SVX Engine cooling "Again & Again"

[oab_au]

Originally Posted by shotgunslade

I guess all will be revealed when I take it to Watkins Glen May 1. If it boils over, we'll be back in the shop to enlarge he water pump inlet to 45 mm and install a transition immediately out of the radiator outlet from 35mm to 45mm. I think another issue will be to insure that the entire overflow tank connection is flooded, so that when the engine cools down, it only draws in water, rather than air. I know that my connection hose, early in my track career was leaky, so I needed to check coolant level in the radiator, rather than in the overflow tank, including running the car at idle with the cap off for a minute or so, in order to purge air bubbles from the system.

One variable that is hovering out there, but which will be eliminated in my car is the possiblity of head gasket leakage. When he rebuilt my motor, Tom found some slight evidence of leakage. It may only have been occurring under extreme use, and thus may not have shown up in the sniffer test I had that probably was done while idling.

We also know that head gasket leakage was not an issue in Jack Laverty's car, but may be a factor in any abused machine that has not had a recent top-end rebuild.

Dan I just don't understand your reasoning for this. You are willing to risk your new engine, and a days racing, just to see if we are right about the pump inlet.

Harvey.

[SVXRide]

Originally Posted by TomsSVX

Bill, you have the water direction from the pump... Both aux ports on the water pump are inlets that feed the back of the thermostat

Tom

Tom,
Did you mean Adam? The figure I posted back on page 56 (?) has both of the aux ports on the pump being returns (one from the LH side of the cross over pipe and one from the heater core).
-Bill

[SVXRide]

Originally Posted by Dessertrunner

Bill a number of cars use a thermostate that when closed lets coolant flow back to the pump with out going through the radiator. When the engine gets hot it open and force all coolant throught the radiator. Thats the sort of set up I want as engine can do with all the coolant going through the radiator when hot.

After what I found on the water pump only I did a set up on the engine just changing the thermo cap and have no radiator in stead had the 45mm clear pipe. At that point there was no air and all was perfect then I put the new PWR the one with the 42mm ID (need to keep it all correct) and found that there was some air only above 4,000 rpm. As a result of this I decided that I needed to move the inlet to the centre.
Tony

Tony,
Gotcha. So, is the ID for your rad's outlet actually 42mm?
Thanks.
-Bill

[Boxersix]

Originally Posted by Dessertrunner

Boxersix are you sure that the heater core goes from the pump not to the pump as the current SVX return ports on the pump are into the suction. I look forward to see you pump testing results.
Tony

Yes you're right I incorrectly placed/drew the feed line for the heater core to the pump. It comes off the normal position up off the crossover tube. not the pump housing as depicted.

The WRX purge tank merely intercepts the heater core circuit and traps any air that may be present in the system. The line coming from the top radiator core(~1/4" ID) is at the highest point in the core as I have the radiator ever so slightly tipped in such a manner as to make it so. Any air in the radiator flows to that point and up the line to the purge tank as well.

I have been been beating the ever living balls off this car for awhile and have yet to get it overheating, although our OAT is a bit lower this time of year than in Austrailia. I have a bit of a "back road" circuit that is void of all traffic and pedestrians that I can physically road test my car at speed to put some serious track-like sustained stress on the motor. Last night/early this morning(3am hahaha!) I even went and drove it for about 10 minutes hard non stop around this loop and then came to a complete stop and still didn't overheat. Again though my setup is drastically different than the SVX's

I took the Sti/SVX pump home tonight and am going to start modeling it in CAD for some fluid dynamics testing in the near future here. I may actually test the pump on the junk case setup tomorrow. see what kinda of free time I have in the afternoon.

-Adam

[SVXRide]

Originally Posted by Boxersix

Yessir, crude but to the point:




WRX purge tank is the highest point in the system. Small line off the upper right-side rad tank(left side of the picture) is the bleed back to the purge tank, found OEM on the WRX and Sti.

Throttle body cooling passage has been bypassed, thus not shown as being plumbed in.

