Running an oil cooler...

[Mettler]

Obviously, oil coolers are the awesomes for turbo engines... but do you guys see any point to running an oil cooler on the VH motor ?

Would the addition of an oil cooler prevent the oil getting warm enough to run at desired operating temperature ?

Would the expense outweigh any potential benefits of running one, and what benefits would there really be ?

Does anyone know if the VH engine has a heat exchange setup with water galleries passing through by the oil pump, to carry heat away from there ? According to a friend of mine, the RB engine is designed like this... I'd assume the VH, having the pinnacle of Nissan's engineering skills at the time applied to it, would also have this intention.

Lastly, what would be the first thing to fail on a VH engine if revved out to 7500rpm on a semi-regular basis... (basically thrashed in a street car to redline, but not sustaining said revs/no burnouts/drifting) ? Obviously I'll regularly maintain the engine, check the oil etc... so what should I expect to go wrong first ?

[Ezekial]

bearings

monitor oil temp then decide if you need an oil cooler mate

[t3lh]

bearings

And why exactly is it bearings? Please explain.

[Q45tech]

Based on 310,000 miles of frisky driving 260,000 of which had a 7300 rpm redline...............nothing internally has failed yet but normally I let the transmission shift at 6600 rpm.

Who is delivering an ecu with a 7500 rpm limiter?

[hannibal]

If you run a oil cooler, you should definitely run a thermostat with it. It will allow the motor's oil to get up to operating temp faster, and only send oil thru the cooler when it gets too hot.

Check out this thread. Some good info about oil coolers and thermostats.zerothread?id=167299

[Mettler]

Cheers for the advice

Based on 310,000 miles of frisky driving 260,000 of which had a 7300 rpm redline...............nothing internally has failed yet but normally I let the transmission shift at 6600 rpm.

Who is delivering an ecu with a 7500 rpm limiter?

Wow that's exceptional reliability! I hope I can expect this from mine too.

Q45Tech, I'm using a Y32 VH41, pretty sure the factory redline is at 7500rpm. Anyway, me & JP will socket the EEPROM and totally reconfigure the maps and everything, this also allows us to change the redline and any other parameter.

[Ezekial]

Well if the engine is tuned correctly and never overheats:headgasket, pistons, rings, valves, seats, etc will be fine

The conrods wont breakThe crank wont break

So we are left with ... bearings ...

I'd check the oil pump chain tension also ... for obvious reasons

[t3lh]

Well if the engine is tuned correctly and never overheats:headgasket, pistons, rings, valves, seats, etc will be fine

The conrods wont breakThe crank wont break

So we are left with ... bearings ...

I'd check the oil pump chain tension also ... for obvious reasons

If we use that logic ^,If you use good oil and change it regular and dont ever loose oil pressure your bearings should last just about forever. Barring any unknown oil system weakness.IMHO

[Q45tech]

When you accurately and precisely measure the hot idle oil pressure regularly you will see it progressively decrease [if you use the same oil not just the same viscosity range] say Mobil 1 at 100k, 150k, 200k, 250k, and 300k.

The bearings are wearing and the clearences are increasing...........eventually the wobble cracks the bearings.

Oil testing can warn you that the copper content is rising

[elwesso]

personally I would run oil through something like the transmission heat exchanger... either that or put it behind the radiator so it doesnt get too cool.... Could get too cool under low loads under a constant cruise....

I think a much better alternative to oil cooler is higher capacity.... Expanding from the 6quarts in the VH45 to about 8-9 Quarts would be a great step in the right direction....

[irax]

here is what you do, get a oil filter relocation kit from transdapt, then run a cooler on the return line. this will increase the capacity and have a cooler. dont worry about havent a thermostat or a switch, just dont get too huge of an oil cooler. I have dual filter pluse cooler on my ka and not only has the oil lasted longer it also keeps the motor well supplied with oil.

[ultrapulse]

personally I would run oil through something like the transmission heat exchanger... either that or put it behind the radiator so it doesnt get too cool.... Could get too cool under low loads under a constant cruise....

I think a much better alternative to oil cooler is higher capacity.... Expanding from the 6quarts in the VH45 to about 8-9 Quarts would be a great step in the right direction....

