Drbobcameraguy Loc: Eaton Ohio

I rebuild also and understand completely how and most times why things fail. I also work on aircraft engines and airframes. The reason unleaded fuel was bad for engines not designed for it was because of soft valve seats. The lead is a lubricant. Without the lead to lubricate the seat in was or is destroyed. Harder seats solve this issue. A great amount of general Aviation single and small twin engines planes use leaded 100 octane fuel to this minute. In California they are trying to remove it but as of today there is no approved substitute. I will say there will be soon. Valves are delicate and work very hard. Yes they still fail. Especially in aircraft engines. We boroscope engines at regular intervals and always when high cht cylinder head temperatures have happened. Unleaded is not an issue except for certain GA aircraft but automobile engines simply replaced the valve seats to stop the gaureentee of failure. If you have ever saw a leaded Head run on unleaded fuel it's actually cool. It beats the valve seat into the head and obviously doesn't seal anymore. You normally don't see many valve issues as far as burnt or broken valves in automotive engines unless you are pushing some horsepower the engine is not designed for or running it at the limits. Yes there are always failures but knowing the actual cause is very important in aviation because people get upset when aircraft fall out of the sky. Cars usually not so much when they quit. Lol

letmedance Loc: Walnut, Ca.

Supposedly the Viper engine had over heated and a hot valve stuck to its hot valve seat and pulled it out of the head.

Drbobcameraguy Loc: Eaton Ohio

I have actually seen that. On a 6 cylinder BMW motor 94 if I remember right. It was chipped and a rally car. I personally have broken a piston because of a high end detonation issue. The aluminum piston swelled due to the heat from detonation and the rings tried to sieze in the cylinder. It broke the ring lands off the piston. It was my own fault. I bumped the timing just before the race because I knew it was doubtful I would win but wanted to give all she had. Beat me by half a car length and cost me a bit of time and money. Lol. Great is the biggest issue in single engine aircraft. The valves take the brunt of it. Burned usually broken sometimes and cracked sometimes. The pilot is supposed to monitor CHT and EGT very closely. Especially on take off and initial climb when the engine is giving it's all. You would think with the velocity and cooler air up higher it wouldn't be an issue but it is the main cause of top end rebuild. Lol. I love engines of all types since I was a kid. They really aren't that complex but it amazes me the amount of rpm an engine can turn and last a long time in normal use. A lot of stuff going on every revolution. The main reason engines last twice as long now as when I was young is the tolerances can be held closer. In the 60s and 70s the manufacturing folks upgraded the machinery to keep up with Japan who modernized after WW2. We were still using the machines from the 30s. Now everyone is on the same playing field. Now the life of an engine will be decreasing due to the turbocharging and supercharging of small displacement engines to increase mileage. They are cool powerful and perform well but they will suffer in longevity.

Leon S Loc: Minnesota

check with an auto zone type store for an additive for leaded motors or have your engine brought up to date.

Leon S Loc: Minnesota

its denatured before it leaves the refinery. we also hauled ethanol in food grade tankers.

letmedance Loc: Walnut, Ca.

A lot of folks do not realize that an engine running at 3600 rpm has pistons that hit TDC 60 times per second, it does not take long for a broken part in the combustion chamber to destroy an engine.

I think the last engine I did a valve job on was my 61 Mk2 Jag, that was a long time ago, any more I just buy a good car and maintain the hell out of it.

letmedance Loc: Walnut, Ca.

That truck is long gone.

Drbobcameraguy Loc: Eaton Ohio

Yep engines are amazing. When I broke that piston it scattered debris thru all eight cylinders because I had a single plane manifold. I had to have both heads touched up a new piston balanced and if course new rod bearings and rings. The damage was not to bad considering. If I had been running a dual plane manifold like the performer style from Edelbrock I would have only had debris in 4 cylinders. Lol. But it wouldn't have went as fast. Lol. I to have stopped building new toys. I still have 2 I maintain and play with but I seldom break them anymore. Sad how a man matures. LMBO. Have a great day and best in all you do

Drbobcameraguy Loc: Eaton Ohio

You can still get leaded fuel at a lot of smaller and medium sized airports in 100 octane. Pricy but effective.

travelwp Loc: New Jersey

What is hard for me to grasp is: with all that mechanical movement each second, my 2003 Lincoln Towncar is expected to last to at least 200,00 miles........... amazing.

Drbobcameraguy Loc: Eaton Ohio

It is very amazing. Especially when you factor in the temperatures and pressures of everything. Along with the frequency of it happening. Not to mention the small amount of maintenance required to make it happen. Lol. ICE a miracle created by mankind. Not popular but true. Lol

letmedance Loc: Walnut, Ca.

Keep the maintenance regular and it will likely last much longer than that.

travelwp Loc: New Jersey

Thanks, that's very encouraging !!

anotherview Loc: California

Thanks to materials science and mechanical engineering along with competition from Japan. You may recall that at one time, American automobiles required an overhaul at 50,000 miles. Then the Japanese cars entered the market with engines that lasted 250,000 miles with basic care (like regular oil changes). Car buyers switched to Japanese cars. Etc.

travelwp Loc: New Jersey

Yep; however for me, I will keep my old Towncar.