---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Wed 09/06/06: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:14 AM - Re: Re: R912UL Initial Engine Test Run (Thom Riddle) 2. 05:45 AM - FW: Re: Allegro 2000, 912UL Initial Engine Test Run (Hugh McKay III) 3. 06:43 AM - Re: R912UL Initial Engine Test Run (PWilson) 4. 07:13 AM - Rotax 447 (John Esch) 5. 07:18 AM - Re: Rotax 447 (Dave) 6. 08:20 AM - Re: Re: Allegro 2000, 912UL Initial Engine Test Run (Dave Austin) 7. 08:54 AM - Re: Re: Allegro 2000, 912UL Initial Engine Test Run (Hugh McKay III) 8. 09:14 AM - Re: Re: Allegro 2000, 912UL Initial Engine Test Run (Jack Kuehn) ________________________________ Message 1 _____________________________________ Time: 04:14:50 AM PST US From: Thom Riddle Subject: Re: RotaxEngines-List: RE: R912UL Initial Engine Test Run --> RotaxEngines-List message posted by: Thom Riddle Back in the dark ages when I was a drag racer in the very hot summer days in the south, my cars would sometimes get vapor lock. The solution for us was to install an electric fuel pump at the tank to make sure the whole fuel system was pressurized to something above ambient pressure from the tank to the carburetor instead of below ambient pressure due to the suction action from the engine mounted mechanical fuel pump. Rotax has the engine mounted fuel pump which draws by suction from the tank which is frequently mounted lower than the engine. Many aircraft have electric fuel pumps as either back-ups or required due to location of the fuel tanks. If your airplane has an electric fuel pump located such that it pressurizes virtually the whole fuel system (except the tank), try turning on this boost pump to eliminate the vapor lock. The increase in pressure was always enough to solve the vapor lock problem on our old dragsters and may work for your airplane. Thom in Buffalo ________________________________ Message 2 _____________________________________ Time: 05:45:04 AM PST US From: "Hugh McKay III" Subject: FW: RotaxEngines-List: Re: Allegro 2000, 912UL Initial Engine Test Run --> RotaxEngines-List message posted by: "Hugh McKay III" -----Original Message----- From: Hugh McKay III [mailto:hgmckay@bellsouth.net] Sent: Tuesday, September 05, 2006 4:02 PM Subject: RE: RotaxEngines-List: Re: Allegro 2000, 912UL Initial Engine Test Run Thom/Gilles, and all: I called Lockwood Aviation this morning concerning this whole subject and regarding my specific engine. After giving them (Dean Vogel, Engine tech.) all the specific information concerning the initial test run, he as well as his associate Kerry were convinced that I had done no harm to the engine with the oil and CHT temperatures I saw for that short of time. In the course of our conversation he did give me additional information concerning Coolant venting, and oil venting as follows: (Coolant Venting) Dean stated that on initial start with a new engine, or after changing coolant, air pockets could occur unless one follows certain steps to get rid of them if they are present. First, fill the engine and expansion tank to the maximum, and then place about 1 inch of coolant in the overflow bottle. Run the engine for a minute to circulate the coolant, shut down, and let cool as necessary. Check the coolant level in the expansion tank. If it has lowered, air was in the system. Refill to the maximum level and run the engine again for one minute, and repeat the procedure until the coolant level in the expansion tank stays the same. Then fill the overflow bottle to the halfway point. (Oil Venting) In addition to the venting procedure given in the Rotax Operators Manual (which everyone gets with their new engine) there is a Rotax Service Instruction SI-04-1997 (rev 3) dated September 2002 (which new engine owners know nothing about) on the Rotax website. I might say at this point for those of you who may be like myself (new to this engine), and Kit Builders (Allegro or otherwise), after talking with Lockwood I would recommend you take their 912UL engine course if at all possible. I wish I knew ahead of time how helpful it would be. They cover this and many other matters that Rotax, your Distributors, and Dealers don't give you. As some of you have told me "we who build Kits simply are buying a "pig in a poke" (i.e. its up to us to figure it all out, including the engine with a little help from my friends), no further advice given. You are on your own! Enough "venting" on my part (no pun intended). Back to the oil venting SI. Just read it. It is markedly different and requires more effort and work, but it makes sense. Having gone through this frustrating exercise, I wish there was some way to for-warn or counsel individuals such as myself about these pitfalls, because