High Flow Racing vs Fail Safe Thermostat

[dluna11w]

I'm wanting to put a thermostat in my new 602 crate motor. In the past I've used the high flow racing type. I've been reading about the fail open type and was wondering if the racing type have this built in? It doesn't say anything about it in any of the racing catalogs. Would a fail open from Oreilly's be a better choice or high flow racing from Speedway?

THANKS!

[Egoracing]

See of Stewart Race pumps is still selling T stats.

[DaveBauerSS6]

The Fail safe is not a high flow from Oreilly. That should be enough reason not to run it.
The High flow being a racing design should be a better quality piece, so there should'nt be a concern about failure.
There is a chance that shutting of the motor hot , the temp may rise enough to trip the lock and keep it open. Now you are running on a restrictor.
I don't know of High flow fail safe combo.

I would stay with the high flow

[joedoozer]

Run the high flow racing style. We don't put enough miles on these motors to see thermostat failure, especially if you replace it every year. If this technology was as prone to failing as some people make it sound, some time in the last 125 years it would've been changed.

Good point.

[dluna11w]

Thanks for the feedback. I've always used the high flow type but just recently I've been hearing more about the fail safe.

While we are at it, I was reading the book on the crate last night and it recommends setting the lash at 1/4 turn after zero HOT. What is a good COLD setting for when I go to break in the motor? I've always set my flat tappet and roller motors COLD. This will be my first hydraulic motor.

THANKS!

[mbaker76]

On the ones I have worked with we usually set them at 0 to maybe 1/8 turn past 0 cold. Then when everything is warm and tightens up just a little you maintain a very slight amount of preload. Since everyone pushes these to the limit and valve control at speed becomes marginal, setting them at 0 means they can’t pump up and hang a valve open. You don’t want to let them get any looser though as the small circlip wont hold up and the lifter can come apart. With the ‘high rev’ type hydraulic lifters you could actually run small amounts of lash (0-.005) but they have a heavy duty retainer clip, more like a solid lifter, to prevent it from coming apart.