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Zx12 running a bit warm
locostbuyer83 - 7/5/11 at 07:06 AM

Hey guys,

I let my car sit and idle for a while yesterday to see how it can cope with cooling but with the bonnet on it slowly gets to the top of the temp gauge. I've got a polo rad and fan attached but with the bonnet on there is no room for the hot hair to vent.

What have others done to help cooling?

I noticed hellfire had made vents in the bonnet to help.

Just concerned of they leave the engine running with the bonnet on for some time during the IVA.

Thoughts?


graememk - 7/5/11 at 07:08 AM

bonnet off for iva and they stick a big fan infront of your car


ReMan - 7/5/11 at 07:12 AM

Is the fan actually coming on?
It should do this before the temp gets too high
My blade overcools if anything with the polo rad but because of where the thermoswith is it does not always swith the fan on reliably, so I have a manual overide switch too


eznfrank - 7/5/11 at 07:19 AM

Have you got a fan override switch?


locostbuyer83 - 7/5/11 at 07:24 AM

The fan comes on as it should and keeps the temp in the middle with the bonnet off but I've got a big sump guard below the engine so there's literally only the exhaust manifold hole for the air to vent.

Are you allowed to remove the bonnet for the IVA to help cooling?

I'm sure normally it would'nt be an issue but if they want it to sit with engine on it's gonna overheat.

I don't have an override switch but the fan is on constant once the temp reaches about 80degrees


ReMan - 7/5/11 at 07:33 AM

You need to consider real life more than the IVA
I expect he IVA guys will not (need to) sit it idling any more than absolutly nessesary for emmisions etc ,
The bigger issue would be if you are in v slow traffic on a hot day.....


locostbuyer83 - 7/5/11 at 07:35 AM

quote:
Originally posted by ReMan
You need to consider real life more than the IVA
I expect he IVA guys will not (need to) sit it idling any more than absolutly nessesary for emmisions etc ,
The bigger issue would be if you are in v slow traffic on a hot day.....


Yeah agreed. Think I'll make some vents in the bonnet but I'll do it after the IVA.


David Jenkins - 7/5/11 at 07:37 AM

It's worth sorting this out, regardless of the IVA - you are very likely to get held up in traffic jams when out and about, and it's no fun having to pull into the side of the road because the engine temp is rising too far!

(damn - too slow!)

I used to have this problem when I had too small a mesh on the grille - the fan couldn't suck the air in fast enough. Changed to a stainless woven-wire type of mesh and temps reduced massively. I also added a few discrete holes to one side of the bonnet to allow air into the carbs, so duplicated them on the other side for appearances sake. I'm sure these help to clear warm air out of the engine compartment.

Maybe a tasteful vent or two will help your problem?

[Edited on 7/5/11 by David Jenkins]


locostbuyer83 - 7/5/11 at 07:42 AM

quote:
Originally posted by David Jenkins
It's worth sorting this out, regardless of the IVA - you are very likely to get held up in traffic jams when out and about, and it's no fun having to pull into the side of the road because the engine temp is rising too far!

(damn - too slow!)

I used to have this problem when I had too small a mesh on the grille - the fan couldn't suck the air in fast enough. Changed to a stainless woven-wire type of mesh and temps reduced massively. I also added a few discrete holes to one side of the bonnet to allow air into the carbs, so duplicated them on the other side for appearances sake. I'm sure these help to clear warm air out of the engine compartment.

Maybe a tasteful vent or two will help your problem?

[Edited on 7/5/11 by David Jenkins]


Hadn't thought about the mesh on the grill. It's quite fine. Dont want to make any changes to effect IVA on tues but once it's passed I will certainly sort it. Been there and sitting on the pavement with a hot engine sucks.


ReMan - 7/5/11 at 07:44 AM

Just a thought, and not meant to undermine your intelligence
The fan is definatly blowing the right way is it?


locostbuyer83 - 7/5/11 at 07:57 AM

quote:
Originally posted by ReMan
Just a thought, and not meant to undermine your intelligence
The fan is definatly blowing the right way is it?


Only fits one way round. As I said it works fine with bonnet off. Just fails when there is no airflow.


adithorp - 7/5/11 at 08:23 AM

quote:
Originally posted by locostbuyer83
quote:
Originally posted by ReMan
Just a thought, and not meant to undermine your intelligence
The fan is definatly blowing the right way is it?


Only fits one way round. As I said it works fine with bonnet off. Just fails when there is no airflow.


I think what he meant was, is the fan rotating the correct way. There's been a few wired the wrong way around on here in the past.

My SVA was done with the bonnet open for the engine running bit's (emmisions) and I've seen plenty of pictures of sevens being tested with the bonnet off. A few vents won't go amiss though. I have an override switch on the fan which I fitted as the fan coming on/off made holding steady revs for the emmision test difficult.

