My camry uses a 0.9 bar radiator cap, but I noticed my ipsum uses a 1.1 bar radiator cap. What's the benefit of the higher pressure radiator cap? Higher boiling point? Water gets hotter? Any danger if I switch to the 1.1 bar radiator cap?
i would doubt a camry would require a 1.1bar rad cap. nissan skyline gtst uses 0.9 bar stock.quote:
Originally posted by Ken4:
My camry uses a 0.9 bar radiator cap, but I noticed my ipsum uses a 1.1 bar radiator cap. What's the benefit of the higher pressure radiator cap? Higher boiling point? Water gets hotter? Any danger if I switch to the 1.1 bar radiator cap?
The thermostat controls temperature by manipulating flow.quote:
Note-That a thermostat now only controls temperature but flow also.
That simply is not true. By suppressing boilover with higher running pressure, a liquid medium will accept more heat and measure correspondingly higher temperature before it boils. Given that ANY water-cooled internal combustion engine generates much higher temperatures in operation than the boiling point of its liquid cooling medium (that's why we have radiators), then it follows that increasing the liquid cooling medium's operating pressure WILL result in elevating the liquid cooling medium's temperature, too, all other things being equal. The radiator, though, would militate that temperature increase in normal operation and "heavy duty/increased capacity" radiators even more so to accomodate operation in severe load conditions and hot climates.quote:
Originally posted by Kestas:
...The higher pressures will suppress boiling. It won't make the coolant run hotter...
..hmmm...a whole lot of "ifs" there... If I walk in the street too often ..I'll increase my risks of being hit too. You've come up with potential sceneros that may create problems. The same could be said for just about anything if you decide before hand to construct an argument against something.quote:
Gary: Look at the viscosity of PG @ -10°F. It's like Jello. I don't have to put it in a vehicle to see the potential problems with that. Look at PG's density change with temperature. PG expands more than 50/50 water/EG mixtures. If you have a system designed for use with water/EG with a presuriuzed expansion tank, you may have to run with a lower coolant level with PG so that it doesn't blow out the top of the tank since there may not be enough expansion space designed into the tank. If the coolant level gets too low, you risk pulling air into the cooling system and you may be regularly staring at a low coolant warning light or an overtemp light if your vehicle is so equipped.
Oh really? I thought that they only integrated temperatures.quote:
The Engine Control Unit (ECU) and the corresponding temperature sensors are calibrated using water/EG coolant.
For some reason you've assumed that you would be running hotter with PG. Again, if you put in a 195 thermostat ...it will open @195. Why would you think that PG would react otherwise? In "my" reference to running hotter due the LACK of local cavitation, these are typically street rod or trail (sand dune, desert, etc.) high performance engines that have never seen a computer. You may recall that I referred to "compiled" cooling systems ..as in constructed to try and fill the need of a high output engine. Not one designed for the vehicle in some air contitioned office using AutoCAD.quote:
Running a higher temperature with PG may fool them into thinking that your engine is overheating causing it to retard the ignition timing, cut boost, (if turbo equipped) richen the mixture for additional cooling, or light your Malfunction Indicator Light.(MIL) The ECU may also shut off the air conditioning compressor unnecessarily or change automatic transmission shift points if it's electronically controlled.
Again you assume that you would run at a higher temperature with PG.quote:
Many engines have aluminum heads and a cast iron block. Aluminum has a coefficient of thermal expansion about double that of cast iron. Heating the heads beyond the normal 250°F suggested range causes additional stress due to the additional expansion at the head gasket where the expansion slip plane usually takes place. That can lead to premature head gasket leakage and/or failure.
Perhaps (I'll skip the redundant retort this time) ...but most components have a fatigue limits that are weighted along several curves. For example 3" schedule 80 CPVC has a pressure rating of 550 PSIG @ 70 ......that rating decays greatly as the temperature approaches 325 (close to it's temp during extrusion). That is, under ZERO pressure your hoses and radiator will IMHO suffer less fatigue than that under less severe heating (heating and cooling cycles) WITH a radical change in pressure.quote:
Higher coolant temperatures cause cooling system hoses and other components to fail sooner, especially the coolant return/outlet hoses and plastic tank radiators.
Heck, unless its something simple and isn't a maintenance item ..I don't expect the manufacture to stand behind their warranty at all. Everyone always gets the song and dance if its an expensive job that "can" be blamed on the owner.quote:
Don't expect your vehicle manufacturer to stand behind their warranty based on recommendations they never made though!