Ric, You got me seriously confused (I might even have used the word "crickey", but for the fact that I have never been to the antipodes and find it hard enough to learn even Queen's English). Since the discussed RPM limitation seems to originate from Limbach (and I quote from page 10/48 of their Operating Manual:
Engine Rotational Speeds Max. permissible speed 3400 RPM Max. speed for cruise See flight and maintainance manual of airframe manufacturer. Min. continuous speed 2300 RPM Idle speed 800 ± 100 RPM) I had assumed it was regarding the welfare of the motor itself rather than the propeller. Please share with me the results of your intended investigation. I have enjoyed the Dimona for the short time since I became its owner 4 months ago but sadly it is grounded now pending new registration and ARC. Regards Jarek pon., 22 paź 2018 o 08:54 Nigel Baker <[email protected]> napisał(a): > You have seen it Rick and not at the pub over a beer.. > > Look in brackets below. > > 2300RPM > > Nige. > > > > 9 > > > > Hoffmann > 2 > H 36 > DIMONA > Limitations > > > > > > 2.4 *Engine Limitations* > > > > Engine Type: > Limbach L 2000 EB 1C > > > > RPM Limitations > (Indicator Markings) > > > > Maximum take off RPM (maximum > 5 minutes) 59 KW (So hp.) 3,400 RPM > > > > Maximum ambient atmospheric temperature + 380 C (+100 F) > > > > Maximum RPM (METO) 53 KW (72 > hp.) 3,000 RPM > > > > Red Line > 3,400 > RPM > > > > Caution Range - > Yellow Arc 3,000 – 3,400 RPM > > > > Operating RPM - > Green Arc 700 – 3,000 RPM > > > > *CAUTION* > > > > Avoid RPM during cruise below 2300 min –1! > > > > > > 2.5 *Oil Pressure:* > > > > Maximum Oil Pressure (red line) 4 bar (55.8 psi) > > > > Minimum Oil Pressure (red line) 1 bar (13.9 psi) > > > > Operating Range (green arc) 1 - 4 bar (13.9 — 55.8 psi) > > > > 2.6 *Oil Temperature*: > > > > Maximum Oil Temperature (red line) 120 C (248 F) > > > > Operating Range (green arc) 50 - 120 C (122 — 248 > F) > > > > Minimum Temperature (red line) 50 C (122 F) > > > > 2.7 *Cylinder Head Temperature:* > > > > Maximum Cylinder head temperature (red line) 250 C. (482 F) > > > > > > 2.8 *Voltmete*r: > > > > Maximum voltage with engine running: (red line) 14 VDC > > > > 2—3 > > > > > > > > *From:* [email protected] <[email protected]> *On > Behalf Of *Ric Sutton > *Sent:* Monday, October 22, 2018 4:39 PM > *To:* [email protected] > *Subject:* RE: [DOG mailing list] Zenith 150 CD 3 - oil > > > > Hi Jarek > > I’m sorry but i have had a look and can’t seem to find a reference to my > second imaginary number. I don’t know whether it was obtained through > conversations with Hoffman people or limbach people or dimona people or > people from a random encounter at a pub. It may have been obtained from > what felt about right ie. the bottle of beer in my cup holder didn’t froth > over or go prematurely flat below those revs( just kidding, though if > anybody here has a clever idea on where and how to mount a cup holder that > would be great). All jokes aside i do recall a conversation with a > propeller service agent that told me of an aluminium based air frame that > was financially written off after cracks were found due to the bad > harmonics of an “alternate” propeller so from that i took it as being a > serious thing. i also found some you tube videos of propeller blades self > destructing.( propeller resonance > <https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=video&cd=1&cad=rja&uact=8&ved=0ahUKEwiLtIzSsJneAhVLMI8KHY8YAUEQtwIIJzAA&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DPQjmDmcWJn8&usg=AOvVaw048W5y_0kGNdO0WaB0eUdi> > ) > > What you have done now though is inspired me to finish my home made > accelerometer/balancer and gather some actual real data to see if i can > establish some numbers for my own curiosity J > > Welcome aboard and may you enjoy your dimona as much as many of us do > > Cheers > > Ric > > > > > > *From:* [email protected] [mailto:[email protected] > <[email protected]>] *On Behalf Of *Jarek Steliga > *Sent:* Friday, 19 October 2018 3:31 AM > *To:* [email protected] > *Subject:* Re: [DOG mailing list] Zenith 150 CD 3 - oil > > > > Michael, Ric thank you. > > > > > > Ric, where did you find the "range" of unrecommended RPMs as opposed to > just a lower limit of 2300? I leafed through both attached documents and > didn't come accross the second number. I also tried to google "Limbach L > 2000 harmonics" and got nothing. If it isn't harmonics (wchich I hope it > isn't) then the RPMs lower limit would suggest excessive load torque with > prop in just the