280i temparature

[Classic Chim]

mrzigazaga said:

Hi mate

I think the original V6 rad was 2.5 core and I had mine rebuilt to 3 core...however the onset of a supercharger meant big changes, Tim at ACT sorted me out a few years back with an alloy rad...


I then fitted an 18" turbo boost Kenlowe....Shame about the dodgy heads I bought...

What a lovely engine bay, made my day.

Hi Zig
I didn’t know you’d had a serious V6 too, respect.
I loved my 2.9 in the S still sounded like an EFI Granada but I liked that too as it showed it worked

I better not side track
Alloy rads are ok if they are designed for the car, I’ve seen a few in Chims that don’t fit or the pipes are at odd angles.
I got mine via Powers and its the correct dimensions and pipes exit correctly.
I seem to remember it was below £300 more like 260. Seems like I got a bargain but I shouldn’t tempt fate ! I spent heavily on other stuff so possibly influenced the price at the time.

[mrzigazaga]

Classic Chim said:

Hi Zig
I didn’t know you’d had a serious V6 too, respect.

Did have....

Thats another story......

[tvr-280i]

I'll try to get some hose temps for you but temps and wind chills are expected to be 5F tomorrow in Connecticut. I can say that the stock set up on a 280i is good enough to keep it mid dial in 95 degree summer runs. The AC is another story.

[mrzigazaga]

tvr-280i said:

I can say that the stock set up on a 280i is good enough to keep it mid dial in 95 degree summer runs..

Hi Richard

I think the bonnet design is a telling factor in this, after a conversation with Oliver Winterbottom it was confirmed by the man himself that the later 280i/early 350i bonnet design was the most efficient at helping to elevate under bonnet temps...its fair to say that he was bemused to hear that TVR then went ahead with a bonnet design with no vents whatsoever?....The ford cortina/granada rad struggled to keep those cars cool let alone a fibreglass bodied car!

Cheers

Ziga

[tvr-280i]

Temps taken at idle on a Connecticut day in the forties:
Upper hose- 164F
Lower hose- 135F
Taken about six inches fron metal pipes. Dash gauge reading fraction above midway.
I hope you get your car sorted so that you can enjoy it!
As an aside, many members of the Aston Martin club previously owned a TVR. I was going to sell mine but my daughters said" you can't sell that, Dad, you've had that forever!" (Since 1986). So I have both. On a nice day I open the door, look at both and say " is this a great country or what!"

[v8s4me]

So your rad is reducing the coolant temp by approx. 16°C which seems pretty healthy. Presumably this is with the car stationary and the fan(s) running? I'm guessing the temp drop will be greater than that once the car is moving and getting a good air-flow over the rad. It's all pointing to your rad Toby.

[440Interceptor]

Hmmm, it is a bit isn't it... can't afford it at the moment as the cars getting a full stainless exhaust system over the holidays, and I'm buying a set of factory alloys for another car for $2k tomorrow.

One question though, doesn't an alloy radiator plus a cast iron block equal electrolysis?

[adam quantrill]

With an alloy rad you will need an inhibitor in the coolant.

[v8s4me]

440Interceptor said:

...... and I'm buying a set of factory alloys for another car for $2k tomorrow.

....

Blimey! Are they gold plated?

Presumably they go with the frankincense air freshener and myrrh leather cream?

[440Interceptor]

v8s4me said:

Blimey! Are they gold plated?

Presumably they go with the frankincense air freshener and myrrh leather cream?

Haha, that's actually quite good for Quattroporte Sport GT 20' rims. The original owner helpfully opted for the standard 19"s so I'm putting things right, but I digress.

Adam, re electrolysis, I wasn't aware that corrosion inhibitor prevents it? My very imperfect understanding is that stray current can occur in coolant where unlike metals exist (aluminium rad and iron block) if earthing isn't up to scratch.

33C here today and the car was struggling to stay under 3/4 on the dial at speed or idle so I might need to bite the bullet and look into a custom rad.

.

[mrzigazaga]

Hi Toby

A copper core rad extended to a 3 core or whatever you can get in there and a 17-18" Kenlowe boost fan will be what you need...Also a rad cowling will help tremendously .

Ziga

[440Interceptor]

Thanks Zig, yes the guys I'm thinking of using made me a rad for my Jensen and that needed some serious cooling.. They recommended a SPAL brand fan when I spoke to them about the Tiv the other week.

I was looking at the car today and there's heaps of room for a thicker (upright) rad so I'm hoping a solution won't be too difficult.

I WILL have a cool wedge.

[mrzigazaga]

440Interceptor said:

I WILL have a cool wedge.

You already have a cool Wedge...You just need it cooler...