they could lead to very expensive repairs or even worse (God forbid), fatalities. I am fortunate, I found out "with a little help from my friends". Thanks again everybody, God Speed, and enjoy that freedom we all experience in FLYING. Hugh McKay in North Carolina Allegro 2000 N661WW 912UL -----Original Message----- From: Hugh McKay III [mailto:hgmckay@bellsouth.net] Sent: Monday, September 04, 2006 5:17 PM Subject: RE: RotaxEngines-List: Re: Allegro 2000, 912UL Initial Engine Test Run Thom/Gilles: I have followed your dialogue with great interest, and it has helped me immensely. I have no experience with this engine, so I was alarmed when I saw the CHT continuing to rise. I was even more alarmed when I shut down, and heard the coolant boiling in the overflow bottle. I still don't know why this happened. There is no question that the engine was not being cooled properly, the question is why? It may have been a combination of existing circumstances (i.e. static engine run, no horizontal movement of plane, tarmac temp 88 degrees+, engine fully cowled with spinner, horizontal radiator, and length of operation). I do know that with the spinner on, the 91/2 inch diameter spinner flange eats up most of the free area for air to enter the engine compartment. In fact there is only 18 square inches of free opening left for air to enter the engine compartment. This may be fine with the plane traveling at, say 90 mph, but maybe not with the plane sitting on the ground for 10 to 15 minutes in 88 F. I don't know, but certainly I would think the plane designers would design for this condition. What free opening does Rotax require on fully cowled engines? Since this was the initial engine start, I am going to call Lockwood Green tomorrow and explain every thing that happened to them and get their opinion. I'll keep both of you informed as to what they say. Again, thank you for your advice, counsel, experience, and knowledge. Hugh -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com]On Behalf Of Gilles Thesee Sent: Monday, September 04, 2006 4:30 PM Subject: Re: RotaxEngines-List: Re: Allegro 2000, 912UL Initial Engine Test Run --> RotaxEngines-List message posted by: Gilles Thesee Hi Thom, > I think we are in general agreement and the discussion has been of value to anyone who cares, or at least I hope so. > Agreed. Rotax engines are very tough. I don't think Hugh's engine was damaged, though I tend to treat my own engine more kindly ;-) Nice discussion. Best regards, Gilles http://contrails.free.fr ________________________________ Message 3 _____________________________________ Time: 06:43:01 AM PST US From: PWilson Subject: RotaxEngines-List: RE: R912UL Initial Engine Test Run --> RotaxEngines-List message posted by: PWilson Thom, Good point. Hard to believe there are planes in use that do not have a backup electric fuel pump mounted low in the system. I am a Kitfox guy and many of these planes have the electric backup as well as a fuel return. The standard deal is to operate the electric pump for prestart, takeoff, & landings. The prestart e-fuel pump operation allows the fuel bowls to both fill and aids in a less rough start. The reduction in engine roughness is because the electric pump allows both carb bowls to fill and thus all 4 cylinders fire at start instead of one bank lagging due to slower filling of the carb bowls. The return provision is built into the Kitfox design because they wanted to provide for fuel injected engines (IO240) which all require a fuel return. If your plane does not have the extra fitting in the tank then a mod will to the tank would be required for the return. Vapor lock on this design have not had any reported vapor lock. IMO, the return fuel line is overkill for a carb engine. Good design practice would always indicate for a backup fuel pump. Regards, Paul PS, One has to choose the electric pump that meets the Rotax spec for pressure so as to avoid overpowering the carbs. Most people use a Facet and it installs in series with the mechanical Rotax pump. It does not need a bypass for the engine to operate with the electric pump off. Paul ===================== At 05:14 AM 9/6/2006, you wrote: >--> RotaxEngines-List message posted by: Thom Riddle > >Back in the dark ages when I was a drag racer in the very hot summer >days in the south, my cars would sometimes get vapor lock. The >solution for us was to install an electric fuel pump at the tank to >make sure the whole fuel system was pressurized to something above >ambient pressure from the tank to the carburetor instead of below >ambient pressure due to the suction action from the engine mounted >mechanical fuel pump. Rotax has the engine mounted fuel pump which >draws by suction from the tank which