Screw
04-03-2004, 07:13 AM
Dear Abby,
First of all, I'd like to point out that I can be a little dramatic and things usually are'nt as bad as I make them out to be. I get this from my Irish mother.
1. "DaScrew-Driver" is what I want to talk about and I feel like I need some possible solutions and advice. Right now she weighs in at 295lbs with me and gas 563lbs and she flys fine. The problem is, I'm over heating and worried about blowing the motor. MY CHT is mounted under a head bolt and I'm seeing Temps in the 400-450 range (redline is 450 if it were mounted under a spark plug). My oil temps are 220-230. My tach only ranges to 3500 and I'm pegged most of the time.
2. Geat Plains says that for takeoff, pegged is fine but cruise should be no more than 3000-3100. I'm decending if I throttle back less than about 3400RPM, and he says I'm running the engine way too hard.
To cure #1, I've order a lager oil cooler. 11x11x1, and this is supposed to drop my oil temps 20 degrees. I'm also switching to a synthetic oil (Mobil one 15-50), hoping to keep the engine itself cooler. Finally switching to straight Avgass. This too, I was told, will help keep things cool, give more pep, but is harder on my exhaust valves. I'm also working a deal on a set of 23' Dragon Wings hoping the more efficent blades will give me as much lift as the 24 Brocks without working the engine so hard and with less ground clearance problems. If taking these steps to cure #1 doesn't cure #2 I'm screwed.
To cure #2, the cheapest way to go would be to:
A: Add a redrive to my existing engine ($1295). This complicates things 10 fold because it raises the thrustline 6 inches, plus a mast replacement to accomidate a 60 inch 3 blade prop. Also have to buy a starter, altenator, battery, control rods, and re-work the pre-rotator, and raise the seat. Add on the pounds means the 23 foot dragon wing will need to be replaced with larger ones. End the end, who knows how much money this will cost or if it is worth the additional weight.
B: Send the engine back, and have it rebuilt into a 2130cc (75 hp verses 60hp) and another wood 2 blade prop with more pitch. This is the $2200-$3000 range. This will cause a wieght increase but nothing will have to be changed mast or otherwise. Will the money be worth the power?
C: Since we going through the motions, the best of both worlds are available...Rebuild to a 2130cc and add a re-drive. 75hp on a 3 blade prop sounds good to me. But with this expense, I could probably just build another gyro.
I'm considering doing #1 and leave well enough alone and hope I don't blow the motor. This certainly hampers ideas of cross country because the heat make me worry after about 30 minutes of flying.
John-
First of all, I'd like to point out that I can be a little dramatic and things usually are'nt as bad as I make them out to be. I get this from my Irish mother.
1. "DaScrew-Driver" is what I want to talk about and I feel like I need some possible solutions and advice. Right now she weighs in at 295lbs with me and gas 563lbs and she flys fine. The problem is, I'm over heating and worried about blowing the motor. MY CHT is mounted under a head bolt and I'm seeing Temps in the 400-450 range (redline is 450 if it were mounted under a spark plug). My oil temps are 220-230. My tach only ranges to 3500 and I'm pegged most of the time.
2. Geat Plains says that for takeoff, pegged is fine but cruise should be no more than 3000-3100. I'm decending if I throttle back less than about 3400RPM, and he says I'm running the engine way too hard.
To cure #1, I've order a lager oil cooler. 11x11x1, and this is supposed to drop my oil temps 20 degrees. I'm also switching to a synthetic oil (Mobil one 15-50), hoping to keep the engine itself cooler. Finally switching to straight Avgass. This too, I was told, will help keep things cool, give more pep, but is harder on my exhaust valves. I'm also working a deal on a set of 23' Dragon Wings hoping the more efficent blades will give me as much lift as the 24 Brocks without working the engine so hard and with less ground clearance problems. If taking these steps to cure #1 doesn't cure #2 I'm screwed.
To cure #2, the cheapest way to go would be to:
A: Add a redrive to my existing engine ($1295). This complicates things 10 fold because it raises the thrustline 6 inches, plus a mast replacement to accomidate a 60 inch 3 blade prop. Also have to buy a starter, altenator, battery, control rods, and re-work the pre-rotator, and raise the seat. Add on the pounds means the 23 foot dragon wing will need to be replaced with larger ones. End the end, who knows how much money this will cost or if it is worth the additional weight.
B: Send the engine back, and have it rebuilt into a 2130cc (75 hp verses 60hp) and another wood 2 blade prop with more pitch. This is the $2200-$3000 range. This will cause a wieght increase but nothing will have to be changed mast or otherwise. Will the money be worth the power?
C: Since we going through the motions, the best of both worlds are available...Rebuild to a 2130cc and add a re-drive. 75hp on a 3 blade prop sounds good to me. But with this expense, I could probably just build another gyro.
I'm considering doing #1 and leave well enough alone and hope I don't blow the motor. This certainly hampers ideas of cross country because the heat make me worry after about 30 minutes of flying.
John-