Partial engine failure - lesson learned

[facthunter]

The bridging is called whiskering on two strokes. The oil will be there if the cylinder isn't firing. The insulator can short out as well without the bridging . Lubricant additives are metal salts and can coat the insulator. Most just replace rather than abrasive blast and regap these days. Might be an idea to look in that cyl with a boroscope Nev

 

 

[gandalph]

D.R. What device(s) do you have for recording the engine data? Seems like pretty impressive gear.

 

 

[Oscar]

The bridging is called whiskering on two strokes. The oil will be there if the cylinder isn't firing. The insulator can short out as well without the bridging . Lubricant additives are metal salts and can coat the insulator. Most just replace rather than abrasive blast and regap these days. Might be an idea to look in that cyl with a boroscope Nev

Inverted engines will - mostly - have this problem at some time. Gypsy's were notorious, and it didn't always happen on start-up. My brother had to land on the only croppie strip on Razorback one morning on the way to work at Bankstown, to clean the plugs. The farmer who owned the strip came out to ask him if he was OK; since he didn't have any chocks aboard, he asked the farmer to hold the tail while he started her up again - which the farmer did, and as soon as it fired, let go! Luckily, it was an Auster, so brother was able to scramble aboard... being late to work, he hurriedly tied it down outside deHavilland's and went to work; mid-morning, one of the workshop crew came up after smoko and asked him if he'd like them to remove the bits of tree from the u/c, or did he want to take them home as a trophy?

 

Quite seriously - is it worth taking the bottom two cylinder plugs out and screwing in blanks (or even better, inhibiting plugs) if she's going to be sitting around for a while? I know that Mark Willard - I'd imagine you know him - does a fair bit of work on the Chinese version of that engine for the Namchang crowd, he may have some ideas for you?

 

 

[dutchroll]

D.R. What device(s) do you have for recording the engine data? Seems like pretty impressive gear.

JPI EDM 740. This picture (not of mine) gives a deceptively large impression of its size. It's quite compact, which I needed due to lack of panel real estate and limitations of what was available at the time. With 9 cylinders displayed it can be a bit of information overload. A double-edged sword in some respects. The company is a total pain to deal with in my experience, but the equipment is good quality. There are better compact engine monitors out there now.

 

Attached also is the data stream for EGT and RPM (on SavvyAnalysis you can select any monitored parameters for display and comparison when you upload the data) showing the taxy across to refuelling. EGT #5 is quite erratic, presumably the early signs of fouling, until it drops off at the 6 minute mark. That erratic movement would not be noticed with the resolution of the display, and I have to say I also never noticed it drop right off as I was too busy watching outside.

 

 

Quite seriously - is it worth taking the bottom two cylinder plugs out and screwing in blanks (or even better, inhibiting plugs) if she's going to be sitting around for a while? I know that Mark Willard - I'd imagine you know him - does a fair bit of work on the Chinese version of that engine for the Namchang crowd, he may have some ideas for you?

I don't believe so. This aircraft is equipped with a very good electric oil scavenge system which pumps residual oil back to the tank after shutdown. The engine also has modified pistons and rings and leaks/drips far less oil than, say, a Yak or similar. We have consulted with our resident M14P engine expert over in the USA and we think the fouled plug problem has been a ground handling technique issue on our part. He has advised that we need to "aggressively lean" the engine on the ground to lower the chances of this occurring. We were not routinely doing that.

 

 

[dutchroll]

out of curiosity, what type of engine is this?

Sorry I missed your post.

This is a Russian Vedeneyev M14P 9 cylinder supercharged radial. It has been modified by a US aero engine overhaul company called Barrett Precision Engines. Those mods include new pistons and rings to increase compression and power, and reduce oil consumption. Also they replaced the Russian carburettor which works well, but is increasingly difficult to get parts for, with an Airflow Performance fuel injection system. The other main item they replaced was the Russian magnetos (and massive but not so reliable spark plugs), with an electronic ignition system and auto plugs. Again, the old mags are hard to get replacement parts for. With the upheaval and disintegration of the former USSR, production of the engine ceased and a lot of original tooling was destroyed or lost. So new spares can be hard to come by, with most found from "old stock" sitting in the dusty dark corners of old hangars etc.

 

The design harks back quite some decades, and it is renowned as a very solidly built "pilot tolerant" radial engine with a very impressive power to weight ratio. Curtiss Pitts designed this aircraft around this particular engine.

 

The "stock" Russian M14p is 360 HP. They also produced a 400 HP version (M14PF) by gearing up the supercharger.

 

The Barrett mods take a stock 360 HP engine and turn it into a 430+ HP engine (without changing the supercharger) through the increased compression, fuel injection, and ignition systems. Engineers believe the basic design to be quite capable of taking 450+ HP and they've run it at these powers on their test stand with no issues. However MT Propellers in Germany refuse to warranty their 2.6 metre props for that much power.

