V8 Cooling Problems and a Solution

Note: Even if you don’t live in New Zealand here is some useful advice!

Having checked everything people have suggested to improve my cooling with no change, I pulled the rebuilt radiator and the water pump and took them to Trevor French Radiators in Auckland (www.trevorfrenchradiators.co.nz ).

He saw nothing wrong with the water pump, so he suggested that he unsolder the radiator and check it out. First they put a hose into the top, and water flowed out the bottom, but he said that did not mean that it was travelling through the cooling fins. Not sure I understood that one, but as it turns out, he was correct.

For a fixed fee of NZ$90, he completely disassembled it and found the engine rebuild resulted in debris that had blocked the reportedly rebuilt radiator. He rodded it out and soldered it back together. He began at 2 pm and handed it back to me at 5 pm with a fresh coat of black paint. He also recommended that I take a woman’s nylon stocking and put it over the entry of the upper hose to catch any more debris.

He also said that the radiator design was quite good… more sophisticated in construction and should last another 30 years before needing attention.

On reinstalling it, I hooked up a second capillary temperature gauge and discovered that the Smith’s gauge was reading 140 C while the aftermarket gauge was about 93. Without that second opinion, I probably would have presumed I had not cured the problem. Unlike previous runs, the engine was not making those noises related to high temperature, so I am more comfortable that it is running in the 90’s. The fans going off and on seem to agree,

After a few runs up and down the hill, I pulled the upper hose off to inspect the nylon stocking. I found significant debris, blue engine paint and other junk that would have contributed to the need for a 3rd disassembly of the radiator.

Advice to others in the future…

1.      When you install a newly rebuilt or cleaned radiator, or if your car has been sitting and may have built up scale in the engine block, use the nylon stocking trick to protect the radiator.

2.      If the car overheats, it is easy enough to remove the Bristol radiator and have a shop take off the top to check for any obstructions to water flow. Even if it was just rebuilt, it could be blocked again.

3.      Do not rely on the Smiths temperature gauge. The engine block has nearby places to add a second temperature gauge, which costs less and is more reliable than an infrared gun.

4.      Other advice they gave was to never use a water blaster that comes near the radiator fins. It flattens and does damage. I’d never given it much thought, but it makes sense. He showed me an example.

Finally, anyone in NZ needing radiator work, these guys are highly recommend. Three older fellows, all white hair, the oldest radiator in the shop was from a 1927 Alvis. Good prices, great service, super knowledgeable.

Understanding Anti-freeze

Technology moves forward and new products are constantly being launched with claims to improved formulations and performance. As we found out with the bitterly cold weather in January 2010, antifreeze can hit the headlines, with some alarming stories reported which at first seem to be about the well-known tendency of antifreeze to find the tiniest hole and cause leakages – but in these cases it has led to catastrophic engine problems.

Traditional blue ethylene glycol is a toxic but highly effective antifreeze and contains silicates as an inhibitor to help prevent corrosion in an engine with mixed metals in its make-up. Bluecol and Blue Star are well known brand names and both of these are declared suitable for ‘classic cars’ on their company websites. Be aware that there are also low- or no-silicate ethylene glycol formulations (usually red) available which may not be suitable for all engines. Propylene glycol is another well-known and less toxic antifreeze formula and usually contains silicates but Comma, the main manufacturer, have now discontinued it in favour of an ethylene glycol product containing ‘bittering agents’ to make it less palatable and minimise the risk of accidental poisoning.

Both of the above products use inorganic additive technology (IAT). Recently problems have been reported concerning the use of antifreeze mixtures using organic acid technology (OAT). OAT was introduced in the mid-1990s and the products are biodegradable, recyclable and do not contain either silicates or phosphates and are designed to be longer lasting. However these products do seem to cause problems in older engines; over and above the ability of antifreeze to find the smallest crevice and leak, OAT antifreezes have been accused of destroying seals and gaskets and causing a great deal of damage in ‘old’ engines. For this reason the manufacturers do not recommend their use in historic vehicles. These products are usually coloured red, pink or orange.

The final category is HOAT. These products use hybrid organic acid technology in an ethylene glycol base with some silicates in the formulation alongside the organic corrosion inhibitors. The product is usually coloured green and are not recommended for use in historic vehicles.

The Federation are still researching this problem but our advice at the moment is:

  • only use blue coloured IAT antifreeze in historic vehicles;
  • only use OAT products (‘advanced’ or ‘long life’ antifreeze) if the vehicle used it when new and if specifically directed by the vehicle’s manufacturer;
  • never mix different types of antifreeze without thoroughly flushing out the system;
  • always replace the coolant within the time scale specified by the antifreeze manufacturer as the corrosion inhibitors break down over time.

Holden’s – 4Life Advanced Engine Coolant/Anti-Freeze is a proven advanced coolant for road & track. Uses latest additive technology to provide the highest levels of protection for classic & performance cars with normal pressurised cooling systems. 4Life’s Coolant/Anti-freeze has a boiling point of 180 degrees C at 15 p.s.i. for extra safety margin, has no coolant loss though evaporation and has an anti-foam agent that prevents engine hot-spots. 4Life’s Coolant/Anti-freeze additive gives you 10 years of protection to -42 degrees C (which removes the need for bi-annual coolant change), preserves rubber hoses, gives protection from frost expansion damage, and is PH balanced with no acidic impurities or lime scale. For more information and to purchase, click here.

