Super high time engine

CT Arrow said:
While I have heard of the benefits of MMO, I erred on the side of aviation caution and decided to use Camguard about 4 years ago after reading countless users who had great success with this additive.

Sadly, I'll find out if firsthand if this additive has added benefit when in January, my engine shop tears down my perfectly running engine to replace a perfectly good crank all due to Lycoming's idiotic SB-569A.
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Good to see you back Andy. Anecdoteally I was just talking to a guy who is analy meticulous in his Mx with his plane. He has a Lyco 360 with close to 1800 hrs. I saw his logs which showed compressions of 77 65 77 75 for a number of years. He started using Camguard last February and said since he has notice sludge comming out with his oil changes and just last month his compressions were 77 75 77 75. I guess the rings could have been lined up for a number of years but that is quite a jump in compression for the #2. He stops well short of saying that the camguard cleared out the sludge and caused his compression to jump but it sure was an odd coincidence.

Ted DuPuis said:
A rare sight on this board for someone to admit being wrong, but one I wish we'd see more frequently. You have my respect. :)
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Amen Ted RE: H.A.S.
 
Ted DuPuis said:
I think you misunderstood me.

We have two CONTINENTALS and are very happy with them. We're selling the plane that has Lycomings in it. The powerplants were part of the decision process in that.
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No misunderstanding. That decision may work for you but it does not for me. There is nothing wrong with the engine. However my hands are tied due to Lycoming's SB. Trust me, next aircraft will contain a Continental.
 
AdamZ said:
Good to see you back Andy. Anecdoteally I was just talking to a guy who is analy meticulous in his Mx with his plane. He has a Lyco 360 with close to 1800 hrs. I saw his logs which showed compressions of 77 65 77 75 for a number of years. He started using Camguard last February and said since he has notice sludge coming out with his oil changes and just last month his compressions were 77 75 77 75. I guess the rings could have been lined up for a number of years but that is quite a jump in compression for the #2. He stops well short of saying that the camguard cleared out the sludge and caused his compression to jump but it sure was an odd coincidence.
Amen Ted RE: H.A.S.
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Hey Adam, nice to be back! Interesting stuff and stories like you have reported seem to be the norm. I just can't find anything bad about the stuff. I suppose in January, I'll get to see for myself what 4 years of using camguard has done to the IO-360. Hopefully, (fingers crossed) all will be good!

A-
 
Tom-D said:
Let us assume for the sake of argument, that some poilot and or their fasmily got hurt in an accident with any engine that far over TBO.

How would the A&P-IA defend themselves in court?
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It’s a recommendation only I believe for part 91 activities.
 
My only experience with MMO was quite spectacular. I purchased a truck for my company with about 200,000 miles on it. Didn’t have a lot of power for a 351ci engine.

Compression test revealed 5 of 8 cylinders had low compression. Pulled the plugs and filled all the cylinders with MMO. Let it sit through the weekend and pulled all the oil out. Did another compression check in every cylinder was back in spec.

IDK about putting it in the fuel but would think a low concentration in the fuel and oil wouldn’t be a bad thing. But the cost for a new IO470 if I’m wrong....
 
1600vw said:
Lead in fuel does nothing but lubricate the valves. Period. No More, its there for the valve train.
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Excuse me, but there are only so may higher order "tanes" in a barrel of oil. hexanes, heptanes, octanes, nonanes, decanes, and so on. Each one contributes just a little to the way fuel burns. We have chosen "octane" as our standard, and have designed our engines around a particular "octane" mix. In WWII we needed engines more powerful than those currently available, but found that even with perfect "octane" at 100% the damned things would suffer detonation (explosion of the gasoline in the cylinders as opposed to burning) and trash pistons et al.

Somebody (in England???) found that adding traces of tetraethyl lead to the gasoline boosted the "octane" rating WAY UP, compared to the amount of TEL per gallon, and thus we could get "octane" ratings of 115 and 145 to power these high-compression motors.

The gasoline industry latched onto TEL like a godsend from heaven, and in the 50s and 60s, not only avgas but cargas had TEL added to it because it was WAY cheaper to produce low octane gas and goose it up with TEL than to produce pure high octane gasoline.

Then folks found out that there was a fairly significant lead contamination in the atmosphere and we started backing off of using TEL, to the point where it was prohibited in mogas.

Regular 100 avgas (green gas) had about 4 ml/gallon (forgive the mixed measurement system) and 80 avgas had a MAXIMUM of 1 ml/gallon and most 80 had zero TEL. Then somebody got the bright idea that we ought to have only ONE grade of avgas (may their souls fry in eternal hell) and we are now at 100LL, which has 2 ml/gallon of TEL. Problem is there is only ONE supplier of TEL in the world, and if they ever shut down we are totally screwed for our avgas. WIth the exception of the fleet that can burn 80 unleaded out of the auto pumps.

Lead has nothing to do with lubricating the valves. As a matter of fact, they have more to do with STICKING the valves than with lubricating them.

Jim
 
Tom-D said:
Let us assume for the sake of argument, that some poilot and or their fasmily got hurt in an accident with any engine that far over TBO.

How would the A&P-IA defend themselves in court?
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That would depend on the cause of the accident now, wouldn't it?
 
1600vw said:
Lead in fuel does nothing but lubricate the valves. Period. No More, its there for the valve train.
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No, not at all. Lead is the leading cause of sticky valves. Lead was put into fuel to raise the "octane" rating, and slow the flame front.
To eliminate detonation/pre-ignition.
 
1600vw said:
Tony, when I found my hangar and opened the door there sat a 172 and a Comanche. They both have been setting for about 25 years.

Today the 172 is flying again, the comanche just sets. I believe the owner received a DUI years ago and lost his PPL.

Back to the thread.

