Cooling System Swirl Pot

[BlackSupra]

nascar run an air "spring" to save coolant being pushed out, instead the air pressure increases in the spring chamber.


i run the greddy style breather tank in my race car, i was getting wildly fluctuating temp readings on the track which i assumed was air pockets, so i put one in. i tapped the back of the head water outlet in the highest place for a bleed. it seemed to work, im now seeing much more stable temp readings but every now and then i get the variation again.

i now plan to build a swirl pot and run that in conjunction with my bleeder tank. kinda like so

Any pics of where you tapped at the back of the head?

[cri_ag]

no, this is in a 4age mind you. i just tapped into the water outlet on the rear of the head.

generic photo of rear water outlet

[TheStitt]

Would I be right in the wagon as the top of the rad is higher than then the head??

[thechuckster]

Chuck,

How does one address point #1?

What would be your suggestion to improve the 7m cooling situation?

without spending lots of money on development:
- play around with the cooling bypass circuits (that goes to the turbo housing, throttle body, cabin heater, etc) by changing/reducing pipe diameter
- breather tank at highest point in engine bay (could be tricky) which feeds radiator top tank
- consider a falcon (EA-ish era) radiator fill tank as a combined breather/fill tank
- widest radiator possible
- significant tank capacity (above & below radiator core)
- ducting to radiator core & engine bay tray
- shrouded fans
- anti-boil only for summer
- chemical flush of coolant galleries in motor

spending money:
- analyse the 7M head cross sections posted by andrew_mx83
- drill thru to coolant passages and feed them to the breather tank (test on dummy head first, size of water ports would require some thought)
- other suggestions above as required
this may not end well as it would seriously change the coolant flow thru and around the thermostat.


fwiw: a while ago I was talking to Crag Aggio (owner of the replica TA64 up here in Qld) about cars-n-shit-n-turbos. He mentioned that he found the excel alloy radiator (plus thermo fans) did a better job of bringing down high coolant temps in his rally car than a thicker 3-core radiator. This is for a car that might be under high engine loads at fairly low road speeds. It has a substantial FMIC core up-stream of the radiator. His theory was that as the air passed thru the radiator core it heated up so the rear-most vertical cores had poor heat rejection to the now quite hot air-stream.

His solution was the wide mouth radiator (aka the excel alloy jobs) which from memory are 30-35mm thick? (feel free to correct this), plus some ducting at the front plus cold air induction.

I know this forum has had previous threads discussing radiator core efficiency (sorry, havn't searched for them) and this runs counter to the arguments in them, but it's a real world example of improving heat rejection from the cooling system.


off the wall suggestion: reduce intake air temps with water or water+methanol injection?

[cri_ag]

without spending lots of money on development:
- play around with the cooling bypass circuits (that goes to the turbo housing, throttle body, cabin heater, etc) by changing/reducing pipe diameter

this is exacty what im doing atm. do you still have the heater core connected in the car? i know i just bypassed mine, but now im thinking this is causing excessive coolant to be re-circulated into the engine without going into the radiator (not sure what the 7m setup looks like but thats how a 4a works) so im thinking with the removal of the heater core this needs a restrictor to work as factory designed.

[cri_ag]

i also read an interesting article about subaru cavitation problems that was eventually traced to the bottom inlet pipe simply not being large enough to supply the water pump with suficent flow at rpm, this caused cavitation, thus causing bubbles in coolant and the engine running hot.

[oldcorollas]

inneresting..

Glennn, have you checked the type of impeller in the water pump? massaged it for non-cavitation goodness? considered pump speed etc? coolant additives to change vapour pressure/surface tension?

[cri_ag]

link for the above article http://www.mrtperformance.com.au/res...boiling-theirs

[boxh34d]

Air in the coolant passages will lead to hot spots in the head, which can cause detonation or warpage which could lead to engine failure in many various expensive ways.

Yeah, understand the general concept of why one is used, more wondering if there was any known problem with the 7M trapping air, or Glen's car specifically.

Glen: Did you find that this was the problem leading to your head troubles, or suspected, or just trying to eliminate any chance of shit going south again in general?

[BlackSupra]

without spending lots of money on development:
- play around with the cooling bypass circuits (that goes to the turbo housing, throttle body, cabin heater, etc) by changing/reducing pipe diameter Removed cooling bypass to throttle body and turbo does not have a water feed so the system is fairly basic. Still have the heater core connected.
- breather tank at highest point in engine bay (could be tricky) which feeds radiator top tank Can utilise strut tower or firewall space and be above rear or motor
- consider a falcon (EA-ish era) radiator fill tank as a combined breather/fill tank Will investigate this option
- widest radiator possible Can't get much wider than factory
- significant tank capacity (above & below radiator core)
- ducting to radiator core & engine bay tray Check my member ride, huge duct for the intercooler and radiator installed, air can't go around core anymore. Will be installing undertray splitter soon.
- shrouded fans AU falcon thermos installed, probably could seal them a little better
- anti-boil only for summer Always run toyota red
- chemical flush of coolant galleries in motor Brand new rebuilt 7M that hasn't been run in yet

spending money:
- analyse the 7M head cross sections posted by andrew_mx83 I've asked for another cross section through a lower hex plug to see if it goes to a water jacket
- drill thru to coolant passages and feed them to the breather tank (test on dummy head first, size of water ports would require some thought) This is what i was thinking with the hex plug on top of the head, alternatively use the old feed line to the throttle body on the intake plenum.
- other suggestions above as required
this may not end well as it would seriously change the coolant flow thru and around the thermostat.


fwiw: a while ago I was talking to Crag Aggio (owner of the replica TA64 up here in Qld) about cars-n-shit-n-turbos. He mentioned that he found the excel alloy radiator (plus thermo fans) did a better job of bringing down high coolant temps in his rally car than a thicker 3-core radiator. This is for a car that might be under high engine loads at fairly low road speeds. It has a substantial FMIC core up-stream of the radiator. His theory was that as the air passed thru the radiator core it heated up so the rear-most vertical cores had poor heat rejection to the now quite hot air-stream.

His solution was the wide mouth radiator (aka the excel alloy jobs) which from memory are 30-35mm thick? (feel free to correct this), plus some ducting at the front plus cold air induction.

I know this forum has had previous threads discussing radiator core efficiency (sorry, havn't searched for them) and this runs counter to the arguments in them, but it's a real world example of improving heat rejection from the cooling system.


off the wall suggestion: reduce intake air temps with water or water+methanol injection? Not at this stage, going to get a cold air setup working first to reduce intake temps, have also installed bonnet vent above radiator to extract hot radiator air. I also have some vents to place in the guards at the back of the engine bay to extract more hot air.

Answers in quote above.

[BlackSupra]

link for the above article http://www.mrtperformance.com.au/res...boiling-theirs

Very interesting article, might need to measure the size of the the pump inlet!

Stew - standard but new water pump, haven't tested anything.

Box - old engine developed alot of air in the cooling system and was forever blowing out of the overflow. Trying to address this straight up this time.

[TheStitt]

the O-D of the pump inlet is 35mm So subtract wall thickness for ID

[RiceburnaGTV]

I just built one of these for a 351 supercharged corolla burn out car and worked a treat,enables you to put a non standard rad on there that can be bigger as you are not as restricted with having to replicate the original exactly. It's a shit load easier to bleed and eliminates any chance of air trapping in the head as you can generally run it nice and high on the strut tower.

[RiceburnaGTV]

Also seeing its a 7m is suggest you get some of my coolant which cannot boil,just incase.