ddgonzal

Thanks for your reply.
I have a non-genuine termostat in at the moment.That is why I want to put in a genuine nissan termostat with the correct temp.I am going to throw a turn at the radiator shop when going home today.I am going to ask the guy for all possible solutions and then decide which one.I think I must go with a bigger radiator.First I will replace the termostat and see what happens.

The thing with a bigger radiator is that I don't want to cut any part of the body to make it fit.I just maybe want to drill new holes and then bolt it in.
Any suggestions?

Hi all.
Just a update on my previous mail.
I was just at the radiator shop.
The guy said my radiator is too small for the temp here in SA and contains to few of those mesh fins between the little pipes.
He showed me that when you look infront of the radiator you can see the engine on the other side.
He said that there is also too few pipes to circulate water through.
We have decided on a double core with more of those fins in between the little pipes.
I am changing to be safe to triple core not double core with more of those fins in between each of the pipes.
He also showed me that the new core will contain more of the small pipes that water circulates through.
I can put in a A14 utility radiator but then I will have to cut on my body that I do not want to do.
Will let you know how she goes after the radiator.
He said he had similar problems with a A12 in the past and that solved the problem.

L18_B110
If the faster circulating coolant sheds less heat due to spending less time in the tubes of the radiator, surely it would pick up less heat due to spending less time in the engine.
Yes, the engine produces more heat at the higher speeds, but the radiator sheds more heat due to the greater volume of air passing through it at speed.
Things that make you go Hmmm.
Chris

ddgonzal
I will dissagree with you on the "bigger means faster" theory in terms of speed of coolant flow through the radiator. If the total cross section of the tubes is greater than previously then there is a bigger diameter "pipe" [add the total of all the tubes] than before. If we assume that the VOLUME of coolant is fixed at a given engine speed, restricted by, oh, lets say, the thermostat, which should not be fully open under normal conditions, then this fixed volume will slow down in the same way as a river will slow down when it opens out, but speed up in the narrow parts. More speed is needed to shift a given volume through a small opening, & less speed through a larger one.
More tubes= lower coolant velocity.
Lower coolant velocity = more time to shed heat.
More tubes & fins = more surface area to shed heat from
Well, thats the way i see it.
Chris

dodgeman, you could be right. Would you agree that a bigger radiator would probably help this situation, but not because it slows down the flow?

ddgonzal
IF, & only IF, the heating up problem is directly attributed to the radiators inability to shed heat faster than the engine can make it, either because it is too small, or because it is blocking up, THEN, a replacement will help.
Remember that these little Datsuns that we all love were built to sell at the lowest end of the price range & the manufacturer did whatever was necessary to keep costs low. Radiators would have been supplied by the vendor who could meet specs, with the LOWEST tender price. It doesn't take Einstein to figure what that means.

Major car makers here offer towing packages as a factory option, & these often include a heavier duty rediator. This often takes the form of an extra row of tubes. This is also an admission that the stock radiator is only just adequate for normal driving. As i wrote previously, the more surface area that you can expose to the airflow, via more, or bigger tubes, as well as a higher fin per inch count, the more efficient a radiator becomes.
Desirably, this is achieved with a larger frontal area, exposing more fins to the coolest air, but when this is not an option, the next best thing is to make it thicker by adding one or more rows of tubes.

I wrote to 1200GXman, saying that, within reason, you can't have too much radiator, & you can't have too much battery. [but thats another story] Forget the Mack truck radiator in a 1200, a stock dimention, heavy duty one will be just the ticket for those that do not wish to cut any body panels in a pristine car.

I had a similar problem on my 1200 4 door and I tried all the obvious things like flushing the system, new thermostat even a new waterpump & new temp sender but it still kept getting too hot. So I came to the conclusion thet it was simply that the rad wasn't up to the job. Eventually i fitted a bigger rad from a late model A15 engine sunny (B310 model in the uk 210 in USA - circa 1982) and I have had no problems since. It was easy to fit required ony 2 holes drilling and a new top hose. Curiously my coupe has no problems at all!!! Eliminate all the other causes before you throw your money at a new rad though. Incorrect ignition timing and even a blown cylinder head gasket can sometimes cause overheating.
Mike

If you fit a wider radiator, you do not need to cut the sheetmetal. When I put the B210 radiator in, I just let it overlap a bit. Similar to this picture:



quite thin but works quite well

something you could also try is a 'tropical' thermostat.the stock thermostat opens at 82 degrees celcius.you can get thermostats that open at 71 degrees here in australia,cause i got one today.i seem to remember getting a thermostat that opened at 62 degrees once,but that was nismo part,& it was a long time ago,in a pay scale far,far away.so try changing the thermostat to one from the more equatorial areas of africa,it might help some.

Thermostat guidelines:

- colder = better performance
- hotter = lower emissions, better fuel economy. Many cars have 195 degree F thermos, which also requires a 14lb radiator cap
- 180 degree F = optimum for oil life
- 160 degree F = good to stop pinging engine, plus you can put a 7lb cap on your radiator to lessen the pressure

In years gone by, many parts houses carried a "summerstat" & a "winterstat" for popular cars, & many owners switched them twice a year to help heaters work better in winter, or to help the engine run cooler in summer. This can still be a good idea, & the cost is minimal. Just buy a fistfull of housing gaskets & keep things under control for years.