Friday, June 12, 2020

Engine Mounts

I've learned a lot putting new engine mounts in Nellie.  One, it's not a hard job.  Two, selecting the proper engine mount is critical.  

Nellie's factory-original Cushyfloat mounts had no model number.

The first new set of mounts, Cushyfloat 17-1609-65's, were dramatically noiser than Nellie's factory-original Cushyfloat mounts.  I then removed the 65's and installed Cushyfloat 17-1608-45's.  The graph below compares the wheelhouse noise level with each mount type.

On average the 45's are more than 50% quieter (-12bB) than the 65's. 

Why?  Because as the graph above shows, they're better at dampening the engine's vibration. 

Bottom line, Nellie has never run quieter or smoother.

An Update on Portlight Screens

Nellie's new bronze screen.

Nellie D. 37VT63 wasn't lucky enough to get factory window screens and it was a struggle to come up with a good alternative. Particularly irksome are the little portlights in the shower, head, and stateroom.  An effective, inexpensive and now time tested solution is to use the port's stainless ring to hold a screen in place.

Screen caulked inplace on backside of portlight ring.

The installation process is very straight forward. In fact, the hardest part of the job is removing the stainless ring. It is bedded in polysulfide but will yield with patience. I used a razor knife to cut the joint around the inside of the window. Then working around the inner circumference, with two screwdrivers and a putty knife, I gradually wedged the ring away from the cabin side. Two things to watch-out for: don't scratch the gel coat and don't bend the ring. With the ring off you'll note that the port itself is well bedded. If there are voids in the port's bedding, fix them now as I suggest the ring be reinstalled without bedding—it makes replacing a damaged screen much easier. Use the ring as a template but cut the screen about 1/4" smaller. A thin layer of silicone caulk will secure the screen to the ring. After the caulk is dry reinstall the ring. As always, make sure to bed the screws.

In 2013 I installed $3 worth of 18 x 16 mesh, aluminum screen in the four ports. Last month, after seven years in use, I noticed some galvanic corrosion on the aluminum screen.  The aluminum screen was easily replaced with $18 worth of bronze, 18 x 16 mesh, screen.  Why bronze screen?  Well, it should last longer than aluminum as it's closer in nobility to stainless steel.  But, more importantly, it looks cool!

By the way, worth considering too is the size of the screen's mesh. A 20 x 20 mesh will keep no-see-ums out.