skippydiesel

15 hours ago, anjum_jabiru said:

Hi everyone

 

I was just doing a desktop comparison between the Jabiru J160 and J170. One of the things that got my attention was the difference in stall speeds between the 2 aircrafts. The clean stall speed of J160 is 55KCAS (58KIAS), whereas that of the J170 is 45 KCAS. A difference of 10 knots!!

 

Just wondering if this raises any eyebrows or is it a cause for concern, as it appears to have a very low threshold or safety margin, before it can enter a stall or spin, especially if one happens to do a steep turn and if the speed was to bleed off rapidly and unintentionally. 

 

I would like to know of any real life experience or any thoughts on this high stall speed in a J160?

Anjum - I am trying very hard to resist the temptation to promote a certain aircraft manufacturers products (for fear of being abused)- the stall speeds you quote are a good 15 +knots higher - scary in a LSA!

52 minutes ago, Old Koreelah said:

I can’t find it now, but years ago in discussing oil cooling on the Jab engine, someone said the original oil sump had the cooling fins on the wrong side; they should have been inside,

The idea being that would provide sufficient surface area inside the oil reservoir for heat exchange with the outside air.

 

It makes sense to me that deep fins both inside and outside the front (and perhaps also the bottom) of the sump would provide similar surface area to the external oil cooler and eliminate quite a bit of complexity. 
 

No more oil lines to check for leaks, a bit of weight saved.

The original engine was elegantly simple, so perhaps, with a redesign of the sump, we could go back there.

OK, I admire your philosophy - in the technological environment, we should always strive for simplicity (the KISS principal) . Unfortunately we must sometimes accept an increase in complexity, to achieve certain performance goals ( eg the fitting of an external oil cooler). I think we would all hope for technological improvements that  can be incorporated, that result in simpler systems.

Your idea external/internal sump fins would certainly present as an excellent KISS solution to a tendency to overeat the engine oil but as Thruster points out there is a significant potential down side, that might then need to be "managed" using pilot or thermostat  controlled variable air flow - complexity again.

In my, very limited understanding, manufacturers TBO only does two things:

• Signals to the prospective purchaser that the manufacturers has a level of confidence in their product ( a marketing tool)
• Provides a "base line" for legislators & commercial entities in the hope of limiting their liability.

There are so many variables in the service life of most aircraft (piston) engine's that the accurate prediction of its safe working hours is impossible, so the manufacturer comes up with something to satisfy the above.

2000hr TBO would seem to be the current industry standard. As we all know, this is a near meaningless figure, as some engines will make & exceed TBO, without any form of major surgery,  while  others will have all sorts of life prolonging interventions but somehow still make TBO - go figure.

15 minutes ago, Tigershark21 said:

Nice set up! 

Luckily, the Fisher 404 is tiny. I'll have to build an enclosure like yours. The dust here is terrible. 

 

I'll leave the top coat purchase til the end then! 

 

I do love painting. I do a lot of airbrushing using waterborne automotive paints by Createx colours usually from airbrusmegastore.com however they are not for aircraft and not sure of their UV rating if any. I really do like the IWATA air brushes.

 

Did you use Superflite 101 Fabric with your plane or another fabric brand with Stewart chemicals?

 

Adam.

Can't remember what brand of fabric I used (would be in my records somewhere). If I remember correctly, SS offers 3 "weights" of fabric - I went with the middle one (whatever that was) as recommended by SS, based on the expected performance of the aircraft.

The SS undercoat is an excellent UV protection not just for the fabric but also for my composite fuselage. The undercoat comes in a regular and a thick grade. You will use mostly the regular however the thick is good for "building up" so that you can sand back to a smooth surface .

The SS adhesive is mind boggling effective however as with the painting preparation is everything.

SS have quite a good colour range however as an ametaur, I stuck with one of the whites (Arctic?) and also used a matt black on the instrument panel.

• Refurbishment DONE!
• Gun modified with hydraulic fitting to facilitate painting under fuselage - I had no way of rotating the fuselage. Did come up with a rotating system for wings.
• Panel painted
• Panel in flight 

38 minutes ago, Yenn said:

When I bought the engine for my RV4 the Aussie dollar was worth  US$1.04

Eighty cents is still a bit low and the reason our government likes to have a low dollar is that all export deals are in US$s.

True but what so many forget is that we are an importer of equipment that is also in US$ and therefor relativly expensive - the grain farmer that sells competitively buys his header & tractor at a disadvantage . I have always thought the whole concept of artificially keeping the AU $ down is a bit of smoke & mirrors economics.

1 hour ago, old man emu said:

What would happen to the US dollar if civil war broke out on 21st January?

Yeah ! - anythings possible in that dysfunctional non union.

If it did happen, the likely brick like fall of the US$ would probably only have a benefit (to us) for a very short window, which would likely close due to much of  industry/supply lines shutting down . The exception would be those supplying the respective combatants.

