rodgerc

The 912ULS’ oil cooler is on the suction side of the oil pump....Only sees atmospheric pressure.

Hey Mike, skip the UL520t and bolt one of TurbAero’s engines on the nose of your big-tyred puddle jumper and you’ll be able to scoot along at FL250 pulling 250kts, leaving Lancairs wallowing in your contrails. 😉

Supercheap have a $29.95 set with a selection of brass sizes included

This info has been posted elsewhere and is shared here at JG3’s prompting. For the past 6-1/2 weeks my 37 hr total time 912ULS powered RANS Raven has forlornly sat in the hangar due to a persistent 350-400 RPM drop at 4000 RPM. I had become so frustrated that selling her off cheap was becoming a serious consideration….so was burning it. 😡 Last Friday I finally discovered and rectified the fault, tipped off by a Vans RV12is engine installation instruction. Cutting to the chase, one of the 4 ignition trigger coils’ air gap was 0.002” (0.05mm) below the minimum spec set by Rotax. Yep, about half the thickness of a human hair is the difference between a barely detectable mag drop and one that made the engine rattle and shake….and it was clearly set that way in the Rotax factory. The specified air gap range is 0.012” to 0.016”. My gaps were 1 x 0.016”, 2 x 0.012” and 1 x 0.010”….The problem trigger coil was the 0.010” gap. (I had previously thought that closer trigger coil gaps were always better, provided there was no actual contact. Those with electronic expertise may be able to explain why that is not necessarily the case….?) I now have 4 x0.014” gaps (actually 5 counting the tacho) and a very smooth running engine. So if you’re suffering a mag drop in the 300-400 RPM range on a Rotax, buy yourself a set of brass feeler gauges and check the trigger coil air gaps.

https://issuu.com/raaus/docs/sport_pilot_34_may_2014/18 Article from a few years back may be relevant. Page 18

Notwithstanding the legalities, Peter Leonard is a true gentleman and an exceptional supporter of and asset to, the Australian experimental aircraft community. The SAAA will undoubtedly be a poorer organisation as a result of the action on multiple fronts.

Rotax installation manual is very specific about the height of the oil tank in relation to prop shaft. When I queried the detail with Flood Imports I was advised it was to avoid hydraulic lock from the tank being mounted too high.

I used self-fusing silicone tape that worked a treat and cost me a kidney….However I noticed last week that Supercheap sell self-fusing silicone tape for about 1/5th of the price I paid from my fire sleeve supplier.

I just read an article in New Scientist about chimpanzees eating their own

No leakage from my float bowls….During reassembly of the carbs post cleaning, the needle valves’ spring load were measured, floats weighed and needle valves pressure tested for leakage.

My brand new from the factory 912ULS leaked (poured) fuel out of both carbies the first time it was connected to fuel. The carbies were duly removed, stripped and ultrasonically cleaned by an attending L2. The cleaning process yielded about a teaspoon of rehydrated “gum” in the bottom of the cleaner’s bowl. I was informed by the L2 that it was not uncommon in brand new, out-of-the-box engines test run in Austria then shipped.

Austenitic grades (304/316) of stainless steel are generally considered non-magnetic....But your engine mount will likely provide more trouble than a few tiny washers.

I’ve just acquired 5 of these US army aluminium tent stakes, 12m of 8mm polyester rope and an 8oz SCA ball-pein hammer in a draw string bag. Total weight = 1.63 kg

Another STOL aircraft in the works out of Czech Republic mentioned in the latest RA-Aus news

Thanks for the update. I’m comforted by the information, although that’s no consolation to you.

Can’t assist with advice on the Zhongshan, but as an owner of a Rotax I’m very curious to learn from your experience and the response you’ve received from Bombadier and Tecnam.

Might also be worth mentioning at this point that low wing aircraft utilise/benefit from a different model Facet pump (higher head) than that used in high wing designs.

