How much coolant capacity does a Griff 500 need?
Discussion
Assume there is a large, fairly efficient radiator, the car has reasonable power and there is no problem with locating otter switches etc.
I was looking at my Impreza cooling system today, and thinking that it doesn't appear to have quite the volume of the Griff system (they are similar power cars), and it looks to be considerably better thought out (eg the engine has an internal bypass for when the stat is closed. etc...)
I was therefore wondering what could possibly go wrong if the standard swirl pot and header tank were replaced with a somewhat smaller header tank arranged to be at a suitable height? Does a Griff really need as much thermal storage capacity as it has? There may be the chance of coming up with a better packaged cooling system... Going to bed now in case I have any more daft ideas
I was looking at my Impreza cooling system today, and thinking that it doesn't appear to have quite the volume of the Griff system (they are similar power cars), and it looks to be considerably better thought out (eg the engine has an internal bypass for when the stat is closed. etc...)
I was therefore wondering what could possibly go wrong if the standard swirl pot and header tank were replaced with a somewhat smaller header tank arranged to be at a suitable height? Does a Griff really need as much thermal storage capacity as it has? There may be the chance of coming up with a better packaged cooling system... Going to bed now in case I have any more daft ideas
Isn't part of the problem that the fibreglass body is not as efficient as a metal body at radiating heat?
In the engine bay you get a higher heat build up with a TVR than you do in a metal bodied car and the cooling system has to work harder. I've no doubt it could probably be made more efficient though.
In the engine bay you get a higher heat build up with a TVR than you do in a metal bodied car and the cooling system has to work harder. I've no doubt it could probably be made more efficient though.
I should add that the car is already "slightly modified". Here's what the engine bay looks like - it's a crowded mess at the moment, and needs a bit of tidying up. (But note the lack of precats)
Sorry about the quality of the picture, it was a bit too dark.
It doesn't suffer from cooling problems and has not done so for many years since I solved the overcooling problem by fitting a hotter thermostat.
If I can redesign the engine bay to not have anything immediately behind the radiator then it makes the intake design easier and gives options for ducting the air exiting the radiator to somewhere more useful.
Sorry about the quality of the picture, it was a bit too dark.
It doesn't suffer from cooling problems and has not done so for many years since I solved the overcooling problem by fitting a hotter thermostat.
If I can redesign the engine bay to not have anything immediately behind the radiator then it makes the intake design easier and gives options for ducting the air exiting the radiator to somewhere more useful.
Colin RedGriff said:
Isn't part of the problem that the fibreglass body is not as efficient as a metal body at radiating heat?
In the engine bay you get a higher heat build up with a TVR than you do in a metal bodied car and the cooling system has to work harder. I've no doubt it could probably be made more efficient though.
YES Colin, that's true mate...In the engine bay you get a higher heat build up with a TVR than you do in a metal bodied car and the cooling system has to work harder. I've no doubt it could probably be made more efficient though.
dnb said:
I should add that the car is already "slightly modified". Here's what the engine bay looks like - it's a crowded mess at the moment, and needs a bit of tidying up. (But note the lack of precats)
Sorry about the quality of the picture, it was a bit too dark.
It doesn't suffer from cooling problems and has not done so for many years since I solved the overcooling problem by fitting a hotter thermostat.
If I can redesign the engine bay to not have anything immediately behind the radiator then it makes the intake design easier and gives options for ducting the air exiting the radiator to somewhere more useful.
Interesting to see your engine bay Potter !! Sorry about the quality of the picture, it was a bit too dark.
It doesn't suffer from cooling problems and has not done so for many years since I solved the overcooling problem by fitting a hotter thermostat.
If I can redesign the engine bay to not have anything immediately behind the radiator then it makes the intake design easier and gives options for ducting the air exiting the radiator to somewhere more useful.
I have to say this is a subject that interests me also
Good to see you have piped the big filters from over the top of the manifolds to the front of the car Dave.
Are you running twin wide band and narrow band sensors Dave ?
Good point there Rob. I suspect the Impreza is getting on for 20% more efficient than the Griff in general use. However, the volume of water contained in a system, all other things being equal, should not add to the steady state performance of the system. It might, however, be useful for dealing with transients but other than that it just adds to the warmup time.
The following shows the warmup curve of my TVR and Impreza on the same axes. Note how the temperature drops on the TVR chart when the stat opens and a whole swirl pots worth of coolant is allowed in the engine. I've never seen a temperature related problem with the TVR in its current configuration other than the slightly annoying extended warmup issue. Hence why I thought removing a litre or so of coolant volume, plus a slight reorganisation might be a good thing.
The following shows the warmup curve of my TVR and Impreza on the same axes. Note how the temperature drops on the TVR chart when the stat opens and a whole swirl pots worth of coolant is allowed in the engine. I've never seen a temperature related problem with the TVR in its current configuration other than the slightly annoying extended warmup issue. Hence why I thought removing a litre or so of coolant volume, plus a slight reorganisation might be a good thing.
What i was kinda trying to say is and i know your no muppet so dont take it the wrong way! you are basically trying to heat 2 x 4 cylinder engines, the heat build up in an engine is 90% from the cylinders the more you have the more heat you need to control etc..., on the warm up front (stat) you ought to drill a couple of 5mm holes around the stat, this allow a small amount of hot water to flow through the rad, to try and equalise temps, yes it sucks when you have a motor running at 82 deg then it dumps stone cold water in from the rad!
Ditch the stat in the inlet manifold & implement a proper flowed bypass ala cerbera. Top hose to swirl pot, to stat+bypass, stat to rad and bypass teed into return hose (swan neck). Tap the top of the water pump for a hose tail and get rid of the silly long rad hose over the belts + exhaust.. at the same time 
Gassing Station | Griffith | Top of Page | What's New | My Stuff