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OldMav

Very good reading in that article. Only about halfway through. Going back to a question in the other thread about radiator caps, I am understanding from this article it would be better for the system to be running a 2 bar cap than the 1.1 bar. I know in the other thread a couple of you stated it would be fine to leaver at 1.1 but is there any risks of going to the 2 bar? From my understanding, raising the pressure at the radiator cap would allow for greater pressure in the chambers lowering the boiling point in there, therefore limiting the chance of steam pockets.
Am I on the right path with this or understanding this incorrectly?

https://www.ebay.com.au/itm/HIGH-PRESSURE-2-0-BAR-RADIATOR-CAP-FOR-NISSAN-PATROL-Y61-GU-3-4-5-ALL-YEARS/262557286962?epid=2233596805&hash=item3d21a24232:g:H00AAOSwKIpWAM-7
Just a link to the higher pressure cap that I was looking at.
 

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Well, read through to the bottom. It is very well written and extremely informative. Thanks for posting OldMav. I now understand far more than when I started.

I believe the following that I grabbed from the article pretty much wraps up what you are trying to state OldMav in these 104 pages;

Conclusion

If you want to build a bad-ass, race-ready, high performance cooling system for competition or just trouble-free trail riding, you need only follow the BV 7 Secrets to Cooling:

  1. HIGHEST coolant flow possible.
  2. HIGHEST airflow possible.
  3. BIGGEST radiator surface area fitable.
  4. HIGHEST water content tolerable.
  5. HIGHEST pressure rad cap tolerable.
  6. HIGHEST turbulence achievable.
  7. HIGHEST quality radiator on the market - which for off-road trucks, buggies, Jeeps, and 4x4's (or any other vehicle) means a high-tech extruded aluminum radiator from Griffin Thermal Products.
Noting a couple of things that were repeated in the post quite a bit was the surge tank and that it was only filled to 3/4 of the tank to allow for air expansion and to allow the "bubbles" that form in our system to be expelled through the radiator cap when the pressure gets high, as this should be the highest point in the system. Reading this and following the diagrams, this appears to be a beneficial item to add to our system. Would changing the radiator cap for just a blank cap then using the overflow section on the throat to go to a surge tank work, or would this be too small to allow for the system to work? Would this size need to be around 1/2" for better flow and "bubble" removal?
After the coolant flows though the surge tank, where would the best place be for the line to come back into the system? From my understanding of the article, it states it should be into a low pressure zone. Would this be in the inlet to the pump?

Second part that propped my ears up was the constant talk of high flow electric fans over mechanical fans such as we have in our trucks. I have noticed these on fleabay but didn't pay much attention to them. I have often thought, and noticed, that when I am off road and trying to climb long hills with the load pedal pushed down that I would be getting bugger all flow through my radiator. Considering that I am using 83% reduction gears and highly tuned, the revs on the car are not high but the excess heat building up in there is. By having low revs the fan will not be rotating as much as required to draw air through the radiator to cool it as quick as it is heating up.
Would I be better of in this situation to remove the standard fan and place two of the fans noted in the article behind the radiator with a custom built shroud to allow maximum flow of air at low revs and high heat build up?
My thoughts are this should not affect highway driving, as the air is being forced into the radiator anyway just with the shear speed of the truck. Would this thought be correct?

Thirdly ( I know I said two, but anyway), I discussed previously where my turbo coolant line comes back into the heater return hose. It created quite a bit of debate. If the option is to install a surge tank for it's benefits, would turbo line be better to go into the surge tank or stay in the position where it is?

Sorry for the long dribble, just starting to understand these systems a little better now than I did before.
 

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Just a few comments on the ' the 7 secrets' is there is no direct mention to water pump requirements.
-1st thing the pump MUST perform is have absolutely NO cavitation.
-2nd thing is good flow.
-3rd thing is pump MUST make pressure, especially at idle.

The rest of the system can be perfect but if the water pump doesn't perform these 3 necessary functions then it will be very difficult if not impossible to control the cooling system.

