K&B 3.5 engines
#26
Senior Member
Weston made me aces regulations muffler and irun engine first time after 20years.
20% castor 10% nitro
Ma 8x5 scimitar 18000rpm
Ma 9x4 scimitar 17400rpm
Apc 9x4 15000rpm
But ihave great proplems get engine run properly.
20% castor 10% nitro
Ma 8x5 scimitar 18000rpm
Ma 9x4 scimitar 17400rpm
Apc 9x4 15000rpm
But ihave great proplems get engine run properly.
#28
Senior Member
I have one on an outboard, I understand it is a reverse rotation engine. How would I know if its a conventional or reverse rotation? Perhaps that could explain running issues is someone tried to convert an outboard engine for aircraft use?
#29
You can rotate the front housing 90 degrees. I forget which way, but at TDC the crank closing edge should be pretty much centered in the intake. One of the great things about the 2 piece case. Usually the opening/closing is about 40 deg BTDC, and closes about 60 deg ATDC.
#30
My Feedback: (8)
Jeff...I think all of the K&B Outboards could be called "reverse" rotation compared to what we typically use for airplane duty...I know the 7.5's are...and the way they set up the drive system, and the way the prop rotates, it appears they rotate opposite to an air prop.
Take the carb off and have a peek at the crank's induction port as you turn it over to confirm.
Take the carb off and have a peek at the crank's induction port as you turn it over to confirm.
#32
The reverse rotation crankshaft for outboard K&B has a "L" punched on the crankshaft disk and a longer crank pin to engage the PTO.
#33
My Feedback: (1)
Join Date: May 2003
Location: Orangeville, ON, CANADA
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I have two Graupner 8x6 pushers unused if you end up needing them. If it is a marine/DF-timed top end these seem like they will be too much shaft load, I am guessing an 8-6 would probably clamp it down into the 16's. I've seen 8-6 props on piped .25 - .32's.