coolant passages??WTF?
- Thread starter jagpride
- Start date
My "guess" is that's how they trimmed the resident time in each section based on temps at different areas.
^^^ I get what you're sayin' and it makes sense to me.
You'll notice the intake side has only one passage per cylinder, and the exhaust side has two, maybe thats just to keep the exhaust side cooler?
Who really knows though...
Sam
You'll notice the intake side has only one passage per cylinder, and the exhaust side has two, maybe thats just to keep the exhaust side cooler?
Who really knows though...
Sam
You can also see this effect, in a different way, in many "floating cylinder" engines. Only those engines use the headgasket, with different sized holes to control flow. Shown here... http://www.hybrid-racing.com/store/...5e06319eda06f020e43594a9c230972d/c/r/crv1.jpg
Yeah, just the design. This is the only evidence i have found of someone messing with it, though i cant imagine why you would considering there had to have been a reason.
http://www.supracarparts.com/info/?p=35
http://www.supracarparts.com/info/?p=35
for whatever reason they did this on the 7m, however on the 2jz, all of the ports are open and symetrical as you would expect. I am thinking the 2jz way is better and more desirable. Toyota learned.
supradjza80;1575751 said:
Toyota just switched from doing it on the block to doing it with the headgasket. The coolant passage holes in the JZ headgaskets are quite small, and vary depending on cylinder.
Jeff
jagpride;1575813 said:
Not really. I mean yes the average overall temperature will probably be slightly lower, but you will end up with some parts cooler than others, instead of the proper temperatures.
Jeff
In reality, if the combustion chamber is TOO cool, a lot of energy is lost trying to heat it. It's why emissions change depending on temps.
Jeff Lange;1575819 said:
But i mean to begin with doesn't our cars run hotter than most?Not only that i am sure the 2j has bigger cooling passages then the 7m and it runs with proper temp.Also as far as proper temp goes wouldn't the thermostat do its job to begin with as far as proper temp goes?I dont see why we as the supra community have not taken advantage of boring these holes out i mean who wouldn't want a cooler running head especially on the intake side and like i said we have thermostats we should be fine as far as temps.
2j head notice coolant passages are open on both sides also another thing to point out look at the coolant passages on the sides of the block tooo : )
Ok it's been mentioned several times in this thread but on the 2JZ, coolant flow control was moved from the block to the headgasket. Look at the block, now look at the headgasket.
You want even cooling throughout the motor. Because it allows for a more even and thorough combustion process across the cylinders. The thermostat only opens and closes based on temps at it's location. The coolant holes are sized to ensure that temp is as balanced throughout the whole engine as possible. If the passages were all opened up, one cylinders temp could be dramatically different from another. This is not ideal for the proper operation of the stresses in the motor, fuel economy, and (even though it's not high on anyones list) emissions. These are the reasons Toyota designed those ports as they did.
You want even cooling throughout the motor. Because it allows for a more even and thorough combustion process across the cylinders. The thermostat only opens and closes based on temps at it's location. The coolant holes are sized to ensure that temp is as balanced throughout the whole engine as possible. If the passages were all opened up, one cylinders temp could be dramatically different from another. This is not ideal for the proper operation of the stresses in the motor, fuel economy, and (even though it's not high on anyones list) emissions. These are the reasons Toyota designed those ports as they did.
supradjza80;1575751 said:
lol, do you think these engines were engineered by somebody in a back yard, with no understanding of heat transfer and fluid mechanics?
Dirgle;1575892 said:Ok it's been mentioned several times in this thread but on the 2JZ, coolant flow control was moved from the block to the headgasket. Look at the block, now look at the headgasket.
You want even cooling throughout the motor. Because it allows for a more even and thorough combustion process across the cylinders. The thermostat only opens and closes based on temps at it's location. The coolant holes are sized to ensure that temp is as balanced throughout the whole engine as possible. If the passages were all opened up, one cylinders temp could be dramatically different from another. This is not ideal for the proper operation of the stresses in the motor, fuel economy, and (even though it's not high on anyones list) emissions. These are the reasons Toyota designed those ports as they did.
I see what you mean but none the less if the intake coolant holes were cut evenly wouldn't all the cylinders be equally cooled?I know there's people out there running low temp thermostats with 3 row radiators and there engine is running cool as hell and they don't get any problems i don't see how boring these passages would create any problems sense all the cylinders would stay at a consistent temp to begin with.
---------- Post added at 12:53 PM ---------- Previous post was at 12:45 PM ----------
adampecush;1575922 said:
lol uumm power steering reservoir,intake pipe running on top of the engine,non thermostatically controlled oil cooler,and possibly coolant passages which we are discussing. i am just saying : )
"Don't have any problems" is a terrible excuse. If you'ves seen the systems they use to tune each cylinder (usually EGT sensor and I've seent ehm run widebands on each one) to get everything running correctly.
The point is they would NOT be running at a constant temp, why you think you know better than the company that spent millions on designing the engine is beyond me...
-Power steering is where it's supposed to be (seen any of the earlier M engines?).
-Same thing here, look at a 2JGE, a FFIM works best with forced induction, which was designed first?
-Thermostatic controlled oil cooler isn't as reliable as pressure based.
The point is they would NOT be running at a constant temp, why you think you know better than the company that spent millions on designing the engine is beyond me...
jagpride;1575985 said:
-Power steering is where it's supposed to be (seen any of the earlier M engines?).
-Same thing here, look at a 2JGE, a FFIM works best with forced induction, which was designed first?
-Thermostatic controlled oil cooler isn't as reliable as pressure based.