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Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 5:08 am
by Warmi
What is the min oil temp you consider safe for taxing ?

My understanding was that the 120f min limit was for high rpm engine ops - ie 3500+
My normal operating procedure is to warm up the engine at about 2200-2500 till about 90-95f , then start taxing at about 2800-3000 and by the time I am at the run up area , I am at 125-130f + at which point I do my run up etc ..

Curious how you guys are managing cold startups ...

Thanks

Re: Oil temp and taxing

Posted: Sat Feb 23, 2019 5:26 am
by joey4420
I presume you are speaking about the Rotax engine? My Continental only need 100 degrees and I max at 2500 rpm.

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 6:30 am
by lsaviator
Section 3.5 of Rotax 912 Operators Manual: "Start warming up period at approx. 2000 rpm for approx. 2 minutes. . . Continue at 2500 rpm, duration depending on ambient temperature, until oil temperature reaches 50 °C (120 ° F)."

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 7:08 am
by drseti
This time of year, I'm a big believer in preheating the Rotax before engine start. Here's an article about how to build an effective and inexpensive preheater:

http://avsport.org/publicat/nonfict/preheat.pdf

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 7:15 am
by drseti
joey4420 wrote:I presume you are speaking about the Rotax engine?


Yes, as the subject line says. Rotax powers about 80% of the modern LSA fleet.

My Continental only need 100 degrees and I max at 2500 rpm.


And the Continental powers most of the legacy LSA fleet. It's much less temperature sensitive, because of the higher cylinder wall to piston clearance.

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 7:41 am
by FastEddieB
I do not hesitate to taxi right after engine start, since not much in the way of rpm is required to taxi at the speeds I prefer.

For takeoff, I like to wait until my oil temp gauge has at least moved off the peg, which means about 50°C (about 120°F) has been reached.

These are modern engines running multiweight oil, so should not need a whole lot of warmup, much like car engines today.

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 8:07 am
by Sling 2 Pilot
Warmi, yesterday temps were a balmy 34 F -40 F here in NY. I booted my G3X and oil showed 46F and coolant 41F. I preheated with my old Surefire heater while I preflighted and checked my tires ( A laborious task with wheel pants ). Start up was quick, but took some time to reach 120F. I started taxing from the hanger to the runway at about 80F. Sat for a while in the run up area. Oh, and I had removed the tape from my radiators...Bad move on my part.

I took off, leveled at 2600’ and as soon as I retarded power my coolant temps went to yellow (Below 122F), oil droped some also, but stayed just above 120F back to the hanger. It was a short flight. Late in the day and I was too lazy to the retake and fly again.

I flew a week earlier with extra tape and ground temps at 29F, no issues all temps in all phases of flight.

I’m still not used to the Rotax quirks, having flow with Lycoming and Continentals the past 35 years, but I’m learning and really like the Rotax.

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 8:24 am
by Warmi
drseti wrote:
joey4420 wrote:I presume you are speaking about the Rotax engine?


Yes, as the subject line says. Rotax powers about 80% of the modern LSA fleet.

My Continental only need 100 degrees and I max at 2500 rpm.


And the Continental powers most of the legacy LSA fleet. It's much less temperature sensitive, because of the higher cylinder wall to piston clearance.


To be fair , I added Rotax to the title after getting a reply from Joey :D

I kind of assumed that everyone on this forum pretty much speaks “Rotax” ... well, forgot that Joey flies his lovely Ercoupe ( his fault really I forgot , he posts so rarely :D ) and I am sure there are a few Jabiru owners here as well hiding in some corner ...

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 8:33 am
by Warmi
Sling 2 Pilot -

I do have an oil thermostat installed but it is not enough - if it gets really cold, I do need to tape the radiator , usually just one or two stripes and I pretty much keep it on until the spring .

And oh yeah, I do use dr seti heater setup as well - not the heat gun variety :D but a stand-alone little round heater with a tube connected to the underneath of the plane cowling ...

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 8:42 am
by rcpilot
drseti wrote:This time of year, I'm a big believer in preheating the Rotax before engine start. Here's an article about how to build an effective and inexpensive preheater:

http://avsport.org/publicat/nonfict/preheat.pdf

That's fine if you have electric available. Quite frankly if I did i would get a Reiff preheater. Someone I know has a Coleman camp stove that runs on white gasoline that he used to preheat his 152 that he's going to "donate" to me(I'll have to treat him to lunch a couple of times :) ) It looks like it should do the job.

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 8:55 am
by roger lee
Since you should be warming the engine at 2000 - 2400 rpm you can taxi at anytime as the engine warms. You aren't loading the engine and it doesn't make any difference if the wheels are stationary at 2300 rpm or rolling.

Really cold starts are hard on the engine.
During these cold winter months it's a good idea if you have an engine pre-heater. I would recommend a Tanis over a Reiff, but either will work. Tanis just does a better full engine heat and is specifically designed with the Rotax in mind.

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 10:49 am
by drseti
roger lee wrote:Really cold starts are hard on the engine.
During these cold winter months it's a good idea if you have an engine pre-heater. I would recommend a Tanis over a Reiff, but either will work. Tanis just does a better full engine heat and is specifically designed with the Rotax in mind.


I've use both the Tanis and the Reiff; both are good. But, in the case of an SLSA, installing either requires a Letter of Authorization. In some cases, the manufacturer may not be willing to issue an LoA. That's why I designed my heat-gun portable preheater.

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 12:23 pm
by 3Dreaming
rcpilot wrote:
drseti wrote:This time of year, I'm a big believer in preheating the Rotax before engine start. Here's an article about how to build an effective and inexpensive preheater:

http://avsport.org/publicat/nonfict/preheat.pdf

That's fine if you have electric available. Quite frankly if I did i would get a Reiff preheater. Someone I know has a Coleman camp stove that runs on white gasoline that he used to preheat his 152 that he's going to "donate" to me(I'll have to treat him to lunch a couple of times :) ) It looks like it should do the job.


I haven't found the reference yet, but not long ago on one of the forums or Facebook pages I frequent I saw someone post about a battery powered preheater. I know Dewalt makes a battery powered propane fired heater.

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 12:40 pm
by Sling 2 Pilot
drseti wrote:
roger lee wrote:Really cold starts are hard on the engine.
During these cold winter months it's a good idea if you have an engine pre-heater. I would recommend a Tanis over a Reiff, but either will work. Tanis just does a better full engine heat and is specifically designed with the Rotax in mind.


I've use both the Tanis and the Reiff; both are good. But, in the case of an SLSA, installing either requires a Letter of Authorization. In some cases, the manufacturer may not be willing to issue an LoA. That's why I designed my heat-gun portable preheater.


drseti, I plan on installing the Reiff in my Sling at annual. Their website states all that’s needed is a logbook entry.

Re: Rotax Oil temp and taxing

Posted: Sat Feb 23, 2019 5:52 pm
by drseti
Sling 2 Pilot wrote:drseti, I plan on installing the Reiff in my Sling at annual. Their website states all that’s needed is a logbook entry.


By "their website", do you mean Reiff's, or Sling's? If the latter, you're good to go. If Reiff is telling you that, you'd best verify it with Sling.