Fastest pre 81 fan cooled one lunger?

[poiboys]

Thinking about getting a one lunger for the upcoming oval racing season in Minnesota. What was the fastest pre-81 fan cooled one lunger?

[Long time cat man]

Yamaha made a 292 one lunger that was pretty dam quick in the early to mid 70's. Don't remember the exact year, and not sure if it was fan cooled or free air.

[outlaw04976]

if you can find a 372 jlo they were pretty nasty for a single

[vintage sled head]

some pretty fast machins hade sachs 340ss, like a starjet(mine), of the older cats, and some other ones had it . I know a scorpian did...i think it was a mark3?

[Snojet Steve]

Sno-jets 292cc SST from 1972-74 s probably the best and most powerful 1 lunger. The engines are 27hp Yamaha reed valve/fan cooled with an HD carb. The big thing is that the engines have very mild compression in stock form and there's alot of room to mod compared to other engines.
Even though the engines sit on top of the frame they still handle pretty good despite that.

Yamaha's GP 292 uses the same engine but is outfitted with oil injection. The whole sled is about 20-30 lbs heavier than an SST and the suspension pales in comparison to the Sno-jet. However, they manage to be fast too.

Skiroule's RTX 300 from 72-73' is fast and also handles well. They are sleek machines. They use Sachs 290cc singles with an HD carb and make 25hp.

[snopro59]

I have heard the Sachs 290SS and 340SS are fast. The Yammy 292's are good too. 340 Hirths are fast too.