Hi All,

I've recently installed 2 carb'd 540ci's in a formula f303. The engines were purchased used/complete from a chap in Kentucky and shipped to the UK. The engines run like rockets, but after an hour or so of running have started seeing swiss cheese type emulsified oil in rocker covers and blowing through breathers onto flame arrestors on both engines. Before installing the engines I fitted temp senders into the oil pans and gauges ready. The engines are running water crossovers with bypass and I've installed pressure relief fittings into the hull from them. The engines are running 140°f thermostats. Pulling a steady 25psi of water pressure at WOT and after a good run engines reach 140°f and hold it no problem, however I can't get oil temps above 140°f either and so seeing as its both engines I'm hoping that this is the route cause of the emulsified oil in rockers. I'm assuming that the lake water temp in kentucky is considerably higher than the 45°f in the UK Sea and therefore contributing to the very low oil temps. So, finally to the questions 🙈. Is the oil pan the best location for the senders? ( pre and post cooler seemed to be the 2 main options with many arguments for either online) Are oil oil thermostats the best way forward? Would running a hotter stat help?

If any more info required please ask, all the best, Anthony

I use Canton oil thermostats, they hold my oil temp. 180-230 depending on how fast I run,, I use a 140 water thermostat w/ no moisture in the oil even in spring time cold water

Hi 253, thankyou for the fast response! I'll look into Canton thermostats 👍 where are your senders located? Thanks

Perma cool makes one too ,perma-cool 1071,opens fully at 180°, has -10 an ports, reasonable price- $60 . Down side, no mountings brackets.

I’ve used those also. Cheap and just as effective. Easy to plumb just no bling but who cares.

Thanks fellas, I'll look into both options 👍

I think it comes down to preference ease of installation but I think most would say put it in the pan

Cold oil and water is not your problem.
I`d look for the real cause there are many unfortunately .

It looks like Canton uses an actual thermostat, 22-480NEW.pdf (cantonracingproducts.com)

How does the oil look in the pan?