The Lotus Grand Tourers

rbgosling wrote: ↑

Mon Mar 06, 2023 15:05

Thanks for sharing your experience Richard, a useful further contribution to the sum of knowledge on these things.

With mine it seems to be so far so good - I did find myself topping up the coolant after the first few outings, which had me worried, but now it seems to be holding OK so I guess it was just various pockets of trapped air working their way around to the tank after the coolant was all drained.

Thanks Richard - I read that thread a couple of days ago - and certainly looks as though it would work. I'm trying to stick to an original (recored/exchange) if i can at at the moment.

Well..... the radiator is leaking!!!

Not sure how quickly it started leaking, but I've been topping up the coolant more and more frequently over a number of months, it's now a weekly job, so a couple of weekends ago I finally found a moment to put some serious effort into finding the cause. And it's definitely the radiator, leaking where the core meets one of the end tanks.

I've tried contacting the seller, but had no response after a week. The winner_racing account is now entirely in Chinese, on the Hong Kong ebay website. However, a surprising number of new accounts have appeared (winner_racing_spares, winner_racing_sports, winner_cooling_super, winnerautoparts, Winner_Racing_Radiator, Winner_Racing_Manufacturer, winner_racing_usa, winnerautoparts) all selling the same radiator, same price, and a mixture of the same product photos, shipping direct from the UK in 2 days, so clearly they are connected, I'm giving them a shot.

There are also are a bunch of other accounts (no doubt linked to each other, but I'd guess separate from Winner) selling a radiator from the Czech republic for a few quid more.

I'll let you know how I get on.... I might mention how close-knit the Elite/Eclat/Excel community are, how we all know and communicate with each other, and I'd really like to be able to give a positive report to other owners about my customer service experience!

Lozza74 wrote: ↑

Mon Mar 06, 2023 14:34

In the early Excel the radiator is mounted with 2 threaded studs through the radiator duct at the top, and 2 stubs through the undertray. There is no lower beam.

My 1992 SE also has the two stubs through the undertray as you described Richard. No lower beam here either.

Sorry to hear about your trouble with the Chinese Radiator RB, I opted to get my original rad re-cored. All the best with chasing up customer service. The multiple accounts seem to indicate that they avoid all aftersales responsibility but as you say, things are close knit in all things Excel which is bound to have some sort of say in the matter.

Dwayne

Dwaynem884 wrote: ↑

Mon Oct 16, 2023 14:29

Lozza74 wrote: ↑

Mon Mar 06, 2023 14:34

In the early Excel the radiator is mounted with 2 threaded studs through the radiator duct at the top, and 2 stubs through the undertray. There is no lower beam.

My 1992 SE also has the two stubs through the undertray as you described Richard. No lower beam here either.

Dwayne

Maybe my lower beam was an addition by a previous owner then. It does look very home-made (even by '80s Lotus standards), and its heft does not follow the "add lightness" ethos.

That said, with the previous radiator mounting method there would be nothing to stop the radiator falling out, if the lower beam wasn't there, since the top was only held in place by pegs passing through rubber grommets, which could easily drop out if there were no other support. I wouldn't want to rely on the plastic undertray to hold the radiator in!

My 86 has two 10mm bolts into the top of the radiator duct but no metal beam just two more 10 mm through the undertray.

Bash

My Early Excel sounds to have been the same as Bash's - threaded studs top and bottom, so with the undertray out the radiator hangs from the top mountings in the top ducting.

Sorry to hear about the leak though Richard. Thats a pain. Im going to keep a close eye on mine now, but Ive not done many miles in it yet.

Richard

And it's definitely the radiator, leaking where the core meets one of the end tanks.

Exactly the same happened to my Winner rad after about one years use. In my situation the Winnerr rad was in a tad tight and it wasn't rubber mounted at the time.

My interpretation of the cause is that aluminium radiators expand and contract much more than the OE rad, so they shouldn't be rigidly mounted or their greater expansion be restricted by the rigid aperture walls.

Refitted the OE rad with DIY rubber mounts with no issues so far during past 5 or so years.

I've also heard some of the ally rads utilise aluminium studs that break easily. Although I have one on the shelf with steel inserts.

Lotus-e-Clan wrote: ↑

Mon Oct 16, 2023 18:48

And it's definitely the radiator, leaking where the core meets one of the end tanks.

Exactly the same happened to my Winner rad after about one years use. In my situation the Winnerr rad was in a tad tight and it wasn't rubber mounted at the time.

My interpretation of the cause is that aluminium radiators expand and contract much more than the OE rad, so they shouldn't be rigidly mounted or their greater expansion be restricted by the rigid aperture walls.

Refitted the OE rad with DIY rubber mounts with no issues so far during past 5 or so years.

By my reckoning the expansion should be only about 2 mm, so whatever the issue I don't think that's enough expansion to cause a problem, the fibreglass can flex enough to accommodate that even if it is a tight-ish fit.

Thermal expansion coefficient x temperature rise x radiator width
0.00002 x (110 - 10) x 1.0 = 0.002 m = 2.0 mm (approximately)

If the radiator is being squeezed it is worth checking the front body mounts. These can crack and if they do the width of the gap the radiator is mounted in will be slightly narrowed.

I imagine that body flexure, which can have an impact effect can take up small gaps and may lead to radiator joint fracture.
Perhaps with a new Chinese radiator it is worth reworking to provide a larger gap and reinforce support struts and have steel bolts.

Dave the cog

2mm would be significant in my case as from side to side it was an interference fit in the aperture! Enough to push the fins into the side tanks which had no space to move with the fins.