Next Radiator caps.
If your system uses a 1.1 bar cap and has ample room for expansion and your not losing water through the cap, then raising the pressure in the cap will not change the system pressure.
 

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I was looking for some stuff on you tube when I came across this. You will either enjoy the Leisure Suite Larry Music or not. Not sure what country this is from but this patrol has on it what I am alluding to in my posts above and what I read in the link OldMav posted. Nissan obviously saw a problem with these trucks. At the end of the clip you can see the entire engine bay.

Have a look at the size of the shroud over the fan. It is like a wind tunnel.

It also has the surge tank with the overflow bottle setup. You can see at the end where it has the air gap at the top of the surge tank.

Is anybodies Patrol setup like this? Mine is defiantly not. Not yet anyway.

I put a picture below if you don't want to listen to the music.

 

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I haven't watched the vid, but to me the engine in the photo is a zd30. ( I think). The plastic tanks on the guards are not really surge tanks, but an expansion tank/deairation tank and overflow. This exact setup was used on the td42 from 2004-2006 (TD42ti)

Having tested my cooling system extensively (2004 td42ti) I believe this setup is a substantial step back from the previous cooling system on early td42's.
The expansion tank/deairation tank is of poor design and the feed into the thermostat housing promotes cavitation.
It's probably only saving grace is the standard water pump struggles to push water through this part of the system saving it from its consequences.
 

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I haven't watched the vid, but to me the engine in the photo is a zd30. ( I think). The plastic tanks on the guards are not really surge tanks, but an expansion tank/deairation tank and overflow. This exact setup was used on the td42 from 2004-2006 (TD42ti)

Having tested my cooling system extensively (2004 td42ti) I believe this setup is a substantial step back from the previous cooling system on early td42's.
The expansion tank/deairation tank is of poor design and the feed into the thermostat housing promotes cavitation.
It's probably only saving grace is the standard water pump struggles to push water through this part of the system saving it from its consequences.
Do you think all the over heating issues are water pump related and can only be fixed by replacing the water pump ?.
 

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No.
If you have overheating issues it's important to ascertain what is the problem.
We also increase the load on the engine by increasing tyre size, adding weight, increasing drag, towing or just engine mods to make more power.
A cooling system that copes with a standard engine can fall short when extra load is placed on it.
This is where testing comes into it's own. Having a known result and an understanding of the result.
It's only then a remedy for the problem can be made, rather than an assumption and hoping for the best with no accurate testing.
And yes I place the water pump as the critical piece in the system.

I have 3 criteria for the pump,
  • NO cavitation.
  • good flow.
  • good pressure.
 

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No.
If you have overheating issues it's important to ascertain what is the problem.
We also increase the load on the engine by increasing tyre size, adding weight, increasing drag, towing or just engine mods to make more power.
A cooling system that copes with a standard engine can fall short when extra load is placed on it.
This is where testing comes into it's own. Having a known result and an understanding of the result.
It's only then a remedy for the problem can be made, rather than an assumption and hoping for the best with no accurate testing.
And yes I place the water pump as the critical piece in the system.

I have 3 criteria for the pump,
  • NO cavitation.
  • good flow.
  • good pressure.
My original water pump has got 315k on it and is probably the next thing I will change. Is there no pump on the market yet you see as a worth while investment? (Not trying to sound like a smart ass.)
 

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For the td42??
No. Unfortunately.
A couple of days ago i heard that the JPC water pump was put through a cavitation test over in W.A.

It failed.

As probably most are aware I have a modified cooling system and water pump that is still in testing.
The results so far are the pump NO longer cavitates. It produces clean water(absolutely NO bubbles) while having a good flow and making pressure.
I can confidently say the pump is finished as it achieves what is desired, but there are a couple of other areas in the cooling system that need to be addressed.
If everything goes to plan I will have tackled these before Xmas to test system over the Vic summer.
 

