DS1980

Of course it weighs more. What would a 410 HP Lycoming weigh? More than the Chevy. What would be the BSFC for an IO-360 capable of 410 HP? Higher than the Chevy. Again, auto engine comparison is irrelevant, and I wasn't the one to bring it up. My point was that our engines are low stress. How would you explain 70,000 engines hours running at 50 ROP without an engine problem?

Because 100% power is relative. Asking a 360 CID engine to produce 200 HP just isn't asking a lot. I get the fact that it's doing it at low RPMs, but it just isn't impressive. Making them less impressive are the recent problems some of our more experienced members are having. The fact that a lot of us were taught to run them at ROP settings that are the most abusive, and we aren't dead is testament to the low power, low compression engines we fly behind. I have said before that the comparison to auto engines is lacking, and i still believe it. But take a look at Edelbrock's Power Package for a small block Chevy. What power does it produce at 2700? About 180 HP, and this is an engine that's going to spend a lot of it's life at 5000 RPM. Will it make it to 2000 hours turning 2700? Yes. What about turning 5000 RPM? Nope, but neither would a Lycoming turning 5K. I agree that auto engines have a terrible track record in aviation. The same way an orange makes a terrible apple. Here is a recent excerpt from a conversation I had with Ross in a thread titled "High Power N/A ops LOP vs. Full Rich": "I learned to fly in Vernal UT and Craig CO, so both high altitude airports. My instructor was very seasoned and was retired from flying money from bank to bank, in a twin, at high altitude. I asked him how many hours he had and he said very casually "Well, I stopped counting at 35,000." I also asked him how many times he had to set his airplane in the dirt. He had one precautionary landing in a sage brush field that turned out to be nothing. One! In 35,000 hours! 70,000 engine hours! Guess where he taught me to run the engine? 50 ROP, just as he did for 35,000 hours. How did I, and most importantly, he, get away with running engines so harshly for so long with hardly any consequences? The engines we fly are low stress and overbuilt. A contributing factor-flying out of high density airports.Thank goodness they are forgiving for a ham fisted classic Austin Mini driver as myself." Our aircraft engines are ancient, unimpressive and too dang expensive for what we get. Now, what was this thread about. Oh yea, GO SHELL!

High strung? An aircraft engine is about as low stress engine as one can get. I guess if comparing it to a box of macaroni and cheese, yes, it's high strung.

I was joking. But seriously concerned about the emphasis on cockpit tech and not on stick and rudder skills. Another topic. If you use the iPad for more than aviation go with it. I hear it's hard to read a book or surf the net on the 696.

What's an iPad?

Good points, but I would concentrate more on pre-ignition than detonation, as an engine is more tolerant of detonation than pre-ignition. For your 2 points about harming an engine, here's my additional thoughts. 1.) On takeoff, our engines usually aren't' heat soaked like they become in climb or cruise, so they are actually stronger at takeoff because they simply aren't as hot. This is why it's important to stay out of the red box, as the engine could be generating damaging ICPs, but these would not show up until the CHTs began to rise, which is a lagging indicator. 2.) Agreed, but would be more concerned with pre ignition. Again, not going to show up until the engine has been operating in a damaging way for a while. It does all come down to heat. Excessive heat is the byproduct of something not being right. That's why I think that in the original post, when Ross was seeing 306 CHT, even if the ICPs were higher than normal, they weren't damaging, as his F doesn't have THAT much cooling capacity to suggest artificial cooling to that degree, even if he has the cowling closure and spot on baffling.

So Aaron, your thoughts?

Agreed, and well said. But it's relative. We are asking a big engine to put out modest HP at modest compression ratios at modest air densities. I learned to fly in Vernal UT and Craig CO, so both high altitude airports. My instructor was very seasoned and was retired from flying money from bank to bank, in a twin, at high altitude. I asked him how many hours he had and he said very casually "Well, I stopped counting at 35,000." I also asked him how many times he had to set his airplane in the dirt. He had one precautionary landing in a sage brush field that turned out to be nothing. One! In 35,000 hours! 70,000 engine hours! Guess where he taught me to run the engine? 50 ROP, just as he did for 35,000 hours. How did I, and most importantly, he, get away with running engines so harshly for so long with hardly any consequences? The engines we fly are low stress and overbuilt. A contributing factor-flying out of high density airports.Thank goodness they are forgiving for a ham fisted classic Austin Mini driver as myself.

