Thread: coolant overflowing in bottle

Background: did a sr20ve with sr16 pistons shaved 1mm off the crown. BC springs n1 cams calum ecu. Gtir main bearings.
Also polished and removed all sharp edges from the Cc... Bout 1-1.5Cc of material removed.

Problem: when the car is revved hard the overflow bottle fills up with coolant. No matter what I do. We changed the rad cap to a 1.1/16lb cap. The rad fans run all day, and there is no thermostat.

Question:
Currently the car has a stock head gasket... Will the sr20vet head gasket lower the comp a bit?

And most importantly what's causing the coolant bottle to overflow?

Not having a thermostat can cause bottle to overflow.Put one on and if that dosn't fix it you might have a bad headgasket.Most likely if bottle is overflowing while reving you might have a bad headgasket.As for the vet head gasket it does bring your compression down like 20.

What do you mean that the fans run all day?Is your fans stay on always?

Ok that's a start I will reinstall the thermostat. And yes my fans run constantly.

What do you mean by lower it by 20?

Also if the hg is bad that implies I will have probably skim the head and or the block before reinstalling right?

When it overflows do you fill it back up again?

It's probably overflowing because there is too much water in the system. Let it overflow once and don't re-fill it. Then you'll have the right amount of water in there and you should be okay. When the engine is cold the bottle should be almost empty. When it is warm it should be half full or a little above half full.

It's an expansion tank. As the water heats it expands in volume so the tank is where it goes. Fill the tank full while the engine is cold and it will overflow every time.

this doesnt happen to me or any vehicles ive had.

Your fans could be turnning on costantly because by not having the thermostat the operating water tempeture is allways staying close to the fan turnning on tempeture wich is 212.in other words by not having the thermostat there nothing to hold the water in the radiator to cool the water and the water is maintaing hot because it's always ciculating threw the the motor maintaining it hot causing your fans to turn on constantly.I don't know if I expalained my self good enough but hope I did.

As for what I mean lowers it by 20.Is for example,if your compression is 260 with stock headgasket.When you put on the vet head gasket and you do a compression test after it will read 240.Meaining that it lowers your compression in general.That's what I have seen in two different engines testing before and after with same cams.

If you endup with a bad headgasket you should resurface your head especially if your engine is over heating.Your machine shop guy should be able to tell if it needs to be resuface or not.They can tell if it's warped or not.

When you rev up your engine and the tank overflows does your engine over heat?If it does you might have a bad headgasket and if you keep reving it up it's going to over heat more frequently and faster the more you keep reving it up.Remember these are just possibiltys if it's overheating.Can't realy tell since I'm not there to see what is exactly doing but just letting you if you wre to have a bad headgasket.

Then they never get up to temp?

You have the coolant system backwards. Having no thermostat will keep the engine cold. It will likely never warm up at all.

That's if your on a long drive air will keep getting forced threw the radiator cooling the water.But if your daily driving making frequently stops the water will always maintain hot cause it's constantly running threw the hot block and it's not getting enouph time in the radiator to cool off.Your water will maintain hot close to the fan turnning on tempeture and your fans will keep turning on very fast.That's what I have experienced with my car when I took the thermostat off thinking it will keep the engine cold.Plus it even got worse when days were realy hot.I could be wrong but that's what I have experienced in my car.

sr20venosfreak could you say points wise for compression ratio what 240psi per say would average out to be, also if a stock healthy motor is 240 psi (assumed to be 10.3:1)would the vet gasket put it to 220psi? also do you have any idea whats the static compression ratio numbers of a 10:1 sr20de