Thermostat Question...

[MacGyver]

Anyone ever drill small holes in your thermostats to increase cooling on your engines?

[Blue Thunder]

Its really more to let air pockets out from under the tstat so you don't get hot spots in the engine. It is a good thing on a boat engine. It should not change your cooling though once all in in equalibrium.

[Ratickle]

I have never heard of that. Any thing else anyone can add?

[PatriYacht]

It's true, 2 or 3 1/8 dia. holes drilled around the outside of the thermostat allow any trapped air to escape. It also helps to even out the pressure and temperature fluctuations if you run a crossover.

[Ratickle]

It's true, 2 or 3 1/8 dia. holes drilled around the outside of the thermostat allow any trapped air to escape. It also helps to even out the pressure and temperature fluctuations if you run a crossover.

Thanks Ian.

[OldSchool]

I don't run thermostats in mine, but I have heard of people drilling the holes in them.

[Ratickle]

I don't run thermostats in mine, but I have heard of people drilling the holes in them.

I can't imagine not running thermostats up here in Lake Michigan. The water right now is a balmy 44 degrees.I'm afraid the computers on the Empress would think due to temp it was running too rich and keep leaning until it puked.....

[MacGyver]

I should have posted this earlier. I just changed my stat. But I might pull it back out and do a little drillin'.

[cigdaze]

I run crossovers on my new engines. I have 150* T-stats in place, and we drilled four 1/8" holes around the perimeter. Temps are perfect and steady. It allows for water circulation through the block at all times including during cold-start and idle to avoid hot-spots and air pockets. It also alleviates the situation where often times when running crossovers with bypasses, the t-stat won't open up due to the raw water dumping on top of the t-stat via the bypass which artificially keeps it cool. It takes a little longer to get up to temp, but I can maintain 150* right on the money.

[OldSchool]

I run crossovers on my new engines. I have 150* T-stats in place, and we drilled four 1/8" holes around the perimeter. Temps are perfect and steady. It allows for water circulation through the block at all times including during cold-start and idle to avoid hot-spots and air pockets. It also alleviates the situation where often times when running crossovers with bypasses, the t-stat won't open up due to the raw water dumping on top of the t-stat via the bypass which artificially keeps it cool. It takes a little longer to get up to temp, but I can maintain 150* right on the money.

Good stuff. I have crossovers, but no bypass. Seems to work fine with no t-stats in mine. My water temps are a constant 125 and my oil temps are right at 220 during normal running. The oil temps never go over 240 when running the snot out of it and the water temps stay at 125.

[Scarab KV]

I think mine were drilled also.

[boomer35]

i've got 3 little drill holes in each of my t-stats. good for airpockets, start ups, and idling.

[Tony]

Both sets of my engines have had drilled Tstats. This actually allows me to pump my engines full of antifreeze (after draining the cooling system) without having to start them and wait for the T stats to open.

[niceguy]

Does anyone have a pic of this done to a t-stat they can post. I know it's silly, but I want to make sure I do it in the right spot. LOL

[cigdaze]

Here you go, niceguy.

[niceguy]

Thanks CigDaze!!

[Chris]

I learned this trick from the jet boat guys 25 years ago. If you route your raw water through your exhaust manifolds first, then into your engine, you pre-warm it. Then all you do is put a drilled thermostat in and you have a bulletproof cooling system that never runs cold. On this setup, the engine outlet water runs to your exhaust tails.

[MOBILEMERCMAN]

The old Mercruisers in the 70's and early 80's were like that as well.

[OldSchool]

I learned this trick from the jet boat guys 25 years ago. If you route your raw water through your exhaust manifolds first, then into your engine, you pre-warm it. Then all you do is put a drilled thermostat in and you have a bulletproof cooling system that never runs cold. On this setup, the engine outlet water runs to your exhaust tails.

(In my best Guiness beer commercial voice) BRILLIANT!!!

[Warlock28SXT]

I can't imagine not running thermostats up here in Lake Michigan. The water right now is a balmy 44 degrees.I'm afraid the computers on the Empress would think due to temp it was running too rich and keep leaning until it puked.....

I've got no t-stat per say. It's a restricter washer, T-stat with no guts in it. Had to for Michigan, other wise it would stay in cold start mode and run fat. Temp stays about 125-130* I run a oil stat as well.