Radiators and over-heating

[snamelc]

I haven't seen this subject addressed in the forum so here goes. My Series II has always had an over-heating problem. It's been bored out 0.060 over so I've assumed that was the cause, but upon further investigation, I'm not so sure. I pulled the radiator out and inspected it and it seemed unclogged and in good shape. I pulled the radiator out of my parts car and compared the two. The spare had 50% more tubes (three rows vs two) than the one from my driver. If the spare had been in better shape, I might have put it in. Instead, I went to a radiator shop and asked them what they could do. They found a core with twice as many tubes as my driver so I had them put it in. I am very anxious to see how it works. Now I am suspicious about the original core with two rows of tubes. I suspect that radiator had been re-cored from three rows to two, making the car prone to over-heating from that time on. I had a Series II back in the 1960's and never had a problem with over-heating, but even though I had it re-cored once, I couldn't tell you the number of tubes it had. I suspect it was three rows. I'm quite sure the radiator frame was completely full of core, where the one in my driver was only about 2/3 full.

All this brings up another subject on cooling, and that is the popular use of electric fans. Electrics make a great deal of sense since they pull air through the radiator more efficiently when the car isn't moving and the engine is at idle speed. I had thoughts of doing this but nixed the idea because I have had over-heating problems even at highway speeds where the ram effect should have provided plenty of air, even without a fan. That's when I began to think I simply needed a more effective radiator. Oh yes, I did check the thermostat and the water pump. The engine cooling chambers were boiled out when it was over-hauled.

I would appreciate anyone with knowledge of radiators, tube count as originally built, over-boring vs heat load on the radiator etc. weighing in on the subject.

Thanks,

Bill

 

[Jay Laifman]

I can only add this oddity. My SV tended to get hot in the hotter So Cal days - 90s 100s. I had a recored radiator with more rows put in. Don't know how many - but I can go out and count later. It helped, but not perfect. I had a flex fan from Sunbeam Specialties. It definitely helped at idle. But, still I could get hot. Then I put on the Holbay head. It NEVER gets hot anymore. It's like a rock. I don't know what differences there are. But, that's all I changed, cooling-wise, and got such a huge difference.

Jay

 

[alpine_64]

Bill,

When you rebuilt the motor did they just boil out the block.. or did they actually physically agitate the cooling passages, especially in the back where there tends to be casting sand and corrosion sits.

Another thought... what about your mixtures and yout timing.. they can also cause th car to run hot.. maybe you are to lean?

Is the gauge accurate.. are you loosing cooling out of the overflow? is the radiator cap correct.. the caps from the early cars are an unusual depth.. perhaps yours is to shallow and its not pressurised enough.

Just some thoughts.

 

[RootesRacer]

All the SII rads Ive ever seen are 3 row (not cores).
This isnt to say they came from the factory that way, too much time has passed to make that plausible.

I have seen 3 row SII rads with fewer number of tubes than what seems available now for recores.

Now the bottom line to radiator function is the inlet and outlet water temps.
The lower the difference, the less effective the radiator is, or the lesser the airflow across the tubes.

In my own case, I have a 3 row SII, recently recored and a 20 over 1725 engine which is fairly tricked out (big cam and twin DCOE carbs).

In 90 degree heat, it idles at around 200 degrees, take it out on the road and the temp goes down to 180 which is the thermostat temp.
I run the 7 blade fan, but there is no shroud so the airflow is limited to what the fan can pull at idle.

An infrared thermometer shows that only the tubes inline with the fan are cooling, these tubes show temps around 170 near the outlet tank.
Tubes not inline with the fan show outlet tank temps above 200.

This to me says that a shroud or a supplemental electric fan could work wonders in improving the efficiency of the radiator.

Now other things to mention are that SII expansion tanks have 5 or 7psi reliefs on them, which will puke coolant above 200 degrees.
200 degrees is not very hot, and since that coolant is lost forever (caps are not sealed so recovery doesnt work), running 200 degrees for any time will cause a fatal loss in coolant.
I modified my tank to have a new filler neck and a 13 psi cap, which has yet to puke a drop of coolant into the recovery tank.

I hope this info is useful.

 

[mickjj]

I had overheating problems and the constant flow of coolant into the overflow bottle on my Series I. I had a new core put into the radiator. I also had a new filler neck installed with with a higher psi cap and have not had a problem since.

 

[Bill Blue]

Bill, here is my contribution.

I too had a Series II back in the day. Would occasionally get a little temperature spike, never overheated. Don't have a clue what's going on these days.

