Cooling system question

[stefan1200]

Hi all,

thinking of altering the cooling system on my 1999 chim 500 a bit.

can anybody tell me the purpose of the swirl pot; is it necessary for the correct operation of the cooling system or is it also possible to replace it by a metal pipe/hose arrangement to connect the stat housing to the rad? Otter switch is in the rad, so that's no factor. One of the reasons i'd like to get rid of the swirl pot is that it must be transferring considerable heat from manifold to coolant.

Many thanks,
Stefan

[spend]

You need to have somewhere to separate gas & liquid, to prevent it collecting in the highest point (cylinder heads - which is not good). Look at the later PRVT arrangements in smaller Rovers & LR's which relocate the stat & allow flow when it is closed, but you will still need to have an expansion tank which is the high point of the system.

Dave

[stefan1200]

Dave,

thanks, makes sense. Think I should stick to the present outlay.

Stefan

[2 sMoKiN bArReLs]

Generally speaking, the cooling system on a well maintained Chimaera is perfectly adequate. Some mods made are potentially covering up the root cause of the problem.

[Cider Andy]

If you were to warm up the engine with the top off the swirl pot, you'd notice expansion of the coolant. If you increased engine revs you'd notice further expansion: on dropping the revs again, the coolant level in the swirl pot would then drop. If your car is fitted with a separate swirl pot and expansion tank, this effect forces air down the thin tube into the expansion tank under revs, drawing coolant back down the tube to replace it when the revs drop. The overall effect is to remove air from the main part of the cooling system to the expansion tank. If there is too much coolant in the expansion tank it tends to spit it out under revving (an effect you'll have read about in other threads on here) and the expansion tank will find its own level.

[stefan1200]

Am I right to assume that the main reason for the swirl pot being where it is has something to do with the rad being much lower positioned than the top of the engine? Thus ensuring that any air trapped in the system doesn't move to the upper parts of the engine but to the swirl pot where it's transferred to the expansion tank according to Andy's description?

I've been thinking of installing a new header tank above engine level but it seems to be difficult to find enough space for a tank big enough to accept the variations in volume of 12 ltr coolant. As the system now works as it should, maybe I'd rather leave it alone.

Many thanks,
Stefan

PS. Out for a looong ride tomorrow, sunshine, 22 deg! :-))))

[spend]

You can do anything you want, but ensuring there are no 'high cavities' where gas will get stuck is not so easy. IMHO the later RV8 stat in a bypass must improve flow and reduce frothing.

Dave