I plugged the ports at the back of the head as the one line ran too close to the steering shaft and was more of a liability for rupture than was worth having.

Stock crossover, stock thermo housing. Single 1600CFM slim fan mounted on fully sealed rear radiator fan shroud(my own) with bypass flaps. Front also has fully ducted radiator shrouding. Far from OEM. No lost air going around the radiator core at either side.

The line from the heater core goes to the top port of the purge tank, return line comes from the bottom of the tank. Any air in the system stays in that purge tank until it's bled off through the cap down to the system reservoir.

Adam
Thanks for posting the figure! I'm a little confused at this point, because I thought the heater core was feed by the port off of the RH side of the crossover pipe, with the return from the heater core dumping back in at the pump. I also thought that the port off of the LH side of the crossover pipe dumped back into the other port on the pump (i.e., both ports on the stock pump are actually returns, not pressurizing anything). Your figure shows nothing tapping off of the crossover pipe. Other than this point, everything in your figure makes perfect sense. :-)
-Bill

[TomsSVX]

Adam, Bill, Dick, and Harry... meh

Update on my front... I cannot keep the car hot... Granted I am not really leaning into it like I prob should be for a proper test but w/o the stat the temp plumets... I have also reset the fan trigger for around 80*C which means about 176*F... I am installing a 160*F stat in the inline housing when it gets here *not today* Will let you know more... I need to get in touch with my dyno to setup a day to get it tuned... Then more testing... Installing oil coolers... Shift lights... Etc...

Tom

[Trevor]

Originally Posted by shotgunslade

I guess all will be revealed when I take it to Watkins Glen May 1. ---------------------

You have ignored my many posts regarding your overheating problem, to which you now again refer. All of my posts specifically recorded a sincere effort to assist you.

The last. i.e. # 849, included --- "The Meantime, would you please acknowledge my efforts to assist you with the specific issue you have raised. Refer posts #817, #830, #831, 832 #839." (#849 now included.)

If you hate my guts, fair enough, but having me needlessly post and post, increases the complexity of this thread, to the disadvantage of other members. The courtesy of a reply will end the situation.

[TomsSVX]

Originally Posted by Trevor

You have ignored my many posts

Yes, yes I have

Tom

[Trevor]

Originally Posted by TomsSVX

Yes, yes I have

Tom

Not nice Tom,

If you had not done so, you would have been able to observe that I have directly supported you throughout, and have been in agreement with your every approach to the cooling issue. In particular your doubts regarding any benefit in changing the actual radiator outlet and tube. The last time being within #926.

Whatever, you have been successful in burying my previous post, this probably being your real intent.

[Boxersix]

Originally Posted by SVXRide

Adam
Thanks for posting the figure! I'm a little confused at this point, because I thought the heater core was feed by the port off of the RH side of the crossover pipe, with the return from the heater core dumping back in at the pump. I also thought that the port off of the LH side of the crossover pipe dumped back into the other port on the pump (i.e., both ports on the stock pump are actually returns, not pressurizing anything). Your figure shows nothing tapping off of the crossover pipe. Other than this point, everything in your figure makes perfect sense. :-)
-Bill

Yes that was brought to my attention and I corrected myself in the last post I made. The feed for the heater core does in fact come off the crossover tube and then returns back down to the pump suction after exiting the WRX purge tank

I goofed on the epicly-precise MS paint drawing

[TomsSVX]

Originally Posted by Trevor

Not nice Tom,

If you had not done so, you would have been able to observe that I have directly supported you throughout, and have been in agreement with your every approach to the cooling issue. In particular your doubts regarding any benefit in changing the actual radiator outlet and tube. The last time being within #926.

Whatever, you have been successful in burying my previous post, this probably being your real intent.

Im not here for supporting opinions, I am here to find a solution

Tom

[shotgunslade]

Harvey:

I don't really think I am endangering the engine. I will be taking it sort of easy the first few track days as I get reacquainted with the car. I will be on the look-out for the familiar overheating behavior. I also intend to observe a 6800 rpm redline, for the foreseeable future. I will also be running an Sti radiator cap, and will have both fans running continuously controlled by the Hydra. As I understand it, removing the T'stat from the pump inlet increases the pump inlet to at least 33mm (from 29mm), so there is an improvement there. I've also learned how to purge air from the cooling system, so that problem which caused some of my woes early on will no re-appear.

