670 Rotax

[avidflyer]

Just wondering what people who have installed a 670 think of them after being in service for a while. Any comments? Would you do it again? How long have you been using one, ect, ect? JImChuk

[Esser]

My friend has one in his 701. I think it’s an awesome engine. I have no real insight except he loves it and would do it again.

[avidflyer]

Thanks Josh, anyone else? JImChuk

[nlappos]

Jim,
I just bought a 670 from Ron Davis, it is in a box on the way to my hangar. It looks great, I will be sure and post the experience. I expect that by end of Feb I'll be in the air.
Nick

[Av8r3400]

I've known three people to install 670s. Two of the planes have been sold with one pilot no longer flying. The other purchased a 912 powered plane. The third example was finally converted to a 912 after several engine-outs and is still being flown. Two of these engines came from the famous "Rotax" guy in Florida.

All three would say the power and performance was extremely impressive when they were running right. To get them to run right in an aircraft takes almost constant tinkering and adjusting. The engines were very temperamental and high maintenance. If you don't mind this aspect of the engine, go for it.

[nlappos]

Well, I am committed now. I'll let you know how it goes. Did they tell you what needed tinkering?

[jabkwab]

The 670 does not have double ignition does it?

[Dusty]

A dual ignition is an easy fit on an early 670

[Av8r3400]

Well, I am committed now. I'll let you know how it goes. Did they tell you what needed tinkering?

I'm not a 2-stroke guy, but what I can remember is that the carbs were in a constant state of change, needles, jets, I don't know what else. There was a lot of maintenance in regard to the RAVE valves. Cleaning, adjusting and such. The one guy who had his the longest seemed to have the head off his engine several times a year to de-carbon or re-gasket. Everyone also always had several sets of spark plugs available as well as a full kit of carb parts to change.

[nlappos]

Well, I am about to find out!

Yes, it is a dual ignition engine, uses the Ducati

[nlappos]

I unboxed my 670 today and started the install. I will use this thread to report 670 specific item for the group

Rod Davis, Rotax Rick zero time engine. Job looks great, high quality, neatly packed, all accessories and hardware.

Mounting- standard Avid 582 brackets fit properly. Looks like it will slide in easily. Details to follow.

Weighed everything:

670 engine 89.5 lbs

Starter and housing plate 5.5 lb

Bing 54 carbs 4.0 lb (2carbs)

Dual air filter and clamps 1.0 lb

total 100.0 lbs

[FoxDB]

Are going with oil injection or premixing?

Sorry for asking you again I get confused jumping between forums.

[TY2068]

What type oil was advised by Rick for Rotary Gear lubrication ?

[FoxDB]

TY2068,
I don't know about R Rick but everyone I know just uses a 2 stroke oil for rotary valve and water pump shaft lubrication. I don't believe this is a high wear area.
Dave

[nlappos]

The oil lube has the same basic reservoir at the top, and the engine was shipped with that system primed and full.
The oil mixing pump was disabled, and Rick makes mixing (at 40:1) a term of his warranty. That means I get back a ton of space behind the dash when I pull the oil tank.

Rick requires Amsoil Interceptor or Quicksilver PWC oil at 40:1

I have the engine mounted now and intend to make all the connections today, oil, throttle, fuel, and begin mounting the radiators. I plan to add a belly radiator for summer cooling, and have a blocker plate that is cockpit controlled for cooler seasons.

[TY2068]

Can you verify if small Rotary valve supply bottle was filled with 2-cycle pre-mix oil or 30w motor oil. I was told that Rick advises using straight 30w motor oil for Rotary Shaft-Gear lubrication. You may want to verify what's in the RV lube bottle.

[nlappos]

I have no idea what "I was told" means, and no I will not verify for you anything.

On his web site, and in the instructions Ron Davis insists on the premium oil types and brands that I just posted. Why is the internet full of people who would believe "I was told?" and apply it to someone's reputation?

What is your angle, TY2068?

