Running an oil cooler.... properly!

[Mettler]

So I want to run an oil cooler. Usually a relatively simple task on most engines. On the VH it should be relatively simple too, but I want to make absolutely sure that there are no changes to oil pressure throughout the engine, so I am going to take into account the following considerations (and any others you guys may wish to add).

1. No reduction in oil path diameter anywhere along the circuit.

2. Trying to keep the lines as short as possible.

My method is simple. I want to make a plate to bolt on in place of the plate holding the oil filter, with two threaded nipples sticking out of this plate. From here, the lines will travel to a remotely mounted filter, through the cooler, and back through my plate and into the engine.

I'll also find somewhere for the oil pressure sender unit to fit into the circuit.

Does anyone foresee any potential complications, or have any recommendations as to potential pressure problems relating to the size of oil cooler I use?

Cheers

[elwesso]

The remote filter kits for VG30's work on the VH's so you could get that. If I recall the RB uses the same filter as the VH so that might be easier for you to get.

Just put the cooler inline with the filter. Personally id put the cooler before the filter.

[gs14racer]

You should also get an oil thermostat, so that it only sends oil to the cooler when it needs to. My remote filter mount has the thermostat built in, it only opens the path to the cooler when the oil reaches 200 degrees if i remember correctly.

[Mettler]

Do you think if I don't use an oil thermostat that I run the risk of the engine running too cool? I wouldn't think so... but you never know!

[gs14racer]

I doubt the vh will run to cool, but id rather have one, as it will put unescary (sp.) oil thru that part of the the system when you dont need it probably 60 percent of the time, i will shortly have an oil temperature gauge and ill be able to see what kind of oil temps im running.

Racerpartswholesale.comandbakerprecision.com

both offer inline thermostats that you can run in all kinds of different sizes and temperatures.

[defrag010]

without an oil temp thermostat, it will take alot longer for your oil to reach temperature, which means you will have to drive the car alot longer before you are at a safe temp to get on it good.

I'd put the cooler after the filter, because if your motor ever spins a bearing or gets any debris in it, it will accumulate in the cooler. This sucks, because flushing out a cooler never always gets debris out and that stuff can recirculate after you have a new motor.

[EstoMax]

as long as you dont live somewhere where it gets way below 32F/0C at winter its ok to not run a thermostat. I dont run a thermostat, and at winter time i just cover up my oil cooler.. put a bag around it or something.

Marko

[ultrapulse]

Following on from that, Ive also been told that most (if not all) oil filters still flow the really small grinding paste stuff after a chenobal meltdown so nothing really saves the associated plumbing anyways.,but yeah sure would be an easier flush without all the big bits in the cooler. I would buy a new one for the sake of a couple of hundred bucks v's the price and effort of a rebuilt anyway.My 90 tt zed (this part of the car all std) has a smallish oil cooler in front of the rad with no oil thermostat. It appears to be plumbed in after the filter and bypasses into the sump so is not under oil pressure, but dont quote me on that as I havent checked the manual.Since a good temp for oil is approx the same as water temp +or-, I would try to somehow use the water circuit for the reason of quick heatup and constant temp, along with simpilicity. The local engine guy here told me that some jappas now have water flowing into a similar housing between the filter and engine, doing just that. Apparently most oils like to be upto 80 deg C to work properly making this the way to go. Sorry about stealing your thread buddy, but just another idea as I have been thinking about what to do as well. I have seen a rally car with a heat exchanger thing which is inline with the rad but has internal tubes where the oil flows thru. It was quite compact too, as I guess liquid conducts pretty well compared to air. Something to think about.

[Spanna Spinna]

I dont have a thermostaticly controlled cooler on my and it does take a while (like twice as long as water temp) to come up, normal street driving it usually matches water temp after 20mins of driving but out on the track it gets up to 110C pretty quick. Im only running a adapter between the filter and block with -10 lines and an evo 1/2/3 standard oil cooler, although dumbass mounted it right behind the bumper suport so it doesnt get the best air flow. It see's 80psi as factory at 3000rpm (i think thats what mettler posted in my oil pressure thread). All in all it works well but for sustained track use it is reaching the safe limit of the oil, maybe moving the cooler to a beter position will help. I did orignally try the setup you are talking about mettler but i found the size of the adapter ment the fittings were very small and caused most of my restriction problems (may be different on 41), a simpler way of doing it is to use a screw on adapter kit like this.



And make sure you get one that has tappered fittings cause i used a cheapo o ringed type fittings on a mates car and we had trouble stoping the o rings from leaking as they were cheap nasty ones (i got some good quality replacements)Your call but if i redo mine i will use a thermostaticly controlled unit.

[Mettler]

Thanks guys. Yeah Spanna Spinna my setup is all going to be custom made, machined from stainless steel and tig welded. I don't trust any of this light duty bolt on/adaptor crap designed for evos and skylines... not even the lines look big enough in diameter for my liking. I'll post up my findings when I get around to it.

When you guys talk about fitting an oil thermostat into the circuit... are you talking about setting up the return from the oil filter to split into two, the first section of which has the oil cooler, and the second being a direct return line to the pump... with the thermostat basically switching between either? Like a Y valve?