Tiger -

Great photo of you & Light Wing - unfortunately that aircraft is no longer at The Oaks

• SS is sold in Australia by Sky Shop however when I did mine the AU$ was almost at parity with the US $ so I purchased direct from SS. Great savings & fast service.
• Yes the top coat is a two part mix, still water born & thinned - Its shelf life is more like 6 months than 3 hrs - you may be confusing the post mix to application time with shelf life.
• Take the SS recommendation and do not purchase the top coat until you are going to apply it. There is a strong temptation to purchase all the SS materials at once, to save on delivery cost, DONT DO IT! If your project time line is anything like mine, I grossly underestimated just how long it wold take to do a good job and came dangerously close to exceeding the shelf life of my top coat.
• When it comes to the top coat application, think about how you will maintain at/above the recommended curing temperature (21+C?) for 24 hrs - I used an old window rattler and cheap digital thermomotors to set & record temps just below the sprayed part(s)
• If you follow the instructions exactly the resulting finish will be spectacular

Some better photos of spray/work booth  - I feel it was critical to my good result.

Note:

Plastic (builders plastic) cover include floor, which was slightly flooded for top coat spraying

Air conditioning material , blue panel, can be seen - this provided clean, dust /insect free air

Double doors one end to facilitate large component entry/exit - cheap industrial pedestal fan went in right side (see inner  frame) & used a home made stiff plastic duct & packing tape

All wood  re used for other home projects

Good oh!

Hi Tiger - I used the Stewart System to completely refurbish my Zephyr about 4 years ago. My experience is as follows:

• The limit of my prior experience - have tried my hand, not terribly successfully , at automotive spray painting (high pressure/low volume).
• Attracted to the Stewart System (SS) for the same reasons as you - much lower toxicity but also less paint drift (aerosol) and aircraft certified, whole system in one package ie fabric, adhesives, paints AND VERY IMPORTANTLY comprehensive do it yourself instructions /bible.
• The SS people are very helpful and there is a stack of "how to"  videos that you can view.
• DO NOT PURCHASE THE TOP COAT UNTIL YOU KNOW YOU ARE READT TO APPLY
• The only down side that I can recall, was there are very few if any, commercial spray painters in my area  (SW Sydney) who have experience with low pressure/high volume paint systems - so my original plan to have a professional automotive painter do the top coat/finish came to nothing & I did it myself - with a result that I am still proud to show off today.
• There is a bit of equipment that will need to be purchased/borrow/hired/steel, so that you can do the job according to THE BOOK
• I chose to build a temporary spray/work booth so that I could minimise dust/insects in, dust and spray drift out. The dimensions are those that will  accommodate the largest section of the aircraft PLUS room for me to move around (from doubtful memory 8 x 3 x 2 m was a bit on the squeezy side but worked) double doors at one end, one of which accommodate a cheap industrial pedestal fan pointing out (shown)and the other end had a large section of air conditioning filter material  (looking other way, blue material). As many preloved fluro lights as you can get hold off  and you may need a revers cycle window rattler.
• Should you be interested, have lots of photos 
• Probably much more I can add - contact me direct/private.

8 hours ago, Wirraway said:

To add some context, i had previously discussed with “Skippy” last week, or the week before. Re his Atar.

I am not capable of undertaking a “project”, which I explained,

I did not think Skippy’s post was OTTL

 

FFS people, lighten up.

 

spend more time flying. Not talking.

 

I am just trying to find something in my price range, which meets some parameters. skippy’s aircraft meets them all, apart from cost.

Wirraway - happy to send photos, have an inspection (You or trusted agent) discuss cost with you (not in open Forum) but for you and any other interested parties, this Zephyr has been my privilege to own & fly for about 10 years (it is not part of ATEC Australasia Aircraft Sales) - I have not put a price on it, as I am open to fair/realistic offers, however the minimum I will accept is the parts value (as a package ie not sold individually which potentially makes more $$)

9 minutes ago, Butch said:

My apologies Skippy,

 

I retract the word "every" and replace it with "most" ! 

Butch - this is my last response  - I like to think I am an active contributor/supporter of this Forum. I respond to every topic, where I feel I might have something worthwhile to say, to seek clarification, or give support.

I do not intend to try and quantify the number of response I have made where I have mentioned my interest in or promoted ATEC aircraft but would hazard a guess that it would be less than 25%.

If that is" every "or even "most"  in your world please be good enough to stay out of mine.

One other thing - I do not attack on my fellow Forum members - I vigorously disagree from time to time , will pursue a reasoned debate, sometimes using colourful language and regretfully respond to attacks on my person  - it is a shame, that any member of this Forum must on occasion be pressed to defend their reputation.

Thank you

7 hours ago, Wirraway said:

 

Why indeed?? I would love to. 🙂

Well Sean, comes down to one thing.
Cash....or lack thereof.

