T

Tom McCutcheon

Well Known Member
I may be able to purchase an MT 3 blade propeller MTV-7-C with Blades 187-129. This is an electrically controled propeller.
I want to use it on an RV-4 with an O-320 Lycoming engine (no hollow crank for hyd prop). Apparently it came off an Eggenfeller engine but I've been assured that it turns the correct way for a Lycoming. Can anyone tell me anything about this propeller model I've described above. Do you know if it will work on an RV-4? or the Lycoming engine? Can anyone tell me what the model numbers mean? Any other help would be appreciated - such as if you know what cowl modifications (if any) will be needed.

Further I believe it has a 13" spinner and I think my spinner is a 12". My cowl is one of the earlier models which is fairly tight. My guess is that some modifications will be needed to accomodate the bracket that holds the brushes that contact the electrical conductor plate at the back of the prop. Apparently the bracket needs to be mounted to the engine somewhere and somehow reach around the flywheel and up to this disk. Like I say, any help will be appreciated.
Tom McCutcheon
[email protected]
 
Tom

I'll compare the RV-8 (IO-360) and the RV-7 (Egg turbo'd STI) with the MT-7 that are in my hangar & get back to you tomorrow.
 
Thank You Ralph

Thank you Ralph. While you are looking can you confirm that the prop turns correctly (same as your IO-360)?

Thanks again.

Tom McCutcheon
 
Tom McCutcheon said:
I may be able to purchase an MT 3 blade propeller MTV-7-C with Blades 187-129. This is an electrically controled propeller.
I want to use it on an RV-4 with an O-320 Lycoming engine (no hollow crank for hyd prop). Apparently it came off an Eggenfeller engine but I've been assured that it turns the correct way for a Lycoming. Can anyone tell me anything about this propeller model I've described above. Do you know if it will work on an RV-4? or the Lycoming engine? Can anyone tell me what the model numbers mean? Any other help would be appreciated - such as if you know what cowl modifications (if any) will be needed.

Further I believe it has a 13" spinner and I think my spinner is a 12". My cowl is one of the earlier models which is fairly tight. My guess is that some modifications will be needed to accomodate the bracket that holds the brushes that contact the electrical conductor plate at the back of the prop. Apparently the bracket needs to be mounted to the engine somewhere and somehow reach around the flywheel and up to this disk. Like I say, any help will be appreciated.
Tom McCutcheon
[email protected]
Click to expand...

I wanted very much to use the MT-7 with my IO360 but it is a no-no - that's direct from the factory.

The MT-7 was originally certified with the C152 and the 0235 many years ago in Germany. When Jan Eggenfellner needed a prop, MT modified it slightly for the Egg H4 engine and later customer Andy Parish had a vibration survey performed with the H6, which it passed with flying colors.

But MT says it is not designed for the larger Lycoming engine. The -7 weighs just 31 pounds, the large Lycoming versions are about 20 pounds heavier.

Of course, you can do as you wish. Perhaps you could get MT to do a vibrations survey with the 0320 the next time they visit the USA. That's how it was done with the Egg engines.

Another reason it may not work is it has AN7 attach bolts. But some 0320's are set up for AN7 rather than AN8, so that may not be an issue.

I liked the prop with the H6, it was good looking, very smooth, but the blades may not have been optimal for that much HP. It seemed to hit a speed wall at 2500 rpm, anything above that and nothing changed. One day when going to 2700, it actually slowed down knot or two.

The 187 is centimeters which is about 73.5" diameter. I don't know what the 129 means, probably something about blade area.

The prop comes with its own spinner. The brush block assembly would be mounted forward of the fly wheel, at least it was with the Subby.
 
Last edited:
MT prop

After checking, I have found that the MTV-7-C prop is really not the prop for my O-320. Thank you to everyone that gave me the input to help make that decision. If anyone does have a good MT propeller for the Lycoming O-320 engine (has to be electric) please let me know.

Tom McCutcheon
[email protected]
 
A nieghbor has an electric 3 blade MT on his Lancair with a 200 hp souped up IO-320 , so it can be done. Check with MT rep.
 
You must log in or register to reply here.