[440Interceptor]

Paid a visit to the radiator company today. They're pricing up a package of an aluminium rad with two wide cores (saw an example which looked 70-80mm thick) plus two 11 inch SPAL fans which move 3200cfm together...

Edit: Hmm. Looked up those fans and they draw 2 x 36 amps which might be a bridge too far for my 55A alternator..

Rad will use the existing uprights but will be moved further forward to accommodate the deeper fans. All to be made to fit existing hoses and fittings.

Edited by 440Interceptor on Friday 5th January 11:13

[v8s4me]

440Interceptor said:

.......... Looked up those fans and they draw 2 x 36 amps which might be a bridge too far for my 55A alternator..

That sounds a lot. Is that at start up or constant running? Start up current will be a lot more than the running current so either way you're going to have to think about how you fuse these and the relay set up.

You could have one fan coming on off the otter switch and the second one off an auxiliary switch. Alternatively, have two otter switches. One switches one fan on at normal maximum and the second one comes in at a higher temperature if the ambient means the single one fan can't quite cope. That would stop both fans coming on at once and whacking a large current through your relay. It would also help to maintain a more even coolant temperature. If you have two big fans coming on at the same time they will drop the coolant temperature quite quickly and then go off only for the temperature to rise again quite quickly to the switch-on temperature causing both fans will whack back on again. This cycle would repeat.

[440Interceptor]

Yeah, I agree with you, and those points have crossed my mind too. Specs on that fan say it draws up to 40A and needs a 120A alternator, so I think two of them is going to be overkill.

It's early days and I don't know what all of the options are yet, in terms of staggered switching etc, but at least there's plenty of room to accommodate a thicker rad.

Edited by 440Interceptor on Saturday 6th January 01:07

[v8s4me]

This is what I had in mind...



This isn't to scale as I don't have the measurements any more, and doesn't relate to available fan sizes, but you get the idea. I did think about a filler neck, as on the alloy rad above, but I didn't think there would be enough clearance under the bonnet. Reducing the height of the rad to allow space for a filler neck would be an option but this would reduce the capacity.

The local company who re-cored my 'S' rad quoted me £220 to make this in copper. This seemed pretty reasonable considering that's what the re-core on the 'S' rad was.

The fans would have been the slim type and mounted on a separate bracket to avoid stressing the fins in the core. This is the bracket I made for the fans on the 'S' ...





The shape of the 'S' rad meant having two equal sized fans. There is a completely separate circuit for each fan. One works off the otter switch and the other one off a switch under the dash. From memory each fan draws about 7 amps running but on start up that more than doubles.

Anyway, just an idea to chuck into the debate.

Edited by v8s4me on Saturday 6th January 14:23

[440Interceptor]

Thanks for posting these. Yes there are a lot of options re fan sizes, outputs, different size or not etc, but I think I'd like them both to work without the need for a manual switch.

I'm seeing my auto electrician tomorrow so I'll be asking about current draw etc.

[v8s4me]

440Interceptor said:

....... but I think I'd like them both to work without the need for a manual switch.....

That's easy enough and give's you at least four options:-

1. Run one large as possible fan off one otter switch.
2. Run two equal size fans off one otter switch.
3. Run two fans off two otter switches with the same tempreature
4. As 3. but one operating at a slightly higher temperature.

Where you want to try and end up, (and I know this is ideal world) is managing the coolant temperature so it might be mapped as a sine graph with wide spacing between the peeks and troughs as opposed to a spiky graph like say a heart beat.

There maybe reasons why the engine will run better with a steady temperature but I don't pretend to understand those. Where I'm coming from here is avoiding a set up which has the fan(s) constantly flicking on and off and shortening the life of the relay.

I broke down on a Dutch motorway in torrential rain because of a burnt out fan relay so that's why I now have the two fans running on separate circuits. I got home by jury rigging one fan permanently on when the engine was running. Despite being stuck in a huge tail back on the M25 (where else!) on the way home the temperature stayed out f the red. This told me that I really only needed one fan to maintain a steady temperature and the other one was only needed for back up. It was as a result of this mod that I also accidentally discovered the bonus of the more even cooling cycle. Now the single fan running off the otter switch comes on less frequently than both fans did when they were connected to the same otter switch. This improved further when I switched from an alloy rad back to an OE copper one which, in my experience on the 'S', is more efficient than the very expensive alloy one.

Edited by v8s4me on Sunday 7th January 10:40

[440Interceptor]

Saw my auto electrician yesterday and he made some interesting points.

He doesn't recommend having two fans staggered because the one that comes on first pulls hot engine bay air through the one that's off.

Modern dual fans have a speed control so they come on progressively as the heat rises. that reduces sudden current fluctuations and also keeps the temperature in a narrower band. After market controllers are available so that's something else to explore..