Van's Air Force
Don't miss anything! Register now for full access to the definitive RV support community.
Motor mount question
- Thread starter Tharpo
- Start date
Russ McCutcheon
Well Known Member
Sounds like a conical mount, just delivered an RV-4 conical engine mount to Van?s yesterday so yes if what you?re asking about is indeed a conical engine it can be used on an RV-4 assuming the rest of the engine conforms.
Russ McCutcheon
Well Known Member
I have no idea about that, maybe someone else will answer this one.
Lycoming
No letters is one of the very early 0 320 engines. No cylinder hold down plates under the nuts, so not eligible for high compression, 150 hp max. I think adding the plates requires changing all the studs but am not certain about this. In any event you have a real antique engine, somewhere in the 1954-55 range.
No letters is one of the very early 0 320 engines. No cylinder hold down plates under the nuts, so not eligible for high compression, 150 hp max. I think adding the plates requires changing all the studs but am not certain about this. In any event you have a real antique engine, somewhere in the 1954-55 range.
daddyman
Well Known Member
Straight mount
Tom,
I have an 1996 -4. About 5 years ago I needed to change the mount bushings because they were deteriorated due to age. It was a straight-forward medium sized job.
Mine has an IO-320.
If you are asking about the mounts themselves, they are fine.
I know most folk use conical mounts, but straight mounts are just fine.
Daddyman
Tom,
I have an 1996 -4. About 5 years ago I needed to change the mount bushings because they were deteriorated due to age. It was a straight-forward medium sized job.
Mine has an IO-320.
If you are asking about the mounts themselves, they are fine.
I know most folk use conical mounts, but straight mounts are just fine.
Daddyman
rag
Active Member
I ran a conical mount (also called a straight mount) O320 and Catto prop for many years on my RV4. I replaced the cheap rubber conical mount inserts with Lord conical mount inserts that are "clocked" for engine sag and vibration. I upgraded to a O360 and a dynafocal mount with a Catto prop about 1-1/2 years ago. The dynafocal mount is noticeably smoother. So much better that I would not use a conical mount if I were to build another RV.
