Original Posted By: "Ignitor"
Pietenpol-List: exhaust valves
Re: Pietenpol-List: exhaust valves
Original Posted By: "Ignitor"
I used to use Marvel until a friend put some in a metal cup and heated itup, It quickly turned into a very very hard slick coating. Then he showed mea couple of valves that had built up such a coating that the valve seized upin the guide and destroyed the cylinder as the guide rode up and down on thevalve.I read a tip in the 150 Club newsletter about 10 years ago and it has workedfor me. Before you shut down your engine, lean it as much as possible at1700 rpm and let it run for 90 seconds. then slowly pull the throttle andlet it die with full lean. On two Cessnas I own, after 600 and 572 hours (the usual life of a Cont. cylinder), the compression is still 76/80 orbetter on all cylinders. It seems to keep the valves, plugs and piston topsvery clean especially if you run LL.This may not be approved, but I still taxi right on by my mechanic's hangarand wave.----- Original Message -----
I used to use Marvel until a friend put some in a metal cup and heated itup, It quickly turned into a very very hard slick coating. Then he showed mea couple of valves that had built up such a coating that the valve seized upin the guide and destroyed the cylinder as the guide rode up and down on thevalve.I read a tip in the 150 Club newsletter about 10 years ago and it has workedfor me. Before you shut down your engine, lean it as much as possible at1700 rpm and let it run for 90 seconds. then slowly pull the throttle andlet it die with full lean. On two Cessnas I own, after 600 and 572 hours (the usual life of a Cont. cylinder), the compression is still 76/80 orbetter on all cylinders. It seems to keep the valves, plugs and piston topsvery clean especially if you run LL.This may not be approved, but I still taxi right on by my mechanic's hangarand wave.----- Original Message -----
Re: Pietenpol-List: exhaust valves
Original Posted By: "walter evans"
Barry, I do like to use Marvel, but the way I use it is to add a quart about an hour before an oil change, run the engine for awhile, then let it sit overnight, then drain it. Marvel has some very good detergent properties, and seems to really clean well. I've never read anything that cited Marvel as causing the problems you mentioned. The worst thing I've seen is that it's kind of a placebo, not doing any real harm or good. It'll be interesting to see other responses. I also wonder how regular motor oil would do under the same conditions that you used to test the Marvel. The leaning practice you use is very similar to mine. I don't think this is an area subject to approval of any sort. Do what works best for your engine. For what it's worth, when I'd burn car gas in my 150 it always ran MUCH cleaner than with 100LL. I ran a mix of about 50-50 of 87UL/100LL, I don't mess with it anymore due to possibility of alcohol in the car gas, and I've gotten lazy.Gary MeadowsSpring, TX.________________________________________________________________________________
Barry, I do like to use Marvel, but the way I use it is to add a quart about an hour before an oil change, run the engine for awhile, then let it sit overnight, then drain it. Marvel has some very good detergent properties, and seems to really clean well. I've never read anything that cited Marvel as causing the problems you mentioned. The worst thing I've seen is that it's kind of a placebo, not doing any real harm or good. It'll be interesting to see other responses. I also wonder how regular motor oil would do under the same conditions that you used to test the Marvel. The leaning practice you use is very similar to mine. I don't think this is an area subject to approval of any sort. Do what works best for your engine. For what it's worth, when I'd burn car gas in my 150 it always ran MUCH cleaner than with 100LL. I ran a mix of about 50-50 of 87UL/100LL, I don't mess with it anymore due to possibility of alcohol in the car gas, and I've gotten lazy.Gary MeadowsSpring, TX.________________________________________________________________________________
Re: Pietenpol-List: exhaust valves
Original Posted By: Gary Meadows
Gary;I agree with you on your use of Marvel. A little in the oil just before anoil change, I believe helps. But, I also agree with Barry insofar as runningit all the time in the oil. I'm suggesting running 4 ounces per 10 gallons(per the can instructions) in the gas. At this mix ratio, I don't think thatthere's enough to cause the kind of sticky issues Barry's friend showed him.I know people who are religious about the Marvel thing and have O-320's thatare 300 or 400 hours past TBO and still running strong. And I know a Flightschool who runs it in all their planes and have not experienced anyproblems. And out here where aircraft ramp temps can reach 165 degrees, yougotta wonder. I can tell you that I ran Marvel in my old 1985 Toyota 4x4with Marvel in the oil for the last 100 miles before I did an oil change. Idid this from the day I drove it off the showroom floor. I towed boats,planes and hauled a couple of complete house remodels with this truck andessentially abused it in every way possible in the dusty Arizona/Mexicodesert, and when I finally decided to overhaul the motor at 155,000 miles asa preventative maintenance measure, I found the inside of the motor prettyspotless. In fact, all I did with the oil pan was wipe it out with a ragwith solvent and I was good to go. For the head, we didn't even vat it. Justrinsed it down, ground the valves and installed it. That motor sold me,especially after working in a car shop and seeing what happens to an enginewhen you run a synthetic and overheat it. I think those motors are whatsailors use to attach mooring balls to. My pennies worth. I think it'swhatever you are comfortable with. And Barry's shutdown procedure isexcellent.ChrisStill Smilin' (after a loooong day at work, but headed to the airport)----- Original Message -----
Gary;I agree with you on your use of Marvel. A little in the oil just before anoil change, I believe helps. But, I also agree with Barry insofar as runningit all the time in the oil. I'm suggesting running 4 ounces per 10 gallons(per the can instructions) in the gas. At this mix ratio, I don't think thatthere's enough to cause the kind of sticky issues Barry's friend showed him.I know people who are religious about the Marvel thing and have O-320's thatare 300 or 400 hours past TBO and still running strong. And I know a Flightschool who runs it in all their planes and have not experienced anyproblems. And out here where aircraft ramp temps can reach 165 degrees, yougotta wonder. I can tell you that I ran Marvel in my old 1985 Toyota 4x4with Marvel in the oil for the last 100 miles before I did an oil change. Idid this from the day I drove it off the showroom floor. I towed boats,planes and hauled a couple of complete house remodels with this truck andessentially abused it in every way possible in the dusty Arizona/Mexicodesert, and when I finally decided to overhaul the motor at 155,000 miles asa preventative maintenance measure, I found the inside of the motor prettyspotless. In fact, all I did with the oil pan was wipe it out with a ragwith solvent and I was good to go. For the head, we didn't even vat it. Justrinsed it down, ground the valves and installed it. That motor sold me,especially after working in a car shop and seeing what happens to an enginewhen you run a synthetic and overheat it. I think those motors are whatsailors use to attach mooring balls to. My pennies worth. I think it'swhatever you are comfortable with. And Barry's shutdown procedure isexcellent.ChrisStill Smilin' (after a loooong day at work, but headed to the airport)----- Original Message -----