 

 

[facthunter]

You will appreciably shorten the life of that engine by uprating it. As with all motors. If you are after competition performance, that doesn't worry a lot of people. The worst thing you can do to a radial is high revs and no load. It puts the maximum load on the crank and big end.(s)

 

Have a search under balanced power for radials. I don't know what will come up but it was a big issue in PNG with the 1830 P&W in the DC3's. The issue affects ALL radial engines. Inherent in the design. Nev

 

s

 

 

[Oscar]

Wow, DR, that's one heck of a hot-rodded engine!, and absolutely, at that spec, I'd only be talking to the 'maker' also!. Good to see her sitting pretty in Dave's hangar this morning, with a clutch of smaller Pitts ( Pittlets? A rash of Pitts?) around her. Dave said she doesn't drop ANY oil, well, maybe one drop - amazing!. Dave did say he 'was a bit concerned', but then Dave is pretty unflappable...

 

 

[djpacro]

I saw that my "old" Pitts S-2A is in Dave's hangar for its annual, right next to DR's airplane.

 

 

[old man emu]

I know of a Pitts 2A that's for sale for around $45K. LOcated at Bankstown. Charge the battery; kick the tyres, and flock off.

 

OME

 

 

[dutchroll]

Depends by how much I guess Nev. The Russians added 40 HP by making the same supercharger work much harder. They did that decades ago and never changed the overhaul times as far as I know. BPE decided not to make the supercharger work harder (from its original 360 HP settings) but they did increase the compression. Time will tell, but most M14Ps around the world these days are lucky to fly 50 hours a year. They haven't set an overhaul time for it yet.

 

Besides that, nice day for a flight back to home base. Engine performance "nominal". Pilot wiser.

 

 

[Oscar]

I saw that my "old" Pitts S-2A is in Dave's hangar for its annual, right next to DR's airplane.

Saw it this morning - pretty schmick too.!

 

 

[Oscar]

[ATTACH=full]43106[/ATTACH] Depends by how much I guess Nev. The Russians added 40 HP by making the same supercharger work much harder. They did that decades ago and never changed the overhaul times as far as I know. BPE decided not to make the supercharger work harder (from its original 360 HP settings) but they did increase the compression. Time will tell, but most M14Ps around the world these days are lucky to fly 50 hours a year. They haven't set an overhaul time for it yet.Besides that, nice day for a flight back to home base. Engine performance "nominal". Pilot wiser.

When did you leave? I was there around 1000 hours, would have loved to hear it fire up (and meet you). The only close experience I have had to radials, is having shut down the engines on the AWM B25 for the last time for inhibiting ( the props are RIGHT beside your ears.. - you can lean out the window and turn the buggers to clear fence posts when road-transporting one, I kid you not, I've done it) but radials have a visceral sound like no other engine. Mark Willard occasionally flies his Numchukka near my place when practicing for airshows - sometimes with a mate or two in Nanchings/Yaks, practising formation manouevers, and it always stops me to just go out and watch and listen.

 

 

[dutchroll]

When did you leave? I was there around 1000 hours, would have loved to hear it fire up (and meet you). The only close experience I have had to radials, is having shut down the engines on the AWM B25 for the last time for inhibiting ( the props are RIGHT beside your ears.. - you can lean out the window and turn the buggers to clear fence posts when road-transporting one, I kid you not, I've done it) but radials have a visceral sound like no other engine. Mark Willard occasionally flies his Numchukka near my place when practicing for airshows - sometimes with a mate or two in Nanchings/Yaks, practising formation manouevers, and it always stops me to just go out and watch and listen.

Must've just missed me. I got there a bit after that. I was gone before their lunch break.

 

 

[BlurE]

Giving this 436HP beast full power

It must take a good bootfull of rudder to keep that straight on throttle up! In fact I image you have to advance it fairly slowly to get some flow over the rudder first?

 

 

[dutchroll]

It must take a good bootfull of rudder to keep that straight on throttle up! In fact I image you have to advance it fairly slowly to get some flow over the rudder first?

You know what? Surprisingly it doesn't and you can move the throttle forward at a good rate as long as you are smooth and don't slam it.

You need left rudder on takeoff, but this engine and prop produce an enormous amount of thrust with consequent airflow over the tail and being typically Pitts, the rudder is very effective. So there is no coarse or severe application of rudder required. Just a moderate pressure on the left foot is all you need. However you need to do it promptly.

 

This was my mistake on my first ever flight under instruction in it. I didn't apply the rudder promptly. Although not much was needed, we were almost on the side of the runway before I got the rudder in. Fortunately we were also airborne by then.

 

 

[facthunter]

Enjoy it while you've got it. Military rated engines only lasted about half as long as the same engine derated for civilian flying or transports.. They were the same engine just pushed to higher boost figures. Nev

 

 

[Bikky]

What a beautiful machine! Need a "jealous" icon right now.

 

 

[Marty_d]

What a beautiful machine! Need a "jealous" icon right now.

Too much plane for me. I'd be more "Driving Miss Daisy" than "Fast & Furious".