is frequently mounted lower >than the engine. Many aircraft have electric fuel pumps as either >back-ups or required due to location of the fuel tanks. If your >airplane has an electric fuel pump located such that it pressurizes >virtually the whole fuel system (except the tank), try turning on >this boost pump to eliminate the vapor lock. The increase in >pressure was always enough to solve the vapor lock problem on our >old dragsters and may work for your airplane. > >Thom in Buffalo > > ________________________________ Message 4 _____________________________________ Time: 07:13:23 AM PST US From: John Esch Subject: RotaxEngines-List: Rotax 447 --> RotaxEngines-List message posted by: John Esch All Last night while trying to diagnose the issue I had last Thursday with my 447, I noticed I have a fuel pump for a dual carb. The two outlet fuel lines from the pump go to a "T" then goes to the carb. My question is, is this a proper setup or should I replace the pump for a single carb setup? Thanks in advance. John Independence, OR ________________________________ Message 5 _____________________________________ Time: 07:18:37 AM PST US From: "Dave" Subject: Re: RotaxEngines-List: Rotax 447 --> RotaxEngines-List message posted by: "Dave" I have a 503 single carb and use a rectangular pump with no issues. I would try that. What was the issue ? I must have missed that last week ? Dave ----- Original Message ----- From: "John Esch" Sent: Wednesday, September 06, 2006 10:13 AM Subject: RotaxEngines-List: Rotax 447 > --> RotaxEngines-List message posted by: John Esch > > All > Last night while trying to diagnose the issue I had last Thursday with my > 447, I noticed I have a fuel pump for a dual carb. The two outlet fuel > lines from the pump go to a "T" then goes to the carb. My question is, is > this a proper setup or should I replace the pump for a single carb setup? > Thanks in advance. > > John > Independence, OR > > > ________________________________ Message 6 _____________________________________ Time: 08:20:31 AM PST US From: "Dave Austin" Subject: Re: RotaxEngines-List: Re: Allegro 2000, 912UL Initial Engine Test Run --> RotaxEngines-List message posted by: "Dave Austin" Re oil venting.. Has anyone seen any advice on what action to take when just changing the oil filter? It would certainly be introducing some air into the system as it isn't possible to fill the filter with oil since it lies sideways. SI-04-1997 dated Sept. 2002 does not address this. Dave Austin 601HDS - 912, Spitfire Mk VIII ________________________________ Message 7 _____________________________________ Time: 08:54:14 AM PST US From: "Hugh McKay III" Subject: RE: RotaxEngines-List: Re: Allegro 2000, 912UL Initial Engine Test Run --> RotaxEngines-List message posted by: "Hugh McKay III" Dave: The Rotax Service Instruction (SI-04-1997 R3) Section 1.5 states that this procedure shall be performed after lubrication system is opened or drained during maintenance work. It doesn't specifically state that after changing the oil it has to be done, but as you say the system has been "opened", so I would think it would apply. The guys at Lockwood can tell you for sure. Hugh McKay -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com]On Behalf Of Dave Austin Sent: Wednesday, September 06, 2006 10:20 AM Subject: Re: RotaxEngines-List: Re: Allegro 2000, 912UL Initial Engine Test Run --> RotaxEngines-List message posted by: "Dave Austin" Re oil venting.. Has anyone seen any advice on what action to take when just changing the oil filter? It would certainly be introducing some air into the system as it isn't possible to fill the filter with oil since it lies sideways. SI-04-1997 dated Sept. 2002 does not address this. Dave Austin 601HDS - 912, Spitfire Mk VIII ________________________________ Message 8 _____________________________________ Time: 09:14:56 AM PST US From: Jack Kuehn Subject: Re: RotaxEngines-List: Re: Allegro 2000, 912UL Initial Engine Test Run --> RotaxEngines-List message posted by: Jack Kuehn Actually it is possible to fill the oil filter at least half way, and quickly screw it into place. It is messy, but better than an empty filter. Then pull the prop through, top plugs removed, followed by spinning the engine with the starter until you get oil pressure, to prime the system. Jack Dave Austin wrote: >--> RotaxEngines-List message posted by: "Dave Austin" > >Re oil venting.. >Has anyone seen any advice on what action to take when just changing the oil >filter? It would certainly be introducing some air into the system as it >isn't possible to fill the filter with oil since it lies sideways. >SI-04-1997 dated Sept. 2002 does not address this. >Dave Austin 601HDS - 912, Spitfire Mk VIII > > >. > > >