SVX Engine cooling "Again & Again" - Page 104

Tireiron · #**1546** 07-05-2013, 02:16 PM

Did some more testing, looks like my current issue is a headgasket. I'm gonna cry. It would've been nice to know about it while the motor was still out. It was obviously bad when I bought the motor but I wasn't told. Now it's time to buy a set of cometics and lots of random gaskets and pull the motor out again.

BackWoodsBob · #**1547** 07-06-2013, 08:53 PM

How did you figure it was a HG issue? Did you have white washed spark plugs?

Tapani · #**1548** 07-06-2013, 10:16 PM

One way to evaluate is analysing the CO2 in the cooling system.

See post #13 http://www.subaru-svx.net/forum/showthread.php?t=58585

/T

Tireiron · #**1549** 07-06-2013, 10:32 PM

Much easier way to tell, coolant shouldn't do this when warmed up and the motor is revved... I've seen too many of this style headgasket failures in my 2nd gen legacys to not know the signs.

BackWoodsBob · #**1550** 07-06-2013, 10:48 PM

oh ****, yeah that things toast.

I saw the CO detector post, I might snag one myself before I go through the trouble of welding up a new thermo housing. Thank Tireiron!

SilverSpear · #**1551** 08-12-2013, 03:32 PM

Quote:

Originally Posted by Dessertrunner

Tapani,
I can all say what we do and what we have found if that is wrong then so be it,

- Dash temp guage won't move much till the car boils. I can't remember but Bazza found it in the maunel and I think the guage stays solid for a 25C drift. (got to ask why Subaru need to do that).

- Never in a million years would I jack the car to get the air out of the system, just fill the system run with cap off till fans come on put the cap back on and make sure there is extra coolant in overflow tank. Then thats it.

- I can grantee you can take the cap off my radiator and it will be full of coolant ever time with my current car (not a race car but still reving it to the red line).

- Our current mods work perfectly with the exception at 7,000 rpm and we are getting air in the sytem build up. This is from caviation and pretty sure we have the soluation we just need to run more tests.

- The goal is for the next round of cooling test will have the pump running at 10,000rpm for maybe 24 hours (pump will be belt drive from electric motor). Then we will confirm this with a running engine at say 7-8,000 rpm continuos. I promised Bazza that I would solve the problem so I will.

Thats my 2 bob worth.
Tony

Quote:

Originally Posted by Dessertrunner

Okay what is happening is when our engines are held at consistant high revs, around 6k they are still caviating enough to cause air to build up in the system and cause coolant to blow out or boil. If I am going to run a engine at 10k I need the cooling system to function better. In addiation I have had a number of people say they need to thermostat housing to be able to install in line.

There is not much chance of increase the flow to the pump suction any more so what I am doing is skinning the cat in a different way. What I have done is redesign the housing so the cover has a massive restriction to limit the maxium amount of flow the water pump can circulate. Just how much is the right amount I hope to find out with some trials.

Attached is a photo with the outlets are 16, 20 & 24mm holes. Remember the SVX is a high pressure water pump so we can get a lot of coolant through a small hole.
Here it is.

Guys what is the update on this problem?

Dessertrunner · #**1552** 08-12-2013, 08:05 PM

Have removed

BackWoodsBob · #**1553** 08-12-2013, 08:25 PM

Quote:

Originally Posted by Dessertrunner

Pretty clear from what I saw the we are on the home run re cooling of our engines, the only issues that did concern me a bit is I thing we need to get more airflow through the radiator if possible.
Tony

Awesome news!

I'm currently working on chopping and fiberglassing my bumper to increase airflow. Might be switching to an inline thermostat this fall when funds become available for aluminum welding gear.

Dessertrunner · #**1554** 08-12-2013, 09:19 PM

Have removed

BRZCory · #**1555** 08-13-2013, 04:52 AM

Quote:

Originally Posted by Dessertrunner

I think a addiational issue might be how you get the air out of the engine bay, it appears that a back pressure in the engine bay restricts the air to the radiator.

Bob has a legacy, so his engine bay is different. Also he has hood risers on the back, so airflow though the engine bay isn't a problem.

and for what it's worth, my EG33 with a massive radiator doesn't have cooling issues. In fact, after sitting in 100 degree weather in traffic, the fans RARELY kick on. I once did a test last winter, idled the car for 2 hours straight. Fans never came on. Unplugged the temp sensor and they kicked right on (This was just to verify that the sensor was working).

So although I can't speak for high-rpm cavitation, I can say that a bigger radiator will keep it from cooking.

BackWoodsBob · #**1556** 08-13-2013, 10:44 AM

I'm still unsure as to how that's possible cory. We have the same style radiator (cross flow). Maybe adding a divider into the tanks to keep the hot water from going straight across the top fins down into the water inlet would help?

My fans kick on even while driving, even tho it's rated for up to a 5.4liter V8.

BRZCory · #**1557** 08-13-2013, 11:10 AM

Quote:

Originally Posted by BackWoodsBob

I'm still unsure as to how that's possible cory. We have the same style radiator (cross flow). Maybe adding a divider into the tanks to keep the hot water from going straight across the top fins down into the water inlet would help?

My fans kick on even while driving, even tho it's rated for up to a 5.4liter V8.

I think it's because mine doubles it back.

So the flow is from top right INLET
<<<<<<<<<<<<<<<<<<<<<<<
D<<<<<<<<<<<<<<<<<<<<<<
O---------------------------- (separator between the 2 cross-sides)
W>>>>>>>>>>>>>>>>>>>>
N >>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>
To the bottom right OUTLET
And then back across through my funky crossover pipe,
And up in a U into the thermostat cover.

So it's traveling twice over the cooling area. Essentially I have a radiator that's twice as wide as yours (But half the height)

BackWoodsBob · #**1558** 08-13-2013, 11:24 AM

Quote:

Originally Posted by BRZCory

I think it's because mine doubles it back.

So the flow is from top right INLET
<<<<<<<<<<<<<<<<<<<<<<<
D
O --------------------------------- (separator between the 2 cross-sides)
W
N
>>>>>>>>>>>>>>>>>>>>>
To the bottom right OUTLET
And then back across through my funky crossover pipe,
And up in a U into the thermostat cover.

So it's traveling twice over the cooling area. Essentially I have a radiator that's twice as wide as yours (But half the height)

Ah, so you DO have a tank divider to keep the coolant going across the ribs? I was thinking it would behoove me to weld in a divider on one or both of my tanks to make the coolant move in an S down the radiator instead of shooting down my outlet tank.

BRZCory · #**1559** 08-13-2013, 11:29 AM

Quote:

Originally Posted by BackWoodsBob

Ah, so you DO have a tank divider to keep the coolant going across the ribs? I was thinking it would behoove me to weld in a divider on one or both of my tanks to make the coolant move in an S down the radiator instead of shooting down my outlet tank.

How else are you going to have an inlet and an outlet on the same side? It's a cross-flow radiator, once it's inside the coolant ribs it can only go straight across.

For yours you'd need to split the "intake" side in half, and move your outlet to the intake side. Then it'd be an exact copy of mine. To get "S" action, you'd need to do it twice (So two divisions on the inlet side, and one on the outlet) though I don't know how much coolant flow that would restrict (that's a LOT of piping)

BackWoodsBob · #**1560** 08-13-2013, 11:46 AM

I wouldn't switch my outlet/inlet sides, I have opposed inlet/outlets I'd just divide the tanks.