That's the only way I can think for this circuit to work... if the thermostat simply opened and closed, well, I'd be blocking all oil feed to the rest of the engine and we don't want that!
Modified by Mettler at 1:44 PM 8/5/2007

[gs14racer]

Maintaining proper oil temperature is critical and the installation of an auxiliary oil cooler helps keep the oil below the 190 deg. F maximum temperature. Installation of a remote oil thermostat, in addition to an oil cooler, provides faster warmup to operating temperatures. When oil temperatures exceed 180 deg. F, the thermostatic valve closes allowing full flow through the oil cooler. At temperatures below 180 deg. F, the valve is open with 90% of the oil bypassing the cooler. The remaining 10% of the oil flows through the cooler to maintain constant system pressure and prevent air pockets in the cooler system. Flows up to 20 GPM at 200 psi. Has 1/2" npt ports.



MOCAL thermostats are designed to prevent engine oil from flowing through the oil cooler until the desired temperature is reached. Prolonged use of engines in conditions that oil cannot reach optimum working temperatures will cause sludge formation and crankcase oil dilution, leading to excessive wear especially in the cylinder bores. Thermostats combat this by regulating oil flow to accelerate warm up. This in turn reduces drag, helping to yield optimum engine efficiency and performance. The proven design and reliability of the MOCAL thermostat make them the choice of automotive and marine racing teams world wide. They are also well suited for industrial and aviation applications.

all can be had from racer parts wholesale, they even have an oil filter mount with thermostat integrated into it

http://www.racerpartswholesale.com/mocal.htm

[Spanna Spinna]

Thanks guys. Yeah Spanna Spinna my setup is all going to be custom made, machined from stainless steel and tig welded. I don't trust any of this light duty bolt on/adaptor crap designed for evos and skylines... not even the lines look big enough in diameter for my liking. I'll post up my findings when I get around to it.

When you guys talk about fitting an oil thermostat into the circuit... are you talking about setting up the return from the oil filter to split into two, the first section of which has the oil cooler, and the second being a direct return line to the pump... with the thermostat basically switching between either? Like a Y valve?



That's the only way I can think for this circuit to work... if the thermostat simply opened and closed, well, I'd be blocking all oil feed to the rest of the engine and we don't want that!

Modified by Mettler at 1:44 PM 8/5/2007

Ah the pic is more an example and i hate to point it out but if the likes of Trust use an adaptor unit then it can be all that bad (1000+ hp skylines and all). If you've ever had an engine apart then you will of noticed that the galaries arent that big so to promote pressure and by using huge lines may lower the pressure (flow will be good though).Pull the standard filter mount off and look how big the oil ways are in it, and the thermostats that gs14racer posted up (very nice too, wish we had as many performance parts shops here to choose from) only use a 1/2" ntp fitting which have an inner hole size of about 12mm so really anything over -12 is an overkill, my 2 cents.

[elwesso]

A heat exchanger idea might be worth looking into, like ultrapulse said. You could get an AT radiator like the factory uses for trans cooling....

I guess youd have to measure your temps and see what it spikes at. If it spikes above 200F it may not be worth doing it that way...

Another thing to consider is having an oil cooler if you are a drifter may not do that much, since you arent really moving at high speeds, and therefore may not have that much air flowing over it to cool.

[darinz]

I've just removed my oil cooler and shifted the remote filter due to it causing low oil pressure. I had used -8 (1/2") lines everywhere and the cooler was 1/2" but it was causing the pressure to be max 40psi. The restriction was the length of the oil line as reducing the length of the line has solved the problem, ie now 80ish psi. My next plan is to use 5/8" line to see whether the increased size will allow the extra line length required to get a ront mount oil cooler for my setup. Even mounting the oil filter on th firewall above the motor was causing a pressure drop. I have now mounted the filter on the chassis rail between the motor and radiator so the lines are about 300mm (12") long.

[Mettler]

Hey guys... opinions on this please:

http://www.trademe.co.nz/Trade...?p=13

It does state the fittings suit 1/2" ID hose... this implies the diameter inside the fittings is even smaller than this... I'm thinking restriction >_<!!

However it may screw straight on, so my lines could potentially be pretty short if I don't have to plumb a thermostat in down the line somewhere.

[darinz]

1/2" ID will cause a drop in pressure, the length of hose will dictate how much! I'm looking at fitting an oil cooler like on so light trucks where water is run through an adapter that goes between the filter and block or remote housing in my case. Having the front mounted cooler using 1/2" hose dropped my pressure down to about 35psi!!!!! A 1/2" hose bypassing everything ie no filter etc gave about 85psi. I now have 1/2" hoses about 300mm long to the remote filter (factory spec) and pressue is about 80psi.

[Mettler]

Are you serious?? That's damn annoying, I don't want any drops in pressure!

Anyone know what kind of I.D. -10 fittings have? I looked them up, outside diameter is 5/8" which is 15.875mm, and accounting for wall thickness of the fitting (lets arbitrarily call it 1.5mm), that makes the I.D. just over 12mm (1/2").

