Vernatherm removal good or bad idea?

[Faztbullet]

Re: Vernatherm removal good or bad idea?

What I don't understand is if the t-stat is stuck in the closed position doesn't the water sit in the water jacket and boil?

No as t-stats rarely stick shut they mostly stick open....and motor has a check valve or poppet that opens at speed bypassing t-stat that why no pressure build up.

Thermostats do nothing for a carbureted outboard like mine.

The reason you see a lot of ring failures on OMC engines are do to running to cold (bad/removed/stuck open t-stats) and the pressure backed rings. Incomplete combustion from running cold can coke up the ring lands and push rings into a port breaking them.

 

[hotwheels1975]

Re: Vernatherm removal good or bad idea?

Thanks so much for all the info. I'm just going to buy a new vernatherm, check valve, gaskets, and replace the two springs just for my own piece of mind.

 

[Joe Reeves]

Re: Vernatherm removal good or bad idea?

(Thermostat Purpose)
(J. Reeves)

Many engines are considered high performance engines and demand a thermostat(s), and many smaller hp engines also require a thermostat for the following reason. The pistons actually distort/twist off round when running. The thermostat is required to keep the outer wall surrounding the steel cylinder, and the cylinder wall itself at a temperature to compensate for the distortion.

With the thermostat removed, the difference in temperature between the inside the cylinder and the water jacket quickly reaches a point whereas (in effect) you have a oblong piston running up and down a round cylinder, or vice versa. Bottom line is without the thermostat, the piston and cylinder wall could be damaged in a short period of time.

The thermostat in your car isn't there simply to have the heater function properly..... think about it.

 

[schematic]

Re: Vernatherm removal good or bad idea?

Pistons are actually cam ground (oblong when cold)....they go round when heated.

70% - 90% of engine wear occurs when an engine runs cold during warmup.

just sayin....

 

[hotwheels1975]

Re: Vernatherm removal good or bad idea?

Okay... I get it. Lesson learned. This is the very first outboard I've owned that has a thermostat.