Justin's Raven

[justin.schoeman]

Hi Justin as i mentioned on "the other forum" , should it have been my fault, i certainly would not have wanted to hide. So no i dont mind being named .And as mentioned, the offer remains the same I truly hope you can get flying soon, a mishap like this is REALLY not welcome at this stage.
Regards
Jean.

And as I said on the other forum, thanks - you are a true gentleman!

[justin.schoeman]

I spent today cleaning, and inspecting the engine. Aside from the cracked #4 bearing web, there doesn't look like any damage (and I wouldn't really expect any with a seize at idle), but I still do need to get everything inspected to make sure. Any hints/tips on engineering shops would be appreciated. Need someone with magnaflux and dye penetrant testing equipment...

I was pleasantly pleased with the state of the rest of the engine though. The engine ran for 1.5 hours on the hobbs. 30 minutes was spent at 2500RPM (18"MAP) (works out at around 40hp) for the Great Plains break in procedure. Another 45 minutes was spent at high power, varying between 2800RPM/22" and 3000RPM/25" (60-70hp). On my instrumentation, the temps never even reached top of the green arc, never mind orange, or red, so I didn't expect any signs of heat damage - and I did not find any. Absolutely no barrel marks on the head. No discoloration, no deformation of the copper gasket, nothing.

Although the ground running was done wioth big baffle extensions, I have no doubts that similar, or better results can be achieved in the air. I am fairly certain that the horror stories I have heard about the VW not being able to cool above 50hp, are garbage.

I did, however, find some signs of strain on the bottom end. The #3 bearing web had a small area of fret marks. All the main bearings showed some light polishing on the opposed faces, and all the big end bearings showed some light polishing at the top, center of the top cap (this is the point of max load, where the piston is pushing down on the rod). This indicates that the oil pressure is not quite high enough for he bearing loads. The lowest pressure I measured was 33PSI (which really is at the bottom end of acceptable).

I will shim the pressure relief for 50PSI minimum when (if) I rebuild, and I may opt for shuffle pins, to stop the fretting. All round, I would say that a well built and set up VW engine should definitely be capable of the advertised 80hp continuous power. I just need to build it properly next time...

[Jean Crous]

Justin, like any other engine , this one needs some understanding and attention. Once that is achieved one CAN put together a very reliable VW based aircraft engine. Look at what Revmaster has achieved
Regards
Jean.

[Induna]

Hi Justin,

I removed my VW engine from my Raven after engine failure. (detonation) So, if you want to rebuild your engine and need spares (casings, baffles, etc) then mine is available as I won't follow the VW route again...

I am currently installing a low hour 582 engine, as the performance figures of Marcel's one in Lambertsbay is outstanding...! Much better than the VW. Another note, my emty weight with the VW was 301kg... Its now WAY down!

Jacques

[justin.schoeman]

Hi Justin,

I removed my VW engine from my Raven after engine failure. (detonation) So, if you want to rebuild your engine and need spares (casings, baffles, etc) then mine is available as I won't follow the VW route again...

I am currently installing a low hour 582 engine, as the performance figures of Marcel's one in Lambertsbay is outstanding...! Much better than the VW. Another note, my emty weight with the VW was 301kg... Its now WAY down!

Jacques

Thanks Jacques, PM sent.

[justin.schoeman]

Heard back from the engineers this afternoon. All the bits and pieces are perfect (magnaflux, dye test and measure). So it is only the crank case to replace (together with the usual rebuild kit - rings, bearings and gaskets)...

[JvTonder]

PM sent!

[AndyCAP]

Any news Justin?

In hindsight and withyour experience withall the engine rebuilds for this project, would you still have gone with VW/aerovee ? Seems like you were very close to having a good running engine?

[justin.schoeman]

Any news Justin?

In hindsight and withyour experience withall the engine rebuilds for this project, would you still have gone with VW/aerovee ? Seems like you were very close to having a good running engine?

That is a very good question, and I won't know until it flies... The problem is that the engine may be marginal for this specific airframe. It started out as a relatively cheap experiment - if it works, great, if not, not a major loss. But in the end, I have invested way too much money in this engine.

The biggest problem with the engine was buying second hand - all the other problems originated there. Even though it was supposedly a flying engine, it was really only an accessory case and crank. Everything else had to be machined and or replaced to make it serviceable.

If I had to do it again, I wouldn't consider a second hand purchase as any more than a starting point (and definitely not spend more than around R5k on it) and consider usable parts a bonus. Alternatively, I would buy a complete new engine - and then I would buy a new Revmaster from Jean Tree. I would probably not consider the AeroVee again, as their shipping policy makes it impractical to buy spares (shipping costs are generally 2-3x the part prices).

Aside from that, I am happy that the VW is a genuine 60hp (at least) machine. Ground runs at ~60hp power level were perfect, and I am sure with a bit of airspeed, it will cool just fine at around 80hp. Mechanically, the engine handles this power with no signs of stress.

All round, I would say that the VW is a very good option. If built properly.

[AndyCAP]

Thanks for the feedback! Good luck with the Engine rebuild!

[t-bird]

Hi Justin
Have you started with the rebuild ?

[justin.schoeman]

Hi Justin
Have you started with the rebuild ?

Had to order a new case from the US. It is still with the engineers there - and will take two weeks to ship once it is done...

[Jean Crous]

Hey Justin, i will let you have the heads-up on the hub flange and main bearing this week.
Regards
Jean.

[AndyCAP]

Hey Justin. Long time no hear.......?

[justin.schoeman]

Hey Justin. Long time no hear.......?

Just received and unpacked a goody bag from the US. Was a bit rushed last week, so forgot to finalise the prop hub order with JeanTree. Should get that soon, get the case machined for it, then start building again!