Cooling system expansion tank

[john12]

Im thinking of fittind an expansion tank to the cooling system of my Roadster fitted with a Pinto engine and Viva radiator. can anyone give me some advice on which is the best tank to fit as I do not have a lot of room. Ive noticed some cars have 2 pipes to the expansion tank whist others just take the radiator spill pipe, can anyone explain the pros and cons of the different systems ?


John Brice

[cameronfurnival]

Re: Cooling system expansion tank

CBS Catalogue has a good basic introduction on cooling systems on page 251...heres a screen grab. coling.jpg

[stevejgreen]

Re: Cooling system expansion tank

CBS provides a pretty good description of the two systems. Obviously a non pressurised expansion tank is far simpler to install as it only uses one pipe and can be located at any height, above or below, relative to the top of the radiator.

If you are losing coolant, is it caused by overheating? Has your old Viva/Chevette radiator been upgraded with an additional core etc. since it was originally designed to cope with an 1100/1300 engine. http://kvisit.com/S1cb2AQ describes the possible solutions.

The top chamber of a Viva radiator is quite large compared to modern cars. I suspect that it has sufficient capacity, to accomodate the exansion of the cooling water, during normal operating temperatures found in a 1300 Viva, or for a B series, once the radiator has been upgraded.

Something to consider is the pressure of the radiator cap, normally 15 lbs on a Marina/Viva. Old unmodified radiators may be less able to contain such a pressure.

[andy4]

Re: Cooling system expansion tank

I used a tank from a late MGB - you can get them on ebay but prices vary as lots of people are after them - hold out for a solid but tatty one that needs painting and you can get a cheap buy. Two main choices when installing - put a pressurised cap on the radiator and non pressurised one on the tank or the other way round. I think I ended up with a dummy cap on the radiator and pressurised one on the tank, but easy to experiment and find what works best for you.

[chris_cussen]

Re: Cooling system expansion tank

Its best to have the venting cap higher than the non-venting cap, otherwise you will loose water.

[stevejgreen]

Re: Cooling system expansion tank

I used a tank from a late MGB - you can get them on ebay but prices vary as lots of people are after them - hold out for a solid but tatty one that needs painting and you can get a cheap buy. Two main choices when installing - put a pressurised cap on the radiator and non pressurised one on the tank or the other way round. I think I ended up with a dummy cap on the radiator and pressurised one on the tank, but easy to experiment and find what works best for you.

A good idea, choose a post '77 MGB as the radiator caps were 13psi. Earlier Mk1 MGB were 7psi and MK2's were 10psi, their tanks may be more susceptible to over pressurisation and leaking if fitted with a 13psi cap.

[john12]

Re: Cooling system expansion tank

Thanks to everyone , your advice has been most helpful, i have just ordered an expansion tank from CBS

John Brice

[cdow]

Re: Cooling system expansion tank

Although the index says page 251 it's actually on page 268 - very handy once I found it! - cheers.

[cdow]

Re: Cooling system expansion tank

I just noticed looking at CBS for a tank myself, that CBS are bloody expensive - 50-70% more than the likes of Merlin, Rally Design etc.