The BMC A really needs to have the heater tap open, or a fitting installed, so that the water circulates through the cylinder head, then back to the radiator return line.
Some will rout the coolant via the old heater return inlet on the lower hose, if you are using a standard spridget hose. Doing this greatly improves cooling for the back cylinders.
Routing the coolant to the engine return (top hose) is better than the factory routing of head, heater core, engine coolant inlet (bottom) hose.
If you don't have a high point in your cooling system when the radiator is lower than the engine. A swirl pot, which should be a high point, is used to fill the cooling system. Without the swirl pot, there will be many trapped bubbles.
The later XIs have a surge tank, or purge tank, that allows bubbles to escape. The tank is the high spot that allows filling of the cooling system.
Cooling
-
erictharg
- Posts: 680
- Joined: Thu Jan 29, 2009 7:50 pm
Re: Cooling
I've plumbed the heater take off into the bleed to the header tank as it is the highest point of the system (instead of the little bleed pipe on the stock Midget rad, that does nothing on an Eleven). The serious Mini Miglia guys "dry deck" their engines taking a large hose from the back of the head to the block to improve cooling to No. 4, but they are running engines whose life is often measured in minutes, not hours. Extreme.
-
11admire
- Posts: 76
- Joined: Tue May 31, 2011 8:40 pm
- Location: Denmark, Munkebo
Re: Cooling
Hi
When I got my XI the cooling system was standard Sprite radiator mounted just in front of the engine, standard impellor on the water pump and an electric fan on the front of the radiator. The heater take off was blocked.
It didn't work very well so I move the radiator to the front and tilted it about 45 dgr., removed the impellor, got a lot of Samco silicon tubing and an aluminium pipe with a radiator cap. Expansion tank was mounted behind the radiator.
One of my freinds have welded the stainles pipes.
With that setup I got an air pocket at the cap as it is the highest point in the system and I allways had to bleed the system. The heater take off was still blocked so no circulation at the back of the head.
[attachment=1]First layout cooling.png[/attachment]
[attachment=0]First layout cooling front.png[/attachment]
So back to the drawing board.
New custom/tailor made 3 core cross flow radiator made as big as would fit in the front, is fitted.
I have had a watertank made (like the original Lotus 11), placed it on the firewall just behind the engine as high as possible. Inlet is from heater take off and outlet taken from bottom centre of tank goes to the top hose just after the thermostat. I had a T-piece made with a cap, but it will be changed to a T-piece with a bleed screw instead of the cap. The T-piece holds the probe/feeler for the electric waterpump I might fit later as well.
Now the tank is the highest point and I have cirkulation at the back of the head. It works OK (95%) so there are still room for improvement.
Sorry I have no pictures of the current layout, but will get later
When I got my XI the cooling system was standard Sprite radiator mounted just in front of the engine, standard impellor on the water pump and an electric fan on the front of the radiator. The heater take off was blocked.
It didn't work very well so I move the radiator to the front and tilted it about 45 dgr., removed the impellor, got a lot of Samco silicon tubing and an aluminium pipe with a radiator cap. Expansion tank was mounted behind the radiator.
One of my freinds have welded the stainles pipes.
With that setup I got an air pocket at the cap as it is the highest point in the system and I allways had to bleed the system. The heater take off was still blocked so no circulation at the back of the head.
[attachment=1]First layout cooling.png[/attachment]
[attachment=0]First layout cooling front.png[/attachment]
So back to the drawing board.
New custom/tailor made 3 core cross flow radiator made as big as would fit in the front, is fitted.
I have had a watertank made (like the original Lotus 11), placed it on the firewall just behind the engine as high as possible. Inlet is from heater take off and outlet taken from bottom centre of tank goes to the top hose just after the thermostat. I had a T-piece made with a cap, but it will be changed to a T-piece with a bleed screw instead of the cap. The T-piece holds the probe/feeler for the electric waterpump I might fit later as well.
Now the tank is the highest point and I have cirkulation at the back of the head. It works OK (95%) so there are still room for improvement.
