Expansion Tank Cap Pressure - Or Waterless Coolant - Thoughts?
- Thread starter Shaun Sizen
- Start date
Ed McClements
Supporter
13psi ?
Your timing is implacable Shaun.
currently looking for one as well.
looking up a Motorcraft / Ford item seems to show 13PSI.
Most of the hotrod/race caps seem to be a bit higher in the presure rating. I have read that when the higher presure caps do open they dump more presure and energy out of your closed system into the over flow tank, so should drop the temperature in the radiator more when you reach the limit. The higher pressure also compresses the air bubbles in the system more as well, making them smaller and allowing for more collant surface area contact.....not sure what to believe.
My problem is that i wasn't sure what size radiator cap i need for the expansion tank i have. I was just going to go down to the local radiator place and see what they recommended or if they had something good in stock. I am not to worried about the pressure of the cap at this point. i just wanted to get something that was good quality and fit the expansion tank well. If it doesent do that correctly, the pressure rating wont make any difference.
Ryan
currently looking for one as well.
looking up a Motorcraft / Ford item seems to show 13PSI.
RS-62 Motorcraft Radiator Cap for Mustang Pickup Ford Ranger Grand Marquis LTD | eBay
Motorcraft Radiator Cap --. 75 Bronco Ranger. 78-81 Bronco Ranger XLT. 75 Grand Marquis Base. 67-75 Marquis Base. 69-75 Marquis Brougham. 75 Marquis Colony Park. 82 Capri (submodel: Black Magic, L, RS).
www.ebay.com.au
Most of the hotrod/race caps seem to be a bit higher in the presure rating. I have read that when the higher presure caps do open they dump more presure and energy out of your closed system into the over flow tank, so should drop the temperature in the radiator more when you reach the limit. The higher pressure also compresses the air bubbles in the system more as well, making them smaller and allowing for more collant surface area contact.....not sure what to believe.
My problem is that i wasn't sure what size radiator cap i need for the expansion tank i have. I was just going to go down to the local radiator place and see what they recommended or if they had something good in stock. I am not to worried about the pressure of the cap at this point. i just wanted to get something that was good quality and fit the expansion tank well. If it doesent do that correctly, the pressure rating wont make any difference.
Ryan
Ian Anderson
Lifetime Supporter
How about that waterless coolant? Where they say it does not need a pressure cap?
Something like this?
www.carparts4less.co.uk
Something like this?
Evans Classic 180 Waterless Coolant 5Ltr | Car Parts 4 Less
Evans Classic 180 Waterless Coolant 5Ltr at the lowest UK prices from Car Parts 4 Less UK’s No.1 for Car Accessories, Car Styling & Car Care. Buy today Online, In store or by Phone + Branches Nationwide – Next Day UK Free Delivery.
www.carparts4less.co.uk
Shaun
Supporter
I had thought waterless as its a new build totally dry, issue wa snot so much the cost but what if I had a leak and it drained!! I think aboit £150 to £200 for waterless?
Ok so lets put that out for discussion, should we keep water only for whisky or is it still ok in rads.
Ryaa I would say great minds thinking alike!! anyhow that's 2 for 13 lets see if we get any more takers, who thought a rad cap selection would be so much fun!! I may need to get out more.....
Ok so lets put that out for discussion, should we keep water only for whisky or is it still ok in rads.
Ryaa I would say great minds thinking alike!! anyhow that's 2 for 13 lets see if we get any more takers, who thought a rad cap selection would be so much fun!! I may need to get out more.....
I say why? Why muck with something that has worked pretty flawlessly (generally speaking) in trillions of vehicles around the globe?
Evans in some good stuff with great results, but should be reserved for the cooling systems of endurance cars and trucks that are being pushed to their limits relentlessly. In many cases, you will still need a pressure cap as the water pump itself will produce a pretty good head of pressure and can expel the coolant with quite a show...
Evans in some good stuff with great results, but should be reserved for the cooling systems of endurance cars and trucks that are being pushed to their limits relentlessly. In many cases, you will still need a pressure cap as the water pump itself will produce a pretty good head of pressure and can expel the coolant with quite a show...
Dan Kasten
Supporter
I have Evans coolant in my GTD and I use a 7lb. cap. I have no issues at all with it and seems to work really well on hot summer days driving around town. The downside is like mentioned above you don't want it to leak out of anywhere because it is expensive.
Neil
Supporter
"Waterless coolant" has been around since the late 1930s. It was originally just ethylene glycol. The military aircraft industry used it as a coolant in Allison V-1710 liquid-cooled engines in planes such as the Curtis P-40, among others. Although it had a high boiling point, it created other problems. One was that it leaked through microscopic openings in hoses, gaskets, etc. The most serious problem was that its specific heat ( the amount of heat absorbed that causes its temperature to rise one degree C) is far less that plain water. A compromise was finally arrived at which worked well- 50% water & 50% ethylene glycol. It had an acceptable specific heat, boiling & freezing point, and was (with additives) non-corrosive.
Evans offers a variety of waterless coolants; their "heavy duty" coolant is a mixture of ethylene glycol and propylene glycol. One thing to bear in mind is that it will not absorb as much heat as plain water. It's specific heat is 2633 J/(K kg) while plain old water is 4182 J/(K kg). That is a big difference. Evan's specialty racing coolant is 100% propylene glycol. Note that their handling instructions warn that it readily absorbs water from the air so the container should always be kept closed. In other words, your cooling system may be "waterless" after it is freshly filled but it will eventually contain a percentage of water.
For racing, you can't beat water as a coolant but you should drain it afterwards to prevent rust & corrosion.
Evans offers a variety of waterless coolants; their "heavy duty" coolant is a mixture of ethylene glycol and propylene glycol. One thing to bear in mind is that it will not absorb as much heat as plain water. It's specific heat is 2633 J/(K kg) while plain old water is 4182 J/(K kg). That is a big difference. Evan's specialty racing coolant is 100% propylene glycol. Note that their handling instructions warn that it readily absorbs water from the air so the container should always be kept closed. In other words, your cooling system may be "waterless" after it is freshly filled but it will eventually contain a percentage of water.
For racing, you can't beat water as a coolant but you should drain it afterwards to prevent rust & corrosion.
Bill Kearley
Supporter
Cost benefit, I use the typical long life 50/50 mix for diesel engines, it's the best fore electrolyses, good for all normal use of everything I drive.
Last edited:
Ed McClements
Supporter
Hi Shaun
I would just use anything up to 50% red antifreeze, and a 13psi cap. In my experience, the red antifreeze works really well suppressing corrosion in engines built from a mix of iron block and aluminium heads / radiator.
I would just use anything up to 50% red antifreeze, and a 13psi cap. In my experience, the red antifreeze works really well suppressing corrosion in engines built from a mix of iron block and aluminium heads / radiator.
Ian Anderson
Lifetime Supporter
And around 13 litres of fluid in mine!
ian
ian
Shaun, my pennyworth, I use 18-20 cap and 20% anti freeze in water.
Search results
allstarperformance.com
predominantly sprint car and dirt track stuff, but they are all higher than the OEM rating.
just make sure your heater core will handle it.
Bill Kearley
Supporter
13 PSI and 50% red stuff
Ed McClements
Supporter
Bear in mind that your entire cooling system needs to be in tip-top shape to run pressures like Frank describes - don't want to blow a pin-hole in your expensive ally rad, or split a hose
Shaun, but do not omit the rear head bleeds , very important !
