tvr s - slow to warm

[Top Gear TVR]

OK - so since my new aluminium radiator, stainless pipes, silicon pipes, thermostat andnow water pump. Why does my S2 take too long to warm up? It used to manage it in about 3 miles, now about 10!

Strangely, normal running temperature is about 5 degrees higher than it used to be once its got there. Its stable.

Could it be that the new thermostat stats very small bypass hole is restricting flow so much that the warm water is not getting to the guage sensor as quick? does this mean i may have trapped v.hot water in the block and i ought to get a bigger bypass hole, cos its not getting to the stat as fast either?

i recognise this is contrary to the logic that a bypass hole will increase cooling, i get that. but my symptoms are that its too slow to warm, wastes fuel and risks thick oil seal failure for longer than it should.

this is all buncom when i read it - but why does it take so long?

[v8s4me]

Slower to warm up but runs at slightly higher temperature? I noticed that after fitting an alloy rad to my V8S. Decided not to worry about it

[Eelblady]

slow warm up is a design 'feature', check out this link that was suggested to me when I raised a similar question a few months back

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

I addressed the issue with a restrictor in the pipe as opposed to re-routing it - works for me but at your own risk obviously.

[Griffinr]

Its slower to warm up because you now have a clean and efficient cooling system so the hot water from the bypass hose that passes through the swirl pot and then to the radiator is getting cooled more efficiently. This is a 16mm bore hose and passes a fair amount of water bypassing the thermostat. This is in my opinion a TVR design error and I have re plumbed the bypass hose to the bottom hose which gives fast warm up and steady mid position gauge in all conditions.
Running slightly hotter is probably down to the new stat.

Rob.

[Top Gear TVR]

OK - this looks like an interesting solution. I'm off on the euro tour this week and will take a view based on my temperatures vs others on the trip. I think there is something in this though, the bypass hose is definately busy with a lot of water to the swirl pot.

The idea of 10 mile warm ups seems very wrong and cannot stay!

[Griffinr]

Top Gear TVR said:

The idea of 10 mile warm ups seems very wrong and cannot stay!

Just for ref, mine is up to normal in 2-3 miles and stays there, gets hotter in slow traffic but the fan cuts in just before the white line under the red. Its never been in the red since I moved the bypass. It basically just works properly now.

Rob.

[Top Gear TVR]

hmmm- just been out for a 1 hour run and its not getting to temp until in traffic, then the stat and fan are doing their stuff.

any ideas for a quick fix, i dont want to drive to belgium over-fuelling......

ideas;

1. restrict air flow to rad at grill or rad itself
2. restrict water flow through bypass hose by inserting a small diameter pipe or similar

what do you think?

[v8s4me]

What’s the ambient temperature? If it’s anything like round here it will take time to warm up, especially with an efficient new alloy rad. What are you comparing with? If it’s your old rad and stat, how do you know you weren’t running too warm before. Do you know your temp gauge is accurate? Your idea of doing a direct comparison with some other V6’s later in the week is probably the best test you can do. Relax! Only another 48 hours and we’ll be there.

[Top Gear TVR]

ok, i maybe am being a bit pedantic, but having spent £900 on stainless and silicon hoses, pump, stat and radiator I feel the need for perfection!

I am sure the gauge is right i have tried a spare too and the otter switch kicks in at 92 / 94 when the gauge shows about that.

It behaves perfectely if driving in slow traffic or idling - but

1. if i start up and set off straight off to the dual carraigeway it never warms up beyond 65/70
2. even when idled to warm up fully (fan been on) if then i go at speed the flow through the bypass and rad is enough to shut the stat and see the temp gradually fall at 70mph, it then settles out about 65-70 on the gauge, which cant be good.

i am tempted to close part of the bonnet grill off so high speed in cool weather is ok. plus its easily removable if its no good. Its a gaffa tape moment!

these high performance rads are probably, well a bit too high performance!

I understand griffr has undertaken a mod which appears sensible to me knowing the granada set up; moving the bypass hose from the swirl pot to the radiator bottom hose (pump inlet)- but i am not prepared to risk fiddling with the new stainless pipework with a day to go (and a day at work).

