Weight/ TBO

[NorthIdahoAvidflyer 374]

My Dad is looking at a Magnum. it has the Lyc O-320. The weight is over 1000 pounds. Is this normal for this plane? Also, what can a guy expect to get to hours out of the O-320. This one has over 1900 hours. 

[Barry Cole 111]

Hello,

i am currently finishing my Magnum build. If it weighs in anything close to 1000 pounds I will be happy. I have the published weights from the factory if you want them. I am also using the O320 and I believe TBO is 2000 hours, but if checks good by A&P, keep flying. 

Good luck!

 

[NorthIdahoAvidflyer 374]

Thank you Barry. The owner stated that the engine was is good health at it's last check-up.  He feels it will run another 1000 hours no problem. One never knows about those things. Keep checking filters and compression is all a guy can do until something does not look right. 

Thanks for the information. 

[Guest]

My Magnum has a 150 HP 0-320. 7:1 compression. I ran ethanol free auto gas. TBO is supposed to be 2000 hours. I only flew it for 450 hours before damaging the plane in a bad landing. (It is next on my list to fix) Mine weighed in at 1050 empty. There are plenty of things I can do to lower that when I put it back together. I should be able to come in at 1000 and still have decent instrumentation. It performed wonderfully, a real ripper getting off the ground and climbing out. It was my first "GA" air cooled engine, so I don't know how they behave for most people, but I love it. I could cruise along around 90 MPH and burn around 5 GPH all leaned out. The nice thing was I generally flew it at very low power levels so I could really lean the shit out of it without fear of hurting anything, so I could get to within 1/2 to 1 GPH of my friends flying 912's on their much smaller Avids at the same speeds. My lycoming burned exactly 1 quart of oil every 50 hours all 450 hours so I never had to put oil in between changes. That is once I figured out that the "top" quart of oil pumped out the breather tube very quickly making a mess out of the bottom of the plane. Once I learned that and put a quart less in to start with, it didn't really use any oil. Compression was/is all 79/80 right up until I quit flying it. 

My Magnum would do about 130 at full throttle level flight near sea level, but it sucked gas like nobody's business so I didn't really fly it that way.

The Magnum is a very special plane, really in a different league than all the other Avids,

I would be comfortable flying beyond TBO if having oil analyzed and cutting open and inspecting filter element every oil change.

Edited 15 Oct 2018 by Chris Bolkan

[lostman 198]

I know someone that just had their 320 rebuilt after 2990 hours since major. I don't think they did much other than change the oil either. If compressions are good and it runs smooth, keep the sucker in the air!

[Allen Sutphin 705]

I've been turning wrenches on 0-320's for many years and they are solid engines if treated right. I've had several go 2400-2500 hours without a major OH.  And I've had several barely make 1000 without a cyl change. Mainly due to poor operation by the owner/pilot. As long as compression, oil pressure, and temp is good, I wouldn't be too concerned.  A smart operator could squeeze 3000 hrs outta one. You will rarely see a cont make TBO without serious rework. Not counting the old A-65's and 85's. I've seen them fly for years carrying 10-15 lbs oil pressure at full throttle and just enough compression to start. When Cont went with the 0-200, things went south somewhat. Probably trying to squeeze more HP outta the same basic engine. I've seen a lot of cracked heads on the 0-200 thru the years. Just my worthless hillbilly opinion.