TD42 water pumps... what would you be prepared to pay

[Bloodyaussie]

I have been doing some research into performance water pumps for the TD42 as they have a real cavatation issue and my 8 month old radiator has sprung a leak and will be replaced under warranty..

Now there are 3 mobs I know of (interested if there are more)

The first and not an option really as I have heard nothing but crap or average revues is the Patrolapart one for $249 that is a standard pump with a different impeller.

The second is a bloke in Lilydale who swears by his product that he mainly sell to the Top End and WA and mostly for rigs towing with a much bigger impeller and larger bearing but still a stock housing for $550

Third is a high performance mob who have been in the game for many many years and have a complete build with billet housing and a completely different impeller for $660.... this mob have built some of the quickest cars in the country and build many comp truck TD42's

Hmmmm....?????

[jff45]

Mate, I'm interested in your comment on the TD42 water pumps having real cavitation issues.
I recently purchased a Jap import TD42T engine that I'm guessing has around 100k on it. I was advised to remove the water pump to check the state of the timing cover as it's an indication of a badly worn engine.

Here's a pic of what it looked like. If I polished the alloy it would look like new..
There is really no sign of any cavitation problem there..

I bought an original Nissan water pump for it.

...

[Bloodyaussie]

Not sure if you are asking me a question or not??

Are you talking about pitting in the gallery as this is not what I mean..

Just checked the spelling and it should read "cavitation"

And also Mark from JPC asked me to come down quickly so they could check something out as he had concerns my cooling system was pressurizing but I got the clean bill of health except for how my radiator is mounted plus it turns out me Copper/brass is Chinese....lol

[Cuppa]

I’m sure there is always room for improvement - at a cost. However with the TD42’s reputation for reliability & longevity it seems most unlikely to me that TD42’s have a 'real cavitation issue’. I could be wrong, but would have thought it would be ‘common knowledge’ if this were so. As I understand it (from a quick sqiz at google), in a diesel the most likely areas of cavitation damage is cylinder liners, heads & pump impellers. I didn’t find any mention of radiators specifically.

https://www.google.com.au/search?q=cavitation+damage+in+diesel+engines&safe=off&biw=1440&bih=772&tbm=isch&tbo=u&source=univ&sa=X&ved=0CD4QsARqFQoTCJu4usK9jscCFQEvpgodfq4O9A

[liftlid]

Is your car getting hot?

[garett]

i think it would be more likely that the engine is earthing out through the coolant, this is unlikely but has happened. more likely a manufacturing issue.
just my 2 cents worth

[nissannewby]

Use a genuine one. Machine it so there is less clearance on the impeller. Have seen 3mm taken out to get the clearance at a respectable gap. Dont waste your money on those "performance" pumps.

You can get a new genuine one landed for about $70.

[Bloodyaussie]

Use a genuine one. Machine it so there is less clearance on the impeller. Have seen 3mm taken out to get the clearance at a respectable gap. Dont waste your money on those "performance" pumps.

You can get a new genuine one landed for about $70.

Trying to work out what you mean...

Jpc tested my car today and said my cooling system is perfect and no issue of the engine pressurizing the cooling and i was told to get rid of my Chinese copper/brass radiator which is breaking apart.

So new radiator is being made tomorrow and should be ready then if not Thursday.

The other radiator has a warranty and will pick the new one up on Friday and sell it.
I wish more gq owners used accurate temp gauges to compare with... i run a good digital job and find it much better than the dodge factory one.

[nissannewby]

Which bit.

[Bloodyaussie]

Which bit.

Where do you do the machining??

[Bigcol]

I had the hi flow water pump in my TD42
when I did the cooling system up in Jan this year, I replaced it with a genuine Nissan one

biggest problem I was having was, when the EGT's went over 450* (while towing) the water temp would sky rocket up past 110* (alarm goes off at 110*)

since doing the complete cooling system it has not gotten hotter than 105* when the EGT's are up to 450
and the temp drops back to 95*-ish when the EGTs drop back to 300*

I had the thermostat replaced - was not quite right
thermostat housing
water pump - Mr Nissan original (water flow was no better with the "hi flow" water pump, but wanted to see the difference with OEM gear)
Viscus fan hub - was cactii
fan - was small cracks, so may as well while there to replace it
all hoses - mine were getting soft
all belts - they were looking old.......
back flush, and pressure cleaned outside of Rad - was new Dec2013 - lots of dirt and crap in the outside of it
re-filled with Mr Nissan coolant

for once I am happy with the cooling system on my TD42

[nissannewby]

Where do you do the machining??

Machine the housing. The face the gasket seals on. Measure it all up prior and make sure you take into consideration the gasket thickness.

[MudRunnerTD]

. Snipp
I wish more gq owners used accurate temp gauges to compare with... i run a good digital job and find it much better than the dodge factory one.

Mate I reckon that's actually your biggest problem to be honest. You were concerned about seeing 90 on your gauge on the snow trip. No one else was bothered at all. Your Nissan gauge would have shown very little change and everything you were running was well within spec.

Your engine will take 100 any day, and all day mate. Mine runs around at just under 90 but sees a rise on big hills. I vote for replacing your radiator and going for a drive. You are letting your water Temp gauge smash your head in mate.

Matty is suggesting having the face of the pump housing machined off by upto 3mm to bring the impeller closed to the block to restrict blowby on the water pump. I run a Nissan Pump on my GQ, when it sh1t itself I replaced it with another Nissan one. Decent coolant will happily run at 110 safely, that's the point of not using Water to lift the boiling point and allow safe operation on your engine at its upper limit.

