• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Aluminum Radiator

Share this page

Thanks to everyone who commented above. Good news is that the car goes back to Paul Tsikuris tomorrow morning where Paul assures me he will get to the bottom of it. I hope my next post on this subject is that I am holding at 180 degrees in July in Florida while idling at a red light.
Charlie Carpenter
 
Charlie -

I live in Hong Kong and all my cars run cool. It is hot here.

A few important tricks:

1) get a 160 deg balanced sleeve thermostat from BCS in Stockton. Makes a huge difference.
2) Dont use more than 20% antifreeze. 80%+ should be pure distilled water. This makes a huge difference.
3) disconnect the hoses and pull out the thermostat and forcibly backflush your block with a very strong stream of water, both from the top hose and the bottom hose. You will be shocked how much crap is in your block.
4) as a last step THEN recore the radiator. Generally speaking the best solution is to go with a four row radiator - larger core means water flows through the radiator 25% slower, meaning better cooling.
5) ali radiators help a little, but they are a pain - you can't rod the core, once it's plugged, you're F****D. you need to put a screen filter on the top hose to keep it from getting plugged up. too much trouble for very little gain - go with a four row radiator core first before going with the ali rad.
6) adding an electric fan doesn't really help much - the pancake motor blocks too much of the radiator. You are better off putting a fat fan on the water pump - again BCS has a great six bladed fan for this.
 
Just as an aside, most rads are painted with black paint which acts as an insulator, is there a paint product that would allow better heat dissipation?
 
Don't underestimate the thermostat!!! Different car I know, but my 65 Mustang had an overheating problem that I swore was the radiator. At low speeds (under 45) it remained cool, but once above temp began to climb. Not to the point of pegging hot on the gauge, but enough to know there was a problem. It would cool abit at lower speeds or while at lights. I thought it was the classic sign of a clogged radiator as I've had with other vehicles. After buying a new radiator - no difference, so I removed the thermostat. Took a long time to reach operating temp, but eventually did and went far beyond. The fluid needs to stay in the radiator for while to dissipate the heat. Next I bought a 160 thermostat (previously was a 193 or 195). The car (per gauge anyway) ran cool as could be, not moving much out of the cold range on gauge - at any speed or idle. Also gone was the stinking hot engine and upper radiator hose under quite a bit of pressure after a long drive when you open up the hood as with the original thermostat. I then put in a 180 thermostat, thinking that the engine was really not at proper operating temp. Result - the gauge registered in the proper zone continously at all speeds, idle, etc. - problem solved.

The factory gauges give no indication as to acutally temp in these old Mustangs, but it was obvious I cured the problem. I'm not as familiar with Healey overheating issues as I haven't driven mine since 1983! My point is that my experience has been that flow through a radiator is critical to cooling. Number of tubes in the radiator, thermostat, water pump, etc. are going to dictate the amount of flow. Other factors too effect temp as have been pointed out (timing, bored engines) but you might consider a much cheaper (<$4) experiment before going much further.

Good luck,

Robert
 
Had a similar problem with a 302 cube ford mustang motor after having some work done, even tried dropping the licence plate to get more flow thru the rad via the opening in the front bumper bar, no diff, went to a four core 351 GTHO rad still the same, then one night on a long run as it started overheating I stopped, left it sit a few minutes, opened the cap, let a bit of steam/water out and went on, no more probs, did this a few times over the next year, all I can think of to this day is an obstruction in the water jacket that would drop out of the way as I took the pressure out of the system, ie a "lost core plug" or similar!
 
zblu said:
Just as an aside, most rads are painted with black paint which acts as an insulator, is there a paint product that would allow better heat dissipation?
Click to expand...
I was told several years ago that radiator shops use a special black paint that does not act as an insulator. If a Healey engine is overheating you can bet it isn't due to paint on the radiator. I run an AC in Texas in Texas in the summer and have no problems. I had my radiator rebuilt and a larger capacity core installed and that kept everything cooler. Correct thermostat, timing, belt tension are all factors to be considered.
Patrick
 
Keoke makes a good point....I actually have two temp. sensors the original one in the front of the engine feeding the original Smiths mechanical gauge, and a electronic sensor at the location of the heater supply line at the right rear of the engine. My fuel injection computer uses the electronic sensor to determine whether it's a cold start, etc...I don't have a gauge on that sensor but I can see what it is reading when I have my laptop plugged in for tuning....anyway the point is that the temp. difference between the Smith mechanical gauge and the electronic gauge is fairly dramatic....sometimes as much as 30 deg. with the biggest difference at the higher temps. I tend to believe the electronic gauge. I've been told it's not uncommon for the Smith gauge to be as much as 20+ deg. off...and mine was recently rebuilt. So my mechanical gauge may say it's about to overheat and the electronic one says it's fine. FWIW

Steve
 
I had a bad overheating prob with my BJ7. I bought an alum rad from cape. The water still came out the overflow when hot. I also took off the mech fan and replaced with an electric one. Still losing water. Eventually I had a brainwave and put a 17psi lever action rad cap on and the problem stopped. I think this pressure may be too high for the older brass rads so watch out if you have one of those.

I also installed an electric pump in line so that when the car is stuck in idling traffic it will pump water at good speed around the engine. This is wired so that when the engine is switched off both the pump and the fan continue to operate until >180f is on the gauge. This stops heat soak and boiling over whilst stopped. It used to be V embarrassing to have folks coming over to me all the time to tell me my car has just blown up every time I parked!

An observation: If I understand thermodynamics correctly matt black paint will help the dissipation of heat not act as an insulator. It would have to be a very thick coating to insulate would it not..?

Another observation: I think we disproved the theory of 'water needs to spend more time in the rad' to lose its heat some time ago did we not? I think Sparkie that you must have had some other problem rather than that in your muzzie. Certainly my water speed is now considerable with 2 pumps operating and there is no cooling downside to this speed. Explanation: Sure, a given quantity of water spends less time in the rad, but on the flip side MORE actual quantity of water is in the rad doing its cooling business in any given time period, so it balances out.
 
Back
Top