Nailhead is. Dead

Sounds like he's getting closer. I know a lot of you are 50/50 guys, but I'm running the Royal Purple Ice in my BBC, and took 10 degrees off my high temp. Works better than Water Wetter, IMO. Also running it in two race cars with similar results. It's not cheap (Speedway), but it definitely made a difference.

 

this may sound dumb, but i had a '63 cadillac that had some trans issues that created a hot running engine, which masked the trans problem. that heat from the trans goes right into the radiator is you're using the internal cooler.

 

Very good point!! Had that happen when my Powerflite went bad! Engine got hot as hell.

 

Those are the symtoms of a collapsed lower hose. Does the lower hose have the anti-collapse spring? If not - install one.

Dave.

 

Hey, Vega1;

A couple of Q's.

Didn't see that you mentioned that this hot issue is just recent, so:

I know you said that you flushed the block, but did you probe & scrape around the lower portions of the cylinders (esp the rear) & along the pan rail of the cooling jacket? Not unusual for casting sand & wire to be stuck in the jackets. I had that problem w/a '64 Stude 289. Cleaned all the crap out of it, & instant cool-running engine.

Another possibility may be that either the fan blades are backwards, or the fan is turning backwards - pushing air out through the front. Could've been a hosed-up deal from the mfgr & not caught when installed. It'd cool at idle, less so at higher rpm, not at all at speed when fan comes on.

I think the comment about collapsed/partially blocked lower rad hose is a good one, as was the t-stat comment. I'd look to installing a new one & check it 1st, in a pot of water on the stove. Just cause they're new doesn't mean they will be good. & make sure there is a hole in it at least 1/8" for bubble bleeding.

Hope you get the issue fixed.

Marcus...

 

With the lack of temp drop across the radiator try taking temps from different areas of the radiator . It acts like parts of it aren't flowing.

 

Let's see...
The factory gauge is inaccurate.

Will idle all day at 190 on the factory gauge but is actually a bit cooler. Maybe 180ish.

Temp goes up with increased RPM to what you call hot. What is the actual temp, not what the inaccurate gauge says?

Is it hot enough to puke coolant?

You've checked most of the common stuff.

Gets hot at 2500 RPM sitting still, not driving. Correct?

Have you tried taking off the electric fan and shroud and putting the stock fan and shroud back on?

Have you checked to see if the heat riser is stuck closed?

Check the heat riser. If it's ok, put the stock fan and shroud back on and see how it does. And don't depend on a factory gauge.

 

Or the elec fan isn't moving enough air.

 

We have a 1960 Buick LeSabre with a low mileage 401. I had the same problem with overheating. I did a lot of inspecting and replacing. I found that my muffler was plugged up. I changed the muffler to a glass pack and I have never had any problems after all that.

 

180 top hose and 187 lower hose????
Must be the trans heating up the colant.
if you have the trans cooler in the bottom
tank
If you take in 187 degree colant in the
Engine no wounder it overheats

 

Has dual exhaust both are flowing no restrictions it seems every time I try one thing it starts doing something else last night I went out started her drove her down the road got her to steady 65. And I'm thinking cool problem solved then no sooner then I look back down gauge is at 210 then 220 and I pull over and shut her down now I have tried it with Mechanical fan and shroud electric fan with shroud no shroud put head gaskets on had heads checked flushed block put screen in hose to catch any debri tried timing put clear section in rad hose to see it flow tried new thermostat tried without same results pressure checked system good

 

The gauge spot on? Does the car boil over hot or just read hot? Is the reading hot while out on the road doing the 65 MPH? Or after slowing and parking?

 

New gauge is correct I can drive from my house to town and it won't get past 190 5 miles but after that it starts heating up and won't cool down

 

While going down the road? Or when you slow and park does the heat build? Does/has it boiled over?

 

This is what I have been waiting to ask. Pops got there first.

 

Yep but It doesnt matter now engine and trans are out sitting on garage floor next to the ol Buick

 

I am not sure if I missed it or not, but what kind of radiator do you have? The reason I ask is I had a new fairly expensive aluminum radiator from a reputable supplier that was built using that epoxy to hold it together and a little excess came loose in the upper tank and plugged some of the flow to my small block chevy. Was this happening before the new radiator?

 

Yes it was happening befoe

 

Weld your nailhead valve covers over top of the sbc covers paint the engine buick green and call it done.

 

I'm not sure I'm gonna put the small block chev. In her but the way I see it if I do nothing to be ashamed of
And if I did put a sbc in it I sure wouldn't hide it I have a corvette 350 and everybody knows that they are automatically. 150 horse more than a regular 350

 

I'll never get over spending time and money trying to hide something from people whose opinions mean nothing to you. Can someone please explain the thought process because I just don't get it. I'd rather spend my money on Go Faster stuff.

 

It's too late for the original poster but others might find this helpful. Turn off or remove the fan, get the engine up to the temperature that it gets hot and try running water over the radiator core to cool it. Set the engine to the rpm that causes problem and see if it cools with the water running over the radiator. If it does, the radiator doesn't cool sufficiently with air flowing over it. If it doesn't the system isn't flowing enough coolant when it gets warm.

After changing a leaky water pump on a late 60s Buick, the engine started running hot. It would start and run cool for quite a while, but once it warmed up it kept climbing and there was no heat from the heater. We suspected the impeller was slipping when it got warm. The water pump was removed and put in a pan of boiling water for a few minutes. When it was lifted out, the impeller fell off so it was pretty conclusive.

 

I hope for your sake that when you put in a new engine it doesn't do the same thing.

When you said that the top and bottom hose temps were only 7 degrees different, that tells me that the radiator is not removing the heat from the coolant. Whether the size of it or airflow through it is not enough, it is not removing the heat. It may be like engine man says too that the impeller is not doing it's job to move the coolant.

Please post back here to let us know if the vette engine shows the same traits. This is assuming you will use the same rad and fan combo.

 

id check the thermostate you didn't mention you did that. also try removeing it and the rad cap then start it and see if the fluid is moveing by looking into the radiator cap hole. if it runs cool you know you have a problem with your thermostate .simple and dosnt cost anything

 

Aren't all 350's Corvette engines?

 

Worked as a parts rep for a car manufacturer. A body shop was having a cooling issue after front end repair. Turned out that the aftermarket radiator the insurance company insisted they use had smaller tubes. It looked the same. Bolted in the same. Replaced it with OEM and problem solved, but only after a week of the same trial and error that the OP is talking about. Just because the radiator is new doesn't mean it's good.
Norm

 

NO....all 327's are

 

Vega1, read all your replies. To bad you pulled the engine already. You could have tried a restrictor plate in place of the thermostat. Why?, I've had thermostats wanna close as water flow increases or as you say, faster driving speeds. That simple test may or may not have answered the underlying problem. But it would have been nice to see if indeed it was a stat. issue only.

 

It has the same trait with the old rad and stock fan as it did with the new rad and electric with shroud. Replaced it because it was leaking and needed recored pulled all freeze plugs to check for sediment none checked timing good had heads checked good new head gasket new water pump blocked flushed flowing good coolant flowing good I didn't wanna pull it but hey sometimes you cut your losses all the fuckin around with it I could have had it up an going with another engine trans combo but hey live and learn. I will be totally dissamantling the nailhead this winter to find the culprit even if I don't use it or rebuild it.

 

Actually I did that very thing yesterday took new thermostat apart put washer in the middle and tack welded. It to cent. Same prob