30 replies to this topic

[RallyRed]

Hi all,

 

So here is the story. Sorry for the long read.............

 

VE HSV GTS, LS2 stroked to 408, rebuilt to be good for 15 psi, drive train upgrade etc etc. Twin turbo'd. XR6 Garrett style turbos, turbo bearing oil and turbo cooling water fed. Water is plumbed into the normal cooling system, water flow through the turbos is good.

Car  is running at 9psi boost and makes great power and torque.

 

The issue

 

Car does not overheat, even on dyno run.

Water pump and radiator and 2 stage electric fans all working fine.

Correct coolant and mix.

However, even after a cooldown idle, about 10 seconds after the car is turned off, the water in the lines,immediately near the turbo casing boils.( I actually replaced this piece of hose with a clear section, and can see it occuring)

This to me is understandable, as the water has stopped flowing, and is now stationary, and subject to the full heat load that is now trapped in the turbo.

The downside to this is that the water in the turbo cooling line turns to steam, and thus over pressurises the radiator, and it dumps its coolant to the overflow bottle. Yes it does siphon back in to the radiator, once cooled down, but it just seems no good to me.

I am told by turbo people that it is not normal.

 

I am also told that -

To allow for ""auto siphoning"" in the turbo water lines ( where the local water from the turbo gets really hot after turn off , more water will sort of be naturally pulled through the turbo just by the fact that the hot  water  will rise  and pull more water through.)  anyway , to achieve this, I am told that - 

1 The turbo shouldnt be the highest point in the water sytem - they arent the highest point.

2 The turbo mounting/water lines ( in versus out) should be skewed about 6 degrees uphill to help with the auto siphoning  - they are at 6 degrees.

 

Thus, the installation seems OK. 

 

Having fiddled with this for months on and off I am now at the point of thinking - 

 

1 Its all too hard, should have gone S/C instead.

2 Run the turbo water to an independant/seperate cooling system and keep it electrically circulating after turn off, for a few minutes. This would be painful in my mind as it would need a pump, mini radiator, cooling fan, more plumbing etc etc. i.e more failure points.

The engine bay is already 99% full.

3 Swap out water pump to electric style, but unsure i we can fit it in, as that area is already full of catch can, 2 x wastegates/dump pipes etc etc.

4 Try some of this waterless coolant stuff, boils at 375F / 190C. 

    To try this will cost around $500, and I'm not sure it's as good as they claim.?

 

Has anyone used it?

Any experience with this turbo/turn off heat issue??

 

Thanks in advance.

 

 

 

 

[N/A-PWR]

Here you go Mate:-

 

https://www.google.c...chrome&ie=UTF-8

[warrenm]

I haven't any personal experience with these coolants, but my brother uses it in his speedway engine, he say's the engine temps have reduced considerably when the car comes off the track, it was running about 230°-250°F that has reduced to 190°-200°F.

[RallyRed]

Thanks gents.
Like I mentioned...the car is not getting hot, just localised boiling in the line immediately at the turbo,on turn off.
I'm thinking I will add an electric "booster" pump into the turbos water line..and automatically run it for a few minutes after turn off...to keep the water mooving.
I did a test yesterday where I totally removed the turbo waterlines from the car cooling system..ran a garden hose in, and a hose to a bucket out. Even at 1 litre per minute flow and holding the car ( in the shed) at 4000rpm for 90 secs..the bucket water never exceeded 23degrees. At engine turn off..it rose to 26 degrees. Admittedly its cool water going in. Thus...I'm thinking keeping the water mooving at turn off is the go. If that doesnt work..will go to the waterless stuff. Thanks for the feedback guys.

Iam a little interested in how XR6 turbo cars solve this issue though.?

[Bigfella237]

Just out of interest, Col, what length of time do you usually "cooldown idle" for?

 

Do you have an infrared thermometer to observe how long it takes for the pyro temps to stabilize with the engine idling?

