The Triumph 2000/2500/2.5 Register Forum

I want to move my radiator cap to the casting on the front of the head.
Why? Its the highest point and seems a sensible place for it and would negate the fitting of a header tank. But why? Well I want to move the radiator forward to give more clearance in the front of the engine for electric fans and stuff.
I am sure I have seen a photo of this mod somewhere in the past but can’t find it now, perhaps the 1970’s rally cars?
Does any one have any experience/knowledge of this mod?

Hello Bernard,

I don't know of this modification but there is room in front of the radiator for an electric fan, what other stuff do you want to fit?

Alec

I have electric fan and an oil cooler fitted in front of the radiator, and changed the radiator cap to a sealed top like an MGB and fitted a Stag overflow bottle with the pressure cap on it. Works a treat.

I believe that the World Cup Rally 2.5PIs were modified along the lines described. Page 255 of Bill Price's book has a picture of the engine bay of what I think is the WCR test car (WRX 902H) with a filler cap on a modified thermostat housing and the filler port on the radiator blanked-off, but with the addition of a pressurised expansion tank (Dolomite type?) with its own pressure cap, also fed from the thermostat housing.

Jonathan

Jonathon is spot on but works cars also had a bonnet blister for clearance

Maybe you need a filler plug like a stag on the thermostat (weld a boss / thread on or use Ford Fiesta thermostat cover? )and a Stag remote overflow bottle?

WCR set-up as photographed on XJB 304H at Gaydon in 2010.


As Andy points out, the WCR cars do indeed have a small bonnet blister to clear the revised thermostat housing and filler cap, though I have been told that this was necessitated by the engines being mounted slightly higher than standard in order to increase clearance under the sumps.

Out of interest, the later versions of the front-wheel drive Triumphs (1300TC, 1500) also had a set-up not dissimilar to this, apparently to overcome airlock problems after re-filling due to the extra height of the engine relative to the radiator, brought about by the engine block sitting on top of the gearbox and final drive assembly on these cars. Don't think that you could easily swap the FWD thermostat housing onto a 2000/2.5 engine, however, though I might be wrong...

Hope this is of some help/interest.

Jonathan

Thanks for the photo Jonathan, knew I have seen it somewhere.
I intend to weld a fitting for the cap in to the existing casting. This will mean that the coolant fills the engine and head, which is probably why the setup was used on the WCR car.
My car is Australian build with the fan in front of the radiator, I have it working with a thermal switch in the top of the radiator as an emergence unit. I have also fitted an electric fan behind the radiator which is controlled by the EFI computer. So I don't have a cooling problem.
There is a clearance problem with the removal of the fan/steer belts and I have had to off set the fan to get it in. I am thinking along the lines of a small blower in the future so would need another pulley.
The supplementary is:- Apart from allowing clearance for the radiator cap is there another reason why the radiator has a space between it and the bulkhead?

Why not use the front fan only ?
I think it's big enough to do the job.
Tony.

Hello Bernard,

"The supplementary is:- Apart from allowing clearance for the radiator cap is there another reason why the radiator has a space between it and the bulkhead?"

I don't understand what clearance you are talking about, can you explain further or show a picture?

Alec