the posts on #19090 on the mMain Forum. The OS oughtta make a pretty good B-T/R engine.

The OS29R was used with some success in B T/R back in the 60's and 70's in Australia. Only mod was to replace the large bore venturi with a smaller one (9/32" - 5/16"). Performance was around 100-105 mph for 40-45 laps on a fuel containing 20% Nitro and 15-20% Zylene or IPA to increase the laps, prop was an 8/8, although the prop to use today would be a 7/8 or 7/9 APC which work well on ST G21/29..