[RallyRed]

yeah Andrew, have tried all sorts of cooldown idle times...up to 5 minutes. Doesnt seem to make much difference. I think its just that we have a hot piece of metal

( turbo ) that is exposed to the full exhaust gas temp.  at about 100mm from the head. Once the water stops flowing , ( and it's only in a -4 AN line) it just too much heat and too little ( still) water.

 

I would also comment that I have noticed that even after 5 minutes at idle, when turned off, the turbos take 36 - 39 secs to run down ( unrelated to this issue, just interesting)

[fx48_eh64]

i was going to switch to waterless coolant, but was told that you cant have so much as a drop of water left,  so its really only suitable to use after a rebuild etc,  to totally purge your system of all water is almost impossible and not worth the effort i was told.   happy to be proved wrong though if anyone knows a way to do it

[grumpy xu1]

The ls style engine has a water drain plug each side of the lower block. On the drivers side it's in behind the starter motor, they should be grub screws.

[grumpy xu1]

& mazzire offer a ls style electric water pump. There's a water circulation set up, being used on the lsa in the USA, but i can't remember the details of it, it's been a while since i looked at it. You could try a Google on it.

[RallyRed]

ta guys..re the Meziere setup..yep...scoped that out..it even has a dummy pully so the orig. belt can still be retained. Down side is that in Aus they are appx $1500!. Davies Craig offer a Elect. Booster Pump that can be inserted inline, and just energised after turn off. Or ran full time and turned off after a set time. I am leaning towards this solution ....as even the waterless tech. dept. ( yesterday ) said they were 98% sure just waterless coolant would fix the issue...however ,we MAY still need to pump it after turn off.

[S pack]

[lx308]

Hi all,

 

So here is the story. Sorry for the long read.............

 

 

 

 

Having fiddled with this for months on and off I am now at the point of thinking - 

 

1 Its all too hard, should have gone S/C instead.

2 Run the turbo water to an independant/seperate cooling system and keep it electrically circulating after turn off, for a few minutes. This would be painful in my mind as it would need a pump, mini radiator, cooling fan, more plumbing etc etc. i.e more failure points.

The engine bay is already 99% full.

3 Swap out water pump to electric style, but unsure i we can fit it in, as that area is already full of catch can, 2 x wastegates/dump pipes etc etc.

4 Try some of this waterless coolant stuff, boils at 375F / 190C. 

    To try this will cost around $500, and I'm not sure it's as good as they claim.?

 

Has anyone used it?

Any experience with this turbo/turn off heat issue??

 

Thanks in advance.

 

Yep, number 1

[jpxu1]

Hi Col,

 

My LJ XU1 and hot weather/heavy traffic do not mix well at all and it always overheats/boils without much trouble. Prime spot is getting out of Phillip Island after a Historic Race Meet which I always attend.

 

So I converted to Adams Waterless coolant to see if it would help the problem.

 

The guy selling the stuff told me all the race guys use it. His theories that the main problem with overheating was the air formed from bubbling and therefore lack of water where there was air seemed coorect.

 

The waterless coolant has such a high boiling point that it doesn't boil in the engine and therefore no air/lack of coolant in the head.

 

So what happens in my XU1?

 

Well it still gets hot, just as hot as before, actually it can get even hotter - because I can let it get hotter, as it no longer boils I can let the temperature go all the way around to 260 (if you know an XU1 temp gauge there's not much room left after that).

 

The engine runs fine, there's no extra noise, the oil pressure doesn't change on the gauge, the coolant doesn't overflow.

 

The only thing that says the engine is hot is the temp gauge, otherwise you wouldn't know.

 

I think the stuff is brilliant.

 

And the traffic jams getting out of Phillip Island? I now just sit in the line and pity the poor souls I pass with bonnets up of cars with steam everywhere boiling their brains out.

 

JPXU1

[jpxu1]

And purging the system... The Evans stuff doesn't have to be zero, it does have to be a very low percentage, can't remember exactly, maybe 2-5%?<br /><br />I drained the radiator and the block from the tap after flushing the system with the thermostat removed. I then left it for a week to dry out.<br /><br />But if time is of the essence I'm pretty sure Adams have a flush solution to rid the water from the system.<br /><br />JPXU1

[Bigfella237]

~ There's a water circulation set up, being used on the lsa in the USA, but i can't remember the details of it, ~

 

LSA & LS9 (and I assume LT4) supercharged engines have a separate cooling system and pump for the WTA intercooler, that could be what you're thinking of?

