Nissens Radiators?

[amarshall]

Has anyone fitted one of these to their car?

Models 69209 and 68729 are listed on eBay - but the online spec. sheets don't mention Lotus applications.

[fueltheburn]

Are the dimensions correct.
Most eBay sellers seem to just list "fits Lotus Excel" even if it has no right being written.
For example - "standard equipment Bosch fuel injection pump that fits Lotus excel"

[amarshall]

That's the thing - they get the model changeover year right in the descriptions, but I don't actually know the dimensions of the original to check and, even though mine is leaking, I can't afford to take it out to check because the car's in use so often.

However - reports elsewhere suggest that they develop problems, in normal applications, after about 3 years because of the plastic tanks. Given the radiator's propensity to twist and spring a leak, I suspect they might only manage 6 months in my car before dumping coolant in the station car park.

[fueltheburn]

Treat yourself to an aluminium Chinese one for Christmas.
I have bought other aluminium items from them for French based rocketry years ago and the quality of the welds was very good.
Pretty sure Peter was running one of these alongside his EWP setup.

[amarshall]

Treat yourself to an aluminium Chinese one for Christmas.
I have bought other aluminium items from them for French based rocketry years ago and the quality of the welds was very good.
Pretty sure Peter was running one of these alongside his EWP setup.

Pretty much exactly what I've just done - except I've gone down the cannibalisation route and bought from a breaker. Tam's old rad should be with me this weekend. It seems to have survived the crash.

[DavidOliver]

Is it correct that early Excel cars had metal only radiators, no plastic? My 85 model was recored locally here in Malaga.
We may have a rush from S.E. owners to buy up these earlier radiators.

Dave the cog.

[rs blu]

Pretty much exactly what I've just done - except I've gone down the cannibalisation route and bought from a breaker. Tam's old rad should be with me this weekend. It seems to have survived the crash.

check well before mounting it on your Excel,
my 1988 MY excel had a copper and brass 3 row core original radiator, without plastic.When I bought the car I removed the radiator to wash and check it (it did not leak) Before putting it back on the car I had put it under pressure, everything seemed ok.
Unfortunately after a few months it lost water near a side cover
I took it away again .... and it has been rebuilt by a specialized company.They kept the original covers and put a new radiating part like the original 3 row core. I spent about 300 € but it works great and it's like the original.
why buy an aluminum radiator?
it is lighter than the original radiator but the brass and copper dissipates heat better

[fueltheburn]

Mixing of metals within a fluid system causes electrolytic corrosion as you are effectively creating an electro plating process - 2 dissimilar metals as the cathode and anode plus the solution in the middle(coolant). During electroplating one metal sacrifices its molecules to plate the other, hence corrodes. The original radiators are brass only with no copper as copper reacts very aggressively when there is aluminium present in the system.
The alumnium head would become severely pitted and the first you would notice it is when you change the coolant. You would see dark almost black sediment in the coolant.
The next thing you would notice is the head failing to seal correctly due to pitting caused by corrosion. The 912 doesnt readily suffer this due to having brass with aluminium components.

Brass is less of a conductor than copper or aluminium but also less reactive as a result.

Brass is also easy to braze and repair.

At the time it would likely be a well informed choice but with advances in metallurgy and cost of production plus the weight saving.... Aluminium is the smart choice.

[rs blu]

I had always believed that the tubes inside the radiator were made of brass and the cooling grid was made of copper

[Lotus-e-Clan]

I'm convinced that vibration/torsion was the cause of most of the failures I've had. Two recores plus a new Aluminium rad ended-up with premature leaks not caused by corrosion nor stone damage -as my leaks occurred at the side tank joints with the core.

I also believe that speed bump cushions exacerbate the process. Despite the inherent stiffness of true MONOCOQUE GRP/composite body shells, the Excel composite shell is a component of the resistive car structure in partnership with the back-bone chassis -it isn't a true monocoque. Also think about why the need for the service recall to re-enforce the anti roll bar mounts -the loads through the suspension have concentration points into the chassis and shell and the shell in the region of the radiator void isn't massively stiff....even if the wooden crash structures aren't rotten

The Clan, like the original Elite, is more of a true GRP/composite monocoque - very stiff in torsion -suspension loads are dissipated by more of the whole composite structure than the Excel.

Bottom line is - best carefully mount the radiator flexibly with sufficient well-damped clearances to prevent transmission of localised torsional loads at the 'nose cone/radiator void ' to avoid leaks within the side tanks.

This is additional to engine vibration (especially if engine mounts are weak) which goes into the radiator via the top and bottom hoses - all the more reason to mount the radiator flexibly.

Aluminium rads expand/grow more than brass rads. If you mount an alum rad solidly into the nose cone with no room to expand horizontally - it will leak. I'd want at about 1cm clearance side to side if I were to fit another alum rad....a couple of millimetres is not enough ...and I had less than that when i fitted the Chinese rad ...it was a very tight fit!

[NickC]

That's the thing - they get the model changeover year right in the descriptions, but I don't actually know the dimensions of the original to check and, even though mine is leaking, I can't afford to take it out to check because the car's in use so often.

However - reports elsewhere suggest that they develop problems, in normal applications, after about 3 years because of the plastic tanks. Given the radiator's propensity to twist and spring a leak, I suspect they might only manage 6 months in my car before dumping coolant in the station car park.

What measurements do you want? Mine (87 SA) is out the car at the moment so is easy to measure.

[barker_001]

I'm convinced that vibration/torsion was the cause of most of the failures I've had. Two recores plus a new Aluminium rad ended-up with premature leaks not caused by corrosion nor stone damage -as my leaks occurred at the side tank joints with the core.

I had exactly the same failures as Peter - repeatedly. Always on the bottom row of the core, where it joins the side tanks. In fact at one point I was changing / recording rads more often than I was changing the oil!

As documented elsewhere I did not have a good experience with the Chinese rads, so after that I had my 3 core brass rad recored again. I mentioned the problems I'd had to the guy in Fastrads, Abercarn. Their main trade is recoring much larger lorry radiators. He said that vibration / flexing normally causes the corners of the rad to fail first - which seemed to be the case. His solution was to crimp and braze up the bottom row, so that it doesn't carry any coolant, but still acts as a structural member. So a marginal reduction in cooling flow, but it doesn't seem to have any noticeable effect. 3 years later it's still watertight, and the longest lasting recore I've had (famous last words... ).