I would dump as much as i could in there to see if that was it. Better to have a ton in there than a little and not get the full effect.

Was the block sonic checked? Maybe it has a thin spot even with the small overbore?

I would also consider the rebuilt pump is bad. It happens.

Jim,



If you'd like, try this, won't cost anything but time, and a little gas,.....if you have a standard radiator cap, not one of those snap locking rad caps,.....check the fluid level in the radiator, put the cap on, tighten it, then back it off to the point were its loose, but can't be removed unless you fully depress and turn it past the locking tabs, the point were it's ready to be removed, but just flops around, leave it like this, start the car, let it warm up, slowly rev it, causeing the overflow tube to purge what fluid it don't need for top tank volume, usually 1 inch below the filling neck,.....if the car is running within temp, take it out for a drive, reason for keeping the cap loose is for pressure not to build in the ststem, as you drive you may purge some fluid out the overflow as engine RPM increases,.....post your results with this test if you would please

Mike

Quote:

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Then Mike said try Zerex G-05. Crossed my fingers and drained the Prestone and put in the Zerex. No good. Still idles as about 210 degrees with an outside temperature at a below normal 82 degrees.

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Did you dilute the Zerex-05 with distilled water and secondly did you add a bottle of water wetter?

Running without a stat can cause the motor to run hotter because the coolant never stays in the radiator long enough to be cooled.

After all the different things you recently tried, you may want to put the stat back in and see how it works now.

Two things:

1) Question I need answered - Does drilling the thermostat 1/8" really help keep the temp down?

2) Years ago my dad was changing freeze plugs and dropped one in the water passage of the block; He said car developed a "hot Spot"? and it always ran hotter after that incident. It was a chevy small block if that matters.

The reason I mention this is the remote possiblity that someone at some point might have left an old punched out freeze plug in the block or head causing a small blockage?

I'm not as knowledgable as some of the previoius posters here on this tgopic, but I thought this might help.

Mike:

I'm taking the car out tomorrow night to the local cruise spot. I'll try leaving the radiator cap 1/2 on and loose and let you know. However, the radiator tech did fill the radiator to within about 1 inch from the top yesterday.

Yep! I followed Mike's instructions exactly.

Mike:

Just got back from the cruise. I did like you said and loosened the radiator cap one notch so it was still on but loose. When I got to the cruise spot it wasn't running hot but it was purging coolant out of both the overflow hose and the radiator cap. About a pint was pushed out on to the ground.

Jim

Mike:

As I mentioned before....after I put black duct tape around the shroud, the engine runs cooler. At idle and outside temperature of about 82 degrees it idles and maintains a temperature of about 210 degrees. I had just gotten off the highway and drove about 1/4 mile to the cruise spot and the temperature was normal. The needle showed mid way on the gauge. That's probably 195 to 200 degrees. I got out of the car and coolant was running out on the ground. The next run will be Friday afternoon for another local cruise about 10 miles away. The reason I don't think I have a cracked head is because the engine rebuilder did a magnuflux check. You're right....I'm running a stock 16lb. cap. I had the coolant checked twice for combustion gasses and both times proved negative so it would seem that the Fel Pro head gaskets are'nt leaking. The radiator tech suggests getting 600 miles on the newly rebuilt engine and then returning to his shop for more tests. I've got 203 miles on it now. Also, the thermostat has been removed. Here again, it seems to now be holding its own at about 210 degrees at an idle. Maybe I can live with this. Some say putting a Miloden 180 thermostat in it will cause it to run cooler. I was going to wait until I had the 600 miles on it before re-installing a thermostat. At the cruise last night a couple of guys gave me the names of so-called experts to take the car to. I figured that may be a good idea since what ever is making this car run real sluggish may be what is causing the warm running condition (no longer completely overheats after installing the duct tape around the shroud). I did not retorque the headbolts....thought I would run that task by the experts when I take it to one of them. I would think they would also do a leakdown compression test. I'm printing your last post to take to either expert for their review as your input seems helpful and contains some probable causes. Since I hi-jacked this thread...maybe I should PM you with the results of the next test that you suggested.

Jim

Sounds good, Jim, I hope you solve this proplem, as I know it can be fustrateing not being able to enjoy the car, after putting so much into it



Mike

I would put the stat back in. It won't cause your problem to be worse. If it did, it would just indicate a flow problem- either due to a bad stat or otherwise.

I would like to see a test with the stat back in there and the G-05 WW combo.

You are right that whatever is wrong might be the reason it isn't running liek it should. Problem in figuring out what that issue is that we can't narrow things down if the basics aren't what they need to be.

The Milodon thermostat is a HIGH FLOW stat like I sugested earlier. Robertshaw also makes this type of thermostat. I use modern high flow pumps (edelbrock- milodon)and 85% distilled water, waterwetter and some antifreez for a cool running car. Make shure your car is not running lean and that the timeing is not retarded.

Did you ever pull any spark plugs from each head to check color/appearance ??? - Lean condition at idle / cruise condition like so many others have mentioned

I agree on the thermostat 160/180 milodon high flow - Has to bee in there

A couple of weeks ago I took it to a profesional
engine tuner and he pulled a plug from one head and said it looked perfect.

I ordered a 180 high flow Miloden stat from Year One about 1/2 hour ago. They said it would take 2 weeks to get it. Right now the Zerex G-05 and water wetter are in it from when Mike suggested it. Ill be leaving that combo as is. In a couple weeks I'll be able to perform that test.

That's a long time for a themostat to come.Did you try somewhere else first?

Cancel if you can and check with Jegs or Summit. I bet it is in stock at those places and cheaper to boot.