V8 thermostat bore size
Discussion
Hi all,
The griff was running very cold on Sunday and I think my thermostat is stuck open. I've looked on TVR car parts which have a 74 and 82 degree standard bore of 27mm, but Race Tech direct have a 74 and 82 degree thermostat with a bore of 31mm.
The questions are:
What was standard out of the factory?
What do people recommend/have?
Obviously the 31mm bore will allow water to flow quicker.
I have an alloy rad and with the fans 'on' using a manual switch in a 2 hour que on the M25, in baking hot weather the temp actually went low. so I assme my cooling system is working ok.
The griff was running very cold on Sunday and I think my thermostat is stuck open. I've looked on TVR car parts which have a 74 and 82 degree standard bore of 27mm, but Race Tech direct have a 74 and 82 degree thermostat with a bore of 31mm.
The questions are:
What was standard out of the factory?
What do people recommend/have?
Obviously the 31mm bore will allow water to flow quicker.
I have an alloy rad and with the fans 'on' using a manual switch in a 2 hour que on the M25, in baking hot weather the temp actually went low. so I assme my cooling system is working ok.
spikep said:
Hi all,
The griff was running very cold on Sunday and I think my thermostat is stuck open. I've looked on TVR car parts which have a 74 and 82 degree standard bore of 27mm, but Race Tech direct have a 74 and 82 degree thermostat with a bore of 31mm.
The questions are:
What was standard out of the factory?
What do people recommend/have?
Obviously the 31mm bore will allow water to flow quicker.
I have an alloy rad and with the fans 'on' using a manual switch in a 2 hour que on the M25, in baking hot weather the temp actually went low. so I assme my cooling system is working ok.
TVR used Wahler thermostats which have a larger bore of 31mm compared to Land Rover's 3.5L thermostat (Part #602687) with 26.5mm bore. Both have a bypass hole with jiggle pin and may explain why Serp engines don't have the heater by-pass. Land Rover's 3.9 thermostats are 88 degs C.The griff was running very cold on Sunday and I think my thermostat is stuck open. I've looked on TVR car parts which have a 74 and 82 degree standard bore of 27mm, but Race Tech direct have a 74 and 82 degree thermostat with a bore of 31mm.
The questions are:
What was standard out of the factory?
What do people recommend/have?
Obviously the 31mm bore will allow water to flow quicker.
I have an alloy rad and with the fans 'on' using a manual switch in a 2 hour que on the M25, in baking hot weather the temp actually went low. so I assme my cooling system is working ok.
I've used a Wahler 82 Deg c for years without any issues but mainly because I don't like the thought of using the same small thermostat bore as a classic Mini (Quinton Hazell QTH100K or equivalent) and without the by-pass hole. Over cooling isn't an issue because the thermostat will start to close below 82 Deg c.
Sorry, I don't have the Wahler part number as I bought the last one from RaceTech or you could try your local European car parts store and ask for a Wahler branded thermostat for a 3.5 Rangie as the 3.9 ones are 88 Deg c.
For further info see http://www.pistonheads.com/gassing/topic.asp?t=989...
Good Luck, Steve Sprint
stevesprint said:
Nice one Sardonicus and ChimpOnGas, that's another one for the Griff parts list.
Its not a good idea to run a CAT car too cool as the standard ECU only calculates the lambda long trim about 88 Deg c when stationary.
What Steve said Its not a good idea to run a CAT car too cool as the standard ECU only calculates the lambda long trim about 88 Deg c when stationary.
OK for the likes of us running 3rd party ECU's cold enrichment can be dialed out where we like 
Sardonicus said:
stevesprint said:
Nice one Sardonicus and ChimpOnGas, that's another one for the Griff parts list.
Its not a good idea to run a CAT car too cool as the standard ECU only calculates the lambda long trim about 88 Deg c when stationary.
What Steve said Its not a good idea to run a CAT car too cool as the standard ECU only calculates the lambda long trim about 88 Deg c when stationary.
OK for the likes of us running 3rd party ECU's cold enrichment can be dialed out where we like 
I'm not going to bite the bait 
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