Cooling the 1KZ-TE motor:

[Shayne]

I got the TRD 71 degree stat on ebay Beau i thought it was coming from Japan so paid extra for quick delivery and it arrived less than 48 hours later . Not much point in speeding up the cycle without improving the viscous though .

 

[Beau]

Thanks Bob and Shayne.

Do you have a link to the TRD one you got off ebay Shayne?

And I'm not too keen (yet) on doing anything with my Viscous fan. It seems to work as it should so I'll monitor it before changing the fluids. Plus, I think the coolant going through the engine does more for cooling than the fan, what do you think?

Ideally I'd like to change the entire way the coolant enters the engine and have the thermostat on the top side, but I'm not sure if it's possible.

 

[Shayne]

I took a chance on this fitting and i won't know until i try http://www.ebay.co.uk/itm/TRD-Sport...153?pt=LH_DefaultDomain_3&hash=item1c528549b1 I can only answer your viscous question with a question of my own which is what cools your coolant when your in a traffic jam in a heatwave ?

 

[Beau]

I took a chance on this fitting and i won't know until i try http://www.ebay.co.uk/itm/TRD-Sport...153?pt=LH_DefaultDomain_3&hash=item1c528549b1 I can only answer your viscous question with a question of my own which is what cools your coolant when your in a traffic jam in a heatwave ?

I might as well wait until you've fitted yours so you can tell me what you think

Good question. The water pump is still spinning and they'll be cooler water somewhere in the system. However, I imagine after sometime of water circulating but not getting much cooler (due to the radiator getting no air flow) that the coolant will eventually be heat soaked and no longer be able to cool the engine down. So this is where the fan kicks in and creates that air flow needed. I think I've just answered my own question!

Now that I think of it, a electric fan that kicks in at lets say 10mph or less sounds like it may work well for low speeds/traffic. Although from what I've read on these specific engines, overheating tends to occur whilst they're being driven hard, not in traffic.

hmm another question, does the Viscous fan ever come on during motorway speeds? I can't tell because at that speed you can't hear it... In my head, it doesn't make sense for it, when driving at that kinda speed, the natura airl draw created by punching through the air should be adequate enough, right?

 

[Shayne]

Low speed cooling is as important as high speed when you go off road i'm forgetting yours is a street machine I imagine the fan is just an ornament at motorway speeds .

My own unqualified recently devised not fully investigated and perhaps nonsense theory about why these engines blow is - The crank gas recirculating the way it does causes it . I expect to be shot down in flames by someone with more knowledge but nothing was ever solved by not discussing it so here goes .

If oil deposits are carried up to the head along with recirculated crank gas - does it reach the piston ? If it does will it ignite ? if it does ignite will it not burn at a far higher temperature than diesel ?

I don't know it all results from a sleepless night of aimless reading but it could possibly explain why some blow heads and some don't and i am thinking very specifically of your truck Beau which irrc blew at very low miles . I will say no more and wait to see if i get shot

 

[BobMurphy]

Fumes from the crankcase come out of the cam box via a breather and are fed back into the inlet tract.

This means that the motor, instead of sucking in fresh air, is ingesting something that might burn. Diesel is then injected into this mix at the appropriate time.

I have no idea what this does to the Exhaust Gas Temp (and hence the temp of the block).

I would have thought it would have produced the diesel equivalent of 'pinking' if it was a problem but maybe someone has the figures to show what actually happens.

Interesting theory.

Bob.

 

[Beau]

haha Yes "Street machine" but there have been a few times I've taken her off the pavement and through mud. In those cases momentum served me well. Over here, I'll be on the beach a lot so keeping her cool at low temps will be a priority.

I had thought the fumes coming out from the cam box go back to the sump? I guess I was wrong... I'll need to have a look and see where this pipe goes. So surely fitting a catch can along this line will remove heavy oily deposits and the engine won't have to deal with burning these off instead?

 

[Shayne]

Thank you Bob it seems i may have dodged a bullet .

If that is the cause then a catch can is the cure Beau all big diesels such as JCB and Cat have an oil air separator for a reason .

I would have been a prime candidate to test the theory because 10 minutes at 80 + mph would show a rise in my factory temp gauge so i could have tapped into the vent pipe with a pressure gauge to see if there was any corresponding increase .

 

[Owen_Heller]

As far as my knowledge go, a diesel requires more coldish air than fuel to keep engine combustion heat down . Petrol is exactly opposite this statement. Therefore bring fresh cool air in more and map the ECU to deliver less fuel consistently through the range. Combustion temperature should never exceed 700-750°C , Aluminium alloys start deforming at 900°C.

Sent from my Vodafone 785 using Tapatalk

 

[Beau]

It's not just Diesels people tend to fit these catch cans too. Vehicles like VW's and Volvo's have a PCV system ([FONT=arial, sans-serif]Positive Crankcase Ventilation System), which takes top end crankcase pressure/ air, which goes towards a OEM catch can. Heavy oil deposits fall to the bottom and fall back into the sump, and the fumes go back into the inlet to be burned off. This is just a more complex system...

