X-Flow cooling upgrade

[Bullman]

Is it possible to change the cooling system on a supersprint to a modern sealed system.What parts are required? Plumbing ,how do you go about it? Anyone done it ? Does it make a difference to cooling.How do you fill it up without getting an air lock ? I took my supersprint for a blast last w/e covering some 34 miles, ok the weather was warm ,it initially ran at 80 degrees then climed steadily to 95 degrees.The radiator fan switch came on at approx 85 degrees.This caused me concern enough for me to pull over to let the engine cool .Has anyone got any suggestions.

 

Bullman

[c7kjt]

I had similar worries with my old radiator on my 1700 x/flow. I switched to an alloy radiator with improved fan assembly and new header tank (to minimise airlock worries). My temperatures often got hotter than those you mention, esp. on my return from Le Mans last year. Much improved with new assembly, normally runs between 80-85, though can still creep up towards 100 if sat in traffic for a while.

 

Take a look a the modifications page on my website here.

 

 

Kevin Thomas

kevin.thomas@bigfoot.com

www.7gallery.co.uk

 

[Roger King]

It is easy to convert a Crossflow car to a sealed header tank system. the bits are not even very expensive.

 

Many years ago when Caterham were running a race series for Crossflow cars, we suffered several head gasket failures. The next year we developed a sealed cooling system and we had no failures at all. We will not build a race engine for a customer who will not fit this type of system.

 

A common failure at track days is overheating after lunch. What happens is that the driver has a good morning, but doesn't check the water level after the engine has cooled for an hour; what has happened is that the water has expanded as it warms up and has been expelled into the expansion bottle (in theory this is pulled back into the system as it cools, but it never works). He then goes out after lunch with an airlock in the cooling system and cooks it. This cannot happen with a sealed system because water is retained within the system as it expands with temperature.

[tbhall777]

Bullman

 

You can run any water cooled engine as a sealed system, expansion tank etc.

If you need to know how just open the bonnet of any Mk2 fiesta, which run

the Valencia (forgive spelling) crossflow 950cc / 1100cc; a poor mans 3

bearing crank, naff head version of the Xflow (emmissions / economy etc).

They run a sealed system with expansion tank. These were about the last UK

fords to use the crossflow. Even a Mk1 post 83 fiesta runs a sealed system.

No tell a lie, early KA's use the Valencia Xflow and also MK3 fiestas in

950cc / 1100cc.

Wierd, you buy a brand new radically shaped / modern looking vehicle (KA), that

after a few K miles, rattles like a bucket of bolts (must adjust those tappets).

Ford have been very slack in producing an all alloy, multi valved, fuel injected

small capacity engine for the likes of the KA and fiesta. They need to learn a

lesson from the likes of Nissan etc on the art of the small car engine.

However the new 2 litre Duratec all alloy engine, although heavier than a Kseries

has immense tunning potential and in a few years if that, R500's will be relegated.

Caterham will almost certainly use this engine, because it has the potential to

produce well over 300 BHP, normally aspirated. Also the Honda Vtech series are

awesome, but a tad heavy. You can buy a brand new V6 duratec (not to be used in a 7)

from ford for 2.3K and approx 1.5k from discount suppliers (Brand new). So one would

assume the 2 litre 4 pot duratec would be somewhat cheaper.

 

Errrrr sorry,I have just come back from the pub (leaving doo for 2 guys at work),

what the hell this has to do with your original question is unknown to me.

 

Regards:- Terry Hall.

[Westfield]

I have the same problem as Roger describes. After a good run the water expands into the header tank and remains there until I take the cap off the thermostat housing. It then drains back into the engine to the correct level. I though I had a sealed system but now I am not sure. How do I tell?

 

Can anyone send me a picture of a car with a sealed system on so I can compare it with my set-up.

 

My car is a 1990 W*******d with 1700 cc, 135BHP Xflow by the way.

 

Thanks

 

 

Tony

 

[Roger King]

Tony,

 

A header tank system will generally have the water filler cap on the header tank itself. This will take the form of a screw on cap. There will probably be no other way to put water into the system.

 

The header tank should be mounted higher than the engine, will be sealed against atmospheric pressure and will not have any overspill pipes coming out of it into a catch tank.

 

A non header tank system will generally have the filler cap on the thermostat housing or radiator. This cap will typically be a bayonet fitting and there will be a pipe from the thermostat housing leading to a catch tank that is not sealed against atmoshphere.

 

I have e-mailed you a schematic diagram of a header tank system.

[Satya]

Hello everyone,

I have a 1700 x'flow in a 1990 Caterham S7.I have the same problems with the coolant overflow tank.Could someone help me with the following questions;

1.Why does the present system not suck the water back in from the overflow bottle?

I checked my "radiator" cap at top of the filler neck, and it has both a way to release pressure and a vacuum valve as well.So ,in theory again ,there appears to be a mechanism already in place for the coolant to be drawn back into the radiator and engine.

Also, I checked Caterhams set up with the sealed system of a 1990 Mazda Miata and a 2000 Honda Accord coupe.Both the Mazda and the Honda have a very similar system as far as the coolant overflow bottle and the radiator cap goes. Additionally,the coolant overflow bottles in both the Mazda and Honda did not appear to be all that well sealed from the atmosphere.Both the Honda and Mazda have a tube going in from the top of the coolant bottle to the bottom of the bottle.

 

2.Does any of the Caterham Specialists sell a kit that would convert the present system on the x'flow Caterhams to a sealed system?If so, where can I buy one?

 

3.Is it necessary to have a header tank to make a sealed coolant system work on a Caterham x'flow?

How does Mazda and Honda do without a header tank?

 

Sorry about all the silly and dumb questions.Any and all information on this topic would be greatly appreciated.

Thanks.

Regards,

Satya Widyaratne

Portland, Oregon, USA

1967 Lotus Super 7 1500 Cosworth

1990 Caterham De Dion X'flow

 

3.

 

Satya Widyaratne

[TravellinMan]

I got a complete K-series header tank kit from James Whiting a couple of years ago. Brilliant. Cured the problem.

 

Travellin' Man

Tony Boyd

97,000 miles in 6 years!