I used Nelson 15's a lot.

Use a prop that gives you 30,000 RPM.  Due to supersonic tip speed you need to keep the diameter under 6". which makes for a low aspect prop.

I only used one Nelson 36.  It has a lot a lot of power.  It takes a strong plane to hold one.

Here is a link to a article written by Henry Nelson on the N36c engine:
http://www.clcombat.info/henrysez.html

I have six Nelson 15's.
Back when it was "all you got" I used 40%.
When the rules changed I used the 10%.

They went faster on 40%.  The engine can take all the nitro you can put in it.
One reason the Nelsons went by the wayside was the 10% nitro 4 mm venturi rule.

They were built heavy to take a lot of fuel and air.  With limited fuel & air it was possible to make significantly lighter engines that would still hold together at reduced HP.

The muffler was another nail in the coffin.  New engines built for mufflers from the ground up put the Nelson out of F2D.

Black Master or Tornado 7x4 cut down to 5.8 x4.

Henry used one(obviously) at our last contest, for speed limit.  It was choked down 4mm or less.  Maybe he can chime in here.  The APC 7/4 trimmed down should work OK too.  I believe he said he was using 10% nitro and 30% oil.  Sure smelled like a lot of Ucon LB625.  It kept up nicely with the 25's. 


Phil C

For high speed operations stick with one the APC long fiber(2x price).

100 with an X15 is an achievement.

It's an achievement to get all castor into 40% nitro.


MM