geoffreywh

oooh that is expensive for a flathead 4 ! What is the 6 going to cost? six fourths of twenty large? ....I wont be buying one anytime soon. I would rather a 3300 Jab with all the foreign fruit on it...and some change...

That is sooo scary. EFATO with no known cause. especially a Rotax.. ..Did the engine stop suddenly or lose power and splutter to a stop? I mean. The engine needs fuel, spark and compression which one was missing?.....

As an aside Quote "Car engines spend their working life at 30% throttle or less. Aircraft engines spend their life at 75% or More ". I've seen this statement quoted quite often and whilst correct it appears to credit the aero engine with some sort of mystical property. Yes aero engines spend their lives at 75% max output. And do it for long periods ....I am grateful for that....But.. this setting is particularly easy on an engine. Up and down the rev range with vastly differing loads + hundreds of cold starts is harder on an engine! ....Plus the specific output of an aero engine bhp/ltr is abysmal. ( 0-200 is 30 hp/ltr IF you are lucky !) So you have a great big engine loafing along at steady throttle not doing a whole lot of work. A Honda car engine of similar size puts out 3 or 4 times as much..(and probably costs about 80% less ) Please, give credit where it's due........................................

to right!

bugger there goes my credability again.............

That's terrible, I'm so glad you live in China....

I'll see your thru' bolts and raise you a cracked cylinder

Dear F/H .........Wouldn't leaving the mags switched off do? Or should the plugs still be earthed??? you also mention the compression of the preceeding cylinder... IMHO you ABSOLUTELY MUST have at least one plug per cylinder and plug caps removed.. The previous poster ( mr. Crayon Box) mentions that he saw approx 110 psi on each cylinder. I would have expected to see more. If the number should jump quite a lot ( up to, say, 150) after a couple of squirts of oil in the cylinder (at any crank position ) I would recommend a leak down test. You may have worn rings.....The engine may well still be operational for some considerable time ...........but showing wear

Trelleborg in Dandenong south supply 6 or 10 ply 5 or 6 inch tyres of differing widths. I bought some recently and the were about 80 bucks for two with tubes....please don't say they are for an aeroplane....

abso bloody lutely.........

The edit button is U/S... the last bit should read............If all the readings are low (0-100 ) then your engine is probably buggerd ... AND I refuse to be intimidated or concerned by expressed fears of an engine starting with the plugs removed or someone walking into a prop arc while I'm doing a compression test. Murphy's Law belongs with the fairies at the bottom of my garden...On the other hand a performing a leakdown test on your own can be quite interesting at times. It should really only be done with two people!

When I did a compression test on a 100hp rotax a couple of weeks ago I got in the region of 155 per cyl. which is very good, considering it had 2000hrs on it.(average 75-80) on the leakdown.) .....I can't say exactly what compression reading you will have in your engine as some factors are unknowns. Valve timing , compression ratio, general wear influence readings. BUT what you can know is if you have a weak cyl. Get used to your own engine. A compression meter does not have to be calibrated. You are doing a comparison test. If your meter reads 150 pounds sq.in. on 3 and 130 on one, then you MAY have a problem. My advice would be to refit the plugs, run the engine briefly and check again. The valve may have had a bit of carbon trapped under it ( I have seen that in maybe 10% of tests I have done over 50 years) The carbon is liberated when plugs are removed. If at the retest, the number is still low , a couple of squirts of oil into the cylinder will seal the rings, retest , if still low you have valve problems in that cyl....... Generally compressions are 140-170 even my 0-200 reads 140 and that at 7-1 compression BUT with very "slow" valve timing. IF you test a "hot" motorcycle engine with heaps of valve overlap you may still get a "lower number" reading.. I would look for the 1 ( or more) "low" cyl. reading to identify a problem...of course If all the readings are low (80-120 ) then your engine is probably buggerd and probably uses heaps of oil... Get to know your own engine. Look for changes...Thats why I LOVE solid lifter motors ....Sorry to go on a bit.......Geoff

Quote "You can't do a compression test on an aero engine like you can a car. There's a big heavy whirling thing on one end that can get in the road." What nonsense is this? The dynamic compression test is a significant part of engine condition diagnosis. Don't leave it out. With at least one plug per cyl removed you screw the meter adaptor into the plug hole get in the aeroplane and hit the starter for ? about 8 revs. The reading should be around 150 pounds sq. in/ ( Jabiru.).. Got plus / minus 10% deviation ? Then do a leakdown test .... A compression test will tell you if there's a leak , the leakdown test will tell you where.... Warm engine of course..... Note the 150 number is arbitrary and depends on the compression ratio.. so long as they are all nearly the same. Look at the numbers together with leakdown result.... Get used to your own engines' numbers and look for changes.

sorry Turboplanner. I couldn't get the laughing face to work. I was not terribly serious. .......................Although I have always used Exxon Elite 20w50 in both continental and jab 6....I just don't like how long it takes for 50w oil to get around an engine in winter...OK Shell 100W in summer. Excellent even. But the stuff is like treacle in Melbourne winter...

"because where are all the air cooled engines? Nev"..................In the front of just about every light aircraft in Australia today?

good looking forged? crank....nice big journals... how you gonna arrange the mains bolts? right through?

carpet on gravel works fine, when it rots away. 5-7 years ? put new over the top.....at least you can find stuff when you drop it. try that on gravel or dead grass........

the name is completely naff..........

I would think that the igloo type is probably ok. My hangar has a dirt floor I dont see much evidence of condensation. Although a concrete floor is preferable. You pay your money and take your choice...

There is just such a place, its called the "Incidents and accidents" Forum, don't read it if it upsets you. I, for one, read all I can about incidents and accidents in the hope I might learn something and save myself some grief...Even to the point of getting annoyed at the pilots last night in "Air Crash Investigations" I only have 200 hours but feel I could have done better than some of those blokes.....One had 17000 hours but appears he wasn't all that

really simple answer, no

One shot of Redex or two Sir? Upper cylinder lubricant may well be relevant. Always stopped my Dad's M21 outfit from seizing even whilst lighting his fag on the glowing exhaust pipe. (oo er! that doesn't sound politically correct )

do yourself a favour and dump the VDO sender and gauge. They are notorious for inaccurate readings....Use a real one (mechanical) Then you know what the oil pressure actually is....youi may be chasing your tail....

The half veedub from Leonard Mullholland does not use a cut case, has 90mm barrels, twin mikunis and looks quite good......................I saw info on a 1/3 ! corvair......But hardly a certified aeromotor...If, as you say, the others are in the doldrums .I see your point.......................An update, The Valley engineering " Big Twin " has had some revamps and is now the "Big Bad Twin" Last news I found was late 2012. A little search shows a nice 40hp engine ...............savoiacars.dot.com... comes from citroen....