 

~ The guy selling the stuff told me all the race guys use it. His theories that the main problem with overheating was the air formed from bubbling and therefore lack of water where there was air seemed coorect.~

 

There are a few tools around that evacuate the air from the cooling system before adding coolant, which should help with that problem, one example is the Uview Airlift...

 

[jpxu1]

There are a few tools around that evacuate the air from the cooling system before adding coolant, which should help with that problem, one example is the Uview Airlift...

 

It's not the problem of air in the sysytem when you fill with coolant (most engines with that problem have a bleeder installed to evacuate that air), but the air and steam created when the coolant/water boils. If the coolant doesn't boil there is no air/steam created.

[RallyRed]

Thanks again gents,

 

Having spoken at length to both Evans and the Liqui intellegence mob ( the  2 Aussie suppliers)
of the waterless stuff, I agree that all water needs to be gone, otherwise it can still boil/  steam will still form and make pressure. 

The go seems to be to drain it, flush with water, fill with the Prep Fluid ( a super hygroscopic water grabbing  fluid), drain, open up what ever you can and blow out with air, connect a vacuum cleaner ( on blow) into the radiator, water pump etc and let it run for a couple of hours, then leave it open for a few days.....then.....fill with the waterless product.  Time consuming, but easy.   As Mr Fx said...easier on a new/fresh/dry engine.

 

They give perhaps accurate, but on the surface confusing info....that the car runs cooler, but the gauge may show hotter. This is explained logically? by the fact that the fluid is moving more heat away from the metal engine surfaces and into the fluid. i.e. metal cooler, but liquid ( where the gauge comes from) hotter.  Make sense to me. Backs up JpXu1s experience.

 

I do like the fact that there is little or no pressure in the closed cooling system, as with this car there are several addition hoses, and to me , every extra hose is a potential failure point, that is less likely to fail if not under pressure.

I dont like the fact that IF you ever spring a leak somewhere, you cant top it up from a tap.

 

I'm thinking  - 

 

A

If we remove the water pump and replace with the $1500 Meziere electric unit, ( with dummy pulley to allow eisting belt to be retained) it will solve the issue, and we have the flexibility to keep the entire cooling system running after shut off. However, any failure will kill the entire cooling system, with bad results

There is presently no engine overheating issue, so why change something that isnt an issue.?

No existing hoses would need to be altered or new ones added.

There is space for it in the crowded engine bay, but only just.

B

If we run the $350 Davies Craig electric booster pump in line with the turbo water lines, then the normal turbo cooling will be via the car's waterpump,  and then will be maintained for a time , via the booster pump when turn off occurs.

This addresses the actual issue - no turbo cooling  flow at turn off.

Existing hoses would need to be altered and 2 new ones added.

C

Just run  waterless coolant, total installed cost around $500.....claimed to be a 98% chance of fixing the issue . It also gets rid of pressure, but so what, every other car on the road has pressure.

If the 2% chance of not fixing the issue actually occurs, then we are still up for a pump anyway.

Warren and JP and others have eperienced/have heard that it does work. Also theres a local dirt/Targa type rally guy here in town who has run full Rally stages with no radiator cap with this stuff fitted, and wasnt even aware of it until he saw the cap missing. ( again,this is a story about heat and pressure with water flow, whereas our issue is heat dissapation/absorption  at zero flow).

 

I'm sorely temped to run the snake oil.....

 

Will ponder some more over a few beers later on.   Again, thanks for all the input.

[S pack]

The downside to this is that the water in the turbo cooling line turns to steam, and thus over pressurises the radiator, and it dumps its coolant to the overflow bottle. Yes it does siphon back in to the radiator, once cooled down, but it just seems no good to me.

