u-cooler question/temp question

I got my port engine running today. I didn't do any adjustment on the rebuilt carb but it sounded great - at least at idle.

The temp is 180 after idling for 20-30 mins. It stayed solid and wasn't climbing any higher. Almost the whole cooling system has been serviced, new risers/elbows/manifolds, coolant, thermo, raw water impellor, H/E rodded out, all new hoses.

My question is on the oil cooler. I've only run a garden hose through one end and out the other and replaced the zinc. Both hoses going in and out are basically cold to the touch. One side of the "U" (metal tube) gets warm and the otherside stays cold. Does that seem like normal operation?

I was hoping that it would be lower than 180 at idle, not sure what it will be underway. In the few hours I used the boat last year it seemed to run around 195-200.

I verified the 180 with an IR gun and the gauge and sending unit are new as well.


Bob

Your temp numbers are a bit high. 167 at cruise at the thermo housing is what I get with the same setup. A real 180 at idle is high. If you sure the temp is that high, i'd verify the thermostat is a 160.

Since that is a FWC engine, the 180 wouldn't concern me--especially if it doesn't get much higher in cruise mode. The oil cooler (tranny?) should be dead cold at idle without running the boat. On the IN and OUT temps, don't over analyze yourself so much! Just keep an eye on things on the shakedown cruise.

Jeff

fastjeff said:

Since that is a FWC engine, the 180 wouldn't concern me--especially if it doesn't get much higher in cruise mode. The oil cooler (tranny?) should be dead cold at idle without running the boat. On the IN and OUT temps, don't over analyze yourself so much! Just keep an eye on things on the shakedown cruise.

Jeff

Click to expand...

I concur

ok, so the oil cooler is pretty much out of the picture at idle (yes, FWC w/ 160 degree thermostat).

I'm hoping they'll stay in this range underway.

Bob

Bob:

If the temp stays there at idle, you could be ok.

Sounds like the oil cooler is the only "unserviced item" left. Make sure the belt is tight and try this at the slip. Make sure you mooring lines are secure and engines warm. then drop the engine in gear and watch the temp gauge. If the temp climbs, I'd clean out the oil cooler assembly.

An oil cooler with some 'zinc pencil parts' in it will flow more than enough water to cool the engine oil at idle; its output fitting may be a couple degrees higher than the inlet (not much heat tranferred from the oil with the engine idling). The problem is that it will restrict (and potentially aerate) the water flowing into the heat exhanger which could be the cause of your elevated idle temp.

Let us know the results.

Mark,

I'm not in the water yet but will run that test (or just take it out) and see where the temps wind up. Both my gauges were off last year so I'm at least starting with real numbers this time.

Yes, the oil coolers are the only unserviced items. I'm thinking about buying one new one and taking apart the remaining two for cleaning. Re-install one and have a spare ready to go.

Update to follow in a couple of weeks.

thanks