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For the td42??
No. Unfortunately.
A couple of days ago i heard that the JPC water pump was put through a cavitation test over in W.A.

It failed.

As probably most are aware I have a modified cooling system and water pump that is still in testing.
The results so far are the pump NO longer cavitates. It produces clean water(absolutely NO bubbles) while having a good flow and making pressure.
I can confidently say the pump is finished as it achieves what is desired, but there are a couple of other areas in the cooling system that need to be addressed.
If everything goes to plan I will have tackled these before Xmas to test system over the Vic summer.
Mine never sees over 100°c but as you say the thermostat has lost control by than. I will hold off on the pump for now and wait for your findings
 

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After 18 mths of kettle issues, a new qikazz fan thru radiator, dt97a and finally cracked head I have done the following and have won.
After cracking head and replacing with new genuine I replaced everything in cooling system with new genuine. Fitted td42t fan and hub, original thermo, original radiator cap and td42gu radiator. I have a 93 blacktop, 16 mamba, original 10mm fuel pump, top mount hpd.
After reading all of these I kept coming back to forming a negative air pressure behind radiator. After checking my vehicle it was obvisious the negative pressure was forming just below bullbar and in front of radiator causing a big percentage of air to not flow thru radiator but under truck. Air will take the path of least resistance.
Got some rubber matting and blocked it off as in pic. Now negative pressure forms behind radiator low under the block causing alot more air to flow thru radiator. Temps are alot more stable and on 35 plus days will not go over 105c with aircon on pushing up hill in 5th at 110 on motorway. Previously would go berserk.
Also need to understand these motors operate safely from 76c (thermo open) to 118c.
Also with the negative pressure now situated under the block, its pulling alo tg more heat out which makes the gearbox alot cooler can feel it in stick and tunnel.
514129
 

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For the td42??
No. Unfortunately.
A couple of days ago i heard that the JPC water pump was put through a cavitation test over in W.A.

It failed.

As probably most are aware I have a modified cooling system and water pump that is still in testing.
The results so far are the pump NO longer cavitates. It produces clean water(absolutely NO bubbles) while having a good flow and making pressure.
I can confidently say the pump is finished as it achieves what is desired, but there are a couple of other areas in the cooling system that need to be addressed.
If everything goes to plan I will have tackled these before Xmas to test system over the Vic summer.
I thought you might of been that derek bloke on fb selling water pumps that supposedly cure over heating

Sent from my SM-G950F using Tapatalk
 

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I was looking for some stuff on you tube when I came across this. You will either enjoy the Leisure Suite Larry Music or not. Not sure what country this is from but this patrol has on it what I am alluding to in my posts above and what I read in the link OldMav posted. Nissan obviously saw a problem with these trucks. At the end of the clip you can see the entire engine bay.

Have a look at the size of the shroud over the fan. It is like a wind tunnel.

It also has the surge tank with the overflow bottle setup. You can see at the end where it has the air gap at the top of the surge tank.

Is anybodies Patrol setup like this? Mine is defiantly not. Not yet anyway.

I put a picture below if you don't want to listen to the music.

Because its a 4cly so the fan is a long way from the radiator it needed the huge shroud

Sent from my SM-G950F using Tapatalk
 

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I thought you might of been that derek bloke on fb selling water pumps that supposedly cure over heating

Sent from my SM-G950F using Tapatalk
No I'm in Vic.

I don't have any pumps or cooling mods for sale.
This exercise has been purely for my own benefit and at completion I will guage the interest as to where it goes.
 

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This post from 2010 would indicate it is not his technology in the first place, unless he talks about himself in the third person:

"hi there im new to this and this site,i have finally found today some one that can help me fix my overheating problem that have had for the last 6 years,and he builds his own impellors for the water pumps so he will be able to tell u what the specs should be and he can explain to u what causes low pressure boiling witch is the cavitation behind your pump.derk brocx 08 93304177 wa"

First and only ever post here.
 
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