New engine

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svenolivier
Posts: 21

New engine

Postby svenolivier » Fri Jan 10, 2020 9:54 am

Hi All
Just blew the #4 cylinder on my Ardem X 1845 cc engine as i was cooling her down after aerobatics - at 51C and 2300 rpm the barrel and cylinder disintegrated, I was hi key for circuit so throttled back and landed without further incident.

This happened at about 30 hours of flying the last 9 months after the aircraft not flown for 20 years - so perhaps not unexpected (the engine had not bee run after the 1845 conversion (which was done 20 years ago).

I would very much appreciate advice from this august group - rebuild? great plains? Aerovee? other VW conversions?

the le burgh ignition works really well so i am content to swing the prop

I look forward to any suggestions

Sven Olivier
worcester south africa
ZS-UDT

Neil Spooner
Posts: 535
Location: Ardleigh, Colchester, Essex, UK
Contact:

Re: New engine

Postby Neil Spooner » Sun Feb 09, 2020 10:05 pm

Hi,
Gt Plains 2180cc engine, force1 hub & Aluminium cylinders would be my first choice.
Neil
A little help goes a long way.
Nipper G-BRPM and G-BALS
RV4 G-IKON

svenolivier
Posts: 21

Re: New engine

Postby svenolivier » Tue Feb 11, 2020 12:00 pm

Hi Neil

I got hold of an Aerovee 2.1 with 50 hours together with the propeller. It seems to me that the starter wont' fit, and as it won't start by hand-propping that i have to go back the the LeBurg / Surefire ignition systems.
So have stripped the wonderful ignition systems out and the engineering shop has fitted the alternator which was in the old engine.
So i can start fitting things soon - i hope.
I suspect the i will also have to upgrade the original carburetor - i have a single Zenith Stromberg i can use?
Any comment or re-directions are most welcome :)
Many thanks

Sven
Last edited by svenolivier on Tue Feb 11, 2020 5:44 pm, edited 1 time in total.

svenolivier
Posts: 21

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Postby svenolivier » Tue Feb 11, 2020 12:00 pm

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Neil Spooner
Posts: 535
Location: Ardleigh, Colchester, Essex, UK
Contact:

Re: New engine

Postby Neil Spooner » Tue Feb 11, 2020 1:47 pm

Hi Sven,

I have no experience with the Aerovee engine, the block will be fairly standard, however, having just done some research ( http://www.aeroconversions.com/support/ ... Manual.pdf ) I see that the prop' flange is elongated relative to the VW one......I would not be comfortable with this in an a/c that is used for aerobatics, as it puts enormous stress on the crankshaft end that was only designed to accommodate pulley loads originally. (Hence my suggestion for the Force 1 hub). The gyroscopic forces are significant. Depending on the crankshaft it may be possible to substitute it with the original hub from your Ardem engine?

I used an Ed Sterba prop' on my Nipper, which was wooden and very light, it also worked very well. There is a PTL (Prop' Type List) here for the Nipper: http://www.lightaircraftassociation.co. ... %20123.pdf Interestingly it is not complete, as it doesn't show my prop' on G-ONCS. Sadly I have sold it and don't have that info' now.

The engine/propeller combination needs to be matched to the airframe......a draggy airframe will have a fine pitch, conversely a slippery one will have a course pitch......you may be lucky depending on what this prop' came from. I would highly recommend fitting a vacuum gauge either permanently or temporarily during development of the installation. I find it very useful during "tuning" of the prop'/engine setup, and also for detecting degradation of the engine during service.
Have you looked at the weight of the Aerovee against the Ardem? I recommend you weigh both for W&B.
The Stromberg should work fine, but you may have to fit a new needle. Do you have CHT and EGT gauges? That will help setting up the Carb'.
Neil
A little help goes a long way.
Nipper G-BRPM and G-BALS
RV4 G-IKON

svenolivier
Posts: 21

Re: New engine

Postby svenolivier » Tue Feb 11, 2020 5:44 pm

Hi Neil

The next step is to substitute the prop flange set-up which also includes the magnetic pick-ups for the Le Burg. Given your advice that is now a definite step.
I will check the prop specs (- it is a Sensenich W54JV5L 44 -) it came with the engine from a Sonex - and thank you for the link
I will fit a vacuum guage
and i have CHT and EGT gauges :)
The Stromberg is in for an overhaul and i have asked to fit it with the correct needle.
I also purchased a new oil cooler - i think there might be a lot of metal bits in the present one
No doubt is W&B will be done - the weighs seem similar ex the manual (162 lbs if i recall correctly).
Many thanks again