When I installed my 912ULS fuel return line the BPR-Rotax Installation Manual’s specified “pilot jet 35” oriface was 0.35mm / 0.014”

In 1998, Bruce’s Jab was almost certainly built under the old Amateur Built Aircraft Acceptance (ABAA) rules that were administered jointly by SAAA and CASA. It was very restrictive in terms of the allowable deviation from the “accepted design”…(ABAA was phased out between 1998 and 2000)…The ABAA process was jointly administered by CASA and the SAAA and culminated with the issue of a type acceptance document. If you want more info look here: https://www.casa.gov.au/certification-amateur-built-abaa-aircraft A Special Certificate of Airworthiness for experimental aircraft (Experimental Certificate) is an entirely different beast with much greater freedom to innovate. It is not “owned” by the SAAA. If you want more info look here: https://www.casa.gov.au/experimental-certificates It’s quite misleading to consider them as one and the same.

It is perhaps worth mentioning that SAAA is not the sole pathway in Australia to an experimental (Special) CASA CoA. Whilst it is a very good idea for first-time builders to follow the SAAA pathway, there are a considerable number of experimental aircraft registered every year in Australia via independent Authorised Persons.

I’ve flown a few hundred hours behind a VW conversions….Here’s my experience/opinions: 1. They’re inexpensive, 2. They require a cylinder head overhaul every 120h or so, 3. The electrics (ignition and alternator) can be problematic if not effectively cooled, (Read as: require blast tubes) 4. Whilst many VW users complain about cooling, with a great deal of baffle work and judicious removal of cylinder head casting flash, they can run cool, 5. The AeroVee 2.1 prop hub is heat shrunk and keyed onto a forged crankshaft. This has overcome early VW crankshaft problems, but if I were to ever own another, it would have the Revmaster style front bearing, 6. Almost all heads (EMPI et alia) develop shallow cracks between the valves, 7. Nikasil barrels are to be avoided at all costs. (Long story), 8. They need to have a minor mod to an oil gallery to ensure adequate lubrication of the front bearing, (It’s simple to effect), 9. They require a good deal of tinkering. Expect to remove the engine cowls after every day’s flying. If you only remove cowls at annual intervals, don’t consider a VW. 10. The HP claims by the various suppliers are wildly optimistic. Mine ended up at 2297cc and only then did it come close to the 80HP claimed…60-70HP is more realistic for a 2180cc variant, 11. They’re simple engines, easy, fun and inexpensive to overhaul, 12. The “standard” AeroVee 2.1 crankcase is magnesium with reinforcement. Optional aluminium cases are impractically heavy. 13. No oil filter is fitted (or required) so 25h oil changes and valve adjustments are a good idea. (Always replace the cork rocker cover gasket or you’ll have issues with rockers contacting the covers), 14. Despite claims to the contrary, a well built VW won’t leak oil. Now for some person opinions… 15. Every auto conversion engine is an orphan, irrespective of who the supplier is…The owner must consider themselves to be the manufacturer, 16. Auto-engines are not designed to run at high power settings indefinitely as required by aero-engines. (My car lopes down the highway doing 100kph at <1500 RPM.) The laws of thermodynamics cannot be avoided thus hot-rodding MUST impact reliability. 17. The Type 1 crankcase was originally designed to provide ~30HP, not 80+. Turbocharging a VW to attempt to extract 100HP is an exercise in hope over common sense. My personal view is that it doesn’t make any sense for me to spend a single cent more on an aero-engine, UNTIL the instant the cheaper option gives a hint of trouble. These days I don’t fly behind VW’s, but I won’t denigrate anyone who chooses to….It’s simply the level of informed risk that the owner/pilot is prepared to accept. If my circumstances changed and I was looking for a VW derivative, I’d lean toward a Limbach.

These work a treat….I use the 10L version but younger and fitter folk could save time with the 20L

I’m hanging on to my Rotax, but I’ve got an Atmos clock that I’d part with if anyone’s interested.

My Warrior and Sling numbers are pretty rough but not out by anything like an order of magnitude. Based on Rotax’s published data and using a RON 95 ULP specific gravity of 0.72, 285g/kWh converts to ~0.297L/h/HP i.e. 20L/h approximates 67HP..... similarly 18L/h ~61HP, 16L/h ~54HP and 13L/h ~44HP. IFF Rotax’s data is reliable and your 130kt @ 16L/h expectations are realised, you’ll have built a very slippery airframe.

If it is the Ray Allen type, you can adjust the clevis fitting on the push rod. Download the installation instructions and don’t forget to get a dual check before you fly.