Running out of ideas

[romantic comedy]

You can also check the amount of water that is flowing. Take the hose off the manifold where the water exits. Put another hose and fill a bucket. Watch the flow. Maybe time how long it takes to fill a certain amount.

I think that Don may have a spec for that.

[tenders]

Not sure what you mean by "cover the gauge." I have a valve on the bypass loop, and right now it is completely closed off so that all the water is going through the block and none through the t-stat.

Hmmm, I wonder about that last statement. If your engine is plumbed like mine, closing the valve at the bypass attempts to push all the coolant through the block/head and through the thermostat. Until the engine is warm the thermostat is closed, leaving no coolant to bypass the block/head and go to cool the exhaust except what slips through a little hole drilled in the thermostat to prevent complete exhaust cooling starvation. If the exhaust is hot that little bit of coolant is gonna turn into steam.

Your engine's behavior sounds like this is what's happening and the thermostat is set to open at 195, which is what some FWC thermostats are designed to run at.

I would suggest removing the thermostat entirely. Then when you play with the valve you should go from quite cold when closed (mine for example runs at about 110) with all the coolant running through the block, to warmer as the valve gets opened and less coolant goes through the block.

I've run my RWC engine cold like ths since 1994 with a bolt stuffed into the bypass so that virtually all the coolant runs through the head. No thermostat, no bypass valve...and no problems either. If the engine gets even close to hot I know there's something wrong.

[Baltimore Sailor]

Too much success? I took out the t-stat and ran her hard for two hours, and she barely got over 120. Valve all the way open or closed, no difference. At halfway it just lifted off the 120 mark. Shot water out the exhaust like never before,too.

Now how do I warm her up a bit?

!

[Mo]

Don't bother. A nice hotter running set of plugs to keep the combustion chamber clean and all is good. I am using NGK XR4 plugs....have been using them just over a year and so far all is good. They always look good when I take them out to check things....you may want to use the hotter running plugs recommended by MMI - - the NGK hotter version of those is a 6. The 4 that I use is little hotter again than the 6. With NGK the lower the number the hotter the plug.

I'd have to check the engine hours on running NGK XR4 but I think right now it's in the 80-90 hr range. I plan to use them for a couple of hundred hours and see if there are any "side effects" These plugs were recommended by a engine rebuilding shop so I figured I try them for a while and see how things turn out. Please note that I have a spare engine in my garage, but, my current engine has never run as well as it does since putting the XR4's in there. Combustion chamber stays clean.

Baltimore...one other thing to remember is that you have some major peace of mind when pushing the engine in a sea or chop....I have never had my temp creep up on me.

[positron]

My engine sounds similar to yours when you started, only with fewer new parts and not cleaned out. It is RWC and runs at a very steady 180 once it warms up. In late summer when the Bay warms up it might get up to 185. I am having a hard time talking myself into the thermostat bypass since the motor gives me no actual problems... It seems pretty happy running at that temp, but I do worry about salt clogging the cooling channels.

[Baltimore Sailor]

I am running the hotter plugs -- RN12Ys? Whatever, the hot ones. I'll stick with those for tje rest of the season and see how they look. Nice to not worry about heat any more!

[Mo]

You will be pleased and the boat will be cooler on the hot days.