Ok I have finally pulled my finger out and have commenced an upgrade on the cooling system. I thought I would post my journey as there are a lot of posts on the forum regarding cooling or should I say over heating.

A bit of background... I have been having intermittent overheating issues for 6 months that had no rhyme or reason (so it seemed). Pull over and let it cool down then drive off without further overheating. The only thing I could put it down to was a marginal cooling system that barely coped.

My other motivator is future modifications (turbocharging) so I needed to upgrade the capacity as well.

I have already pulled out the old rad I will post pictures over the weekend.

After a considerable amount of research I have decided to have a custom 2 pass rad made. There is a company in Victoria Aus called Desert Coolers who are manufacturing the new unit. This will be a 2 pass system with 2 inlets and one outlet on the SAME side LHS of the vehicle. I should have the new rad early next week I will take some pics and post them up.

Specs of the rad are high capacity dual 26mm cores manufactured as per original except for the following mods:-
- RH inlet relocated to LH end tank for 2 pass
- Delete the banjo bolt setup and add expansion tank connection to LH end tank.

I know I have broken from what a lot of others are doing by going 2 pass instead of single pass. My reason is that a good 2 pass system is more efficient than a single. It will also be painted black to increase its emissivity.

cheers W

 

W - Are you doing the work yourself? If so, would love to see some pic's along the way.

I was surprised to hear you're going 2-pass. I hadn't heard that the 2-pass system is more efficient. I've just read about the merits of switching to single-pass if the radiator ever needed to be replaced. Curious to see how it works out for you. Good luck with your project.

 

Hi Dave,

Yeah doing all the work myself, except for making the new rad.

2 pass is way more efficient than single pass, hence why NASCAR and INDYCAR use 2 pass radiators, VW also use 2 pass in the GTI and over on the VW forums the guys upgrade to GTI rads experience greatly improved cooling.

The biggest problem with the Jag 2 pass is the bars leaks Jaguar put in every time they serviced the vehicle which gums up the rad. My water pump showed signs of this building up on the impeller.

I will take some pics on the weekend and post them up

Cheers WJ

 

Excellent! I (and probably others) appreciate when others share their maintenance lessons. Luckily both my old Jags have had no radiator / cooling system issues. But it's probably only a matter of time... Thanks, WJ.

 

I haven't posted pics up yet because my new radiator has not arrived hopefully Monday. I'll post pics as soon as I have the new rad.

I thought I would share an interesting finding - I was over at Jag Works the other day and Bruce had his XJS V12 twin turbo race car on the hoist. He was kind enough to move his other cars and drop the hoist so I could take a look. This was one of 3 cars Gary Walker built. HE was rebuilding the gear box for the second time I know of the torque of this monster must be tuff on the trans. BTW the box is a straight cut Jerico.

He was telling me he had a single pass high capacity radiator and the car would overheat after 1 lap of Bathurst. So he went back to a STOCK XJS radiator and no more overheating......... Who would have thought a 600 plus HP twin turbo with a stock rad would not overheat NOT ME thats for sure.

 

Finally received the Rad... Does not fit spoke to the guy earlier and he will arrange to have it collected and rectified WOW what service.

So no more updates but here are the pics it is much thicker core... I have been trying to upload the files and it just keeps timing out I'll try again later and down size the pics

cheers

 

Ok got the pics done.

The new rad is MUCH thicker than the old one hopefully it will keep the engine on the thermostats.

 

Cool. I'll be watching for updates to see how well it works!

 

Update - Its too wide so on its way back to Melbourne to be rectified. Oh well another couple of weeks.

The guy who made it has really good 1st class service he is organising to have it collected and shipped, nothing like good old fashion service.

 

Update - after some too and froing I decided to re-install the stock radiator after having it re-cored. I will tackle the install of the new alloy rad later as it will need to be modified locally to fit - it currently sits too far forward which prevents the install of the AC condenser and engine oil cooler. There is not enough room between the Rad and the bumper supports for the AC.

As I am moving house in a few weeks I needed to have the car operational to get it up the drive into the garage. I burnt a lot of time on the OH I'll just do that while I have it apart you know what its like - new plugs and leads, hoses, Stainless Xover and header tank, installed the larger front swaybar with new PU droplink bushes, fixed some leaks