I also dont fancy 3+ hours driving on over-fuel / thicker oil.

Probably Gaffa tape for now to take the radiator moving efficiency down but without too much effect on its stationary performance, then chat with all the 's peeps; in dunkirk / spa.

thanks for any further thoughts - its got under my skin now!

GRRRR

[phillpot]

When I had the Chimaera it behaved in a similar way, anything other than scorchy hot days I had a piece of cardboard blocking 1/3 of the rad !

[Maffe]

phillpot said:

When I had the Chimaera it behaved in a similar way, anything other than scorchy hot days I had a piece of cardboard blocking 1/3 of the rad !

My father always used the cardbord trick on our old cars back in the days during the cold nordic winter.
I see no reason not to try it, if it not give you the result you want then it´s pretty easy to revers

[Top Gear TVR]

£900 of high performance cooling upgrade and I need cardboard. Laughable isnt it!

'Make it so', oh no, thats the wrong programme

[TurboTony]

Worth comparing notes and gauges on the trip. My system is standard apart from recored rad and runs cool until in traffic. Never boils and warms up quickly. My old Essex V6 Scimitar was the same - and they were noted for being boilers!

[Top Gear TVR]

i too had a scimitar..........immense cars with no space in them, i kind of reverse tardis with good noise. SE6a.

[GreenV8S]

Top Gear TVR said:

I understand griffr has undertaken a mod which appears sensible to me knowing the granada set up; moving the bypass hose from the swirl pot to the radiator bottom hose (pump inlet)- but i am not prepared to risk fiddling with the new stainless pipework with a day to go (and a day at work).

I would say that design flaw accounts for all of your problems. Unfortunately, blanking the radiator off sufficiently to prevent it from being able to over-cool at cruising speed is almost certainly going to impact the cooling when stationary. |If it's any consolation, a lot of cars have run like this for many years without any obvious harm.

[TJC46]

Top Gear TVR said:

It behaves perfectely if driving in slow traffic or idling - but

if i start up and set off straight off to the dual carraigeway it never warms up beyond 65/70

In my expierience with my Chimaera this is normal. At a steady speed over 40mph the amount of airflow thru the rad keeps the temp at about 70. This average can rise slightly during periods of warmer weather.
I have a hand held laser temp gun i could bring along, you can check the temp of the rad, swirl pot, etc, at tickover and see what your gauge reads for comparison.
Have you tried turning the heater to off, this could help get the temp up a bit quicker.

[v8s4me]

TJC46 said:

......I have a hand held laser temp gun i could bring along, you can check the temp of the rad, swirl pot, etc, at tickover and see what your gauge reads for comparison.

Excellent idea! You can then compare with other V6’s. Also monitor your fuel consumption on the trip. If it’s not much different to before, and similar to all the others, then you’ve probably got noting to worry about. Relax!!I In 24 hours you’ll be on your way.

[Eelblady]

Top Gear TVR said:

hmmm- just been out for a 1 hour run and its not getting to temp until in traffic, then the stat and fan are doing their stuff.

any ideas for a quick fix, i dont want to drive to belgium over-fuelling......

ideas;

1. restrict air flow to rad at grill or rad itself
2. restrict water flow through bypass hose by inserting a small diameter pipe or similar

what do you think?

Personally I went with option 2 - I inserted a blank with a 3mm hole and get 3 mile warm up and no detectable associated problems in the 600 miles since I did it, but very quick to reverse if necessary.

My view was that the pipe in question is a 'de-gas' pipe designed to vent any bubbles from the water pump (fords had this pipe routed to the expansion bottle as I understand it). I was not happy to recirculate those bubbles via the other mod. Restricting the flow vents bubbles and speeds warm up. Once the ' stat is open the restriction is of little consequence.

[TurboTony]

Top Gear TVR said:

i too had a scimitar..........immense cars with no space in them, i kind of reverse tardis with good noise. SE6a.

SE6a as well!

[Top Gear TVR]

I may be the only S to bring a sponge along. Its not a cleanliness thing but to restrict airflow through my grill. Works a treat!