Sorry I have no pictures of the current layout, but will get later
- Attachments
-
-
-
sgrant
- Posts: 333
- Joined: Thu Jan 29, 2009 10:44 am
Re: Cooling
I ordered a take-off pipe to fit the back of the head - as soon as it arrives I'll plumb it back into the header tank return circuit.
stephen
stephen
-
Westfield 129
- Posts: 882
- Joined: Sat Jun 04, 2011 4:20 am
Re: Cooling
Well, that's a lot of improving.
You could have just put a standard swirl (with a radiator cap) pot where your cap is (coolant in the top, out the bottom) and taken care of your air bubble problem. I have one that just sits in the top hose. It doesn't need any support. The swirl pot gives a good, high, fill point, and eliminates the bubbles.
If you put the fan behind the radiator, and get rid of the mounting plate, you gain 30% in radiator area, and the engine cools much better. This simple mod made every overheating US Westfield cool very well, even in the canyons, behind a slow truck, on a 40C day. Sure, it hit 95C, but it did not overheat.
Putting the fan, with its large hub, and the mounting shroud that blocks off several square inches of radiator, really causes a lot of problems when it comes to cooling the engine.
My personal XI has a stock cross flow radiator, with a rear mounted fan, and a 45º forward slant. It runs cool here in the Southern California Deserts. My new construction will use a double pass racing radiator, slanted back, aft mounted fan, with the air exiting beneath the car. The entire system will live in a duct, as it does on the original Lotus 11. I am using a Harrison alloy surge tank from an early Corvette, slightly modified to handle the return line from the engine. This will act as the fill point and surge/header tank.
The racing rad is thin, very light. Single core, but extremely efficient. A big advantage is that both the inlet and outlet are on the same side. At 16X11", if fits between the frame rails. Typically, these radiators are run about 30% blocked off when racing, as they do too good a job. I am running a fan and a thermostat. It should be just fine.
I also run an oil cooler.
You could have just put a standard swirl (with a radiator cap) pot where your cap is (coolant in the top, out the bottom) and taken care of your air bubble problem. I have one that just sits in the top hose. It doesn't need any support. The swirl pot gives a good, high, fill point, and eliminates the bubbles.
If you put the fan behind the radiator, and get rid of the mounting plate, you gain 30% in radiator area, and the engine cools much better. This simple mod made every overheating US Westfield cool very well, even in the canyons, behind a slow truck, on a 40C day. Sure, it hit 95C, but it did not overheat.
Putting the fan, with its large hub, and the mounting shroud that blocks off several square inches of radiator, really causes a lot of problems when it comes to cooling the engine.
My personal XI has a stock cross flow radiator, with a rear mounted fan, and a 45º forward slant. It runs cool here in the Southern California Deserts. My new construction will use a double pass racing radiator, slanted back, aft mounted fan, with the air exiting beneath the car. The entire system will live in a duct, as it does on the original Lotus 11. I am using a Harrison alloy surge tank from an early Corvette, slightly modified to handle the return line from the engine. This will act as the fill point and surge/header tank.
The racing rad is thin, very light. Single core, but extremely efficient. A big advantage is that both the inlet and outlet are on the same side. At 16X11", if fits between the frame rails. Typically, these radiators are run about 30% blocked off when racing, as they do too good a job. I am running a fan and a thermostat. It should be just fine.
I also run an oil cooler.
-
Alan FIAT
- Posts: 18
- Joined: Mon Mar 21, 2011 6:05 pm
Re: Cooling
Hello
Dont forget the coolant return pipe - thats the little hose underneath the thermostat housing. For an ideal cooling circuit this should be blanked off, so that all coolant flows through radiator.
If you do this, also drill a 3mm hole in mounting plate of thermostat itself. This will promote a small flow of water over sensing bulb before the temperature valve opens. Some thermostats already have the hole for venting reasons, usually with a 'jiggle pin' inserted, if so remove the pin.
Alan
Dont forget the coolant return pipe - thats the little hose underneath the thermostat housing. For an ideal cooling circuit this should be blanked off, so that all coolant flows through radiator.
If you do this, also drill a 3mm hole in mounting plate of thermostat itself. This will promote a small flow of water over sensing bulb before the temperature valve opens. Some thermostats already have the hole for venting reasons, usually with a 'jiggle pin' inserted, if so remove the pin.
Alan