What would the power output comparison be between a current .30-.40 four stroke and a .30-.40 two stroke of early sixties vintage? Have plans for project from that time frame.

There are some other factors in that in the early sixties, everyone flew the planes at full throttle and most people no longer do that.

I believe the Saito 30 and 40 to be very close in power to early 60's engines of the same power.

Enjoy,

Jim

4 strokes engine ares really different than 2 stroke

I put in my Super Sporster a OS 70 Surpass II and my boy friend put a 46 fx in his RV4

theses planes have exacly the same weight 5.2 lbs
os 70 1.1 hp
os 46 fx 1.6 hp
in flight the 46 fx have little more speed than the 4 strokes but it loss a lot the speed in vertical vs 70 is really great puller
os 70 start to give the thrust at lower rpm than 46 fx
os 70 have constant thrust and nice put put sound for long long time.....