Hello. I have recently purchased an old Ford truck (1952) with a 351w. It was barely running when I got it, but I could see someone was working on it in an attempt to make it run better. It had new plugs, wires, cap, rotor, points, condenser, etc... I got it running like a sewing machine but it would get hot pretty quickly. 230 degrees and more. I pulled the thermostat out and it was new, but I put a 160 degree one in, same problem. I replaced the water pump (old one was pretty new), made sure it was a standard rotation for use with a V-belt, still overheats. I put a big welded aluminum 3 core radiator on it and new hoses... better but eventually still overheats.

Here's what it does... I can run it around town and it slowly creeps up to overheating. On the highway it creeps much faster. The rear end is geared so that I can only cruise about 45-50. If I slow down, the temp comes down a little but still overheats. So I'm pretty sure it's not an air flow issue. It has an electric fan on it. I checked to see if the head gasket tabs were sticking out at the front of the heads and they are, indicating proper orientation I think. I'm about to try running it with the cap off to observe flow and shoot different areas on the heads, intake, and block with the IR gun to see if I can see anything unusual.

The original water in it when I got it was opaque rust orange. There were chunks int he radiator. I flushed it out many times, ran cleaner through the system and it came out fairly clear before putting the new radiator on.

What am I missing? I feel like there must be a flow issue somewhere.

 

So I just drove it around until the gauge showed 230 and checked the engine with the IR gun and it showed 180 to 210 depending on where I checked. So I drove some more and it showed about 245 but still the intake, heads, block, and radiator hoses showed around 195 to 220 depending on where I tested. So my gauge inside is off apparently.

I put my timing light on and tried to see the marks but they are dirty and the engine is too hot to clean it now. I *think* I saw the mark line up at 0 degrees, so that may be a factor too. Will check tomorrow when it's cooled down.

 

Are you getting those temp readings with a 160 thermostat in?
Is that the correct thermostat?

 

How do you know that it the temperature? Many times, gauges are just bad. If you do have an IR temperature gun, you should have one. They are so handy.

What about the air going through the radiator? Is it sealed? What about the fan? How easy is it to pull air from the surrounding area vs pulling it through the radiator core.

 

Yes, that's with the 160 thermostat in. It's the one the parts house gave me for it, using a 74 galaxy 500 for parts lookup. I don't know what the engine came from.

I listed the temps already from the IR gun. Getting up to 220 on the heads and burping into the overflow tank. with steam coming out of it.

I set timing and drove it around town today and it stayed cool. I took it on the highway and it was borderline too hot in about 5 miles. It just can't stay cool at higher rpm. Water flow coming in the upper radiator hose is rapid. The radiator has a shroud and electric fan that comes on with the ignition on. It's not running so hot that it's pinging and all, but it might if I kept going. I don't want to push my luck.

 

Does the steam coming out of it smell like partially burned fuel? That, and the overheating, are indicative of a head gasket leak.

Have you done a leak test of the cooling system? You can borrow one of those pumps that attach to the radiator cap from your local auto parts store and pump it up to about 20 psi and see if it holds.

I found most aftermarket electric fans to be insufficient replacements for stock mechanical fans, unless the e-fans are really big, or repurposed from another big car that came stock with it.

 

Typically if it's running hot at high speed there is an obstruction in the airflow through the radiator..... but with the chunks you are describing time for a major flush of the system and boil out the radiator.

 

......new radiator... rest of the system is new and the block is flushed and cleaned as mentioned.

No obstructions other than the factory grille and this is a giant all welded aluminum radiator, 3 rows.

I could go with the fan being insufficient but it runs cool around town stop and go. At speed it runs hot. Backwards of a fan problem unless the fan is being a restriction? That's all that makes sense so far I guess.

 

IMHO, the radiator is of insufficient design and let me explain........

One of the greatest impactors that has come to be are the "high-flow" replacement water pumps that were introduced (and still here) in the late 70's......although 99% of it is a better impellor design, it did increase the flow rate of coolant in the system.....Now originally, the increased flow was 3% IIRR which still gave a good amount of time for the coolant to absorb the heat and expel it at the radiator but over the years & especially in the mid 80's the engineers upped the design again and well, that's when we all starting to see our engines running warmer (you also have to remember at the time these same style water pumps were still in use on the new vehicles- which were designed for the increased flow). On our Mustang the flow was so great that it would cause the radiator cap seal to "lift" under higher rpm causing fluid to expel, which we addressed with an overflow/recovery tank (had to home-build that one at the time), which today is a common standard so to speak.

