Dean Vogel rotax webinar

[Dan Kent]

http://www.eaavideo.org/video.aspx?v=2242926960001

 

Roger,

I have attended the Rotax 2 day maintenance course (not line maintenance or heavy maintenance) mainly to learn more about the engine I fly behind. I recently watched this webinar and most of it was familiar. A couple of points that were new to me was how small their aviation business was (2% of all engines) and they suggest that even the Honeywell solid state oil pressure sender to be mounted on the firewall. I have the Honeywell sender but it is on the engine and the presssures are very stable - maybe 2-3 psi change during cruise. So far I have about 140 hours on it.

 

What has your experience been with the Honeywell unit and should I pursue getting it moved to the firewall.? i brought this up with the US importer of my LSA and they were reluctant to move it. At the time I thought the issue was with the VDO sender and the solid state units were ok on the engine, so I didn't press the issue.

 

Thanks in advance.

[Doug G.]

I also noticed (to bring up an old point) that Dean said specifically for a CT with an adjustable prop to set the static rpm to 5200.

[Jim Meade]

Dean also offered the opinion that hoses on an airplane that was cowled and stored in a hangar may well last 10 years. He also pointed out that one could cruise the Rotax at 4500 RPM (this assumes it is set at the right pitch to run 5500 WOT).

 

Here's the webinar. The presentation is almost an hour and questions take up the rest of the hour and a half. Well worth the time to watch it once, even if you are familiar with most of it.

 

http://www.eaavideo.org/video.aspx?v=2242926960001

 

 

[Roger Lee]

Honeywell had numerous issues. Rotax has changed vendors from what I hear. There is nothing wrong with remote mounting the Honeywell or any other oil pressure sender. Mount it like all the rest. On the firewall and low where it may be a little cooler verses up high in the cowl. The Honeywell will setup just like the VDO on the firewall and getting rid of extra vibration and or heat will always help.

Setting a static rpm at 5200 rpm will put you up at or over 5800 WOT. Great if all you want is a climb prop. You have to take into consideration all the different aircraft, props and especially installations. Rotax basis all its comments on a 5800 WOT setting. We need to balance that so for us a static right around 4900-5000 will put you in a fairly good spot around 5600-5650 rpm WOT. That said you need to determine what your average flight altitude is and prop for that. If you live at sea level and never get over 2'K agl then prop for that. If you live up in the Mnts. and you usually fly around 10'K then prop for that. There is a difference.

 

 

I'm working a new class and can't say much more right now, but if it comes to volition then all these things will be better addressed and explained in a public class type atmosphere for inspections and setups.

[Doug G.]

I understand though that FD (and Rotax?) no longer recommend Evans.

[Roger Lee]

There is nothing wrong with Evans other than it carries a 20-30F temp penalty. So that usually puts you over the red line anyway if your already having high temps. 50/50 has the water which is a better heat transfer median. In an open air engine Evans usually isn't an issue. Put it in a tightly cowled engine then there isn't enough heat dissipation.

Rotax originally thought that the 270F boil temp for 50/50 might be too low and too close to the 266F max engine temp and could have the potential for a vapor spot forming some where and that area wouldn't get cooled. So they thought Evans with a boil point of 370F might be a better choice to get to your max engine temp of 266F. Then they recommended that anyone using 50/50 reduce their max engine temp to 248F to give a little buffer before the 266F temp. In theory it was a good idea, but the temp penalty could be too high for your specific installation setup. Most of us stuck with 50/50.

I tried Evans in the CT early on, but had to dump it because of the max temp issue. I have never had an issue with 50/50 if your engine is set up correctly. This means carbs synced, proper needle position, prop pitch, air flow.

[Flying C Farms]

So Roger, now that you are working on a new class and you have recent TV experience, will we be seeing a webinar by Roger ?

Dean's was a good refresher.

[Roger Lee]

No, stardome is not for me.

I just like helping others. It's time in my life to pay forward all the nice things people have done for me in my life.

[Roger Lee]

The coolant from FD will be a European Glyco water mix and most likely purplish in color.. That's fine. After two years change it out to a US 50/50 mix.

My guess is the oil will be in the plane already to. It will most likely be Aero Shell Sport Plus 4. That is a 10-40W semi synthetic. That will be fine. You could stay with Aero Shell for ever or use the GN4 Honda oil or the Golden Spectro oil. These are all semi synthetics for use with 100LL. If you use mostly a diet of 91 Oct. you can stick with the semi synthetic or use full synthetics like Amsoil 10-40W or 20-50 W (for the hot months) , Mobile racing 4T, Mobile V-Twin, but no matter what you use it must be motorcycle oil so it will contain ZDDP and other additives meant for engines that share their engine oil with the gearbox like motorcycles do. Do not use a full synthetic with 100LL because the full synthetics can not suspend the lead and it will fall out through out the engine. These oil are some of the top picks. Use any of them and you can't go wrong.

 

You must do a 25 hr. engine inspection to keep your warranty for the engine and that will also be your first oil and filter change. Make sure the inspection is done right and logged in the book.

