Continuing Evans NPG+ discussion...
11-28-03, 02:29 PM
#1
Continuing Evans NPG+ discussion...
OK, no idea why the last Evans NPG or NPG+ thread was closed, but we need to continue discussion on the topic!
From last thread
Another question I have is 'why is everyone worried about the ~15psi of radiator pressure?'. We have seals on the A/C that easily survive at 150psi. We have various oil seals/orings that don't even squeak at 70psi. The number one cause of coolant seal damage is because of the poorly engineered housings. Aluminum/iron expand and contract at different rates. 14psi of coolant pressure shouldn't be an issue.
This is a good point.
The answer I have is that the improved teflon/viton coolant seals are not available in an "O" ring configuration like stock Mazda seals, but sold by the foot.
Because of this, when you use this improved seal you must have an area where the two ends meet and are bonded. If this splice area was constantly under cooling system pressure it would fail more quickly. So, one runs an unpressurized cooling system. NPG+ can run unpressurized and still maintain its cooling capacity.
One "clocks" the spliced area of the improve inner seal so it is at the top of the engine. This puts the inner seals splice in the intake area (not compression/combustion/exhaust) so there is no pressure from the engine (well, turbo boost pressure I guess
)
The outer seal is clocked at the top of the engine as well, and will be the highest point of the cooling system- so avoiding leaks if it fails in a non-pressurized cooling system.
NOW, the online rotary community has enough clout to get these improved coolant seals made in permanantly bonded "O" rings of the correct size for our cooling seal applications so they can be used w/ cheaper standard coolant in a pressurized system as well as NPG+ non pressurised system.
LETS DO IT!
From last thread
Another question I have is 'why is everyone worried about the ~15psi of radiator pressure?'. We have seals on the A/C that easily survive at 150psi. We have various oil seals/orings that don't even squeak at 70psi. The number one cause of coolant seal damage is because of the poorly engineered housings. Aluminum/iron expand and contract at different rates. 14psi of coolant pressure shouldn't be an issue.
This is a good point.
The answer I have is that the improved teflon/viton coolant seals are not available in an "O" ring configuration like stock Mazda seals, but sold by the foot.
Because of this, when you use this improved seal you must have an area where the two ends meet and are bonded. If this splice area was constantly under cooling system pressure it would fail more quickly. So, one runs an unpressurized cooling system. NPG+ can run unpressurized and still maintain its cooling capacity.
One "clocks" the spliced area of the improve inner seal so it is at the top of the engine. This puts the inner seals splice in the intake area (not compression/combustion/exhaust) so there is no pressure from the engine (well, turbo boost pressure I guess
)The outer seal is clocked at the top of the engine as well, and will be the highest point of the cooling system- so avoiding leaks if it fails in a non-pressurized cooling system.
NOW, the online rotary community has enough clout to get these improved coolant seals made in permanantly bonded "O" rings of the correct size for our cooling seal applications so they can be used w/ cheaper standard coolant in a pressurized system as well as NPG+ non pressurised system.
LETS DO IT!
11-28-03, 02:41 PM
#2
Former Moderator. RIP Icemark.
# 1 the old thread was closed because it was over a year and half old, and a poll that some newbie brought back from the way dead.
#2 the only thing added important to the thread since 08/02 was:
#2 the only thing added important to the thread since 08/02 was:
Tech Bulletin E999194 says:
Mazda does not recommend propylene glycol coolants. Available information indicates the following characteristics regarding propylene glycol coolants:* Provides less heat transfer
* May not provide adequate corrosion protection (to meet Mazda specifications)
* Freezing temperature is 10 - 20% higher than ethylene glycol based coolants
Mazda recommends ethylene glycol and water mixture.
Mazda does not recommend propylene glycol coolants. Available information indicates the following characteristics regarding propylene glycol coolants:* Provides less heat transfer
* May not provide adequate corrosion protection (to meet Mazda specifications)
* Freezing temperature is 10 - 20% higher than ethylene glycol based coolants
Mazda recommends ethylene glycol and water mixture.
11-28-03, 02:51 PM
#3
OK.
I get annoyed by polls attached to posts as well.
-EDIT-
here is the old post so we don't cover the same info again and again and again....
old Evans NPG+ thread.
I get annoyed by polls attached to posts as well.
-EDIT-
here is the old post so we don't cover the same info again and again and again....
old Evans NPG+ thread.
Last edited by BLUE TII; 11-28-03 at 02:55 PM.
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