Trevor:

I have to say that half the time, I don't understand what you are saying. Separated by a common language and all that. The other half of the time, I think I disagree with you. One thing I am convinced of is that the overheating problem is localized boiling, caused by unbalanced circulation through the block and heads, or by a temporary vapor lock of the pump caused by cavitation at the pump inlet, or by leaking head gaskets.

With my new engine, we can rule out the last one. Jack's experience and Tony's experience give contrary evidence concerning the first two causes. Given that Jack is running an electric fuel pump, his problem must be unbalanced flow. Tom's new crossover should solve that problem for me. Tony's problem was obviously caused by cavitation. Moving the T'stat to the radiator inlet should go a long way toward helping that problem. I also want to spend some time with the overflow tank to make sure it doesn't allow air into the system on cooldown.

In any event, I have no idea what point of view you are bringing to this discussion. Rather than try to decipher your posts, I mostly ignore them.

[Dessertrunner]

Bill Yes

Adam does your flow molding program enable calc's to be done when the liquid is in vacum?
Tony

[Boxersix]

Originally Posted by Dessertrunner

Bill Yes

Adam does your flow molding program enable calc's to be done when the liquid is in vacum?
Tony

I can introduce thermal changes, pressrue/vacuum, and fluid composition(viscosity, density, etc, etc) So essentially I can make the fluid a 50/50 distilled H20/glycol mix at ~180F and 14psi Or whatever the stars require there after.

It's a complicated program, one that I am not as fully adept with as the actual CAD software, but I can get things really close for what it's worth.

[Trevor]

Originally Posted by shotgunslade

I have to say that half the time, I don't understand what you are saying. Separated by a common language and all that. The other half of the time, I think I disagree with you. One thing I am convinced of is that the overheating problem is localized boiling, caused by unbalanced circulation through the block and heads, or by a temporary vapor lock of the pump caused by cavitation at the pump inlet, or by leaking head gaskets.

I have never inferred(said, posted or written) that this could not be the situation(case). Except that in a certain instance (at one time and in one place) I may have specifically(exactly and only) disagreed with the use of the word "cavitation."

With my new engine, we can rule out the last one. Jack's experience and Tony's experience give contrary evidence concerning the first two causes. Given that Jack is running an electric fuel pump, his problem must be unbalanced flow. Tom's new crossover should solve that problem for me. Tony's problem was obviously caused by cavitation. Moving the T'stat to the radiator inlet should go a long way toward helping that problem. I also want to spend some time with the overflow tank to make sure it doesn't allow air into the system on cooldown.

What the hell has the above to do with the price of fish. (Why post a lot of stuff which is not needed and dose not apply.)

In any event, I have no idea what point of view you are bringing to this discussion. Rather than try to decipher your posts, I mostly ignore them.

I accept your explanation that you are not good at reading and are unable to comprehend(understand and take in) any complicated issue. In the future I will take this into account. (Next time I post anything for you to read, I will remember what you have now posted.) I make a statement of fact. Sarcasm is not intended.

You now indicate that you did not and do not understand my simple question, and the exact topic(thing) involved i.e.:-

"Did you confirm that both radiator fans were working at full speed at all times throughout?"

I will carefully explain for you, covering both my language and what was included within the preceding/previous text/writings. --

During the time when you were experiencing(having) overheating problems, did you confirm(make sure), that both radiator fans were working at full speed, at all times throughout(when stationery stopped/running slow to cool down/running at high speed)?

It was my intention to assist(help), in the event that (if) the automatic controls were not maintaining maximum fan efficiency (not keeping both of the fans going properly and at full speed) thus(and therefore) ensuring(making sure of) maximum (the best possible) air flow after you had ceased(stopped) racing.