 

 

Wirraway - there is more than one way to skin a cat/obtain an aircraft. If you have good practical skills or can access them through friends/associates, check out this Forums Classifieds and  my add for a Zephyr project - I would very much like to see this aircraft fly again and will negotiate accordingly. 

" I will not try and turn every post on this forum into a bloody ADVERTISMENT for the aircraft I sell" your words not mine - gross exaggeration by any measure.

4 hours ago, Butch said:

Gee Skippy,

 

How about making your New Years resolution the following......" I will not try and turn every post on this forum into a bloody ADVERTISMENT for the aircraft I sell ! "

 

cheer's and Happy New Year. 

Thanks for the advice Butch - I will do as you request, when Forum members cease to make the occasional (ie infrequent)  statement or  ask a  question, that leads very nicely into me making  a very infrequent a gentle suggestion or two.

You would appear to fly an excellent all metal Italian job - evidence would suggest that you are given to gross exaggeration -  so why not put your talents in this area to good use - give us a Tecnam spruik or two or do you feel the mark may not stand up to scrutiny?🤣

1 hour ago, Wirraway said:

What am I looking for? Something i can fit into for starters....exclude Aeropup, CH200, side hinged canopy Zenair 601.

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We are fortunate in having a range of aircraft capable of cruising at 80+ knots, just a matter of waiting for something.

 

 

 

 

 

Why limit yourself to 80+ knots when you could be Cruising at 134 knots  5400 rpm @ 18 L/h (75 % power). Stall 27 knots (single pilot) ATEC Faeta NG

4 hours ago, rhtrudder said:

The spring type spread the pressure better, but I worry that they could loose their tension, my fuel lines are mostly inside the cab behind the panel last thing I want is a line coming off 

I doubt that the spring type spread the pressure any better than proper FI hose clamps, which are specifically designed to give an even  (non pinching) pressure all round the hose.

As I said, backed up by Facthunter, the first thing is to get the correct hose size for the job - near enough is not good enough. The clamp (whatever sort to use) is for security not for leak prevention.

I am a bit of a control freak, so while I accept that the spring type ones are probably perfectly OK and what will be fitted by the factory, I prefer ones where I control the pressure (several different types available) 

Okay - will get back to you when I have had time to thoroughly familiarise myself with new aircraft (with CV-19 that may be some time off)

Just a note on the advice to get your engine oil to 100C - water boils at 100C (turns to steam).

The concept is, that by achieving 100C or slightly above, for a sustained period (say 10-20 minutes) the volatile contaminants in the oil (water probably being the main one) will be boiled off - temperatures below this will not have quite the same effect/benefit.

You can run your engine with the oil above or below 100C, without any ill effects, however my personal comfort zone is to see climb temperatures reach a little above 100C , with cruise temps a little below (about 90C is nice).

I suspect that, where pre flight warm up may take a very long time (in cold climates), an oil thermostat  would be most beneficial - other than up in the Australian High Country & possibly Tasmania, this is not a regular situation.

Thanks Glen - between aircraft just at the moment - CO-19 permitting/crossing the Qld boarder - may take up your offer .

So Kyle & Glen - For us less talented types - do we have concise advice/conclusion that we can act on??

Thanks Blue - too old, no time, family (grandchildren) object to devoting so much time to rebuild - in process of purchasing a flying replacement. 

Could put a price on it BUT rather sell to a keen handy person who will rebuild/fly again, at the right price (basically parts cost).

No one in their right mind would purchase a fly away aircraft sight unseen, and this one wont fly until a bit of love/labour/parts are applied,  so rather than have a lot of "tyre kickers" wasting my time - figure a serious purchaser (trusted agent) will want to see first hand befor making an offer. Happy to send photos to serious enquirers.

This is a wood/fabric wing (not artificial composite) - the damage you see is largely what is there is.  Damage incurred at very low (energy) landing speed, into dirt (energy absorbing) at an angle (energy dissipating) so although undercarriage damaged  - was not torn off fuselage.

I have generated a parts list - Purchaser can reduce/increase purchase parts list as ability/desire to do own repairs or purchase off the shelf (deeper pockets) is desired.

I would  like to see this aircraft fly again - so will negotiate price accordingly

Hi Mark,

Just not keen on 2 strokes, except in chain saws, etc - dont even like them in motor bikes - I agree, very racist of me.

So my question stands, was there ever 4 stroke variant/modification (even a private conversion would be of interest)??

I have always admired the Sapphire, they just look like they want to leap off the ground - was there ever a 4 stroke variant/modification??

Well I have had very little interest in my Zephyr, as a rebuild project. A great opportunity to get a truly excellent performing aircraft, at a knock down price ( parts cost). Just requires a bit of labour & some parts to put her back in the air. - So from my perspective the buyers aren't out there.