You have blow by on a new engine, its just not alot. Well at first untill the rings seat you have more blow by but even after the rings seat those rings do not keep 100% of the combustion in the cylinders, no way they can. If they could we would not need a PCV system.
Your PCV, Postive Crankcase ventilation system keeps your rings seated and the gas fumes out of the block. On older cars we called them draft tubes. Next time you see a tractor pull event watch under those engines. That steam you see coming from thos two tubes is the old Draft system. they do not use a PCV Valve on those engines like we do not use them on airplane engines. We use a catch can like the draft systems. They started using catch cans to keep the oil off the road.
A PCV system does a better job a sealing the rings from the draft system. They both do a good job of scavaging the fumes from the block so you do not have a bomb that will go bang or blow up.

Tony

Lead in fuel does nothing but lubricate the valves. Period. No More, its there for the valve train.
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Lead does not “lubricate” valves. It DOES, however, cushion the valves slamming against the seats such that harder seats are not required. This was the biggest problem from unleaded fuel when it came out. Replacing valve seats with hardened valve seats in pre catalytic converter automotive engines, allowed the use of unleaded fuel as long as it had the required octane rating for that engine. That said there were some engines in the early seventies before the cats, that already had the hardened seats.
 
MBDiagMan said:
Lead does not “lubricate” valves. It DOES, however, cushion the valves slamming against the seats such that harder seats are not required. This was the biggest problem from unleaded fuel when it came out. Replacing valve seats with hardened valve seats in pre catalytic converter automotive engines, allowed the use of unleaded fuel as long as it had the required octane rating for that engine. That said there were some engines in the early seventies before the cats, that already had the hardened seats.
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And yet engines that were designed for 80/87 were burning fuel with the specification that it contain a MAXIMUM of 0.5ml/gal of TEL. Conventional wisdom and several FAA refresher courses propounded that the vast majority of 80 octane fuel actually had zero TEL for the plain and simple reason that it was cheaper to refine straight 80 than to buy the relatively expensive TEL to increase octane rating.
Jim
 
There's plenty of evidence that the use of unleaded fuel in an older auto engine where the valve seats are simply ground into the cast iron head will cause exhaust valve seat recession especially at high speed/load. However, aircraft engines with aluminum heads must have valve seat inserts. Presumably these are made from a harder material such as Stellite, and not soft cast iron? If so, no problem without lead.
 
weirdjim said:
In WWII we needed engines more powerful than those currently available, but found that even with perfect "octane" at 100% the damned things would suffer detonation (explosion of the gasoline in the cylinders as opposed to burning) and trash pistons et al.

Somebody (in England???) found that adding traces of tetraethyl lead to the gasoline boosted the "octane" rating WAY UP, compared to the amount of TEL per gallon, and thus we could get "octane" ratings of 115 and 145 to power these high-compression motors.

The gasoline industry latched onto TEL like a godsend from heaven, and in the 50s and 60s, not only avgas but cargas had TEL added to it because it was WAY cheaper to produce low octane gas and goose it up with TEL than to produce pure high octane gasoline.

Then folks found out that there was a fairly significant lead contamination in the atmosphere and we started backing off of using TEL, to the point where it was prohibited in mogas.


Jim
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American chemist and GM employee Thomas Midgely was the first person to add TEL to motor fuel and discover its anti-knock properties in December 1921. General Motors and the Standard Oil Company jointly owned the patents, and formed the Ethyl Corporation to produce and sell the product.

By the end of the 1920s it was widely used in automobile fuel, and as you said, gasoline mixed with TEL, toluene, and benzine provided the Allies with octane numbers approaching 150. The great majority of German avgas had an octane rating of 100 or lower, which became a great handicap for the Luftwaffe.

The high powered engines in American and British fighters benefitted from the additives, while the German Daimler-Benz DB 601 and DB-605 engines in Bf-109s and the BMW 800 series engines in the Focke-Wulf 190 operated slower and thousands of feet below the peak speeds and altitudes of Allied fighters near the end of the war.

As an interesting aside, GM chemist Midgely also co-invented the chlorofluorocarbon compounds that became widely used as refrigerants in 1928, marketed under the name Freon by du Pont in joint partnership with GM.

Midgely has thus become the one man responsible for two of the greatest releases of toxic environmental disaster on Earth.
 
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3393RP said:
American chemist and GM employee Thomas Midgely was the first person to add TEL to motor fuel and discover its anti-knock properties in December 1921. General Motors and the Standard Oil Company jointly owned the patents, and formed the Ethyl Corporation to produce and sell the product.
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Thank you for that, sir. I'll add that to my mental list of interesting things to know. As I understand it, the Ethyl Corp. is no longer in the business of making TEL (due to some horrific environmental lawsuits and judgments), and as i also understand it there is one small company in Britain that is the sole source of all TEL in the world. Can you confirm that?

Jim
 
Jim, while searching for more information to make the post above, I found that while the British company Innospec says they are the only producer of TEL, one source said TEL is being made in China, but didn't elaborate. It did say North Korea and Myanmar buy the product from China.

I really like your comment about storing interesting things to know. That serves me well too. I retain obscure facts, but sometimes I need help in shaping them up to disgorge the knowledge. I had to do a web search to get details about TEL.

I knew a GM chemist had discovered that TEL was an effective anti-knock compound and that Standard Oil produced it, but had forgotten his name, Midgely, and the fact he also discovered chlorofluorocarbons were well suited to perform as refrigerants.

TEL was first compounded in the mid-19th century, and Midgely's discovery of its effectiveness as an octane booster made huge changes in the automobile industry by allowing the manufacturers to raise engine compression levels and thus make more powerful engines.

It also, as you noted, allowed supercharged aircraft engines to make over 1 HP/in³ in WWII.
 
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