MAGNUM XLS .15

1/2A Nut wrote:How many flights do you have on it and what fuel mix oil / nitro ratio?
What did you upgrade to?

Probably 20-30 flights, powermaster 10/22.
Upgraded to a Norvel .15 with a Perry carb and 35% nitro

Jim

Sorry Jim--- slight hi-jack

I am always curious about forum names and spend (probably too much) time trying to figure out what prompted the screen name

Because I know you from another site with, what I assume is, your real/given name...JPvelo has me just wondering

Cool little engine, I hope someone scarfs it up

Fred,

JP= my first and middle initial.
Velo= French for bicycle

My other hobby/passion is restoring vintage bicycles. In fact I'm selling off airplane stuff to fund my most ambitious restoration yet, a hand built Roberts tandem bicycle from England.

Jim

I have one of these it's a good engine but can't seem to turn up the
rpm I had hoped for here is a bench test.




Published on Nov 29, 2015

Magnum XLS .15A APC 7x5 MACS Tuned Pipe
18,100 rpm / 86mph /.49hp / 2.3 lbs thrust / 366w
Break in bench test ran up for a rpm check
Options:
APC 7x6 est 17k / 97 mph
6.5x6.5 race prop if at 20k unloaded 123mph

1/2A Nut wrote:I have one of these it's a good engine but can't seem to turn up the
rpm I had hoped for here is a bench test.

Published on Nov 29, 2015

Magnum XLS .15A APC 7x5 MACS Tuned Pipe
18,100 rpm / 86mph /.49hp / 2.3 lbs thrust / 366w

These engines are simply not timed for a tuned pipe, thats all.

I have an ASP .15XLS that does around 18500rpm on the APC 7x5 prop and 10% nitro. That's with a "super-quiet" muffler from an old MDS .17 engine.

If you want to use tuned pipes, take a look at some of the car engines. These are inherently timed to take advantage of a tuned pipe and they will really deliver also as an airplane engine. The Picco .12 for instance will spin an APC 7x4 prop at around 22000rpm. That's is a very useful propload/size as well.

Right the XLS .15 only has 150 deg timing

Not much of a window for pipe combustion pressure.
The rule of thumb if fuel starts dribbling out of the carb
while running on a pipe your timing is too low to function.

My test had the header a bit long by around 1.5 inches.
Was a quick check of the top end during break in procedures.
Prop would need to spin static at 21.4k to use what pipe
pressure could slip into the combustion chamber.

The engine will take some more prop testing to get to where I
will find it useful for speed.

APC 6.5x6 should be a better prop solution a carbon 6x6
will have it kicking some arse. Pipe length to MRP should be
10.4in. to hit 24k unloaded. Bench tested at 11.75in. MRP.
It will not be much effort to yield a 130 mph plane. The
up swing of less rpm is longer run times.