I have always thought the comparison between auto and aircraft engines to be lacking. I get what you are saying, but the Chevy also doesn't benefit from lower pressures from altitude flying, running at a constant RPM, or being constantly monitored by a trained (hopefully!) pilot. I guess I could say it clearer: In cruise, at altitude, an aircraft engine is a low stress application. Plus, the internal parts are over-engineered to compensate for ham fisted Vette drivers. You're not one of those are ya??

It is possible to generate ICPs that are harmful to an engine at peak EGT. These would be present anytime CHTs are in the range to affect the aluminum alloy that our cylinders are made of. If you believe there is more wear occurring in your engine, what is causing the above average wear? With that said, I think you're OK due to the fact that aircraft engines are a low stress application. If you tuned your IO-360 to put out 400 HP (or some HP to make it high stress), you could not get away with running at peak EGT at 4000 feet. There are enough ICPs to tear the IO-360 apart. I may be a slow tear, but to be fair, it is there. Show a lot of care, I hope in mind this you'll bear. But tell you how to run your airplane? I wouldn't dare.

All comes down to altitude and % HP. At sea level this is no bueno. At 5000 feet there's nothing wrong with it.

As we don't know yet the effects a cold day has on the relationship between CHT and ICP specifically to our make/model, we don't know if this is accurate, although it probably is and makes sense. With cowl flaps closed and the engine heat soaked, how far apart is the spread? How close is it on a warm day? These are the questions that would help a ton in answering a lot of engine management concerns. I think with Ross seeing 306 CHT, the ICPs were acceptable. Maybe even a little higher than "normal."

The only way to have acceptable CHTs but high ICPs is to have some sort of artificial cooling. If Ross left cowl flaps open on such a cold day, I could see the argument. But with cowl flaps closed it's safe to say that CHTs represent ICPs. Regardless, hard to argue with 27 LOP and 306 degrees CHT. That's excellent. I see what you are saying about 250 ROP vs. 50 LOP, but I believe that the combustion event on the lean side of peak isn't as violent as on the rich side of peak. Although I can't remember the flame front off the top of my head.

Hey Ross, This is spot on. I've talked to one of my aviation mega-savant friends extensively about how lean to run and he said anywhere from 35-50 LOP, with his preference being 35 LOP. He flies out of Vegas, so your 23 LOP on a cold day is valid. He always adds a comment about CHTs being the deciding factor. I think when we finally get all details about LOP operation, we will find we were making it too complicated. Balanced fuel flow, run the engine lean enough, and let the CHTs be the deciding factor. Running LOP is simply asking the engine to do less work, and the engine doesn't care where it's ran as long as it's lean enough to allow acceptable CHTs. I also like how you added "with takeoff flaps." This one goes to 11.

What correlation is being referred? The correlation between sitting an engine and iron?

Is there a known cause for these frequently flown engines having corrosion problems? Do you know if Bob or Scott were using Camguard? Oh and agree as assigning only core value to the engine. Iron isn't the only thing on the oil analysis that I don't like.

Yes, we went to 11! Let the Spinal Tap references begin! That's all I was going for. I'm done.

A POH is how that airplane should be flown. Other models have a specific take off flap setting, others say "as desired."

Saying that someone is not able to understand and can't see outside the box leaves nothing to interpretation.

I like how you imply that those who operate within the limitations set forth by the manufacturer and printed in the POH are lesser people than those who do not. How much does Mooney pay you to be a test pilot? Maybe I won't understand the number though since it may be outside the box in which I fly. Bazinga!

Now I get that sarcasm.

What's settled? That you should consult your POH for takeoff configuration? That was settled with fantom's post on page 1.

That's because this post was correctly answered by fantom on the very first reply. I can understand the discussions on ROP/LOP and Camguard (and I enjoy them) since these don't come with a POH, but I don't understand this. Too many opinions and not enough direct quotes from the POH. In this case of a '66 M20E. The answer is page 20, item 6. Mooney_M20_21_OM.pdf

I think I'll just lay down hardwood. Maybe a hickory with clear varnish.

Who are you stealing screws from? Not very nice. So no way to glue the female snap onto the floor? JB Weld? Double Bubble? I'd rather not screw into a floor when the time comes to do this.