[TY2068]

WOW ! OK pheww...anyway I will refer you to this thread where "it was posted" "and I was told" that Rick documented where new engines (582's) were being shipped from the factory with 30W motor oil in the RV lube system. It was said Rick now uses 30W in ALL his 582-670 rebuilds ? I was just wondering if that was in-fact the case with your freshly rebuilt 670.


http://www.teamkitfox.com/Forums/showthread.php?t=7106

[FoxDB]

TY2068,
It is interesting that Rotax would use a different oil in the RV shaft circuit for the aircraft engines. My 582 ran 700 hours. I bought it with 216 Hours and only replenished or refilled with 2 stroke oil. Injected Skidoo snowmobiles use the same tank for injection oil and RV shaft oil. I converted one of my 670 snowmobiles to premixing and had to add the RV shaft oil reservoir. And yes I filled it with 2 stroke oil.
Dave

[TJay]

Company's like Amsoil Make actual rotary valve oil I personnel would just stick with something like that. If it holds together that should make a fun engine/Plane combo

[nlappos]

The 670 I received had its oil tubes filled with Amsoil and plugged together to maintain priming. To some fools, the amber Amsoil looks like 30 weight, and that can launch a thousand baloney rumors, now resurfaced by Mr Anonymous, TY2068.

Rotax Rick and others suffer at the hands of people who "were told" and who have no idea what they are saying, but who can slur the reputation of folks with anonymous ease.

Rick makes clear in all his communications that top end 2 stroke oil is a must on his engines. I can verify that.

[Bluebird19kf]

I recently purchased a rotax ricks 670 engine. It is wrote in marker on the rotary valve reservoir cap "30w oil." I was under the impression that this should be 2 stroke oil also. I called rotax rick and asked about it. He said that it is indeed 30w oil and that his thinking is that 2 stroke oil is not as good of a lubricant for that valve as 30w. He said you can run either or but if you noticed that it started to use oil out of the reservoir that you should run 2 stroke because it is now burning that oil. He also commented that it is really not necessary to run 30w either as he has not seen any ill effects from running 2 stroke. That is what I was told from Rotax Rick himself.

[TY2068]

Well Mr. Nlappos what's the response to that little tidbit of information.... HaaHaa ! I have no idea why you on the defensive about this. My only "angle" was to get to the bottom of this Rotary oil mystery and at the same time give you a friendly-helpful heads up on what "could" be going on with your engine. You could at some point be unknowingly adding 2-cycle mix oil to what is actually 30W motor oil in your Rotary system tank. "They" say mixing different type oils is not a good thing. You certainly don't want to have the Rotary Valve-gear system fail right ?

I don't endorse or condem Ricks Rebuilds. I've had no personal dealings with him whatsoever. Yeah I've read some bad press but also lots of praise and good things.

BTW...I very briefly met a guy with a Rick 670 rebuild and the engine was said to have run perfect so far. I did not have the opportunity to discuss anything with him as he was leaving when we briefly talked.

Thanks so very much Bluebird19kf for the information.

[avidflyer]

My mom used to have a repeat a saying that went like this: Be careful of the words you say, to keep them soft and sweet. You never know, from day to day, which ones you'll have to eat. Good advice I think. Even if we disagree, we don't need to be disagreeable. JImChuk

[nlappos]

Well, I'll have to eat my words, I just opened an email from Rick (I wrote him when this first surfaced) where he does say he ships the new rebuilds with 30w oil (he says he doesn't want them to be dry, as Rotax ships them) and that 30w is better, unless it gets burned. If the level drops, he says just switch to Amsoil.

So I owe TY2068 an apology, I clearly misread his motives. Sorry TY2068.

[Bluebird19kf]

Now that we have that out of the way, lol. The next order of business is to decide if rotax rick is painting the inside of his motors. They look nice on the outside but in another post someone posted up about a junk motor where rick had done just that along with using copious amounts of silicon and red Loctite where it wasn't supposed to be. I am contemplating tearing mine apart to inspect because there is overspray on the inside of the carbs that came with the motor!

[mscotter]

Forgive me if this is a stupid question, but what's wrong with painting the inside of the motor?

[TY2068]

Dave & Bluebird

My research (yeah I read stuff on the internet lol) indicates that using 30W (or other weight motor oil) in the Rotary systems originated with the racing-recreational Snowmobile guys. After repeated failures of the brass gear and/or seals on the Rotary shafts they started experimenting with better lubrication than 2-cycle oil provides. Evidently much better results were seen in the high temp-stress-rev racing and recreational environments. At some point a few guys in the UL-Exp-PPC and Watercraft worlds caught on to this and started using various motor oils (30W, 20-50 and even heavy gear lube) also. I have yet to determine for sure that new motors from the factory do indeed come with motor oil or 2-cycle oil that "looks" like motor oil. It was said (Here) that new motors are shipped with 30W. I have a gut feeling that's not correct and they are shipped dry or with honey colored 2-cycle oil as was mentioned here.

