thermostat modification

[sethgs]

I've heard of some people drilling small holes in their thermostats to allow for more water flow. Others tend to remove the thermostat all together. Are either one of these a good or bad idea? By doing so, do you decrease the system pressure so much that the cooling effect will cease to exist? If you were going to drill holes, how big should one make them. I'm just trying to keep my motor cool...cooler is better, right?

 

[bigbrownbuku]

Re: thermostat modification

i started my trade where the water temp regualrly reached 30+celcius. on some older engines that blew into town we would cut the guts out of a thermostat as a temporary solution to maintain the same restriction.<br />you should really determine what the actual problem is before butchering your tstat.<br />the hotter an engine runs the better, within reason.<br />too cold and wear is accelerated and your oil will dilute.

 

[WillyBWright]

Re: thermostat modification

The only reason to drill holes into an outboard thermostat is to allow a small amount to get thru to make the pee indicator work. Some motors only pee when the thermostat opens. So it's hard to know if the motor is pumping water until the motor warms up. Drilling one small hole into the thermostat allows at least a tiny trickle. That's the only modification to a thermostat I'd suggest.

 

[rodbolt]

Re: thermostat modification

most Tstats are vented, yamahas are,suzukies are and OMC used to be, on a crossflow motor (omcBRP) i use the vented sierra stats or add a vent to the new style BRP ones. it allows water to pass so hot water can actually get to the stat before the top of the head overheats. v6 mercs I use modified BRP stats or the sierra ones for the same reason.<br />the Tstats ,especially on a moden v configured motor, are an intragal part of the cooling system design and pressure control systems and caution needs to be used when modifying the system.

 

[Silvertip]

Re: thermostat modification

Cooler is not better as you put it. The thermostat is there to ensure the engine operates at its design temperature. Running without it means the engine runs TOO cool which can cause varnish and carbon build-up and in some cases "cold seizure". Piston is hot and begins to expand -- engine block is cold and does not expand. The piston becomes tight in the cylinder and you now have a good anchor.