In my ongoing efforts to get my TC (Elan +2) to run cooler I performed a pressure test on the cooling system. I needed to occasionally fill the coolant recovery bottle and was wondering where the coolant went as I did not see any puddles.
I did discover some of the coolant hose connections were loose and would pass a drop or two. Unusual as they had been properly torqued.
We also saw a small amount of coolant accumulating on the front lip at the block/oil pan. It appears to be originating from under the water pump pulley.
I realize the task ahead and am a bit put off as the engine has only around 1000 miles since complete overhaul at time of restoration. But it has been at least 6 years or more from rebuild.
I am planning on using the Bean conversion but I would like some comments on its installation and reliability. Is there any other area under the front cover that can leak?
Would a small leak as described cause the car to run hot but not overheat?
We had a long thread on this not very long ago, search for it.
But to summarize.
There is a drain hole in the water pump boss. It is there to drain out any water that leaks past the carbon sealing disk, before it can get to the actual ball/roller bearing of the water pump and rust it.
A small amount of loss through the drain hole is common after an engine has been idle, but you MUST keep checking that you are not losing a significant amount of coolant. It may correct itself after a week or so or say 100 miles. If not you may need to go through the torture of fitting a new pump unit.
However if you ARE losing coolant it is very serious, by the time you notice that the water temp gauge is rocketing upwards it may be too late, you may have been running with little or no coolant in the head over the combustion chambers and (as I have found to my cost) this can cause the head to crack.
Mine had a small leak from the pump which eventually fixed it’s self, when the level first dropped I did notice the temperature was a little warmer (perhaps 1/8 inch further up the gauge). After this I now check it before each journey and it has been fine, but it never seemed to lose any coolant while driving anyway.
After you have been on a run has the coolant level dropped? if not then I don’t think the water pump leak has anything to do with your overheating. My first sugestion would be the radiator especialy if it is the narrow type, they are marginal to start with, and a scale build up will soon start to cause problems. (also if you have just re-built it check the electric fan is going the right way round)
The radiator is of the narrow type but is a new alloy replacement. The fan works well but the rad fins are so tight little air gets through. At least that is my appraisal.
My gauge (accuracy unknown!) reads 90 when moving and two or three needle widths above when running hot.
I was concerned with the leak as when I shut down the recovery bottle is higher than when cold but once cooled sufficiently it was returning to a lower level. Eventually losing about half of the bottle volume. I fill the bottle to half height to leave room for expansion. So it would eventually be near empty.
My thought was that if there was a leak in the water pump seal could it be hindering cooling system pressurizing? Maybe the pump is not functioning up to standard.
It appears that I should replace the water pump but I have heard that the “cassette” type replacements with the machined front plate which accepts a new, removable pump, also tend to leak past their O ring seals. Has anyone installed a dave bean cassette type pump? Problems?
I too had a densely-cored rad to which I had fitted new fans. I was disappointed to find that cooling was very marginal, with an overheating rad on one occasion.
I could feel some air being pushed through the rad, but it didn’t seem much.
As per the fan instructions, I swopped over the wiring so that the fan ran in the opposite direction. It didn’t seem to make much difference.
So I removed one fan from the car and connected it across a spare battery and noted the air pressure on both sides of the fan when “blowing” or “pushing”. I then unbolted the blade assembly and turned the fan blade through 180 degrees. When I tested it again, the difference was immense.
IIRC Rohan Hodges uses the Bean type design in his race engines.
The “O” ring set-up on the Dave Bean cassette is no different to the standard “O” ring arrangement. Any leaks past these ring seals will only be seen in the oil sump.
If you don’t like the Bean design, the alternative (and maybe considered to be better), is the Burton design which has an “O” ring clamped between the plate and cover.
Sealing of a cassette unit style water pump is similar to the orginal pump and should not give any problems if assembled correctly.
I have run 2 locally made units made by modification of orginal front covers in both my road plus 2 and race engines for many years without problems. Modification of an original front cover to take a cassette unit requires a good quality cover with little corrossion otherwsie you run out of metal when you machine it for the cassette unit mounting and rebuilding it with welding is expensive to do.
The only problems I have been aware of with the current new cassette units being made by the likes of Dave Bean, Burtons and the Elan factory has been casting quality issues with porosity in the castings and generally these guys are pretty good at replacing a unit if you have this problem but its still a hassle to strip it off an assembled engine. I personally would pressure test a new cassette front cover before assembling it onto an engine to make sure it was OK.
I’ve just completed a cassette pump arrangement by modifying the plate and cover as per the pictures posted by Rohan in a previous thread on this subject.
I have recently seen the Burton parts and have the idea of replicating the design principle as it appears to me to have some merit over what I have done to date. The only downside is that the plate as well as the cover will need to be welded-up to create an adequate seal face.
I assume when you say you tuned the fan 180 degrees you mean you flipped the fan blades over.
I dont know if my fan can be flipped. I will look. My experience sounds like yours with little difference in flow when changing polarity.
I have attached a photo of the fan installed on rad. I will take a closer look and see if the fan flip can be accomplished. It seems to me that reversing fan direction would be same as flipping the blades.
Reversing the polarity without flipping the fan only gives half the story.
The fan blades are cupped and formed in 3 dimensions.
The fan surround is also shaped.
You can’t take potential advantage of the fan surround unless you flip the fan blade over OR
mount the complete blade and motor unit on the other side of the surround.
It’s easy enough to do a series of dry tests off the car with a spare battery, and it soon
becomes clear which is the optimal setup.
