Owned or Hire
Joined: Jun 2003
Posts: 13,787
Likes: 0
From: EuroGA.org
Well, the starting procedures are quite similar, and both are well capable of prop strikes 
Agreed, and that's what I used to do when I used to rent mine out. The catch is that there is no (normal) instrument which records airborne time only, in a tamper-proof manner, so you have to trust people. Most can be trusted but not all, and those who can't will ruin the deal for the rest, by claiming silly airborne times which a subsequent EDM700 download proves to be fake.
One could rig up a running-hour meter off a squat switch or pitot pressure switch.
The way that I get pilots to take a little more time on the ground to taxi slowly and walm the engine is to charge from take off to landing.
One could rig up a running-hour meter off a squat switch or pitot pressure switch.
Joined: Jan 1999
Posts: 6,209
Likes: 2
From: north of barlu
At the moment I am looking at fitting one of the loggers that the gliding people you to my aircraft to keep tabs on them.
It would seem that it would provide the type of monitoring that would let me bill people to the second! No doubt it would also tell me the ground speed and the time spent walming the engine before take off.
Returning to the subject of engine overhaul I can only think that Bose-X is a very clever bloke with a lot of kit in his shed if he can save himself that much money on a top end overhaul.
It would seem that it would provide the type of monitoring that would let me bill people to the second! No doubt it would also tell me the ground speed and the time spent walming the engine before take off.
Returning to the subject of engine overhaul I can only think that Bose-X is a very clever bloke with a lot of kit in his shed if he can save himself that much money on a top end overhaul.
Particularly as my group is going through similar. Where is your aircraft Bose and what is it?
Joined: Sep 2003
Posts: 0
Likes: 0
From: UK,Twighlight Zone
Returning to the subject of engine overhaul I can only think that Bose-X is a very clever bloke with a lot of kit in his shed if he can save himself that much money on a top end overhaul.
I picked up a set of 4 pistons for Ł200 from other owners of the same type.
The problem is that most people will believe their engineer when he tells them a piston is Ł400 each and a set of rings is Ł130 because it is aviation after all and we are used to being turned over. The oil control mod is a groove and set of truck oil control rings.
None of this stuff is difficult and if you have an engineer to assist who is not just interested in lining his own pockets the job can be done very cheaply.
Justiceair PM me for details.
Joined: Jun 2003
Posts: 13,787
Likes: 0
From: EuroGA.org
I find top overhauling a Lycoming easier than filing a flightplan on afpex.
Assuming you know how to switch on a computer, I could teach you how to file flight plans using Afpex in under 15 mins. I don't think anyone could teach you about engine overhauls in less than years. It isn't just bolting the thing together; there is a great deal to know about tolerances, balancing, you name it. A lot of expertise goes into engine rebuilds.
Of course somebody could do a "top overhaul" (which is basically a removal of the cylinder assemblies, leaving the crankcase closed and thus leaving that can of worms firmly shut) by unbolting the cylinders, sending them off to various people to overhaul, etc, and then bolting them back on with new pistons. You need a torque wrench and not a lot else. I could do that. But I wouldn't post on a forum claiming to have done a top overhaul.
Joined: Jan 2002
Posts: 1,235
Likes: 0
From: Niort
Well IO I suppose you are a sign of the times!
Top or even bottom end overhauls are technically not difficult. There are a clearly set out set of criteria, components and the order / method of taking them apart and putting back together - where is the problem?
Check the individual components, put them together in the right order, off you go. There is no mystery, no magic. We used to train tens of thousands of people to do this most years whilst we were a manufacturing nation.
We no longer are (well not in terms of our major industrial competitors) and suddenly simply machines become things which need highly specialised and expensive people?
There are still a large number of these people fettling away in their sheds. One of my friends is building a Group 1 replica Dolomite Sprint rally car. Straight forward you might think. But. But. The rules allow him a 2.5lt engine, so he has taken a Rover V6, turned the cylinder heads around, built inlet and exhaust manifolds, the inlets incorporating sequential electronic fuel injection. The engine is no longer transverse but longitudinal and now mates to a sequential geabox, with custom flywheel, clutch etc. Of course minor matters like sump, oil pump, fuel pump etc all need to be sorted out - after being completely re-oriented.