Sounds like the coolant recovery system is working as designed. Probably worrying about nothing.

 

Just my 2 cents.

 

Cheers

Dave.

[RallyRed]

Hi Dave...hearin ya mate.

 

But I would add...keeping the turbo as cool as possible after turn off is a good thing for both it, the oil in it, and the car in general I imagine. ( i.e. not forever pressuring the system to  off blow off point, every time it is turned off.  The other thing I hadn't mentioned, is that occasionally it pushes out enough water to overflow the overflow tank, thus that water is lost.

[N/A-PWR]

I remember the days when the Turbo Cars stayed running after the Owner got out,

 

 it was an automatic thing.

 

These Days, Turbo cars just turn off when we exit.

 

 

I say, the WRX Club Spec10 year 2010, I had from new, the Turbo had oil and water cooling.

[grumpy xu1]

Hi Dave...hearin ya mate.
 
But I would add...keeping the turbo as cool as possible after turn off is a good thing for both it, the oil in it, and the car in general I imagine. ( i.e. not forever pressuring the system to  off blow off point, every time it is turned off.  The other thing I hadn't mentioned, is that occasionally it pushes out enough water to overflow the overflow tank, thus that water is lost.

Col, I'm just Wondering, does this vehicle now have an under driven crank balancer on it ? & if so, are you now running a over driven water pump pulley ? When i looked into this for the SS, i purchased a Evans brand water pump, they were at that time considered the best ls pump on the market with around 10 - 18% more flow, they also do an option on standard size pulley & the over driven size. Obviously they have to match the balancer size, at low revs, the standard pump pulley won't flow as much with the under driven balancer, which is usually either 10 or 25 %. The pump cost me around $430 from John @ Evans, he was knowledgeable and helpful. That would be my first port of call, I'm also thinking about a seperate cooling system possibly just for the turbos if all else fails. If you buy the Evans pump, find out how to set it for water use or waterless though. Gary.

[grumpy xu1]

It's not the problem of air in the sysytem when you fill with coolant (most engines with that problem have a bleeder installed to evacuate that air), but the air and steam created when the coolant/water boils. If the coolant doesn't boil there is no air/steam created.

Ls engines don't have an air bleeder mate, hence the use of steam ports & the high fill points ect, I usually have the over flow up high & the cap off, until after the thermostat has cut in (heater on too) you can also have the steam line of off the radiator & let the water come out of it as you fill, before putting it on the radiator point. That usually gets the air pockets out of them.

[RallyRed]

Thanks Gary..re the pulleys. It still runs the factory serpentine belt..so I think all pulley stuff is stock.
It's actually my eldest son's play car..I just fiddle with it and get each bug out of it..one at a timd..lol.

Re the filling process...yes..we use one of those big filler funnels that fit onto the radiator via a custom cap. Also get it up to temp, thermostat opened (evidenced by full flow in radiator) , park it nose up on a steep driveway, crack a steam port or 2 ( they are now plumbed via Aeroflow piping ).
We were advised in the early days that LS engines are cronic suffers of getting air locks upon refilling.
I reckon all the above relates to the cause of engine overheating...we dont have that.
Re a seperate cooling system...I have scoped that out, a Honda CR125 rafiator is a nice fit. Also would need a 6 inch fan and pump.
Neat and tidy and hidden inside front spoiler..however..just introduces more failure points.
hmmm

hey...edit is working again!!

Yeah Dave...but how do they do it?
That's this week's task...talk to some XR6 heads. ( our car has XR6 turbos)

Edited by RallyRed, 08 July 2018 - 08:00 PM.

[grumpy xu1]

I'd be thinking of running the Evans pump col, I've got a heaps of jobs on atm, or i would have had mine fitted & given you some feedback. The existing water pump, just laid the egg last week, so the Evans 1 should be in probably in 2 weeks time. (I've also ported the Evans pump too, so should be good for traffic & some spirited driving) Gary.

[S pack]

A bit of Turbo discussion on this Ford XR6 Forum Col.

http://www.fordxr6tu...-cooling-turbo/