Crossflow thermostat

[andy couchman]

What's the current thinking on thermostats?

Currently have a 74 degree unit and have drilled one hole in it to allow water to get threough if the thermostat fails.

Any better/different ideas? And would you replace the thermostat when doing a head rebuild as a safety precaution?

Thanks.

Andy

[OliverSedlacek]

74 degrees is much too low! I would certainly replace a thermostat routinely as they are pretty cheap and I'm putting an 88 degree thermostat in at the moment. I've never bothered with drilling a hole, but then I've always run a heater.

[SM25T]

Hole not going to provide enough water flow if thermostat fails. It is intended to let air bubbles pass through ... if positioned at the top when fitted.

[Roger King]

74 degrees is correct. The engine ideally needs to run at around 80 degrees and this is about what you get in the real world with the 74 degree unit. And yes, drill a small hole.

I wouldn't routinely replace it when the head is rebuilt unless it is known to be very old or failing. It can't do any harm though.

[Drumster]

Hi Andy,

Always ran my x/flow with the 74 degree thermostat (that's probably because Roiger told me to do so  )

[andy couchman]

Excellent - thanks Roger et al.

Andy

[OliverSedlacek]

A hole in the thermostat is useful when filling the engine. Without it there's no way out for the air in the block (unless you crack open the heater circuit or equivalent).