Posted: November/24/2005 at 5:31pm | IP Logged

You have acquired two premier racing engines for Quickie 500 (Q500) competition racing.  This is an AMA sanctioned form of pylon racing.

They don't have a throttle becasue they run wide open all the time (about 20K rpm).  They are not designed to idle.  They are either on or off.

If you want more info, here's a website http://www.pspec.com/html/nelson.html

Bob Germaine

Posted: November/25/2005 at 10:12am | IP Logged

Just a bit more information. The nelson Q500 engines do have a throttle, but all it is used for is to shut the engine down. The Q40 versions have a large venturi only and run in the 23-24k range on the ground.  Both versions are exceptional engines but are not designed for sport flying. Q500 engines are tuned to run a prop in the size range of 8.8x8.75 to 8.8x9.25 around 19k on the ground. Q40 engines are ment for a much cleaner airframe and are tuned too run a 7.4x8 prop.

Scott Stringham

Posted: November/25/2005 at 4:22pm | IP Logged

Thanx guys.  The Nelson web site shows several engines, but none matches exactly the ones I have.  Mine are both 6 bolt lug mount without a cast N on the crankcase.  The used one is front intake with a small solid spinner 1 1/4 diameter, no prop cutouts.  The new one has a pie shaped rear intake, a very fancy bar stock radial mount and a hollow 2 inch diameter spinner.  They seem quite heavy compared to some other 40's.  Might they be good for freeflight??

I have a Nelson 36 with a square front intake, a very powerful engine that I use in freeflight.  It is AAC and is lighter than these guys.  One of these days I'll fire up the used one and see how it compares. Thanks again.

Posted: November/25/2005 at 8:59pm | IP Logged

The only ones I know that are 6 lugs are the F3d version. If this is what they are they are meant to be run on 80/20 fuel with a tuned pipe at very high rpm near 30k. I don't what is needed for free flight but these engines are very powerfull. I would suggest going to rcuniverse and ask in the raceing forums.  You can post  pics there also.

Scott Stringham