The more I think about it, the more I realise how a catch can, can help massively with how the engine breathes. [/FONT]

 

[Shayne]

Just had a quick look at at the pcv and the alloy housing suggests to me it vents directly into the intake , which would mean the pipe to the head is likely to be intended as a failsafe . The catch can solution is not looking so good now

I still have the same theory the only difference is how it happens and the why alters to - when pushed hard and struggling for air it creates a vacuum in the crank case and i've no idea how that could be cured unless we drilled a hole in the casing and allowed it to vent into the atmosphere which is illegal thanks to bureautwats .

To be sure i would have to remove the intake from the air box and its pissing down but that's how it looks to me .

 

[Beau]

Just had a quick look at at the pcv and the alloy housing suggests to me it vents directly into the intake , which would mean the pipe to the head is likely to be intended as a failsafe . The catch can solution is not looking so good now

I still have the same theory the only difference is how it happens and the why alters to - when pushed hard and struggling for air it creates a vacuum in the crank case and i've no idea how that could be cured unless we drilled a hole in the casing and allowed it to vent into the atmosphere which is illegal thanks to bureautwats .

To be sure i would have to remove the intake from the air box and its pissing down but that's how it looks to me .

I've never really taken the time to look so would be good to see some pictures when you have some time. In theory there should not be that much pressure in the crankcase. I've revved the engine and put my hand over the engine oil cap and there's a slight pressure created. I think I need to do some investigation as to where those pipes go before I take things further. I just can't remember seeing any pipe run back into the inlet.... but I could be very well wrong

 

[Shayne]

I tried to get a pic but its as clear as mud . The pic below is from a 3.0L 1kz Surf but shows the pipe quite well just ahead of where the intake pipe is off .

I have been looking at things upside down i pulled the pipe off the head to find the head blowing air out rather than the pipe , but the good news is that means a catch can should work .

 

[mallster70]

hey Shayne. i thought the case of that breather had been covered in another thread previously?

i read somewhere,(could of been ausie surf forum) that those guys, when they blank off the EGR valve, they also blank off that intake and put a gauze type breather on to the valve cover.
im sure there is an aussie firm who make a breather kit to do the job.

just a thought. cheers.

 

[Shayne]

I never came across that thread Mall but yeah a k&n filter to replace the pipe would do it even if its not legal nowadays .

 

[mallster70]

something like that. i think the guy used half of the old tube, sliced in two, then useing a suitable bolt and a jubilee clip, blanked it off.

not pretty, but works. the breather though was a small, almost 'thimble' like cap which just covered the outlet pipe.

 

[mallster70]

meant to say....im sure there used to be something similar on the top cover breather of the pinto engine in my old RS2000.

 

[MarkW]

handy pic of an engine breather with occ set up

 

[Shayne]

A brilliant description from a very frustrated guy who claims to be a VW race team mechanic trying to get through to someone who is convinced catch cans are for cleaning oil -

I don't think you understand:

• What I wrote above.
• The purpose of the PCV system.
• The function of the catch can.

I tried explaining it as clearly as possible in the two posts I made, but I'll give it another go:

The PCV system is called the "positive crankcase ventilation system" because it is designed to ventilate pressure from the crankcase.

During the operation of an internal combustion engine, there is blow-by, and the crankcase can become pressurized. If the crankcase is not ventilated, this pressure will cause seals to leak.

A long, long time ago, the crankcase could just be ventilated via a breather filter.

However, due to emissions regulations, manufacturers aren't allowed to emit anything directly to the atmosphere. Also, having a slight vacuum in the crankcase is actually a good thing. As a result, modern PCV systems are routed back to the intake tract. Some only ventilate through the air intake, while others use a check valve to also provide crankcase ventilation through the intake manifold (after the TB) under vacuum.

Now, since there is a lot of oil present in the crankcase, the crankcase gasses usually have some oil vapor present. This oil is now being introduced into the intake tract. That is why you can see oil in the intake plumbing, intercoolers, and intake manifold.

What a catch can does is act as a separator. It separates the oil particles from the crankcase gasses, allowing the crankcase to be ventilated while minimizing the amount of oil that makes it to the intake tract.

The oil that is separated is perfectly useable oil (it just came from the crankcase, where the rest of your oil was) and can be reused. Draining back to the oil pan adds a bit of complexity to the catch can, and requires more parts, but reduced oil consumption, and eliminates the need to manually drain the catch can.

The purpose of the catch can is to keep oil out of the intake tract, not to keep oil out of the crankcase.

Opting to drain the separated oil back to the oil pan does not "defeat the purpose of having a can" since the purpose of the can is not to remove perfectly good oil from the crankcase.

 

[froggy Steve]

mmm, me thinks I have an issue! Saw 107 degrees from aux temp guage that lives in the top hose tonight (on way to another members pad) 38 deg outside temp, but 107! It also made the normal temp guage rise never seen that before! Could it be something to do with the Viscus coupling being on pretty much all the time? Is it time for a new Rad? Has the mech left something off/out? do I fit an aux oil cooler for gearbox? eeeeeeeeeeeekkkkkkkkkk!!!!!

edit - on the way home with hwmbo driving due to me having to much pink stuff, temp didnt reach 90 deg.......I was driving like a girl btw...... and outside was a chilly 28 deg....