My2c.

[mudski]

I went to JPC's this arvo mate. And when I got there, whatshisface and Mark were actually talking about your truck. The conclusion was, the 100c temps are not an issue, the mounting of the radiator was, as you knew. Both said to sort that out, and the radiator leaking and take it from there. I forgot to ask Mark about that water rail too, but I did see it on the dual cab TD they were working on.

[nissannewby]

85-90 degree is perfect. 110 is probably the upper limit.

Water rail has no real benefit on a road car. Waste of an exercise unless your racing it, even then its not really necesary. Many 180+rwkw patrols running around without an issue.

[Bloodyaussie]

My car sits between 70-82 for normal driving this time of year (very cold winter) and on the highway averages 85.

I noticed a change not long ago and had worries but as it turns out it was the radiator starting to fail so i will get a proper radiator today (should be ready) and see how it goes after that.

[moonie]

stock motor only needs a stock water pump but have seen the pumps from patrolapart looks ok but carnt go past a stock pump $$$

[Robo]

Use a genuine one. Machine it so there is less clearance on the impeller. Have seen 3mm taken out to get the clearance at a respectable gap. Dont waste your money on those "performance" pumps.

You can get a new genuine one landed for about $70.

So what would respectable gap measure?.
I assume your measuring the impeller edge to mounting face of new pump,
+new gasket into account also?.
or are we doing depth readings on case also?.

[nissannewby]

O.5-1mm. Depth readings on case also mate. So measure both impeller protrusion from housing and case depth and make your adjustments from there.

[Robo]

O.5-1mm. Depth readings on case also mate. So measure both impeller protrusion from housing and case depth and make your adjustments from there.

no wonder they suffer cavatation at 3mm if .5-1mm is the go.
the improvement .5mm gap maybe like putting in a hi flow thermostat , so to speak.

[jff45]

Any cavitation issues related to water pumps will be more due to high revving hot engines combined with poor coolant quality rather than water pump impeller gap.

Reducing the gap will increase the flow but then you need to be sure that the other components in the system can handle that. Also be wary of pumping coolant too quickly through the radiator..

I'm new to TD42 engines but I've done a fair bit of research since I started my conversion and I haven't come across any other mention of these engines having cavitation issues with standard water pumps.
This is why I found BA's original premise interesting.
As Cuppa mentioned, these TD42s have more of a reputation for solidity and longevity.

Here's a pic of the original water pump I removed from my engine. Not the slightest sign of cavitation erosion.

...60332

[nissannewby]

John is right. Cavitation will usually only occur at sustained high rpm. Cavitation is usually a supply issue so there is not enough water available to be pumped.

Machining will help to increase flow but is not enough of an increase to cause problems. It is still within the control of your thermostat and cap.

You dont have to machine it. You can just replace it with a new one.

[Bloodyaussie]

Thank you guys this is good stuff... in the end I have stayed with the stock pump but have just finished replacing the radiator.

Its a subject I had not heard of until a few weeks ago and the discussions varied... cheers for all the input.

[AB]

Some really good advice in this thread gents on this subject from knowledgable members, well done!

There are bucket loads of wrong information about this on Facebook!

[mudski]

Some really good advice in this thread gents on this subject from knowledgable members, well done!

There are bucket loads of wrong information about this on Facebook!

Thats why I don't use FB. I use NP Book.

Will be interesting to see what temps I will see when I'm up and running.

[Robo]

Any cavitation issues related to water pumps will be more due to high revving hot engines combined with poor coolant quality rather than water pump impeller gap.

Reducing the gap will increase the flow but then you need to be sure that the other components in the system can handle that. Also be wary of pumping coolant too quickly through the radiator..

I'm new to TD42 engines but I've done a fair bit of research since I started my conversion and I haven't come across any other mention of these engines having cavitation issues with standard water pumps.
This is why I found BA's original premise interesting.
As Cuppa mentioned, these TD42s have more of a reputation for solidity and longevity.

Here's a pic of the original water pump I removed from my engine. Not the slightest sign of cavitation erosion.

...60332

Going by the pic of impeller I'd hazzard a guess of some cavitation present given the partial & uneven cleanliness of the impeller.
wouldn't a even flow of coolant produce even deposits?.

[Robo]

John is right. Cavitation will usually only occur at sustained high rpm. Cavitation is usually a supply issue so there is not enough water available to be pumped.

Machining will help to increase flow but is not enough of an increase to cause problems. It is still within the control of your thermostat and cap.

You dont have to machine it. You can just replace it with a new one.

I used to own a boat and my take on cav is its also linked to power supply ( linked to rev's as pointed out by nissannewby )overtaking the ability of pitch of blade to grip the water.
gap and impeller design has heaps to do with cavitation.
nismo gtr performance pump ver's std pump,60349 have larger blade but 1 less and a backing plate on impeller to take care of clearance on other side of pump case.
ie same as this post discussing decking to reduce turbulence on block side if pump.
so any improvement you can do should help.

[jff45]

Going by the pic of impeller I'd hazzard a guess of some cavitation present given the partial & uneven cleanliness of the impeller.
wouldn't a even flow of coolant produce even deposits?.

I think the uneven deposits are because these Jap import engines sit around for a long time.

I gave it a quick clean with a small brass brush and the muck just fell off it.
Trust me there's not the slightest sign of erosion.

...

[jff45]

Also thought this might be of interest. I found this image in a thread where a guy was changing his water pump. He actually bolted a new pump onto this and is quite happy with the outcome so let's not get too worried with what we have..

...