[Mk2] [Turbo] 500HP COOLANT TEMP PROBLEM

[mr2mitch]

Hi,
has anyone had water pump failure when running big HP or when raising the rev limit to 8000rpm plus. has anyone installed a davies craig EWP as a replacement???

mitch

[jannerboy]

Guys, I can add a bit more detail to Mitch's post above as I am responsible for the engine build + spec etc...!

Its highly modified, custom chargecooler, DTA EMS, forged engine etc etc and has been fine until we raised the rpm/boost etc following running in.

I am concerned that with all the modifications, that the coolant system struggles to cope with the increased heat input from "big" turbo, high boost, raised rpm limit etc...

Its as if suddenly the water pump has lost a few impeller blades! Have any of you experienced similar? Changed to an EWP for a constant high flow system? Any input would be much appreciated.

Could be the thermostat perhaps playing up so we'll investigate that soon, but i doubt it as its fairly new...

Q. Is there an Uprated Coolant Pump available???

[greeny]

Usually the coolant system is man enough for anything the 3s can throw at it, with the engine in the back, the volume of water in the system is greater than most cars.

What problems are you actually having?

[mrdb]

water pump may be cavitating at the higher rpm...

i would expect at 500hp you will need to run EWP at constant flow and as a safety measure run evans collent..

[Driftlimits Performance]

davies craig EWP

these things pack up after 6 months on a chargecooler, I'd dread to think how long it wouldn't last on the engine cooling system!

[jimGTS]

Running ARP head studs??

Have you retorqued them after 1000 miles?

Wild suggestion, but werth mentioning.

Temp problems only when high in revs, or anytime your on boost?

[GTS GAV]

Just thort I would throw this out there as it maybe of some help to the thread, as greeny I am sapprised the coolant system isn't working efficiently considering your only running 500bhp, as I'm pritty sure nathen was still running the oem system on his 900hp drag car and once again agree with greeny we have a vast amount of coolant compared to others I.e the celica gt4's etc I wouldn't have thort a EWP wouldnt be needed if you really wanted to go for a larger capacity water pump I think toda do one irl find you the link for it, what temps are you seeing at the moment? The thing that worries me the most Is after shut down were the coolant is no longer flowing causing it to get very very hot and even start to bubble, I have read up a lot about this recently on how the bubbling effect after shut down can cause the coolant to evaporate around the cylinder walls leading to air pockets around the cylinders wich is no longer keeping the block cool in places which can lead to the block cracking etc, to help prevent this I fitted a 1.5bar trd rad cap and also a trd low temp thermostat wich opens much erlea keeping temps around 75 to 80deg or just over a quater on the stock temp gauge, the trd rad cap was very impressive and eliminated the bubbling after shut down etc, maybe think about a trd stat and rad cap

[Gizzmo]

Just to add some more detail here as I map this car...
Temps are absolutely fine when on full boost etc. Runs mid 80deg C water temps.
After maybe 20 minutes mapping and while on the run down, the water temperature jumps from 85c to 130c in about 2 seconds!!
Then it stays there for several minutes, before dropping to 85deg again in about 5 seconds.
Minute later - bang - 130deg again.
It's like there's insufficient flow...
The other night there was a screeching noise from the water pump end of the engine while the engine was allegedly running 130deg.

It's annoying as it's not even running big boost yet!
If head was lifting I'd expect temps to rise while on boost. Also, there doesn't appear to be any water/combustion gas mix.

We'd put it down to water pump failure, but this seems to be so uncommon that now seems unlikely?

[GTS GAV]

this story sounds all to familiar I hate to say it but sounds like you have cracked the block , its happend to geeman recently there's a thread on here about it, its the secound time its happend to him now, I really hope it isn't but maybe time to take a closer look at the block to find out for sure I would be very sapprised if its a water pump failure

[GTS GAV]

http://www.imoc.co.uk/forums/viewtopic. ... sc&start=0

[Gizzmo]

Out of interest....
If a block is cracked, could it then be sleeved and be ok again?
Anybody done this?

[GTS GAV]

Gizzmo why would you want to do this? Imo and this is just mine this isn't goin to do you any favours in the long run even it can be done in the first place as if it is cracked then borring and honing is only goin to make it worse in my eyes, and you will deffantly get some strange looks from your machinist when you tell him what you want doing, the crack will still be behind the liner and will only get bigger wich will lead to lots major issues down the line, an to be hounest if you were having the hole lot stripped would be much more of a decent idea to get hold of the rev5 block wich is ment to be a lot stronger and sleeve that I wouldn't imagen you to have any problems after that but never say never with these engines lol

[Gizzmo]

Yeah, I'm sure you are right.
Just asking if anybody has done this...

[GTS GAV]

Oh no don't get me wrong I'm not taking the p1$$ out of you or knocking your train of thort just thort if your having to spend all that time and cash may aswell just start with a solid block, coz it could cost a lot more if you did try an sleeve it with a cracked block and then it went wrong again you would have to do it all over wich isn't fun

[GTS GAV]

Gizzmo what intake temps were you seing when you were mapping it? And what sort of cooling are you using chargecooler bootmount etc? Also what was the boost set at?

[sjm1984]

Sleeve it ! In reality you just need to do the two middle bores !

The thickness checks I've done with several blocks indicates an inherited weakness in the design of these blocks ( irrespective of variation ) although I've not checked a rev 5 block !

The sleeving will irradicate the issue, the properties of the cast iron sleeves yield an increase in ductility/hardness per mm compared to the cast iron block to withstand the higher boosting pressures.

So although the overall thickness of the cylinder Walls may not be increased, the resistance to cracking is dramatically improved !

Limitations unknown, I push mine to 1.8 bar and its holding together ! Sort the cooling and ramp up my fuelling when I have time and I'll try 2 bar plus daily on a high compression setup !

[Gizzmo]

Gizzmo what intake temps were you seing when you were mapping it? And what sort of cooling are you using chargecooler bootmount etc? Also what was the boost set at?

Between 14 and 25 deg at 1.5 bar.
It's a boot mount 450x250x100mm chargecooler with massive rad at the front and a powerful water pump for chargecooler.
Intake temps are mint.
EGTs are stable as well.

[GTS GAV]

Wow that's super cool where was the reading taken from the hand commander or....? I hope for the op sake it isn't a cracked block but you never no.

[bobhatton]

What fuel are you using?
What is the measured compression ratio?
What boost are you running?
What is you timing advance at max boost?

My feeling is the C/R will be too high for the boost and fuel you are using so the timing is being retarded and that will over heat the block boiling the water.

Bob

[Gizzmo]

Wow that's super cool where was the reading taken from the hand commander or....? I hope for the op sake it isn't a cracked block but you never no.

From the DTA Software - we aren't using an old school PFC! YUK!
Using DTA S60 PRO
Reading was taken from probe just pre-throttle body