I was wandering if Toad has anymore info on his work on the AP .061. Also, how many gaskets go under the cylinder, and how many spacers go under the Nelson head? I tried to report one of my AP's, but it only runs with the starter turning it over.

Hey Rob

I use the Nelson Plug, I obtained a Galbreath head that did not have the combustion chamber cut into it.
I cut a chamber using a .312 ball end mill in the tailstock of a lathe. I did not use the stock head gasket that came with the ap, it was .008 thick. I used one .002 norvel gasket. I cut the case/cyl face down to give me a .008 deck using the .002 gasket. Along with my other mods, this engine setled in at a little over 30k on 40% fuel. I have ran 12oz of fuel through it so far, I have not mounted it on one of my planes and flown it yet. I have been busy doing other model things latly. I will let you know how consistant it is set up like I do my VA's or Norvels. So far, it looks like it will be a bit on the weaker side in comparison. I wish the piston/cyl fit was a bit tighter.

Toad,
I'm a rookie at this stuff , so be patient with me. Just wandering if a new AP piston in a used Norvel cyl would be a tighter fit? Exactly, how do you measure deck height, and could you make a rough drawing to show the areas you removed material from when you reported the AP cyl? Thx.

I have not tried fitting an Ap piston in a norvel liner because the norvel piston has a plating on it I believe. I dont think the AP has any surface prep on the piston other than it being "well" lapped (too much) I am not sure the two would work together. I really am not sure about this, and with the availibilty of Novel Cylinders I just dont want to chance it.
Deck Height is measured from the seating surface of the head on the cylider to the piston resting at top dead center. it is the clearence between the face of the head and the piston, gaskets affect this of course. I cant produce a drawing of this, I am just not that skilled at all this fandangled computer stuff in my old age.

The material that is removed is the face between the case and the cylinder. this will lower your timming some which can be corrected by re machining the ports. Lowering the cyl makes the piston tighter at the top also. What you do is measure the stock deck, then decide what you want it to be using the right gasket, face off the case the difference, raise your ports the same amount. All works out good in the end. You do need to do this on a good mill and have the skill to measure correctly with the right tools. It is very fun to play with these small engines like this.

edited cause I cant spell or type well

Thanks for your info. I drilled out a stock AP carb. to 11/64" and used three Norvel glow gaskets with my Nelson adapter, it sounds like it has more RPM, this is with a stock cyl. I'm using these engines on a 1/16 scale toy tractor in a hobby called Micro-mini tractor pulling. Check out the web site at, www.nmmtpapullers.tripod.com. I have lots of Norvel engines rat holed away, but need to figure out the AP for when I use all of the Norvels.

Rob,

The Norvel uses a nickle plated piston so the AP piston would not work. What would work would be to get a complete piston and cylinder set from AP and just drop it right in.

Thanks. I thought I would try that, along with reporting the AP, since the Norvel has a bigger carb port.