I have been looking at this myself and found that the oil wants to be around 80-100 deg C, so if u can couple it to the water system, and regulated by this surely thats the best initial warm-up and regulation u could hope for. I see quite a few jap cars have gone this way. For an NA VH I think Elwesso has the idea making a bigger volume, that way u havent got the issues of plumbing,blockages,clutter etc. Probably the best for you may be to buy one of those filter blocks which runs water thru the oil filter housing so u get some sort of temperature regulation when its being thrashed or cruising. Daves stockcar (u may have spoke to jim about this?) has problems getting the oil hot enough. He does have however one of those large HP6 type filters and big sump/modified pump. So yeah I'd think either monitor it, but big is always good for sumps if u can fit one in there.

[maxnix]

I think Wes and Irax are onto something, expecially increaseing volume.

But also look at Dixon's dry sump solution (not yet running, but well considered) for a really good approach.

[elwesso]

dry sumps are great in practice but for long term reliability i prefer the good ol mechanical oil pump... i get nervous when i have electric pumps moving my fluids... much more of a chance that an electric motor is gonna fail rather than a mechanical pump/belt/chain to fail.....

really all youd have to do is make a new sump for the oil pan and readjust the pickup, and you can use everything else that came on the car....

Slim has a 8.5 quart setup on his VH45, with a rear sump pan... its a really cool, and VERY SIMPLE design.... he moved the sump to the rear of the motor, and it has a lot more room... the way he designed is the bottom of the pan is shaped like a bowl rather than being flat... plus its baffled like crazy. he said the only time the engine wont get oil is when its upside down!!

slim is also running a small oil cooler since he had to install a remote filter anyway.... i think if i remember right its a stacked plate (from B/M probably) and its only about 3-5 plates tall... so its not very big.... he has it located where the intercoolers are on a Z (since he has a FMIC), on the passenger side i think....

Thermostats + oil make me VERY nervous... your motor can last a while without a flow of coolant under certain temperatures, but it sure isnt gonna last without oil!!!! i know all the science behind it, but still having a known restriction in an oil line makes me shakey!!!

IMO a dry sump is probably the best way, but i think by increasing the volume you get pretty much all the positive benefits and you keep things fairly simple....

its not hard to install a temp sender in the oil pan.... if you need to lower your oil temps, then install a cooler, but i probably wouldnt put a cooler on to begin with... and if i did run a cooler id probably run it as a heat exchanger, not a seperate cooler....

if you notice on the B/D body chevy's that had factory oil coolers, they placed it behind the bumper core support... FWIW.

[ultrapulse]

My comments were keeping in mind simplicity. I'm a firm believer in keeping it simple. I agree with a good old mechanical setup. Simple, compact, reliable. If u decide to run an oil thermostat and cooler, u can get these ones which are in the shape of an 'H' which the verticals flow to and from the cooler where the horizontal is only open when cold to allow an easier path. That way u dont actually restrict the oil flow if **** ever happened. Thats what I am looking at if i decide to run a cooler. I have also seen those heat exchanger tubes, where the radiator water goes thru a largish cylinder, which has the oil pipe maze run thru inside. U can also put them anywhere without needing airflow. Quite like this idea as again for quick warmup yet 'not too cold' when cruising. Basically my first suggestion for Mettler's NA was a cut-down version of this, ie using a filter spacer plate where the water circulates it. Still think just a big sump on your mildly modified engine will be sweet.Good to see the ideas coming forward.

[elwesso]

right on... I wasnt disageeing or anything, i was just thinking out loud like I usually do.

So far I havent really seen any bad ideas in this thread.... just some more plausible than others.

[Mettler]

So does anyone have any clues regarding the water galleries running through/near the oil pump area to carry heat away ?

[maxnix]

So does anyone have any clues regarding the water galleries running through/near the oil pump area to carry heat away ?

Q45tech does. He mentioned it in a past post as being a limiting factor in power production. But if the turbo guys haven't found it so........

[elwesso]

its not listed in the circuit for the cooling system.... so assume theres nothing major..

tech said the limiting factor in making 1000HP or so is the cooling system, but that should be taken care of by a different water pump.....

[Ezekial]

If we use that logic ^,If you use good oil and change it regular and dont ever loose oil pressure your bearings should last just about forever. Barring any unknown oil system weakness.IMHO

yes!! and you'd be correct if you ignored all those factors!

But as Q45tech said ... bearings wear, clearance increases which in turn increases wear and then bearings will eventually fail!

you could however allow for this by increasing the viscosity of the oil as wear increases. Start out at 40, 45, 50 etc ... but you're better off just to replace the bearings regularly!

Mettler ... i still think monitor the oil temps before you put the oil cooler on