stanzahero

OOh thata REALLY bad repair job! Method for hardness testing: First, the head needs to clean. No carbon, oil or sand-blasting residue on the faces to be tested. There are a variety of tools that are used to test haardness, ranging from a fully electronic device to a calebrated hollow tube with a ball bearing in it. They all work by dropping a ball bearing onto the surface and measuring the rebound. Making sure that the tool is flat on the face of the head, test the head in about six or seven places. Include between the cylinders (not on any badly sunken gasket marks), above the exhaust port on the face, above the inlet port and on the rocker gasket rail as well. Generally the higher the average the better but stats are about 65 Brinell as a throw away mark for any low result to about a 75 average min. The higher the average, the happier the head. Nev, ALL cylinder heads should be pressure tested as a process of reconditioning - most preferably with a very hot photofloresent fluid. That way a black light will show any hairline cracks that would not normally be picked up.

It's a good point about the hardness make sure you get it checked. Welding does generally not create tension if the head is allowed to cool slowly. I used to wrap the welded cylinder head in a thermal (asbestos) blanket and give it 12 hours to cool. Like Nev said, interlocking inserts can be a problem because of the difficulty in getting them to both seat in correct alignment with the guides. Alloy tends to have more 'give' than the steel inserts so the second insert to go in will be pushed to the side. It also an issue when the head warms up, because the alloy head expands at a greater rate than the steel insert. This will also push the valve seating position off slightly causing abnormal guide wear because valve seats will move away from each other after warming up. The standard interference (crush) for the valve seats are .007" - .008" for an alloy cylinder head and .006" - .007" for a cast iron cylinder head. With the correct interference fit, they will not drop out unless the head is very soft, or the engine is in the process of being cooked well beyond normal limits. They are reliable enough for just about every manufacturer to use is their engines (disregarding Datsun 1600s and Lamborghini with their bronze inserts). Stan.

Common affair with these critters. If it was a car, I'd remove the inserts, grind out the cracks (they don't look severe enough to hit the water jacket), weld up the holes and fit another larger set of welltite or martite inserts in them. A straght forward job for any one with a TIG welder and a Serdi. Altough I'm not sure as to the protocol with the aero engine community. Stanzahero

Something no one picked up on in your original post (number 8)... It actually cuts power to one set of plugs/magnito to make sure that the other one is working. Most aircraft (possibly all) utilise two sets of spark plugs per cylinder, with each set operated by seperate magnitos. It is a safety redundacy built into the aircraft, as well creating a more efficient mixture burn; which is why the revs drop off a little.

The series A Piece of Cake. It was a seven part mini series shown on TV when I was a little tacker. It was about a Spitfire squadron during the early stages of WW2 till the end of the Battle of Britain.

I waited to give someone else a chance... My guesses are La-5FN (can't read it on the tail - I tried hard though), Yak 1 and an LA-7... Stanzahero.

I was sent off looking for a Skyhook. I was young and nieve, from the country in the big city and a first year apprentice... I feel for it.

flyvulcan.... Lavochkin La-9 dressed in the colours of Sosialist Romania?

Hi Mark, Yep. She was restricted growth because the placenta was dying. We went in for a 33 week scan, got sent to hospital for monitoring for a week, then had an emergency C-section at 34 weeks. She was the size of a 28 week old. They spent over a month in the ICU with my wife in Ballarat and me 130kms away at home. She is now 11 months old and don't show any signs, apart from being a little small, of the trouble we had. The photos are Meg the day after she was born with a 5 cent coin by her foot, Bec and Meg with my watch as a comparison, and Meg at Christmas with Bec. So in all, it turned out OK. Stanzahero.

Firstly, Congrats to both you and Nicole. My wife and I found ourselves n this same situaton last year. After getting our RAA certs, we had done our first trip together and were planning our next when we found about our little bun. I have two things that may be relevant to your question. After Megan was born (six weeks early and only 3lbs), life presented challenges to us. Time had suddenly became too much of a c ommodity to spend driving for two hours to the airport. Money had also become an issue... The other thing is too see how booster seats and capsules sit in the aircraft. You would have a heck of a time getting them secured in the seat. Booster seats are also not designed to absorb verticle forces - such as a carrier (heavy) landings. They only like horizontal forces. So my summary is to wait till they can comfortably sit in the seat restrained by the seat harness. Stanzahero.

I'd feel a heck of a lot safer with the Yamaha than the 1300 cc Harley.....

Side note in reference to the title..... Q. How much force does it take to stop an aeroplane propeller? A. Half a Newton.

yep... I can't uphold to that one...

Can you think of an English word where 'ph' does not make an 'f' sound? Stanzahero.

... Flinging - One night stand

Hi Richard, Welcome to the site. Flying is like a Chinese finger trap. It takes a little courage to get into it, and then you find you are stuck and can't pull out! I can't help you with the fly experience, but can tell you that once you start, you will become addicted to it. Stanzahero.

Looks like the cylinder has done a spark plug electrode. The damage is confined to the squish area in the chamber.

Sounds like (don't take my word as gospel) a big end let go then the crack came around and tried to remove the floating big end from the engine via the crank case / bell housing.

Name the engine De Havilland Gypsy Queen? From the Dragon Rapide? i_dunno

I used to work with a guy who was English. His mate in England Had a surname of Carrott. He named his first daughter Henrietta.

Time to upgrade your current Sim? Check this out as an alternative. Comes second hand though. Great talking point but may need an extension on the house.

*drool* Happy travels and a safe Xmas Tomo. Bec, Stan and Meg.

Air Ambulance....

Wheels would have helped???? A 4WD would have had issues there!

Shouldn't the laptop be logged in to Twitter?