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Overheating - Bigger Radiator?


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#1 al_reidy

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Posted 22 June 2010 - 06:52 PM

I drove 20 miles in this heat (24 deg C) and found that my honda type r engine would over heat. 105 deg c the water got up to unitl i pulled over to let it cool.
at that temp the oil temp had risen to 110deg c when the dash alerted me to the oil pressure then dropping.

i was cruising on the motorway off-vtec. 60 - 70mph.

i have 3 fans on the radiator - 2 pulling and one big to push.

does anyone else have this problem?

does anyone else have a solution? bigger radiator?

i have not yet ventured to a track day but would assume it will kill itself if. i did buy the race spec kit, you would think it would cope...

#2 al_reidy

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Posted 22 June 2010 - 06:57 PM

demon tweeks alloy rad...?


possibly?

#3 e11evns

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Posted 22 June 2010 - 07:11 PM

something not right there ring zcars

#4 R1mini

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Posted 22 June 2010 - 07:31 PM

i have 3 fans on the radiator - 2 pulling and one big to push.

Is that right? try all in the same direction, ie pulling

Cheers
David

#5 al_reidy

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Posted 22 June 2010 - 07:40 PM

i have 3 fans on the radiator - 2 pulling and one big to push.

Is that right? try all in the same direction, ie pulling

Cheers
David


there is no room for my 3 on one side. i had to use the bigger on one the push side...

hmmm

#6 R1mini

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Posted 22 June 2010 - 09:48 PM

Got it now, they are directing the airflow all in the same direction

Cheers
David

#7 philly c

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Posted 23 June 2010 - 05:57 AM

there is no air in the system is there? may sound daft but a few pockets of air wouldt help matters??

#8 cptkirk

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Posted 23 June 2010 - 09:11 AM

I concur with the guys above, sounds like an air lock issue, mine runs sweet with the same rad, never getting above 86degC and when it does the 2x 9" fans kick in and bring it back down to 84degC without any dramas. Plus mines going to running hotter due to the supercharger.

Have you got a bleed on the radiator? if you have try raising the back of the car and bleed the rad out. If not just tap a 6mm hole in the top plastic bit of the rad and use this as a bleed hole and use a regular M6 bolt as a bung, just be careful not to overtighten as you're only tapping 1-2mm of plastic, I used a rubber washer under a regular washer to ease the amount of tightening required.

Where is your temp sensor placed?

You might want to try filling water into your bleed hose on the top hose fitting of the engine (careful not to overfill above your expansion tank level), just to make sure you have fully filled the block, thats why I went for two filling points either side of the thermostat to ensure the block was getting filled at the same time as the coolant lines and radiator.

#9 AllanMcD

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Posted 23 June 2010 - 09:16 AM

It z-cars rad is big enough you have a problem probably air.
Allan

#10 al_reidy

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Posted 23 June 2010 - 10:13 AM

cheers guys, i have bled the system a few times, never getting any decent air out of it (other than when i first filled it). i will flush it all out and add the bleed holes. lets see.

one other question, are you guys running a sealed blukhead? not venting out into the air with no rear windows etc. im wondering if its the bulkhead thats trapping hot air in the engine bay.? (i am venting a bit on the boot lid)

#11 cptkirk

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Posted 23 June 2010 - 10:47 AM

I have a fully sealed bulkhead, no venting from the bootlid and I have the diffuser running underneath and I am not suffering with the heat issues that you are. It does get frickin hot in there but like I said its not causing any other heat issues.

#12 Ethel

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Posted 23 June 2010 - 11:19 AM

The fans could be working against one another. If one is more powerful than the other it might see the other as a restriction - in the same way a car doing 50 can be a hindrance to a car 70. Also, the output won't be uniform; there will be more air shifted by the, faster, edges of the blades than by nearer the hub. Are they also counter rotating?. If the radiator is forward facing I don't think fans should be necessary at that speed - look at the size of blower that's needed on a rolling road, and that isn't really up to the job of keeping a pulling engine cool.

#13 al_reidy

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Posted 27 June 2010 - 04:16 PM

hmm im still stuck on this.
i started of with zcars's solution. just one big fan pulling air though the standard (polo ?) radiator. this failed the IVA due to it overheating at idle.
i added a smaller secondary fan to go next to it still pulling. this passed the IVA at idle and the fast idle test. but i did hide to the tester the fact that the dash was alerting me again right near the end of the test. i drove it for a while noticing that in traffic it would overheat. so i added a third to push the air though the small space left below the small fan.
All this didnt do much at the time hence starting this thread.

Today i couldnt be bothered to watch the football and went about having a go at flushing and bleeding up the system again.
Nothing major found, clear water so no rusting etc. i bled back up again and went for a drive. it behaved exactly like it did before, over heating after a while cruising.
its been 30 deg c outside temp today so it didnt take long to show.

I took all the fans off and replaced them on the rad, one massive one and a small one pushing this time, and the med size one in the gap left by the small one but on the other side pulling. there is no fan fighting for another fan now, they all have clear air and are all spinning the right way.

on my test drive i noticed that it still got very hot, but didnt overheat. 94-96 deg c oil was 100 to 102 deg c. it is a hot day for the UK so this might have solved it. i would like to have seen it stay in the 80's though....

i am using a standard bonnet, not the aero type zcars sell. i wonder if that make a good difference to cooling as it should do with the downforce?

#14 edsmini

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Posted 27 June 2010 - 05:26 PM

the engine should run fine when motoring along the road and maybe after sitting in traffic on a warm day for 5 mins should then klick the fan on, i would be checking that there is nothing restricting the flow of water through the system. three fans seems a bit excessive. thermostat jamming? or not opening fully

Ed

#15 vulpina

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Posted 27 June 2010 - 05:39 PM

Hello ,
Maybe check the thermostat outside of the car in some warm water to see if its working properly .

Maybe your front grill is too restrictive .

Maybe the engine going a bit lean on idle ,
Just throwing some ideas :thumbsup:




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