Red

There are always people who believe Legal = Safe and Illegal = Dangerous .....in absolute terms. Despite what those who fly desks will tell you, pieces of paper dont make anything work

Have you checked tappet clearances BTW?

I wouldnt take the applicability to Hydraulic lifter engines only as a always true case, if only because I dont understand what difference that makes to the rocker box oil delivery and return system

Here is the relevant SB for the Rocker box vent https://jabiru.net.au/wp-content/uploads/2018/05/JSB013-1.pdf Take note of section 3, copied below Jabiru Service Bulletin: Jabiru 2200 Engine Rocker Chamber Vent JSB 013-1 8th August 2006 JSB013-1.doc Page 2 of 5 3 Background The upper valve train of Jabiru engines is lubricated by means of a low-pressure feed which supplies oil to the valve guides and rockers, then flows back into the sump via the pushrod tubes. In the engines listed above the flow of oil back into the sump can be reduced by internal airflow and pressures inside the crankcase. This effect is magnified by a build up of negative pressure inside the rocker cavity (as air is drawn out of the rocker cavity by the normal leakage past the intake valve guide) and by the additional oil flow from the hydraulic lifters. This restriction in the amount of oil flowing back into the sump leads to the rocker cavity filling with oil. As the rocker cavity is at a high temperature (typically over 130° Celsius) the oil is overheated, becoming very thin and gradually loosing it’s lubricating properties. This leads to increased upper valve train wear (valve guides, rocker bushes etc) and elevated oil consumption as the thin oil is sucked down the intake valve guides and burnt in the engine. In some cases oil may also be found in the induction manifold. This phenomenon varies from engine to engine due to differences in operating regimes, different average oil levels in the sump, different engine vent outlet pipe positions and different levels of blow-by past the piston rings. Jabiru 3300 and 5100 engines (including 3300 engines with hydraulic lifters) do not suffer from this problem due to the larger airspace volumes in their crankcases and oil sumps. Drilling a small vent hole inside the rocker cavity removes the negative pressure inside the rocker cavity and allows the oil to drain normally into the sump (Note that as the pressure inside the cavities is generally less than ambient, air is sucked in through the vents – only negligible amounts of oil flow out). The following Service Bulletin details the installation of the rocker cavity vent and ways to manage oil consumption before and after the vent is added

Regulators are not police

Jabs don't have guide seals.

This young British Lady became the youngest person to fly solo around the world and used a Shark https://en.wikipedia.org/wiki/Zara_Rutherford Record soon beaten by her younger brother (talk about sibling rivalry)

Actually at least 3 different named versions (shadow, streak shadow, starstreak shadow), mine had a 503 there are 3 at the airfield Im at now, all have different engines (503 582 912) there are 2 different wing lengths and 2 different body widths though most are the narrow version. I don't remember any pitch sensitivity though flutter was a problem on some and there was a friction mod to alleviate it. I went a different way and lightened the elevator by using light covering that required no paint as I believe the flutter was a balance problem caused by the elevatror trim servo being inside the elevator and then builders using lots of paint...the flutter was quite scary when experienced but I cured it. Apologies for the thread drift.

Hello Gordo, Sorry I don't know the spec. The designer David Cook states the use of a standard and available in the UK irrigation pipe in his book "Flying from My Mind" I had a copy of the book but lent it out never to be seen again but I don't think he states the actual spec in the book. Bare in mind it was an 80s design. I owned and flew a Shadow for some years, fantastic view and very benign handling. There is a shadow facebook site at https://www.facebook.com/groups/263902687415672 But I dont have a facebook account so can't ask questions there...good luck in your search

The CFM Shadow microlights used Irrigation pipe, it wouldnt surprise me if used on other designs

Were a handfull of these at Blois back in 2016, very impressive to see performing but expensive. Unfortunately I didnt get to have a ride

Whilst recognising I live in a tiny country so may well not appreciate the reality of flight in Australia, are there not a few strips along your routes wher you could refuel?. Though I have done 7 hours in a day, I tend to need to get out and stretch my legs (and back) after a couple hours flying anyway

That doesnt mean put as much weight in as you want as long as you weigh it and stick a placard up, obviously it has a ZFW and MTOW that must be adhered to

nt, sORRY AN EDIT TURNED INTO A DOUBLE POST

As an aside, a fellow Rotax user I know once priced that square plastic Bottle and was quoted about 150 aud! Needless to say he used something else.

Yes, I've watched some Videos on Arnold's design a long time ago but there is new stuff (to me) here Thanks Max

Exhaust wrapping has nothing to do with cooling drag, it simply keeps exhaust gases hotter which may increase engine efficiency, its rather complex but I suspect the wrap in this instance is simply to stop burning the closely fitting cowl. Cooling drag is all about the reducing the drag from the airflow that is used to cool the engine, in other words careful design of inlets, outlets and the flow between these points. theoretically cooling drag can be reduced to a negative figure I.E. thrust.

Fitting a line there wont do any harm but, If the valve in the coolant cap is blowing out enough coolant into the expansion tank (plastic bottle) for it to overflow then you probably have a lot more to worry about than a bit of mess on your firewall. The hole in the cap is really only an air vent there to prevent the expansion tank itself becoming pressurised not to as an overflow Admit it Marty....you just wanted to talk about Nipples😁

Notwithstanding that safety should of course always be the primary consideration, there are no flying policemen up there waiting behind a cloud to pull you over.

Yea its an early farman quite possibly the one flown by Dimitris Kamberos

Oops sorry BrendAn, slip of the tongue, but "at the moment"????!!!...😁

Been watching Thunderbirds Brenda?

They look to be a boundary layer control device, possibly energising an area of flow stagnation

Personally If the location of the runway is decided, Id build a stout hangar for the aircraft before anything else.