He rebuilt the top end of an A65, including new metal fuel lines, rebuilt carb (inc butterfly bushes), exhaust, baffles, new cylinders and after market valve gear in 3 days - working part time. His only comment - "boring little engine glad to get back to something interesting"!
My own efforts on a Gipsy and O-200 are somewahr more modest - but these are simple engines to work on, with no real 'gotchas'
Far too many 'aero engineers' are nothing of the sort, hence the mystery and expense
Top or even bottom end overhauls are technically not difficult. There are a clearly set out set of criteria, components and the order / method of taking them apart and putting back together - where is the problem?
Check the individual components, put them together in the right order, off you go. There is no mystery, no magic. We used to train tens of thousands of people to do this most years whilst we were a manufacturing nation.
We no longer are (well not in terms of our major industrial competitors) and suddenly simply machines become things which need highly specialised and expensive people?
There are still a large number of these people fettling away in their sheds. One of my friends is building a Group 1 replica Dolomite Sprint rally car. Straight forward you might think. But. But. The rules allow him a 2.5lt engine, so he has taken a Rover V6, turned the cylinder heads around, built inlet and exhaust manifolds, the inlets incorporating sequential electronic fuel injection. The engine is no longer transverse but longitudinal and now mates to a sequential geabox, with custom flywheel, clutch etc. Of course minor matters like sump, oil pump, fuel pump etc all need to be sorted out - after being completely re-oriented.
He rebuilt the top end of an A65, including new metal fuel lines, rebuilt carb (inc butterfly bushes), exhaust, baffles, new cylinders and after market valve gear in 3 days - working part time. His only comment - "boring little engine glad to get back to something interesting"!
My own efforts on a Gipsy and O-200 are somewahr more modest - but these are simple engines to work on, with no real 'gotchas'
Far too many 'aero engineers' are nothing of the sort, hence the mystery and expense
Joined: Jun 2003
Posts: 13,787
Likes: 0
From: EuroGA.org
I have seen the inside of a few aero engines, including mine when the crank was being changed etc (in the USA - I flew there to "check it out" as I was writing it up for a mag) and sure there is no rocket science to it.
Yet somehow the whole UK engine rebuild business is a walking disaster. Less so in the USA than here but they do have cowboys there too. How do they manage to do crap work on a "simple" engine?
I think there is a number of reasons, mostly to do with some "less than robust" features of these engines, and probably a lot to do with idiots not using torque wrenches, or having them grossly mis-set.
There are special grinding processes on the valve guides. Easy if you know how, sure...
The crankcase skimming is pretty specialised and needs close tolerances between the mating surfaces and the crank bearing surfaces, and not many engine shops do it in-house.
There have been cases of cylinder studs being nearly stripped and they come up at some later date.
Loads and loads and loads of nuts, bolts, studs not being tightened to spec. A friend of mine got a Superior-rebuilt engine (IO-540, UK job) with IIRC 19 oil leaks. Basically, the monkeys didn't do up the crankcase bolts, etc. His mind was probably on his next sh*g, and there was no duplicate inspection.
A large % of catastrophic engine failures are probably caused by under- or over-tightened (nearly stripped) studs. Why should this happen?? Only an idiot should do something like that.
That's before you get onto dynamic balancing. You need special gear for that, to spin up the crank, measure where it is too heavy and (under appropriate FAA approvals) take a very small amount of metal off where there is no stress. Or, if you aren't approved for it, try to match an under-weight con-rod big-end to that crank bearing, and vice versa. Pistons are much easier but they need to be matched to the small ends, correspondingly.
Then there are various details like the very slight taper on the cylinder bore..
And the more specialised processes need equipment which not many firms will have kicking around and will contract it out.
Things are easier in the USA. For example the firm which did my engine, which is the most reputable I could find (despite the naff website) is in a road packed end to end with firms doing other bits, so if e.g. the fuel servo needs doing, they take it next door. Mag overhauls, across the road. This excellent firm is down the road.