Bluecol – Bluecol 2 Year Antifreeze & Summer Coolant is a methanol-free, ethylene glycol based antifreeze and engine coolant. Keep Bluecol in your radiator system throughout the year to maintain maximum protection against winter freezing to -36°C and summer overheating, whilst at the same time protecting the materials in the cooling system against rust and corrosion. Bluecol 2 Year is suitable for all engine types, including aluminium. It does not evaporate in use and is not flammable. * Does not incorporate Organic Acid Technology (OAT). Suitable for classic cars. For more information and to purchase, click here.

Carplan Blue Star – they state on their website that “Blue Star Anti Freeze and coolant has a powerful formula with 2 years protection for all seasons. Using IAT technology it is suitable for all vehicles including Classic Cars.” For more information and to purchase, click here.

It would appear that Blucol and Carplan Bluestar are made by the same people but that does not mean it is the same product.

There may of course be others and one recommendation is for BMW Blue anti freeze or coolant as it may be referred to. Nothing is known apart from “BMW Anti-Freeze/Coolant contains no Nitrates or Phosphates and has been formulated to prevent excessive silicate dropout”.

“I have just returned from chatting with the foreman of my local Jaguar workshop in Western Australia. The shop uses and recommends Castrol “Radi-Cool” for all their Jags. The following technical data on the side of the container reads as follows:-
The “Radi-Cool” comes in either concentrated or premixed form. The pre mixed coolant contains 33% ethylene glycol and 10mg/kg of denatonum benzoate – max bp elevation 109 degrees C (no mention of corresponding pressure). Further, the coolant exceeds the Aust. Corrosion Studies Standard (AS 2108.1) and has a 3yr /60 000km service life – approx $22/5L in Aust.

I note that Castrol also produces an inhibitor called “Radi-Cool” as well. The Radi-Cool inhibitor comes in 200mL containers, 45% of which (not sure if it is by vol or mass) is glycol and contains benzoate as well. One can or approx $5 Aust. worth will treat a small cooling system. I suspect that the inhibitor composition is very similar if not the same as the coolant except for the glycol percentage. The note on the side of the inhibitor container states that the inhibitor can be mixed with the Castrol Radi-Cool coolant.

In summary, I feel that the best prescription for my cooling system is either the Castrol inhibitor+ distilled water or 33% premixed Castrol coolant if I want a degree (excuse the pun) of bp elevation. It’s nice to know that I can mix either freely if I change my mind and require a higher bp afforded by the 33% glycol mixture.

I need to build a new radiator, so I will include the necessary fittings to feed a semi sealed fluid recovery tank. I will take the jag shop foreman’s advice and change the coolant at least every two years. Irrespective of the brand of coolant/inhibitor, I believe that this last point is probably the most important.”

A suggestion extracted from a Forum
What about Evans NPG coolant? Their website, http://evanscooling.com/main22.htm claims it as a cure-all for all ills including overheating since it boils at 190°C. It is a non-aqueous propylene glycol coolant, apparently non-corrosive and non-toxic. I think it is available in the UK, try EBay. Anyone used it or have experience with it?

Smiths Car Heater

While not specific to any particular vehicle, the information contained in the link below seems to cover the early V8 Bristols. It is included so that members may get a better understanding of how things work, and we thank Per Blomquist for sending it in.

Click here to download (TYPE, 2.66MB)

2 Litre Cooling Systems

AC Thermostats

  • Replacement Spindles – available from bearing stockists. (Ransome, Hoffman, Pollard) RHP Part No. FPS15 or the equivalent from another manufacturer. SOURCE = C. Millward Tel: 0121 – 745 – 2087. Note: the spindle has been case hardened and you will need to use a Carbide Drill to drill the cross hole to allow the insertion of the cross pin. It might be beneficial to grind a small start flat with a dremmel or the like, to remove the case hardening (usually a maximum of .025″ deep) to assist the drill start.
  • Replacement Seals – reproduction seals are available from C. Millward Tel: 0121 – 745 – 2087.
  • Replace impellers – are available from C. Millward Tel: 0121 – 745 – 2087.
  • Replacement Thermostat Hosuing – castings may be available soon-  Contact C. Millward Tel: 0121 – 745 – 2087.
  • For those who feel unable to tackle this kind of work, contact C. Millward (BODA Member) OR E.P. Services (Water Pump Reconditioners), Tel: 01902 – 452914. Unit 1 Central Trading Estate, Cable Street, Wolverhampton WV2 2RJ.

The Ferodo Specification was 5/8″ TW – 7/16″ Thick – 32 degrees angle – 39 1/18″ IC – 41 7/8″OC

The Ferodo V155 was the original fan belt recommendation, but was not necessarily the only belt to fit. It seems to have been used on:- AC Ace, Acela and Greyhounds with Bristol engines from 1957 to 1964, and Bristol types 400, 401, 402, 403, 404, 405 and 406.

There may have been other makes of fan belts that also fitted reasonably well. For those searching for a belt, the V155 was also fitted to the following and the relevant clubs may be able to help with an alternative belt.

  • Aston Martin – DB3-S 1955
  • Austin – 14 Taxi 1946, Eight 8 h.p. 1939 – 1947, Big Seven 1937 – 1939, Commercial 6 cwt 8 h.p. K2VV s ton 1952 – 1954
  • Daimler – Ld10 10 h.p. 1939
  • Frazer Nash- 326 & 6 Cylinder 16 h.p., 2 Litre
  • Gardner- Engines LK
  • Jensen – Commercial – Jentug, 5 ton, 1947, Jentug Mark 1 1948 – 51
  • Morris – 6 from 5413 1950 – 1954
  • Skoda – 1101 1937 – 1948, 1102 1949 – 1951
  • Vauxhall – 6, 24.97 h.p. 1937 – 1940
  • Wolseley – Fifty-Four from engine 4447 1950 – 1953, Six-Eighty from engine 3554 1950 – 1955