Pylonracr

I am finishing a Little Toni with an OS91 Ducted Fan engine. What glow plug are people using with DF engines with props on them? I plan to prop it to about 19000 on the ground, which is a little low for these engines, but I am not looking for the last MPH and I think the engine might last a little longer. I plan to run 30% with some casteroil added to bring it up to about 21-22%.

Thanks.

freakingfast

My Feedback: (3)

For 30% nitro K&B HP Glow Plugs http://www.mecoa.com/acc/glowplug/glowplug.htm

For 15% OS #8

Don't run these engines too cool/rich at break-in, richer than you would like to fly it would be about right, good smoke.

Pylonracr

Thanks for the info
Scott

MJD

My Feedback: (1)

With what prop? Sounds like about a 10-10? Watch them rpm versus prop diameter.

An option is Merlin plugs - call for recommendations, I did and bought an assortment of 20 plugs for various engines. So far so good.

Pylonracr

The prop is a 12.5x8.5 Formula 1 cut down to 10 3/4 Dia. I live at 4500' so things are a little weak up here.

freakingfast

My Feedback: (3)

Be real careful, that Master Airscrew Formula 1 prop is way over factory rating on the ground at 19K, even factoring in the cut down. 17200 for Master. Will it let go, I don't know, but I would never be in the plane of the prop arc. It could let go in flight as it unloads, if it does it could kill the plane, engine or both if it throws the blades.

When adjusting the needle be as far back as possible, even better use a servo driven remote needle, which is how most guys adjust these engines during flight. Remember to keep spectators out of harms way.

Pylonracr

Very true.
So far I have only got the engine up to about 17,500 with the cut down prop, which is only a little over the max. You will notice I said I plan to prop it to 19k, I am still looking for a suitable prop for that. The plane has not flown yet, and my running has been on a bench with a remote needle. I posted on another thread my desire to buy some of the carbon props, but I don't think a 9x10 is enough diameter for my plane. If you have any other ideas I am open for suggestions.

Scott

r-c-guy

My Feedback: (37)

Hi

I did the same thing with a 40 to 50 sized Stilletto Mustang a couple of years ago.
It was fitted with an Eagletree Telemetry system.
I used an OS 91 vrdf (best behaved), a Rossi 1.08 vrdf (a beast) and a BVM 96 vrdf (the fastest)
Fuel ranged from 15 to 40% nirto
Plugs which lasted were Rossi racing, Enya 4 and K&B 1L if you can still find them. I used an in-flight glow battery

PM me if you wish...

randy

kmtranmd

My Feedback: (71)

For that rpm range, I've found good durability with the YS/OS 4c (F) plugs. Not sure you can buy the KB 1L plugs anymore, but I did not find them any better than the F plugs.