hey guys, quick question on overheating problem
im overheating mostly at highway speeds...idling it stays at 190
i checked both radiator hoses today with a IR gun and they bother were around 170 ish so i know there is a problem
here is my thought process...the water pump is a victor jr and pretty new. so i was going to take it off and check the impellers to see if something got into during the engine swap, to make sure they were turning first
if that was ok i guess its a new radiator.
Anything else you guys thing I should check?

Ya gotta tell us a LOT MORE about your setup. What engine, car? What did you change??? Everything.

ok, new 68 camaro, just put in a new 468 about 550 hp, had a 396 before..the cooling set up is the same one. 4 core radiator, victor jr alum water pump electric 14 inch fan. this same set up worked well on the 396. what other info do you need my friend

Did you paint the car recently? I have seen a lot of painted radiators causing problems.

How a bout a radiator flush? Tried that? Get the tee in fitting and flush it with a garden hose.

Are you running a fan shroud? If not, get one.

The water pump is probably good, but you can clean it if all else doesn't fix the problem.

How about the lower radiator hose? Is the metal spring that keeps it from collapsing intact?

Getting a recore is cheap and easy at a radiator shop. They have higher efficency designs that sometimes don't work with high volume pumps. Make sure and tell them you have a high volume pump. You can't go wrong with more cooling capacity.

How is your thermostat? Does it stick?

How about your radiator cap. It couldn't hurt to change it if it hasn't in a while. A pressurized system is important.

Overheating at highway speeds is usually airflow or retarded timing.
While a fourthgen or a vette could have highway speed airflow problems (due to debris on the core) pretty easy, sound kinda farfetched in a firstgen.

Where's your timing (at hwy rpm)?
Do you run vacuum advance?

just put a high flow 160 stat in...
I have flushed the radiator
the electric fan has a shrowd and it seems to blows ALOT
havnt painted the radiator ..um
lower radiator hose has the metal spring in it, doesnt colapse when car is running
As i said in getting IR GUn readings of 170 on bloth the top and bottom radiator hoses? they are suppose to be like a 20 degree diffrence arent there to show that the water flow and cooling working?

its a water flow issue isnt it? ........i think i need to go with a big alum radiator and check the water pump...idunno???

oh my timing is set initial at 14 and total around 34....I have a vacum advance as well

thanks for all your help so far guys!!!!

Thanks for the extra info. OH, that 14" fan would be great on a VW! You need 18" with a clutch, 7 blade driven by the crank. Yep. Stock stuff.
And don't forget to use a small pulley on the waterpump. It turns FAST that way.
Edit, are those advance settings with the vacuum advance disconnected? They would be OK if so. The vacuum is just for economy (and running cooler) on the street.

i dont want to go with a stock set up, electric fans is what im looking for
so your saying i need like 2 11inch fans or a big 18 inch electric fan and that should do it??

If it were me I would start by replacing the 160* thermostat with a 180* at the least. A 160, IMO, does not allow the engine to heat up properly in order to burn off the condensation that builds in the crankcase. I see you run a TH400, but what gearing do you run? I experienced the same issue. Around town it would run fine(180* or so with a 180* thermostat), but when I got on the highway it shot up to 220*-230*. I run a Powerglide and 4.10 gears so my RPM's are high on the highway. This was with a 14" fan and no shroud, a 3 core radiator, and stock W.P. I switched to an aluminum 2 core radiator, a high flow W.P., a 16" fan with shroud, and a high flow balanced 180* thermostat and the problem never returned. I can run at 4000-4500rpm on the highway and the engine never gets hot. One thing to note, the fan switch. If you run a 160* thermostat then you will need a switch that turns on a 180* and off at 165*. I strongly suggest changing to a 180* thermostat at the least. You will find that the 180* is the most commonly used model in here(I believe). With the 180*, you will need the switch to turn on at 200* and off at 185*. The radiator needs to be the WIDEST unit you can fit. NOT THE THICKEST. It is a misconception that the thicker the better, but if you think about it, by the time the air had gone through a 4 or 5 core unit, the air has heated up again. I run a small block and installed the big block unit in my car. I had to open up the core support to allow for the WIDER core. You may have to do so as well. THE WIDER THE BEST.

Just a thought, I once had a van that would over heat at highway speeds. It turned out to be a loose, slipping fan belt.

It's hard to think of much to add. You've gotten good advice here. My stuff is mostly original. The radiator is an exact copy of my original except made of aluminum. Same thickness of course. At the strip or on the street it can't be made to overheat. Even idling in the garage. Did I mention mostly original? Or at least the same as,,,,, Did you pick up on the pattern?:thumbsup:
http://epitomesrebuild.com/images/138.JPG
I couldn't post that old picture anymore. Sorry. I took this ten minutes ago. The top picture will probably update because I didn't change the name.
http://epitomesrebuild.com/images/138.JPG
Yep, both the same.

