grantura cooling
Discussion
a friend of mine has just rebuilt/reconstructed a Grantura from almost nothing over a period of 3 years+.
The car will be used for Historic racing and we have some question about the best cooling setup.
What to connect and where.
It has a Swirlpot with rad cap near the windscreen and catch tank for coolant (historic regs).
Alloy rad. The engine is MGA with an Alloy cylinderhead + 2 dcoe webers.
The cicuit at the moment is: Thermostat Outlet to Swirlpot, Swirlpot to top of Rad, bottom of Rad Outlet to Waterpump.
Does anyone agree with the circuit.
Thanks in advance from the experts here
Alan
The car will be used for Historic racing and we have some question about the best cooling setup.
What to connect and where.
It has a Swirlpot with rad cap near the windscreen and catch tank for coolant (historic regs).
Alloy rad. The engine is MGA with an Alloy cylinderhead + 2 dcoe webers.
The cicuit at the moment is: Thermostat Outlet to Swirlpot, Swirlpot to top of Rad, bottom of Rad Outlet to Waterpump.
Does anyone agree with the circuit.
Thanks in advance from the experts here
Alan
I'm not an expert on race car preparation (Someone else will be able to help) but I assume if you have a MGA engine your friends car is a MK2? Or even MK1.
If you look at the Grantura racing thread virtually all the racing cars have extra vents for cooling. Later a number of the MK2's including Tommy Entwistle's MK 2 ran MK3 bonnets.
Most extreme example Chris Summers car.
Not much help on your circuit.
Rob [
If you look at the Grantura racing thread virtually all the racing cars have extra vents for cooling. Later a number of the MK2's including Tommy Entwistle's MK 2 ran MK3 bonnets.
Most extreme example Chris Summers car.
Not much help on your circuit.
Rob [
Edited by RobMk2a on Tuesday 31st March 22:58
System I have used successfully for years on a variety of cars with Triumph straight 6, Ford X Flow and currently Grantura with X flow B series.
Radiator top hose direct to thermostat housing. Bleed from thermostat housing (you may need to fabricate this if thermostat housing doesn't already have a bleed - this should be the highest point in the system) to the top feed into the expansion tank which should have the pressure cap for the system. Overflow from pressure cap into catch tank if required by race regs. Expansion tank output T's into lower rad hose between water pump and rad bottom hose.
This has worked for me for years and was the system that was explained to me by a heating engineer who used to race MG Midgets. Prior to adopting this simple and logical system I always had cooling issues. Since following the advice of someone who understood racing and fluid flow I have never had any issues.
In your example I would presume that the swirl pot would also act as an expansion tank in the system described above.
Radiator top hose direct to thermostat housing. Bleed from thermostat housing (you may need to fabricate this if thermostat housing doesn't already have a bleed - this should be the highest point in the system) to the top feed into the expansion tank which should have the pressure cap for the system. Overflow from pressure cap into catch tank if required by race regs. Expansion tank output T's into lower rad hose between water pump and rad bottom hose.
This has worked for me for years and was the system that was explained to me by a heating engineer who used to race MG Midgets. Prior to adopting this simple and logical system I always had cooling issues. Since following the advice of someone who understood racing and fluid flow I have never had any issues.
In your example I would presume that the swirl pot would also act as an expansion tank in the system described above.
davegt6 said:
System I have used successfully for years on a variety of cars with Triumph straight 6, Ford X Flow and currently Grantura with X flow B series.
Radiator top hose direct to thermostat housing. Bleed from thermostat housing (you may need to fabricate this if thermostat housing doesn't already have a bleed - this should be the highest point in the system) to the top feed into the expansion tank which should have the pressure cap for the system. Overflow from pressure cap into catch tank if required by race regs. Expansion tank output T's into lower rad hose between water pump and rad bottom hose.
This has worked for me for years and was the system that was explained to me by a heating engineer who used to race MG Midgets. Prior to adopting this simple and logical system I always had cooling issues. Since following the advice of someone who understood racing and fluid flow I have never had any issues.
In your example I would presume that the swirl pot would also act as an expansion tank in the system described above.
Sounds spot on DaveRadiator top hose direct to thermostat housing. Bleed from thermostat housing (you may need to fabricate this if thermostat housing doesn't already have a bleed - this should be the highest point in the system) to the top feed into the expansion tank which should have the pressure cap for the system. Overflow from pressure cap into catch tank if required by race regs. Expansion tank output T's into lower rad hose between water pump and rad bottom hose.
This has worked for me for years and was the system that was explained to me by a heating engineer who used to race MG Midgets. Prior to adopting this simple and logical system I always had cooling issues. Since following the advice of someone who understood racing and fluid flow I have never had any issues.
In your example I would presume that the swirl pot would also act as an expansion tank in the system described above.
I have a few observations:
Why do you need a swirl pot? If the system is bled properly there should not be any air in it. As Dave says ensure there is a bleed at the highest point
I have no issues with cooling on my Grantura race car with just the standard orifice for the radiator but that is 'boxed in' to ensure ALL the air goes through the rad.
I would suggest you use a cast impeller water pump rather than a bent metal one and use larger pulleys to ensure you avoid cavitation at higher revs
Unless you are doing modsports historics, alloy rads are not generally allowed unless homologated (such as with the Elan). Generally they are poorer at dissipating heat, you are better off with thicker cores in a standard brass one.
HTH
Edited by Fiscracer on Wednesday 1st April 00:14
hi fiscracker, in reference to why do you need a swirl pot, you answered the question yourself by mentioning cavitation. the pump when over revved mashes the water and produces bubbles which are air. they might not over rev on the way up, but on the way down it's a completely different matter, and of course you are quite right about slowing down the pump as the engine is always in the high rev bracket. the same applies to the alternator. best regards keith.
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