1970 K10, RamJet 350, Electric Fan (Unfortunately was forced into it), 4 Core Radiator with tubes every .25 inches, Reverse rotation pump (new), Overflow tank.

So I am breaking this engine in and have noticed I am running hot. Idle will produce 220 and driving I can jump to 280, at this point I just shut it down and wait and turn around. It will never run below 220.

I have bled the system by parking on an incline and running the engine until it puked out the top and then put the cap on. I have a known high spot in my upper radiator hose, see picture, this is due to where I had to run the hose.

http://i958.photobucket.com/albums/ae61/phantom4F/HighSpot.jpg

From the factory this has an 180 degree thermostat and I would expect to run around 200 for the break in. Day temps here have been around 40 and the lower hose is pretty cool to the touch while the upper is hot enough I can not hold onto it for long.

Any thoughts?

Whats the timing set to? Do the E fans turn on and at what temp? They should be hooked up to a temp switch you might wanna look there first maybe its too hot.

The timing is a base timing of 10*, the computer runs it from there.

The Fan is set to the lowest temp and comes on roughly when the gauge reads 180 although it runs intermittent of the temp. So as the temp climbs the fan will shut off as the probe is in the radiator close to the upper hose inlet.

I am going to wire up this fan for manual operation so I can better control it until this is resolved.

I am still thinking the high spot has air in it, currently considering adding a bleed valve in this location to eliminate air.

Just to clarify air is of concern due to its compressibility and the system not being able to come to temperature due to this lack of compression?

does the fan have a shroud? so that is suck air from the entire radiator or just the imediate area infront of the fan blades?

second look... looks like a dual fan setup? are they both running 100%?

probe? for air temp? why not a ECT probe the sense coolant temp????

Can you possibly shorten the upper hose? You can drill holes as stated above but it the issue will always be there. Tho it is a fix. Maybe your tstate is out of wack? You positive its a 180? I would take it out put it in some boiling water to see what temp it pops at.

The fans are a dual setup that run at 60% at the set temp and 100% 10 degrees above the set temperature. They pull enough air through the radiator you can feel it standing in front of the truck.

I would really prefer to have a coolant probe for the fan. I am not sure what the resistance levels it puts out, suppose I could map them out and search for a compatible probe.

The electric fan I had on my jeep worked rather well once I got the ideal temp setup. I am pretty sure this is not a fan issue.

Regarding the thermostat, drilling a hole will allow air/coolant to pass through, won't air be able to pass through once the thermostat opens? I know the t-stat is opening as my radiator is getting warm and the upper hose is hot.

I just went out and shook the upper hose and I now know there is air in it. I can hear sloshing around rather then a solid feel. It looks like I will have to install a bleed point with this hose being elevated above the radiator fill cap.

looks like a very fresh motor, is this the first few runs?

is the sender the correct one for the gauge?

can you put a laser termo on it?

i have repeateedly had fresh motors run "hot" usualy there is air trapped in the block or around the sender.

i freaked out and immediately installed a mech gauge, temp was dead on, had the wrong sender in.

the upper hose will always have air in it and is not an issue, its air in the block that becomes the culprit. air in the block keeps water from sucking heat away from that spot, at the same time it will expand from heat and steam.

Yes this is a fresh motor. Maybe 1.5 hrs on it total. It has been hot the entire time it has ran more then a few minutes.

The gauge sending unit is correct, both the gauge and sender came from Classic Instruments.

So air in the upper hose is not an issue... I take it then that the "air in the system" is only a concern when it is in the block?

For air in the block is it best to drill a hole in the thermostat? This just seems odd considering if the thermostat is working when it opens any air present will evacuate then.

Although the gauge shows 260, I can not tell a notable difference in the idle and overall engine performance. The engine does not seem to mind.

Unfortunately I do not have a laser temp, maybe a good excuse to buy one!

Still could be wrong. I would get a temp gun. I wouldn't drill it but thats just me. I would check it.

Yes this is a fresh motor. Maybe 1.5 hrs on it total. It has been hot the entire time it has ran more then a few minutes.

The gauge sending unit is correct, both the gauge and sender came from Classic Instruments.

So air in the upper hose is not an issue... I take it then that the "air in the system" is only a concern when it is in the block?

For air in the block is it best to drill a hole in the thermostat? This just seems odd considering if the thermostat is working when it opens any air present will evacuate then.

Although the gauge shows 260, I can not tell a notable difference in the idle and overall engine performance. The engine does not seem to mind.

Unfortunately I do not have a laser temp, maybe a good excuse to buy one!

The drilling of the t-stat is to eliminate the air pocket that is common to be trapped under the t-stat. Not letting the coolant surround the t-stat spring to get it warm enough to open.

that is also assuming that the tstat is working at all.

it tends to take a while before all of the air in the motor works its way out.

you can get lasers for $30-/+

off topic i know but can u tell me where i can get my hands on a set of those valve covers?

I agree that you should check the temp manually, either with a laster or get a temp probe to hook up to a multimeter.... whichever. Also agree that you should put the t-stat in whater and check what temp it opens at. I've never had to drill holes in a thermostat before to get air to bleed.... not saying it can't happen, just never seen it.

Is the radiator new? Sometimes a restricted radiator will give you the issue your describing?!

off topic i know but can u tell me where i can get my hands on a set of those valve covers?

any parts store, summit, jegs.

the lower hose is pretty cool to the touch while the upper is hot enough I can not hold onto it for long.

Any thoughts?

I would be concerned about flow throught the radiator, based on statement above. If the radiator is not restricted, t-stat may not be opening all the way.
or return passage may be blocked due to gasket issue, etc.

Well I took the truck out tonight and drove along until the gauge pegged 280 pulled over and took some measurement using an infrared thermometer. The highest temp I could find was the side of the radiator closest to the inlet it was a blistering 174.

So it looks like the sender or the gauge is the cause of the problem.

When I arrived home I shut the engine off and took some other readings and picked up 210 which is pretty normal for immediately shutting down. I could here the overflow tank burping away so there is still some air in the system but not enough to be the culprit here.

Thats why I use a mech. Temp/oil guage

I used to use one of these when I worked at the dealer to get all the air out.
http://www.amazon.com/Lisle-22150-Spill-Free-Funnel/dp/B0002SR6WK
If I had a really stubborn one that I could not get the air out I had a tool that would (if the cooling system was empty) pull a vacumn in it and then you would turn a valve and basically suck the coolant into the system. This vacumn tool is now a standard tool used in most heavy duty diesel shops. If I ever questioned a tstat I would just replace it. They are not very expensive and really not that hard to do on that vehicle.