Sven

Neil Spooner
Posts: 535
Location: Ardleigh, Colchester, Essex, UK
Contact:

Re: New engine

Postby Neil Spooner » Wed Feb 12, 2020 12:00 am

The sonex is slippery.....you may be able to repitch the prop, there is a prop builder over here who would get a spokeshave out & tweek the prop without even taking it off!
Neil
A little help goes a long way.
Nipper G-BRPM and G-BALS
RV4 G-IKON

svenolivier
Posts: 21

Re: New engine

Postby svenolivier » Tue Mar 10, 2020 7:32 pm

Aerovee installation progressing - dual ignition and carburetor (and new fuel line) installed. New manifold for the dual ports. New prop hub machined and ready for installation. New throttle cable. New oil cooler and new hoses ready for installation. New spark plug leads :)
Attachments
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new prop hub
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Getting there :)
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Neil Spooner
Posts: 535
Location: Ardleigh, Colchester, Essex, UK
Contact:

Re: New engine

Postby Neil Spooner » Thu Mar 19, 2020 9:03 am

Very nice!
Is the prop' hub shrink fit? How much did it cost you please?
Neil
A little help goes a long way.
Nipper G-BRPM and G-BALS
RV4 G-IKON

svenolivier
Posts: 21

Re: New engine

Postby svenolivier » Mon Jun 01, 2020 5:17 pm

Hi Neil
Apologies for the delay in reply. It was not heat shrunk. The price was approx ZAR 6000 (GBP 300) :)
I had to refit the engine cowling and this took me a long time during lockdown - i know a little more about glass work and finishing. I post pictures in the photo section. The engine started first time on the second swing. But we are not allowed to fly during lock down and i will need to jump through some hoops with the paper work. But i have done some taxi tests - which included some long hops:)
I can't wait to get fully back in the air.
regards for now
Sven

Paul1954
Posts: 8
Location: Norfolk

Re: New engine

Postby Paul1954 » Fri Jun 05, 2020 2:45 pm

svenoliver - can you simply put a replacement barrel and head on the engine? I see your comment re cooling down but, did you keep the engine ‘pulling’ after aeros, or did you idle it? You say 51*c is that the OAT? I don’t think you will find any engine/aircraft certified to operate above 50*c. Yes, I realise it’s not a certified type.

svenolivier
Posts: 21

Re: New engine

Postby svenolivier » Thu Jun 11, 2020 9:28 pm

Hi Paul
Apologies for the typo - it was 71C - oil temperature. OAT was around 18C. During the flight the oil temp as never above 80C. I always allow for some cooling before landing - so that the temperature drop is not so much, and also to make it more gradual. If i recall the rmp was around 2300 - so it was "pulling" but i was in level flight and side slipping.
I was advised by two AMO's that the engine was history, but another mechanic said that i should bring it for him to look at.
Hope the above makes sense.
Sven

Paul1954
Posts: 8
Location: Norfolk

Re: New engine

Postby Paul1954 » Fri Jun 12, 2020 1:47 pm

Hi Sven, Tipsy Nippers and engines, eh?

Sorry if your engine problems have taken the fun away from your flying. I hope the following does not sound patronising - NOT my intension at all.

Your situation of having inherited an engine that has sat idle for many years is not desirable. Not even a motor that has been appropriately inhibited is immune to issues after a few hours of operation. Old fluids in an engine can cause, amongst other things, corrosion, blockages and gumming-up of springs and piston rings. Unless those issues are addressed, there will inevitably be issues down the line.

