Extreme Speed Prop Planes Discuss the need for speed with fast prop planes (Screamin Demon, Diamond Dust, Shrikes or any REAL sound breakin'''' plane)

K&B 6.5 Engine


Old 02-08-2005, 08:08 AM
Thread Starter
My Feedback: (67)
smchale's Avatar
Join Date: Jun 2002
Location: Philadelphia PA
Posts: 2,743
My Gallery
My Models
My Feedback
Default K&B 6.5 Engine

I have two older K&B 6.5 RIRE (Rear Induction, Rear Exhaust) Engines, one is well worn with little to no compression, the other is basically brand new and has a ton of compression. I was unable to locate on the K&B website an owner's manual for this size engine. Is there someone who may have a copy they could scan for me? Ideally, what I'm looking for is specs on the engine, recommended props, plug, fuel, etc. to ensure a long lasting engine. Also, I'd be interested in parts (ie. piston and sleeve) so I can refurbish the worn engine I already have if anyone knows a source? The K&B site seem to indicate this is a 'vintage' engine.
Thank you kindly for considering my request!
Cheers, Sean
smchale is offline  
Reply With Quote
Old 02-08-2005, 05:36 PM
My Feedback: (1)
Join Date: Mar 2003
Location: Over da rainbow, KS
Posts: 5,085
My Gallery
My Models
My Feedback
Default RE: K&B 6.5 Engine

Old Formula One engine? You might try Clarance Lee for parts. Certainly he knows how these engines are set up in terms of head clearance and rear rotor spacing. I had 10 of them about 20 years ago, but sold them off years ago when I switched to X-40's (ST). They will run good for sport flying with 15% fuel, and can run on 65% if you don't mind changing pistons and sleeves after lean runs. Use a long plug, standard element like a K&B 1L, it's not too critical. Keep ground rpm in the range of 20-21 K. Start with a APC pylon prop with about 7 1/2 pitch and cut down to get into the rpm range. I think the rear rotor is set at about 0.004 to 0.006 for proper needle operation. From time to time you should surface the rear rotor backend with 600 paper on plate glass with light oil to make flat. You will burn about 2 oz of fuel per minute with 15%, more with the higher nitro fuels. For long life, I wouldn't exceed 30 or 40%, as the needle get more critical. Fly rich or shut down as soon as it starts to go lean over the top. Oh yea, head clearance depends on fuel, altitude, air density, and prop load. Start with plenty of clearance (0.012 -0.015) and the needle will be broad and easy to set. As you bring down the head, it should remain easy to set the needle. If the head is too low, it will be difficult to set, and you will start to see glow plug damage. Good luck, have fun.
HighPlains is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service