Hey Fred,

The car looks great but, that overflow hose has to go ! :)

i think charlie has the closest thing to what i got going on. im running 456 gears so it rev's high on the freeway, so his scenario sounds pretty exact to what i got going on...so im going to start the transition over to that direction...ill keep you guys posted on what happens and I do thank you all for your help on this..

one thing....what is the diffrence between a 180* high flow stat and a 180* 'Balanced' High Flow Stat?

Rob

Rob, go to the Stewert's website. That is where I buy my thermostats from. They have great info on thermostats and cooling in general. Standard thermostats are affected by coolant flow. Balanced thermostats are designed around the "high flow" theory and work much better with higher flowing W.P. Now, I may be off a little on the exact description of a "balanced" thermostat, but some high flow W.P.'s won't work correctly unless you pair it with the proper thermostat. It would probably be best to ask the guys at Stewert's exactly what a balanced thermostat is. I do know that they aren't afected by the increased flow rate like a standard thermostat is. High flow thermostat's usually have holes drilled into them to allow coolant to flow ALL THE TIME, no matter if it's closed or open. Does you thermostat have three small holes drilled around the outer perimeter? I usually run that style in the summer and switch back to the normal style(without the holes) during the cold months. The holes make it take a LONG time to warm up and also drastically affect your heater function. I found that out the hard and cold way.

Rob, what temp is your fan switch set to turn on the fan? Definately switch to the 180* thermostat. I know what you are thinking. I run a 160* now and it runs hot, what's going to happen if I up it to a 180*? Once you get all the other factors in order, the 180* is going to allow your engine to get to a more consistant temp and also allow it to burn off the condensation that builds up in the oil(condensation is unavoidable). Install the 180*, the fan turn on isn't as important as when it's set to turn off. You have to make sure the switch turns the fan off at a temp that is hotter than the thermostat lets the cool down to. For example, I had the 180* stat, but my first fan switch was on at 185* and off at 170*. Once my fan came on, it NEVER shut off because the stat couldn't get the coolant temp down to 170*. Once I switched to the 200*-on and 185*-off, everything was perfect. The car can idle in 100* weather in my driveway or traffic or run at 4000-4500rpm on the highway and the car NEVER goes above the fan turn on temp. As far as the radiator, if you are going to replace it, buy the WIDEST unit you can possibly fit. I had to open up my core support, but it was worth it. I got a big block unit installed and I don't have any problems. The thick rad's look nice, but by the time the air has traveled through all the cores, it's heated up again. Also, I was told that the tranny cooler is another "HOT" spot. If you have the ability, use an external tranny cooler and DO NOT mount it in front of the radiator. Mount it off to the side and use a fan to cool it. The heat from the tranny fluid heats up the air moving across the rad and heats up the coolant. Now, I didn't do that part and I haven't experienced any issues so you may get lucky with that part like I did. I just use the internal tranny cooler in the rad, but if you plan on using both the internal and an external, then you may run into problems. The extra heat from the external unit may be too much and cause you to run hot. Keep us posted. I really want to know how things work out.

Hey Fred,

The car looks great but, that overflow hose has to go ! :)
Yeah, it's older than, well, the hills. Got any suggestions?

I learned something on this site that I want to share. We are explaining temperature in degrees. Most of us don't have a ° symbol on our keyboards. And the little ° sure looks a lot better than *. The * is kindda like posting with spelling errors. It's OK, but there's a slightly more pleasing way. When your cursor is at the spot for the symbol, just hold down the Alt key and type 0176. °! See? works every time. If you're running Windows.

If the system is in good condition, and no air flow restriction, timing like Jims post above
From there I would look at
1/ The pump impeller maybe slipping on the splines..not common but does happen
2/faulty thrmostat ...need a 180 , but check it..take it out and make sure it opens all the way in a jug hot water...hang it inside the jug, with cold water, turn jug on heat up and monitor the water temp....Common
3/incorrect thermostat.. maybe the correct temp but may not open far enough...If u drill 16 or 1/8 hole in the flat part it will fix that issue.....common
4/Bottom water hose, is it soft...is the reenforcing in good condition...if not this can cause the hose to suck closed under higher rpms restricting flow...reasonably common
5/ stuff (like reenforcing springs in bottom hose breaking down) gets caught up blocking lower cores in the radiator..normal flushing doesnt remove this...needs the radiator headers removed and manually cleaned with a transmission dip stick....common over long periods of use even with regular flushing, and new /rebuilt engines where the raditor hasnt had the headers pulled as a matter of good practice.

U can check for blocked cores...cool engine, start up and idle a little above idle speed
put youyr hand on the radiator and feel around...blocked cores will make that part of the radiaror heat up slower.

Fred, the alt 0176 is nice, but it's a lot for us to remember(at least for me it is). I will probably remember it on this post, but by the time I go to the next, I will have forgotten it. I am bad at remembering things if I don't make use of them EVERYDAY.

° hey look I did it. :)