Running without thermostat

adamnreeves · Post by **adamnreeves** » Thu Jun 17, 2010 1:55 pm

I've been wondering how much the standard RV8 thermostat impedes water flow by, when open of course. Running a Westfield which is a summer car. Westfield have a compromised cooling system I need as much flow as I can get.

sidecar · Post by **sidecar** » Thu Jun 17, 2010 2:49 pm

adamnreeves wrote:I've been wondering how much the standard RV8 thermostat impedes water flow by, when open of course. Running a Westfield which is a summer car. Westfield have a compromised cooling system I need as much flow as I can get.

The thermostat is supposed to create a restriction even when it is open, the idea is that the pump can then build up the pressure of the coolant to a figure that is higher than the blow off pressure of the radiator cap. The pressure in the coolant system of the block could be around 30 PSI. This raises the boiling point of the coolant and helps stop steam pockets forming.

I've read in a book that removing the thermostat is a red herring, the temperature of the coolant immediately around the temp sender may be less so the gauge reads lower but the heads could be suffering from local hotspots due to steam pockets caused by the lack of pressue.

adamnreeves · Post by **adamnreeves** » Thu Jun 17, 2010 2:56 pm

I see. I also been informed that it would take too long to come up to temperature if at all. I'll leave it in. At least I can observe what effects changing the cover to lower the top hose will have.

sidecar wrote:
adamnreeves wrote:I've been wondering how much the standard RV8 thermostat impedes water flow by, when open of course. Running a Westfield which is a summer car. Westfield have a compromised cooling system I need as much flow as I can get.
The thermostat is supposed to create a restriction even when it is open, the idea is that the pump can then pbuild up the pressure of the coolant to a figure that is higher than the blow off pressure of the radiator cap. The pressure in thhe coolant system of the block could be around 30 PSI. This raises the boiling point of the coolant and helps stop steam pockets forming.

I've read in a book that removing the thermostat is a red herring, the temperature of the coolant immediately around teh temp sender may be less so the gauge reads lower but the heads could be suffering from local hotspots due to steam pockets caused by the lack of pressue.

topcatcustom · Post by **topcatcustom** » Thu Jun 17, 2010 2:59 pm

I wondered whether the flow would be too quick for the water to conduct the heat quickly enough- meaning the radiator and temp sender would see a lower temp but the block and heads could be higher? Feasable?!

adamnreeves · Post by **adamnreeves** » Thu Jun 17, 2010 3:03 pm

Which leads me to a question I have. When my coolant temperature is 87c and using my infra-red probe on the temperature sender I observe the heads are 110c. not sure what to expect?

topcatproduction wrote:I wondered whether the flow would be too quick for the water to conduct the heat quickly enough- meaning the radiator and temp sender would see a lower temp but the block and heads could be higher? Feasable?!

kiwicar · Post by **kiwicar** » Thu Jun 17, 2010 3:06 pm

Hi,
you can buy high flow thermostats from various suppliers, never used one but they look like a solution.
http://www.summitracing.com/search/bran ... toview=SKU
Best regards
Mike

Ian Anderson · Post by **Ian Anderson** » Thu Jun 17, 2010 4:06 pm

kiwicar wrote:Hi,
you can buy high flow thermostats from various suppliers, never used one but they look like a solution.
http://www.summitracing.com/search/bran ... toview=SKU
Best regards
Mike

a mate with a Ford302 in GT40 (Edelbrock Performer heads) had overheating probs and fitted one of these and was pleasantly surprised by the difference

Ian

unstable load · Post by **unstable load** » Thu Jun 17, 2010 6:50 pm

Take your thermostat and cut the arms that hold the spring mechanism off the body. Toss the spring bit and refit the body. The restriction caused by the body will be the same as an open 'stat.

Did it on my Mini and my Alfa. Rover garaged at present, so not applicable.

unstable load · Post by **unstable load** » Thu Jun 17, 2010 6:51 pm

Take your thermostat and cut the arms that hold the spring mechanism off the body. Toss the spring bit and refit the body. The restriction caused by the body will be the same as an open 'stat.

Did it on my Mini and my Alfa. Rover garaged at present, so not applicable.

TVRleigh · Post by **TVRleigh** » Fri Jun 18, 2010 11:25 am

unstable load wrote:Take your thermostat and cut the arms that hold the spring mechanism off the body. Toss the spring bit and refit the body. The restriction caused by the body will be the same as an open 'stat.

Did it on my Mini and my Alfa. Rover garaged at present, so not applicable.

I'm doing this on my Racer, as I have the non dissy cover, and running with the minimum of hoses, so don't have any bypass
Engine gets upto temp quite quick. within 5 mins
Engine Temp sensor is about 10 oC hotter than radiator sensor.

kev_the_mole · Post by **kev_the_mole** » Fri Jun 18, 2010 11:53 am

I just made up a couple of ally restrictor plates so I can fettle the size of the hole for hot/cold weather use.

Also having an electric pump means that I can warm up pretty quickly in cold weather buy switching it off and on over a couple of minutes simulating a much lower pump speed.

topcatcustom · Post by **topcatcustom** » Fri Jun 18, 2010 2:18 pm

TVRleigh wrote:
unstable load wrote:Take your thermostat and cut the arms that hold the spring mechanism off the body. Toss the spring bit and refit the body. The restriction caused by the body will be the same as an open 'stat.

Did it on my Mini and my Alfa. Rover garaged at present, so not applicable.
I'm doing this on my Racer, as I have the non dissy cover, and running with the minimum of hoses, so don't have any bypass
Engine gets upto temp quite quick. within 5 mins
Engine Temp sensor is about 10 oC hotter than radiator sensor.

How much lower if at all does the engine run like this with no stat centre? It should flow a bit more freely as even with an open stat the centre piece is still there creating a slights restriction, I'd just like 5 or so knocked off my temp.

adamnreeves · Post by **adamnreeves** » Fri Jun 18, 2010 2:56 pm

Yeah that's the kind of change I am after. I'll report back this weekend.

topcatproduction wrote:
TVRleigh wrote:
unstable load wrote:Take your thermostat and cut the arms that hold the spring mechanism off the body. Toss the spring bit and refit the body. The restriction caused by the body will be the same as an open 'stat.

Did it on my Mini and my Alfa. Rover garaged at present, so not applicable.
I'm doing this on my Racer, as I have the non dissy cover, and running with the minimum of hoses, so don't have any bypass
Engine gets upto temp quite quick. within 5 mins
Engine Temp sensor is about 10 oC hotter than radiator sensor.
How much lower if at all does the engine run like this with no stat centre? It should flow a bit more freely as even with an open stat the centre piece is still there creating a slights restriction, I'd just like 5 or so knocked off my temp.

unstable load · Post by **unstable load** » Fri Jun 18, 2010 3:37 pm

Accepted theory is that without the centre the ngine may appear to run cooler, but in actual fact the heads may be experiencing spots where the water is boiling due to the effects of not having the pump "working" against the restrictor.
In other words, the water gets to freewheel about the engine and this can form hot spots. THe pump needs some "back pressure" which is given by the restrictor.

Anyone else out there disagrees, please set me right.

sidecar · Post by **sidecar** » Fri Jun 18, 2010 4:07 pm

topcatproduction wrote:I'd just like 5 or so knocked off my temp.

What stat are you running? I run a 74 degree stat and my stage III 4.6 runs at around 78 degrees.

The V8 Owners Forum -

Running without thermostat

Running without thermostat

Re: Running without thermostat

Re: Running without thermostat