I've just reread the FAQ on changing motor mounts and have a couple of questions. I'm especially interested in results by owners of M35 engines. The Vetus K50 seems to be the choice but considering comments about engine movement and idle vibration, would you reconsider using the K75 mount which has a hardness of 55 vs 45. My calculations (from Vetus's equation) indicate that it exceed the minimum load specified for the K75. With the K50, it sounds like a flexible shaft coupling would be a requirement. BTW, the FAQ on this subject is GREAT!
Think you should ask that question of VETUS!!! ronphylhill@erols.com ;)
Ron, Apache #788
I did not get an email reply so I called Vetus. I spoke to Leo and asked him about the recommended mount. I told him about the FAQs and experiences with the K50 mount.He said that if I want to reduce the fore/aft movement, go to the stiffer mount. He said he had recently received other inquiries similar to mine and said if the Vetus equation indicated a higher mount for the M35 engine, I should use it.
Here's my calculations:
Eng Lbs HP ratio RPMs ft Max Load
M25 285 20 1.8 800 1.67 141.13
M25XP 285 23 1.8 800 1.67 151.61
M35 335 30 1.8 800 1.67 188.56
It looks like all exceed the Max load for the K50 (112) and the M35 exceed the Max load for the K75 (178) but is within limits for the K100 (224). I'm leaning toward a compromise on the K75 since everyone reports favorably on the K50 except for idle viberation.