The importance of keeping a hot engine ‘pulling’ after aerobatics is well known and applies to glider towing aircraft too. If, after a period of running the motor at full power, it is then allowed to idle, then there is a genuine danger of severe damage to heads, cylinders, and other parts caused by rapid and uneven cooling. That is one of the reasons why so many like to install a CHT sensor onto # 4 cylinder of a VW; it helps to give a picture of how hot the warmest part of the engine is. But it is just a clue. Oil temperature, although helpful, will also vary and depend upon the oil type, oil cooler, OAT, how hard the engine has been driven, as well as the general condition of the engine.

More generally the problem of VW engines/Tipsy Nippers/aerobatics has been around for many, many decades. The ‘Master’ is Barry Smith. Sadly, Barry is long retired and no longer involved in flying, but he visited the issues and preached to the great unwashed as to affordable VW engines for decades. Trouble is, too few listened at the time. Anyone who owned or flew behind one of his 1.8 or 2.1 litre VW Acro engines will tell you how good they were - never an engine cough when the aircraft was rolled to the inverted… or stayed there!

https://acro.co.uk/

Assuming you want to operate within the realms of the flight manual and stick with positive ‘g’ manoeuvres. You will need to install a VW that is not too heavy - that way won’t be coming up against the max aeros weight limit or getting your C of G outside the permitted range either.

To do so, you need to consider a light-weight ignition system, a suitable carburation and inlet setup, and oil cooling. You also really need to keep all the above under a streamlined cowling.

I would suggest that 1.8 l engine with aluminium heads will keep the weight down. LeBurg / Surefire ignition systems are the lightest you will find. And when it comes to carburation, the Zenith CD 150 installation with suitable jetting requires a simple induction system that then only requires a hot-air box to be added to it. Note though, the existing Ardem 1600 pipe ID is too narrow for the 1.8 l engine and may also require a different take-off attachment plate too.

To the above, add an oil cooler and oil filter, oil and CHT gauge system, a small modification to accommodate the carb under the cowling, and you are almost there. Finally, consider if the cylinder/engine baffling and sealing is in good condition. From memory, G-NIPR is one amongst many with the above installation; it works!

If you are thinking about an inverted oil fuel system… ask yourself if you want to waste years trying to perfect such a system or if you want to go aviating and just having fun in your Nipper!

Pictures below show an oil cooling and filtering installation.
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svenolivier
Posts: 21

Re: New engine

Postby svenolivier » Wed Jun 17, 2020 7:56 pm

Hi Paul, many thanks for your insightful post - it has been a hard road to hoe on getting some proper guidance, but you and Neil certainly has been most helpful. Old engines - on the first flight in UDT the heads on both sides burnt through at the inserts for the second set of plugs. Fortunately i was high and landed back without incident. Found single heads and continued ... then she really struggled to start and finally would not start at all. Long (very long) process of fault elimination - turned out the pass key for the propeller had sheared and progressively moved out of position. Just when i sorted that out at just over 33 hours i had the barrel and piston disintegrate - again landed back without incident.
Now installed a second hand Aerovee with about 50 hours on the engine - so the set-up is dual ignition LeBurg and Surefire (of which more later) a Zenith CD150 with a hot box. (the old engine was previously upgraded from 1600 to 1800 and the Zenith fitted perfectly (?) to the dual port manifold i sourced to go with the Aerovee engine (this in turn required quite a modification to the cowling)
At the moment the engine starts very easily, even in the relative cold we are experiencing. But, the LeBurg runs at about 120 rpm less than the Surefire. The AMO is concerned about this - i have checked and replaced the sparkplug leads, the spark plugs, and that i have a spark on all plugs. It sounds as if the engine misses on the port side with the Leburg. I have CHT and EGT sensors on cylinders 1 and 3, and they show slightly cooler readings on CHT, but EGT is nearly exactly the same ??
For the moment i am not thinking seriously about any inverted systems - much to learn and i try to keep it simple.
I attach photos as she is now :) Of course i would appreciate any comments and suggestions and advices.
regards
Sven
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Paul1954
Posts: 8
Location: Norfolk

Re: New engine

Postby Paul1954 » Fri Jun 19, 2020 8:07 am

Sven,
What is the max static rpm? If you have already changed/swapped plugs and leads, have a check for a good earth on the electrics.


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