EJ-22 RPM limits

[barnstorm2]

I need to put the range stickers on my Tach.

Can anyone tell me what RPM you cruse at?

Anyone have a manual handy to check the red-line?

Thanks!

[KenSandyEggo]

Tim, an automotive manual won't be of any help. The EJ-22 develops its peak horsepower at about 5600 rpm if I recall. (So much for our claim that we have 130 horsepower). So if you're redlined anywhere under that, you're fine. Most peak out at about 4800 to 5200 rpm. At least those are the numbers I've seen at full throttle on RAFs and AAI modifieds. Cruise can be around 4200 with a Warp pitched in the middle to about 4600, which I now show with my Prince. Seeing as it has to go in for some....er....re-conditioning, I'm going to ask Jim to slow it down a few hundred RPM. The Prince shows a lot more thrust on take-off than the Warp, but I'd give some of that up for a little more economical cruising. By the way, you don't "have to" put range marks on your tach. Your prop will determine the top rpm anyway. It won't be able to go any higher than what it's pitched for. Whether you're ascending or descending will determine your lowest rpm cruise-power setting. You'll do that by the seat-of-your-pants anyway, as the cruise rpms will vary dramatically depending on the passenger and fuel load, especially in the lead-sleds. That's why I like having a rate-of-climb indicator. (I LOVE GAUGES!) :p You can fine tune your throttle and pitch trim by feel and know quickly whether you're climbing or descending.

[barnstorm2]

Thanks Ken!

That is exactly the info I need.

I am going by the book "How to License a Homebuilt Aircraft" by Paul Bergen Abbott. It states that all engine instruments have to have max and min operating limits marked. Of course since I have not flown it because I don't yet have a AW cert I can't state for a fact what my ranges will be.

I set my Warp Drive prop to 12deg and she put out almost no thrust and the RPM shot right up. I guess I will try 14 deg next time and see how she goes but the info you gave me will allow me to sticker up the dials for my inspection.

Thanks again!!

[KenSandyEggo]

Just to be safe for when it's inspected, I'd go ahead and put range markings on everything. If you have a vinyl sign shop nearby, go in and ask for a scrap of red, yellow and green. You'll probably get them for free or a couple buck at the most. Cut your markings with an Exacto-knife and just stick them on the instrument glass where you want them. Even a small scrap will give you numerous attempts to get them right. You never know what an inspector will be concerned about. Mine told me beforehand to be sure to have a compass deviation card on my panel. I didn't have any markings on my tach because I still had RAF's digital tach. I would have probably completely forgotten about the compass card and another inspector may have had no concerns if one was not there.

[StanFoster]

Tim: I have my Warp drive prop pitched to 13 degrees on my EJ22. It statics out at 5100 when it was 40 degrees out. I would guess that it would probably static out another 100 rpm in these warmer temps. Anyway...the pictures I have posted has my cruise rpm 4200-4300....and 70 average airspeed. It will cruise at 80 if I wind it out more...but I am trying to save my engine. I have thought of increasing my pitch to 14 degrees just to see if my cruise would increase.

[barnstorm2]

Thanks Ken and Stan!

Here is a mockup of how I plan the inital placement of the range stickers. After I get some time in the air with her I will adjust them to meet actual craft performance.

[OzyRuss]

Ej22 injected.......heavy ish flywheel, or light flywheel, which is the better??????......Russ

On another engine ie....sub 4 I had an NSI redrive, which had a light flywheel (alloy), replaced 3 in 3 years (cracking each time)