I recently purchased 2 vintage DynaJet kits manufactured by Mike Hoyt. Along with the assembly instructions was a sheet on modifications for the DynaJet. It references the Feb 1971 issue of M.A.N. for rework of the flowjector. I’d be appreciative if someone could scan it for me. My jets generally start easily and run well. I say mine but they actually were dad’s first. I’m curious if my father made the modifications recommended by Mr. Hoyt. I’d like to read the article and inspect/measure the flowjectors to see if dad did the mods. Thanks!
Hi Mike, doing the Mike Hoyt Flowjector modification means grinding the air intake tube that
directs the air over the fuel outlet holes at a precise angle. This means that you will either
have to hold your air nozzle at the exact angle to cause the fuel to atomize before passing
by the valve petals; or you will have to make a fixture that holds your air pressure gun at
the correct angle. Mike Hoyt preformed the modifications to my jet engine. My Cat-Jet
clocked 158 mph on 70' lines running on Coleman fuel. The model would go a bit faster
if I would keep the model at a steadier altitude. This is hard to do because of the older period
design with the initial nose heavy takeoff fuel configuration, then burning enough fuel to render
the model to a proper CG allowing it to stay in a groove. This model is not designed to
to use the modern jet fuel formula required by AMA current rules. It has a fuel tank that is far too small
for the AMA fuel formula.
I got tired of trying to start the engine while holding the air gun at the correct angle, wasting
air from my air cylinder before the motor started. So I bought a stock flowjector, it came with
the appropriate metering jet(old school for white gas!). I soldered a brass tube onto the stock
FlowJector threaded air intake nipple; this made starting the motor much easier, wasting less air,
and the model still logged 155 mph on the Colman fuel.
My Cat-Jet is simply flown every now and then(three years ago) simply for nostalgia sake.
I hope my posting reply helps make some kind of sense, I do wish you the best good fortune
with your Jet projects. Tony G.
