gkamysz

My Feedback: (19)

I see that RCEXL ignitions are rated to 8000RPM. Will they run faster than that? I thought I've read about glow conversions running at 10-12 kRPM. I'm about to install one on an OS FS-52, but would hate to go through all the work and find out it doesn't work.

RC Extreme power

My Feedback: (24)

From what I have read, Once you go over 8,000 rpm the timing starts to retard, Don't think you will have much luck going over 8,000

Milton

Ralphbf

My Feedback: (27)

At one time Ford made distributors that retarded the timing in the upper RPM range, what ever that was.

The claim was more HP. I would assume it would of been around the 8,000 rpm range.

pe reivers

I measured a very slight retard above 8000 rpm. This would not be detrimal to power. The higher combustion chamber turbulence at high rpm makes a quicker flame front and needs slightly later ignition.
For 50cc engines, the 8000 rpm should be a limit anyway due to noise generation, unless one wants to run too small props for racing. In that case, the pickup could be moved to about 2° more advance if needed.

gkamysz

My Feedback: (19)

2° is not enough to worry about. I figure it won't run much over 11k even in the air. I'll set it running anyhow. Reduced volumetric efficiency at high part throttle should prevent any sort of detonation where the 2° is reintroduced. I am wondering if I'll see the advance from 18° BTDC at idle to full advance at 4000 RPM. In normal flight the engine shouldn't spend much time there anyhow.

Thanks guys,

I'll post the results next week maybe.

Pe, On a side note, have you any experience with Runtronic ignitions? I have a unit second hand. Seems it might be 15 years old, but it works. I'm saving it for a smaller four stroke conversion, maybe an OS 30.

pe reivers

No, I do not know that ignition.

My measurements on the RCexl ignition showed about 21° delay at idle rpm of 1500. I set my 58cc at 27 BTDC, so at idle it will be at 6° BTDC. This provides a very reliable tick-over, just as good as the ICU ignition.
The zenoah guys make eyes at me, not to say they are jealous

gkamysz

My Feedback: (19)

I thought the manual states 18° BTDC as the idle advance, maybe they meant 18° retard from full advance.

Runtronic doesn't seem to have a website. The are made in Sweden. http://www.westonuk.co.uk/index_166.htm

Jezmo

I measured a 23 deg. retard on mine (I was told it was supposed to be 24 deg but can't remember who it was I was talking to) and I have used it on my SuperTigre 51 which turns just over 15,000 on the ground. I have never heard it misfire so the limit is over 15,000. Bill or Terry at CH can probably tell us what the limit is as the RCXL is based on his design.

pe reivers

My test bench electric motor would not run down reliably below 1200 rpm. and I tached the timing disk using the ignition strobe light. If I had been able to go down to a stable 600 rpm, I probably would have had more delay, but who knows?
I know that the delay is such, that the engine will not kick back if normally flipped over. To play with the prop in a lazy fashion like is possible with Vlach and ICU is foolish though and the engine will hurt you

captinjohn

Looks like some good RC goodies on this site...just click http://www.westonuk.co.uk/index_166.htm Best Regards, Capt,n

Iflyglow

My Feedback: (79)

I am running RCEXL Ignition on my Baby Zenoah 20, and it performs perfectly at close to 10,000 unloaded in the air. It is propped @ 9,000 on the ground.

togatoga

My Feedback: (42)

Are those in pounds?!!! I can buy a 52cc engine with change back for one ignition unit.

gkamysz

My Feedback: (19)

The RCEXL seems to work just fine on my FS-52 at 10kRPM. I see it listed as good for 12kRPM on some sites.

Yes, those are Pounds Sterling for the Runtronic ignition. I think you could subtract VAT, but it's still expensive. There is a company in the US that had(?) them and the basic unit was 200USD. I emailed and never heard from them. I got mine off Ebay for $24, it even works!