October 25, 2020, 18:54:23 pm

RCMF Donations

Enjoy using RCMF? How about a wee donation to help us keep you in the style to which you've become accustomed?

Welcome to RCMF. Please login or sign up.

October 25, 2020, 18:54:23 pm

Login with username, password and session length

prop size wanted

Started by propwash, January 22, 2020, 11:12:31 am

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

propwash

What prop size for a 2cc diesel engine, ED compspecialplease, thanks.
Well Flown? tell the wife.

PDR

I'd guess something like a 10-6 or 11-6 for general use, but it would probably turn much bigger props for slow/vintage models (just back off the compression).

These things aren't exactly powerful. Even if it's a real comp special rather than a MK2 "penny slot" you'll only see 6-7,000rpm on a 10-6.

PDR
There are no shortcuts on the long, hard road to success. But if your dad's rich there could a limo service...

PDR

FYI - if the outer edges of the mounting lugs are straight then it's an original "Mk2 Penny slot" (a penny slot should also have no compression lever - just a slot to put a penny into to adjust the compression - but the slot thing was so awkward to use that most owners replaced it with a conventional compression lever or T-bar). If the lugs are scalloped inwards between the oounting holes then it's a "Mk2 Comp Special" which had a bigger transfer port and deeper exhaust ports (giving better breathing and more sub-piston induction) which raised it's output to the dizzying heights of nearly a tenth of a bhp or so! The comp special also omitted the exhaust extensions of the penny slot, but as they were onoy ever soft-soldered on it's very common for them to have been removed (or to have just fallen off) from the penny slots, so it's not a good guide.

PDR
There are no shortcuts on the long, hard road to success. But if your dad's rich there could a limo service...

propwash

January 23, 2020, 12:01:07 pm #3 Last Edit: January 23, 2020, 12:02:54 pm by propwash
Deffo Comp special003.JPG

Thanks I'll try 10" prop.
Well Flown? tell the wife.

paulinfrance

Quote from: propwash on January 23, 2020, 12:01:07 pmDeffo Comp special003.JPG

Thanks I'll try 10" prop.
I had one in the 70's I hope your runs better than mine did,,, :-\
Mode 2 THE only way to fly

PDR

I had one years ago - I was given it when I was a kid and it powered by first C/L trainer. It ran well enough, once you allowed for th fact that it had less actual power than a scottish tory.

You seem to have problems with lots of motors, Paul. Are you sure it's the motors that are the problem?

:ev

PDR
There are no shortcuts on the long, hard road to success. But if your dad's rich there could a limo service...

propwash

Had it for 17th Birthday, Sitting in my attic storage for umpteen years.
Want  to demonstrate it to grand son, lost original prop.
Touch of nostalgia got me. ;D
Well Flown? tell the wife.

paulinfrance

Quote from: PDR on January 23, 2020, 12:10:50 pmI had one years ago - I was given it when I was a kid and it powered by first C/L trainer. It ran well enough, once you allowed for th fact that it had less actual power than a scottish tory.

You seem to have problems with lots of motors, Paul. Are you sure it's the motors that are the problem?

:ev


 I have so many of them, :co , they all ended up working, even my Fuji outboard engine in 1970, with one exception, the OS.40fs that I got on eboot,, I think that the head was 'grafted' on from a surpass,,,

PDR
Mode 2 THE only way to fly