cruise position. > > > > Regards > > Jarek > > > > > > > > > > Regards > > Jarek > > > > czw., 18 paź 2018 o 15:53 Michael Stockhill <[email protected]> napisał(a): > > In the States, dashpot oil is readily available from vintage British car > parts suppliers such as Moss Motors for $10-12 for a squeeze bottle. > Claimed to have appropriate preservatives and conditioners. As little as is > consumed, I have found no incentive to look for alternatives. > > > > On Thu, Oct 18, 2018, 5:09 AM Ric Sutton <[email protected]> wrote: > > Hi Jarek > > Here’s my two cents worth- i use automatic transmission/power steering > fluid in my cd150’s. seems to work fine and haven’t had any compatibility > issues with rubber diaphragms etc as yet. The oil and plunger act as a > damper for the piston to which the needle that alters your fuel air mixture > is attached. Over the years i have heard various stories from people that > use these carbies n race cars that actually snip the damper off(similarly > people that don’t put any oil in there), to stories from people that use > them in multi carb set ups (ie 12 cylinder jaguar engines) that can’t get > them to tune properly without the correct oil (though after some discussion > i believe that spindle wear was more their issue). In an automotive > situation there will be some minor noticeable throttle response differences > but in the dimona application i suspect the differences will be minimal > particularly as instantaneous dramatic throttle changes should be rare. > > The rev issue > > The reason the book states that *prolonged* operation in that rev range > is to be avoided during cruise is indeed because of a bad harmonic > (potential for cracked crankshafts etc) Thus, i believe that it is a > problem whether the blades are in fine or course pitch it is just operating > in that rev range with a moderate load on. In saying that, these are a > reasonably robust little engine, don’t be scared. Note the emphasis on the > word prolonged. > > Please someone jump in if they have info to the contrary this is just > what i have learnt over the years and am always willing to learn something > new. > > > > *From:* [email protected] [mailto:[email protected]] *On > Behalf Of *Jarek Steliga > *Sent:* Thursday, 18 October 2018 5:47 PM > *To:* [email protected] > *Subject:* Re: [DOG mailing list] Zenith 150 CD 3 - oil > > > > Hello again, > > > > If my oil "mixture" is too thick (or too thin) what are the symptoms? Does > the carburator respond with a delay or too fast to the throttle inputs? Is > that dangerous or just annoying and easily noticed? > > > > > > Regards > > Jarek > > > > > > > > czw., 18 paź 2018 o 08:43 Jarek Steliga <[email protected]> > napisał(a): > > Thank you > > > > śr., 17 paź 2018 o 23:28 Rob Thompson <[email protected]> > napisał(a): > > Part number 10 on the diagram. > > regards > > Rob > > > > Rob Thompson > > 0429 493 828 > > (Please note that my new email address is [email protected]) > > > > > > On Thu, Oct 18, 2018 at 7:50 AM Jarek Steliga <[email protected]> > wrote: > > > > > > Hello Rob, > > > > > > The oil seems to disappear too fast as you say. Could you help me to > identify which particular o-ring on the attached drawing needs to be > replaced? > > > > When you mention 5/xx multigrade, do you mean 5W/xx? > > > > > > Best regards > > Jarek > > > > > > > > > > > > > > > > > > > ---------- Forwarded message --------- > > From: *Rob Thompson* <[email protected]> > > Date: wt., 16 paź 2018 o 22:23 > > Subject: Re: [DOG mailing list] Zenith 150 CD 3 - oil > > To: <[email protected]> > > > > > > Hi again Jarek, > > You can use straight engine oil but even a 5/xx multigrade is a bit thick > and tends to dampen the piston too much. > > We mix 50/50 light machine oil and engine oil. > > If it keeps disappearing it means that the rubber O-ring which seals the > needle inside the piston is perished. > > regards > > Rob > > > > Rob Thompson > > 0429 493 828 > > (Please note that my new email address is [email protected]) > > > > > > > > > > > > > > > > > > > > Hello, > > > > As per Limbach Maintenance Instruction, only a specific oil p / n: > 170.210.005 can be used to fill up the carburator. Since this seems to me > pretty pricey, can other, readily available oils be used in its place? What > is its recommended viscosity? > > > > Best regards > > Jarek > > > > > > > > > --------------------------------------------------------------------- > You are subscribed to the Dimona Owners Group mailing list. > To unsubscribe, send email to: [email protected] > >
