540 heating up with stat installed
 

:mad: 540 CI carbed with a cross over. Without a stat, temp doesnt come up. I put a 140 stat with 2 small holes drilled in it, temp comes up to 180 to 200. Gauge worked fine last year with other motor..?? Put stat in to bring up water temp alittle. Getting some condensation in breathers. Figured it was better for engine with alittle heat. Engine dynoed with 140 degree water temp, so I should run it like that? Oil temp runs at about 140 - 160 when im under way, comes back down at idle. Why is water temp going up so high? Also bought another new stat, went to same temp, so stat is not the problem.????????????? Is it ok to run boat w/o stat? Everyone has a different opinion on this matter. Do I lose power running engine cool, or gain power? :food-smiley-009:

Any feedback ?:party-smiley-004:

Does the crossover have a bypass?

i could be wrong but it seems to me that crossover motors are supposed to run blanking plates... not tstats. my suggestion would be to get an old tstat and punch the center out of it and try that and adjust that hole size until it does what you want.

The crossover does have a bypass.....................

The hole in the stat sounds like a possibility. How big of a hole should I start with?

I am having the same issue. I have a 142 stat with 3 3/16 holes in it. Crossover with bypass. Mine goes to 200. Prior motor with same set up went to 190 on Gaffrig guage, but on the prior Faria guage it was 160. I still have the Faria guage and I am going to see what it says.

The oil temps of 140-160 are way too low. You need to see at least 212* on a regular basis to burn off any condensation.

The water temps should be fairly stable around 150* with a 140 Tstat. I would drill 2 more holes at least and probably make them all bigger. It will work more like a restrictor plate then.

It really makes no sense that water temps are too high and oil temps are too low.

i may have not made my self clear. w/ a crossover motor i don't think you want an operating tstat at all. i am suggesting a flat plate with a 1" hole in it in PLACE of the stat. an easy way to accomplish that is to knock th center operating mechanism completely out of a stat... thats just an easy way to accomplish the same thing. it is NEVER a good idea to drill holes in a stat in an attempt to change its calibration or act as a by pass.

Off subject a little but what are the advantages of a bypass setup?

Hi griff-

Well, I dont understand why the water temp is going so high with a 140 stat ? With a crossover. Ive tried 2 different stats to eliminate a possible bad stat. If I can get the water temp to 140-150 consistently,the oil temp should come up also . Right?
Im going to get one of those heat sensing laser guns today to be sure that the water temp is at the temp that my gauge says its at. Im getting mixed reviews about hollowing out the stat, but willing to give it a try.