Here in the UK, if I want a fuel servo done, there are about two firms that can do it and neither of them is particularly keen... UK mag overhauls are definitely a Russian roulette, especially the single shaft ones.
None of this is rocket science but you need to be a really good engineer, and they are not being educated anymore because vocational engineering training (apprenticeships) more or less died about 30 years ago. Today's kids want spending money and they want it NOW, and no businessman will be employing "kids" on the same wages as somebody older and far more stable.
Yet somehow the whole UK engine rebuild business is a walking disaster. Less so in the USA than here but they do have cowboys there too. How do they manage to do crap work on a "simple" engine?
I think there is a number of reasons, mostly to do with some "less than robust" features of these engines, and probably a lot to do with idiots not using torque wrenches, or having them grossly mis-set.
There are special grinding processes on the valve guides. Easy if you know how, sure...
The crankcase skimming is pretty specialised and needs close tolerances between the mating surfaces and the crank bearing surfaces, and not many engine shops do it in-house.
There have been cases of cylinder studs being nearly stripped and they come up at some later date.
Loads and loads and loads of nuts, bolts, studs not being tightened to spec. A friend of mine got a Superior-rebuilt engine (IO-540, UK job) with IIRC 19 oil leaks. Basically, the monkeys didn't do up the crankcase bolts, etc. His mind was probably on his next sh*g, and there was no duplicate inspection.
A large % of catastrophic engine failures are probably caused by under- or over-tightened (nearly stripped) studs. Why should this happen?? Only an idiot should do something like that.
That's before you get onto dynamic balancing. You need special gear for that, to spin up the crank, measure where it is too heavy and (under appropriate FAA approvals) take a very small amount of metal off where there is no stress. Or, if you aren't approved for it, try to match an under-weight con-rod big-end to that crank bearing, and vice versa. Pistons are much easier but they need to be matched to the small ends, correspondingly.
Then there are various details like the very slight taper on the cylinder bore..
And the more specialised processes need equipment which not many firms will have kicking around and will contract it out.
Things are easier in the USA. For example the firm which did my engine, which is the most reputable I could find (despite the naff website) is in a road packed end to end with firms doing other bits, so if e.g. the fuel servo needs doing, they take it next door. Mag overhauls, across the road. This excellent firm is down the road.
Here in the UK, if I want a fuel servo done, there are about two firms that can do it and neither of them is particularly keen... UK mag overhauls are definitely a Russian roulette, especially the single shaft ones.
None of this is rocket science but you need to be a really good engineer, and they are not being educated anymore because vocational engineering training (apprenticeships) more or less died about 30 years ago. Today's kids want spending money and they want it NOW, and no businessman will be employing "kids" on the same wages as somebody older and far more stable.
Joined: Apr 2003
Posts: 2,359
Likes: 0
From: Midlands
I lot of the people who work on LAA engines for fun are ex professional engine men. I am based not far from Derby and there are a number of ex RR guys who worked on Merlins etc who appear to be very good. The problem for the LAA is that there may be a huge amount of expertise available now, but most of it is over 70 and there are not many “new” experts coming through.
Rod1
Rod1
Joined: Oct 2008
Posts: 399
Likes: 0
From: suffolk
"Special process for grinding valve guides"???? Standard engine building practices.
Top end ?? did I say it was just a case of bolting on parts ? but its not rocket science either.
As some one that has converted car engines to aircraft engines from scratch ( but to established procedures ) all I was trying to say is that I prefer that work to working with computers.
That doesn't make me incompetent at what I do.Incompetent with computers maybe.
A brain surgeon doesn't need to be a rocket scientist as well in order to be a good brain surgeon.
Top end ?? did I say it was just a case of bolting on parts ? but its not rocket science either.
As some one that has converted car engines to aircraft engines from scratch ( but to established procedures ) all I was trying to say is that I prefer that work to working with computers.
That doesn't make me incompetent at what I do.Incompetent with computers maybe.
A brain surgeon doesn't need to be a rocket scientist as well in order to be a good brain surgeon.