 

The flight school using 100LL is just causing themselves more expense and extra maint using 100LL. They will pay more along the way and later for its use. Since you live up in that neck of the woods you might seek out Jeremy McGregor for continued maint. on that engine. This is absolutely one statement you should trust me on.

[mocfly]

One thing I found interesting is his comment about cleaning out the tank during the oil change if burning a steady diet of 100ll. This is something we don't do.( We do burn only 100ll) The other note was the 50hr oil change. We change the oil every 25hrs. and the filter @50.

 

Question: Forgetting what differences of opinion are in the public domain, what is the best Practice?

 

 

 

 

[Roger Lee]

Rotax specifies 25 hr oil changes for 100LL. It shows 100 hr for oil changes for 91 oct. Most of us use 50 hrs as we have talked about over many years in Rotax classes. Personally I wouldn't go past 75 hrs. It's the life blood of the engine. Disease that and you have an engine with early cancer that needs extra maint. later in its life, but long before it should have been necessary. Cleaning the oil tank is done when using 100LL, but not necessary if all you use is 91 oct. The rational behind the tank and 100LL is to get all the lead paste out in the bottom.

[sandpiper]

I use 99% mogas. Cleaned my tank for the first time at 300 hours. It was basically a waste of time as the tank was basically clean. The only thing satisfied was my curiosity.

[Roger Lee]

Jeremey is in Tracy, Ca. His information is down under the mechanics section.

[Doug G.]

Just heard a new Dean Vogel EAA webinar on fuel and carburation. He was asked if it is bad to run the 912 below 4500 rpm for long periods of time. He laughed at the question and said if that were true there are a lot of powered parachute people out there that are in big trouble. The unequivocally said there is absolutely no issue with it. So the economy cruise in the AOI is a serious option.

[FastEddieB]

Missed that one.

 

Is it available online after the fact?

[Ed Cesnalis]

Just heard a new Dean Vogel EAA webinar on fuel and carburation. He was asked if it is bad to run the 912 below 4500 rpm for long periods of time. He laughed at the question and said if that were true there are a lot of powered parachute people out there that are in big trouble. The unequivocally said there is absolutely no issue with it. So the economy cruise in the AOI is a serious option.

 

It would be interesting to know who at Rotax published the best practices document that said the engine was designed to run at 5,500 RPM and why the published it.

[Jim Meade]

It was in interesting webinar. I liked the comment that a main purpose of the drip tray was to shield the carburetor from heat. I liked his discussion of the vapor relief system and the description of how the carb worked. I will probably go back and view parts of it over again to make sure I understand what he is saying.

[Roger Lee]

Before I jumped in to believe everything someone says contrary to what Rotax publishes I would take Rotax's advice first. Here is my point. Lockwood, unless they changed recently, doesn't sync the carbs at idle. They back off the idle stop screw until it doesn't touch at all then only adjust the carbs with the bowden cable set to 2500 rpm. No where ever has it been listed or suggested to not use the idle stop screw or never set the idle sync. he is right that many of the powered parachute guys run in the mid 4000 rpm's. It's the nature of the beast, doesn't make it right. I can drive a stick shift car in 4th gear at 15 mph, but it doesn't make it right or good for the car.

 

Just a note**

Remember I said 2500 rpm was too low to set the high rpm sync, well there is more evidence coming to the forefront to support that and I hope it will be in writing one day..

 

 

Drip trays are called that for a reason. They aren't called heat shields by anyone. Does it help shield from heat with its placement, well of course. Rotax and many other after market drip trays have holes and tubing attached to route leaking fuel away from the exhaust pipe. If it was just a heat shield it wouldn't need to have a fuel routing design and there are simpler ways to shield from heat.

[C ICEY]

How many parachute operators are putting in 1500hrs on the "moulinex"?

 

I understood the suggested high rpm to be vibration mitigation, and that will ultimately only differentiate over TBO timespans. my expectation is that an optimally tuned and operated 912 will operate on condition for a considerably longer time than TBO. That said, I use the full range of rpm, favouring the highest possible rpm for the flight condition.

[Dan Kent]

I think this link will get you to the 2nd webinar.

 

http://www.eaavideo.org/video.aspx?v=2404699810001

 

Company firewall prevents me from testing this.

[Doug G.]

Missed that one.

 

Is it available online after the fact?

Yes, I just got notice of it. It should be on the EAA site, or if you can't find it I will post the link. It was on 5/22.

[FastEddieB]

Thanks - I'll look for it.

 

BTW, BMW motorcycles used nearly identical Bings over the years. I had two, a 1986 R80RT and a 1990 R100GS.

 

And each of them, at least a couple of times, soaked one or the other of my boots in gasoline when something went wrong with the float or the needle and seat.

 

An aggravating problem when you have a wet foot - gasoline is "itchy".

 

A far more insidious problem if the float bowl is perched, unprotected, above an exhaust pipe in an airplane - which I have seen.

 

As Roger said, they're called DRIP trays for a reason, and there to serve a critical function.

 

Which is not as a heat shield, in my estimation.