The increased flow/cooling issue is really nothing new though, as with the flatheads- had the same/similar problem caused in part by increased HP/TQ & speed- the solution was to install a giant washer (restrictor) at the upper radiator inlet- this slowed the flow to allow greater absorbsion/cooling.I know many seem to be under the impression (marketing) that aluminum construction by itself will enhance cooling, there is a little more to it than that...and in many instances buyers are actually comparing apples to oranges when comparing a copper core spec to an aluminum spec radiator. US Radiator use to have a really nice vid on their site that yeah, it does talk about the company a bit, but also talks about Copper vs aluminum & gives a good presentation of design limitations. US Radiator has been around for 40+ years. The guy who presently owns it started working there 30 years ago and with the exception of 1 or 2 items, everything is built at their facility, so they are very knowledgeable..... no I'm not suggesting you buy a new radiator from them.


Link: U.S. Radiator | The Difference Is In The Tooling

Properly maintained, the oem systems are more than adequate, what has changed is the high flow water pumps etc which reduce the time the cooling system has to absorb heat and dissipate heat.........if the flow is slowed back to OEM spec's, you will see (typically) temp reduction- and the ability to maintain operational temp range greatly increased but that isn't always an easy option.

I’m not going to say just because it's Chinese made its junk...it’s not, but there are a lot of issues with them........example...Assuming all of the seam are properly welded (they have their moments when pre-mature failure- pinholes- occur), cooling is more than the number of tubes or material, its number of fins versus number & size of tubes....i.e. rate of flow and the amount of heat that can be exchanged in a specific amount of time.......many times these units are cheaper because they do not have an adequate number of fins...... Quality of welds........typically poor and pinholes start showing at the 5-8 year mark. Corrosion (internal).....almost all American radiators (aluminum) have or have as an option (and usually recommend if not already permanently installed) an anode- basically acts as a sacrificial lamb for electrolysis-based corrosion (very, very predominant with aluminum radiators, water pumps) and helps keep the ph level neutral. Without this, I have seen a host of promulgated failures including radiator, hoses, water pumps, head gaskets, thermostat covers- where the material is literally eaten away because of electrolysis.

Although I have always purchased from US Radiator, but when the radiator plastic part began failing on my wifes 97 Cougar Sport (which lasted 17 years with an anode), called them and it's too new of a car and they recommended:

Radiator Express

www.radiatorexpress.com

Irvine, CA

866-723-3977

I was very pleased with the product, it was built exactly to the oem specs. What I liked about this place is when I spoke to their support staff, the person I spoke with had definitely experienced getting their hands dirty on a car.......when I asked questions, I got answers....no hesitation. Whit I also liked is they track installation issues that both mechanics & customers have so when you place your order, they order the brand/mfg that has the least amount of reported issues. I would also ensure the thermostat is functioning, but assuming there are not restrictions, then it's the radiator and you should be able to get one at a reasonable price from radiator express.

 

Drifting off the main topic slightly, I was thinking about the optimal configuration for cooling an engine. Assume the coolant can be kept at some constant temperature below the engine temperature. Heat transfer rate is proportional to the temperature difference between the heat source and heat sink. As soon as the cool coolant hits the hot engine parts, its temperature will go up, so heat transfer rate immediately slows down. In this case, you want to flow coolant past the hot engine parts as quickly as possible to present it with as much new cooler coolant as quickly as possible. This maximizes the absorption of heat by the coolant. On the radiator side, you want to coolant to spend as much time in the path of cooling air as possible so it can lose as much heat as possible. So to do that you use enough tubes such that their combine area is some X time grater than that of the hose, so the linear rate through the tubes is much reduces while overall flow rate stays the same. This assumes the radiator also has sufficient fins and airflow to remove the heat from the coolant.

I got a cheap Chinese aluminum radiator off of eBay for my 69 Mustang because I needed one quickly, and its fit was terrible:

https://photos.google.com/share/AF1Q...ZEOUVmWjRfSFl3

It was as if the pieces were hand-held while it was being welded; there was a lot of misalignment of the parts, so it did not fit well onto the radiator support. But it's been over 8 years of use, and so far, no leaks.

Would the anode be just a piece of zinc attached to the radiator somewhere inside?