One thing I do know for sure is that my engine had motor oil in the Rotary system bottle and I wanted to know why. It was not possible for me to ask the pevious owner of the plane about it. Thanks to this forum and the guys whom provided initial information I now have a better understanding on the subject.

[TY2068]

Well Mr. NLappos the apology is accepted and I'm glad you were able to get further info. I probably could have worded my posts differently or explained things a bit more clearly.

I'm a bit puzzled as to why Rick doesn't explain about the Rotary oil a little better to customers when he sends an engine out. Personally I think using 30W or synthetic 20W-50 (High Zinc content and anti-foaming properties) will do no harm and/or actually be beneficial. Any internal leakage or oil usage at some point would signal a return to using 2-cycle pre-mix oil however. Many would see no point in using motor oil and it is not standard advised procedure anyway. Maybe being that TBO is only 300hrs on 582's for example Rotax calculates that 2 cycle pre-mix is sufficient.

As far as me being anonymous anyone can send a private message at any time if they what personal info or private contact with a member. Me..I'm just another guy out there who's been interested in flying since the Stork flew me in. I'm PP licensed, high time Ultralight pilot and a Low time Kitfox pilot/mechanic :)

[nlappos]

Just finishing my installation of the 670 in the former 582 mount on my Avid Mk IV, serial number 1174D. Will post photos tonight. Overall, it was cake, the Rotax Rick engine slid right into the 582 mount. The two upper brackets fit perfectly, the 670 case had been touched up where the interferences were, so there was 1/8" clearance.
I used a Harbor Freight hydraulic lift table, and mounted the engine solo
The Mike Hair exhaust fits well, and stays inside the lateral confines of the cowl, as shown, but the muffler hangs below the lower OML, so I must trim the cowl bottom to fit.
The cooling system fits perfectly too. I retained the two nose radiators, and have a belly rad waiting in the wings for summer to come around.
I put 170 main jets in because I am at 6000 feet here in Utah.
I fitted an EGT system, and also will install the HACMAN mixture control that I had on my 582 (and which worked quite nicely).
I have to install a Facet electric pump to boost the fuel flow, since the old flat Mitsumi pump is only 9 GPM, and the 670 draws up to 11 GPM at full throttle. The two pumps in series should exceed that by quite a bit.
I hope to fly late next week.

[Bluebird19kf]

Are you planning on running AVgas or auto fuel?

[nlappos]

I plan to run on High Test auto fuel (ethanol mix) and Amsoil 40:1 mix.
"Rotax Rick" says this works fine. The ethanol actually helps the octane, and my tanks are ethanol OK.

[Bluebird19kf]

Thats wierd he told me to only run avgas and that is what his website says too.

[nlappos]

Not really. He says 100LL is great, and don't sweat the lead. He also says that old car gas is a real problem, since the octane drops in just a few weeks. That is why he does not recommend non-ethanol car gas, it can't be trusted. He does recommend fresh ethanol high octane car gas.

Here is EXACTLY what his web site says:

"Fuel and Engine Oil
CAUTION

This information is for all aircraft that have metal, poly or non-fiberglass tanks (WITH EPOXY RESIN), not Polyester resin:

Buy fresh Ethanol premium gas preferred from Chevron, BP and Sunoco.
Use either Amsoil Interceptor OR Quicksilver PWC oil (any of the 3 types of Quicksilver is fine)
Run Premix at 40:1 ratio. (16 ounces for every 5 gallons of gas)
DO NOT EVER USE NON ETHANOL GAS (other than 100LL Avgas which is acceptable). Rotax has a warning that it is “old stale gas.”............
Fuel life is 2 months, depending on the amount of moisture it’s exposed to. You can add Stabile to the fuel if you know your flying may be limited.
AvGas 100LL is the very safest gas you can ever use. I have rebuilt 100+ engines that used it 100% of the time. Don’t listen to the know-it-alls."

https://rotaxrick.wordpress.com/fuel/

[Bluebird19kf]

Ah, that must be where i got confused. At the time i didn't have ethanol safe tanks.