The Ghost

Hi All,
Can any one tell me how much HP a Byron 91 Ducted fan can take, looking at building a setup to load up 30cc 2 stroke marine engines on the bench.
Cheers
Andrew

Dave Wilshere

I would say wrong question. I’m sure the limit is RPM, so there is a good chance your 30cc engine will not be loaded enough when it’s at maximum RPM. What is the theoretical maximum rpm your engine will run to?

jofunk

I over heard a few brains talking back in the ducted fan days that a properly tuned 91 DF puts out about five horse power. So if that is true a 30 cc 2 stroke with a belt drive geared to step up the fan RPMs you need would be a little short on HP.

mikes68charger

My Feedback: (34)

Yes max RPM of the motor is going to be your issue, I remember putting a dle 35cc in a little tony, (way to big for this plan) and was running a 12/14 prop but would still hit the 9k rpm limiter from the ignition.

MarkF

I race gas boats and marine engines run around 15,000 to 16,000 in stock form and 18,000 to 20,000 RPMs if modded. Are you loading up the motor so you can tune it to see what advances you made ?

The Ghost

Mark, looking at being able to run new /rebuilt on the stand to reduce run in time and as said to check on mods. Also had this fan just sitting collecting dust, thought I could put it to work.

Cheers
Andrew