My car is a Series V. I first put it on the road with a turbocharged Pinto 2.0. I used an original radiator along with a Volvo fan (moves air like crazy) and cut the sheetmetal that covers the bottom inch or so of the bottom of the radiator. I also blocked the horn cutouts. It never heated. It now is sporting a Duratec 2.3 which I judge is putting out twice the HP of the 1725. It has a viscus drive, 14" Volvo fan and a radiator from a 69 fastback. It does not overheat. I did not use a shroud in either application, but the fan is only about 1/4" - 1/2" from the radiator each time.

I have no idea what all this means, other than it is possible to cool an Alpine with stock radiators. Oh yes, I am also pulling air through an air conditioning condenser, but it has not been operational in the current setup.

Bill

 

[John W]

Bill, Sorry I don't have anything to contribute. I've never had overheating problems, but I think I'll pay my dues. The entertainment value alone is worth it.

 

[RootesRich]

To the best of my knowledge, all Alpines came equipped from the factory with 2 row radiators.

At Invasion VII, one of the Tech sessions discussed a new core Ian used to solve the overheating problem in Scott Christie's S3. I believe it was a "D" core. Perhaps Scott or Ian can confirm this.

A couple of years ago, I was talking to a radiator shop (they were dipping and coating my gas tanks at the time) about a 3 row "D" core and they seemed to know what I was talking about. I was thinking about building a new rad for my SV based on the Tech session, but my 3 row, unknown core is keeping my car cool so I haven't bothered.

 

[V6 JOSE]

Hi Rich,

My Series IV had a three row core from the factory, but it had less tubes and less fins than the heavy duty three core I had to put into it to be able to keep my V6 cool. The stock three row core just wasn't enough to keep the V6 cool.

Jose

 

[MikeH]

I think I would go along with the timing and mixture response. Too much advance and/or too lean will run hot. Are you sure you don't have any air in the system, say in the heater core, that may affect proper flow. Also, you didn't mention the age of your hoses. Hoses that look good on the outside could collapse under flow on the inside. What ratio are you running you coolant?

 

[snamelc]

Fantastic input, guys. Thanks a bunch. I'll try to answer most of the questions you've brought up:

My air/fuel mixture is running rich if anything and the timing is spot on per specs. I'm using a 50/50 water/antifreeze mix with water wetter. All hoses were new at time of engine re-build 5,000 miles ago and I came back and added a wire coil to the suction side hose. Yesterday, I changed out the water pump. The old one was aluminum with plastic impeller. The new one is the original cast iron and makes me feel better if nothing else. I can't answer the question on cooling chamber boil-out but if it wasn't done correctly, I'd be surprised given the reputation of the builder.

I won't be able to get back to it for a couple of weeks but promise a report when it's all back together and I've test driven it.

Bill

 

[AlpineII]

After reading about all the overheating issues I had some concerns. When I did my Series II I made sure my six blade fan was in top notch condition and had a slow-flow/high effeciency three core put in. In addition I put in an oil cooler. In the three years I got to drive it, before the accident, I never had any issues with engine temperature, regardless of the outside temperatire or if I was sitting idling in traffic.

 

[Tom H]

Bill, You say:

I haven't seen this subject addressed in the forum so here goes

I assume you mean the specifics of a Series II. If you really mean in general cooling systems in Alpines, if you do an Advanced Search on the word overheating under Stock and Modified forums you'll find 58 threads. It is one of, if not THE, most discussed subject. I had overheating problems in My SIV in 1966 thru 68. Several warped heads. 3 years ago my SV kept overheating. 2 years ago I had my radiator recored with a 3 row and have had no problems since. I also had the block cleaned out and especially below the rear plug. There is an extensive research and report on radiators, fans, pumps, shrouds, etc.done by a couple Tiger guys. I cannot find it online anymore but I have a copy saved.

Regards,

Tom

Tom

 

[RootesRacer]

One thing I really should mention, particularly on the S1/SII is that the relief pressure being so low causes you to think the engine is overheating when really it is not.

Also since the gauges are not regulated, and seem to read high, many times the temperature is lower than what the gauge tells.

Its in this case that its most helpful having a thermometer down the filler to corroborate the gauge temp, OR having an infrared thermo to test the tank temps while in operation.

 

[Tom H]

I got a link for the Tiger cooling article from a member of TE/AE , Tigers East/ Alpines East. Even tho this is for cooling Tigers, it really is quite applicable to Alpines and, to me, is the most difinitive article on cooling our cars I have ever seen:

Here's the link:

http://teae.org/cooling-the-tiger/

Tom

 

[jumpinjan]

Here's the 2-passage rad cores that Ian had the shop use. This solved the overheating problems that has plagued many Alpines.