The heat soak when suddenly having to stop on the motorway seems to be the biggest strain on cooling. Just the circumstances you don't want trouble in so worth sorting. Make sure you completely seal around the rad/nose as it makes a huge difference.


locostbuyer83 - 7/5/11 at 08:47 AM

quote:
Originally posted by adithorp
quote:
Originally posted by locostbuyer83
quote:
Originally posted by ReMan
Just a thought, and not meant to undermine your intelligence
The fan is definatly blowing the right way is it?


Only fits one way round. As I said it works fine with bonnet off. Just fails when there is no airflow.


I think what he meant was, is the fan rotating the correct way. There's been a few wired the wrong way around on here in the past.

My SVA was done with the bonnet open for the engine running bit's (emmisions) and I've seen plenty of pictures of sevens being tested with the bonnet off. A few vents won't go amiss though. I have an override switch on the fan which I fitted as the fan coming on/off made holding steady revs for the emmision test difficult.

The heat soak when suddenly having to stop on the motorway seems to be the biggest strain on cooling. Just the circumstances you don't want trouble in so worth sorting. Make sure you completely seal around the rad/nose as it makes a huge difference.


Oh right, Sorry I misunderstood... I shall check if the fan is rotating the correct way...


locostbuyer83 - 7/5/11 at 09:44 AM

fan is rotating the right way


ReMan - 7/5/11 at 09:51 AM

Ok
in which case it does seem like the hot air can't escape
What does it do without the huge sumpguard?


locostbuyer83 - 7/5/11 at 10:02 AM

quote:
Originally posted by ReMan
Ok
in which case it does seem like the hot air can't escape
What does it do without the huge sumpguard?


Probably has better air flow but it's a mission to take off


40inches - 7/5/11 at 10:08 AM

This is what I have done.
Vents
Vents


locostbuyer83 - 7/5/11 at 10:14 AM

quote:
Originally posted by 40inches
This is what I have done.
Vents
Vents



Where did you get that mesh from? Its really nice


David Jenkins - 7/5/11 at 11:00 AM

This was my original grille

front (early view)
front (early view)


This is what I'm using now (apologies for the dark picture!).




And here are the vents (3 each side, about 50mm diameter). This picture also shows what happens when you forget to fasten the bonnet...

Rescued attachment bonnet.JPG
Rescued attachment bonnet.JPG


There's also a 5mm gap between the bonnet and the engine compartment sides (deliberate, honest!) that let a lot of hot air out.


[Edited on 7/5/11 by David Jenkins]


Moorron - 7/5/11 at 11:22 AM

Funny thing is i was/have had the same problem. When i swapped out my old ZX12 (2003 model) with a 2001 unit i noticed it ran hotter and was cuasing me to look at the temp gauge all the time when i got into traffic. I even bought a new Kenlow fan incase my second hand sourced one was not doing it job.

My first problem is im not using the bikes clock and my temp sender is in the rad top hose so doesnt read from the same place as the bikes original one does. So its hard to give a like for like comparision as to what Kawasaki running temps are to mine. The next thing is the polo rad and its fan switch, which most likley isnt the same range as the bike rads original one. But i did a good test with it last week:

I took the bonnet off the car and ran it up to temp so the fan would switch on, i took temp readings from my after market gauge and also a multimeter reading from the bikes original temp sender at the same time to see what resistance it was at and using the service manual to cross reference those readings into what the bike clocks would show. I also did this to see when the fan kicking in and out to compare to the markings on the polo rad switch.

What i found was the engine wasnt overheating, just running hot in traffic. The polo rad fan switch has 84/95 stamped on it should kick in when at 95C, but according to my after market temp gauge this happened at 110c and to the resistance reading at 102C.

So i found out my after market guage was over reading compared to what the bike would have shown on its dash.

I ran the test a few times and also unplugged the fan to see when the bike was over heating and if the fan would cool it down to a safe level again.

Sorry for the long post.

Basically i would suggest that just because the fan is switching on doesnt mean the engine is over heating or running hot, it maybe like in my case that the fan switch in the polo rad is too low and switching on at 'running temps'. If you have the bike clocks see if the temp gauge flashes, if it doesnt then its not overheating and i would only worry about the possibility that you need to get a higher fan switch to allow the fan to only run when it does get really hot.


40inches - 7/5/11 at 08:12 PM

quote:
Originally posted by locostbuyer83
quote:
Originally posted by 40inches
This is what I have done.
Vents
Vents



Where did you get that mesh from? Its really nice

From ebay Here


adithorp - 7/5/11 at 08:46 PM

If you're putting in vents then try and use woven mesh rather than thet expanded ally' mesh. It restricts the air flow quite a bit... well actually, a lot!