This is why I'm confused about running an oil cooler, we've got various results and various opinions in this thread.

We have Spanna Spinna saying he thinks -12 fittings are overkill and that 12mm I.D. will work fine, with solid reasoning behind it about other high performance/high oil pressure engines using these sizes successfully, as well as having success with it himself.

Then we have darinz saying that he was getting pressure problems with hose that has the same inside diameter as Spanna's.

So what are the hard facts? Could it be that the oil pump design of the VH in fact causes such pressure problems when various oil circuit configurations are used?

Heh, I was getting ready to type out a bullet pointed list but I just realised that nothing is really confirmed. So we don't yet know whether it's a reduction in diameter in the circuit, or expanded circuit volume, that's causing the pressure problems.

Personally, I have trouble reconciling the reasoning that longer lines (a.k.a. expanding the volume of the oil circuit) can cause pressure problems, because fluid pressure should be universal. If there's X amount of pressure at the pump, I see no way for pressure to drop other than bottlenecks... (i.e. smaller diameter/gallery for oil to pass through in a sandwich plate or remote filter mount) which would suggest running larger diameter lines and fittings could cure this.

I think I'm going to measure the I.D. of the drilled oil galleries going in & out of the oil pump section on the block, and try and retain that I.D. the whole way through. IIRC it looked like it was about 12-14mm.

[Mettler]

Someone on another forum raised a valid point. Where are you guys measuring your oil pressure from?

If there's a bottleneck in your oil circuit and you're measuring before this bottleneck, then technically you should be maxing out the pressure that your pump can generate before its own bypass opens up. (i.e. ~80psi peak)

If you're measuring after the bottleneck, then you'd see the oil pressure drop.
Modified by Mettler at 9:07 PM 9/4/2007

[450Z]

My 90 tt zed (this part of the car all std) has a smallish oil cooler in front of the rad with no oil thermostat. It appears to be plumbed in after the filter and bypasses into the sump so is not under oil pressure, but dont quote me on that as I havent checked the manual. about.

Be careful if you change your oiling system on the TT, as there is a small orifica plug in the return line from the cooler to the oil pan. Change the lines and all of your oil goes to the cooler and back to the pan, not the engine.

[450Z]

My method is simple. I want to make a plate to bolt on in place of the plate holding the oil filter, with two threaded nipples sticking out of this plate. From here, the lines will travel to a remotely mounted filter, through the cooler, and back through my plate and into the engine.

I'll also find somewhere for the oil pressure sender unit to fit into the circuit.

Does anyone foresee any potential complications, or have any recommendations as to potential pressure problems relating to the size of oil cooler I use?

Cheers

I tried the method where you make a plate and run lines to the oil filter. See halfway down: http://www.cardomain.com/ride/563982/2What I found is that, like most modern engine oil systems only about 20% of the oil flow actually goes through the filter. The casting that holds the oil filter actually has a spring loaded ball valve controlling that flow. With my direct system I was getting just over 100 psi oil pressure at idle! I have since relocated the oil filter housing and the pressurizers are now in the normal range. So take this into consideration when redesigning the oil system of the VH45DE.

[Mettler]

So if I use the factory oil filter/sender unit casting, but relocate it using sufficiently large diameter lines I should be ok in that department. Excellent... thank you!

[gs14racer]

Best thing to do is use the stock housing as others have said

I run 85 or so psi and 30-35 at idle

[darinz]

That brings up some interesting thoughts. I had to cut the bypass valve off as it was hitting the chassis rail. What I may look at is using the other half of the housing to mount the oil filter and this has the bypass valve in it, and then fit a sandwhich plate for the oil cooler. Then all I will have done is increase the distance between the pump and the factory mount/bypass valve/filter.

As for the hose diameter. I had pretty lonh hoses and the fitting only had 10mm ID as opposed to the hose 12mm ID. We have drilled some fittings and that has solved the issue. BUT with the same fittings and about 600mm of extra hose (12mmID) we were seeing a pressure drop. The pressure was from the factory location with a mechanical gauge screwed in directly. ie Expensive one used by an engine builder so pretty reliable.

[Mettler]

Well I measured the I.D. of the inlet and outlet from the oil pump housing to the filter housing, and the holes are 16.15mm.

After speaking to a couple of hydraulic engineers, and my own bosses who are also engineers, it appears everyone unanimously agrees that a reduction in diameter at any point is where a bottleneck will occur and backpressure will build up from.

As far as I'm concerned, I wouldn't run anything less than a -12 fitting now... not even -10 has a large enough I.D. for my liking... it's abundantly clear now.

[450Z]

Ke

Well I measured the I.D. of the inlet and outlet from the oil pump housing to the filter housing, and the holes are 16.15mm.

After speaking to a couple of hydraulic engineers, and my own bosses who are also engineers, it appears everyone unanimously agrees that a reduction in diameter at any point is where a bottleneck will occur and backpressure will build up from.

As far as I'm concerned, I wouldn't run anything less than a -12 fitting now... not even -10 has a large enough I.D. for my liking... it's abundantly clear now.

Keep in mind that allot of those cheaper oil filter adapters have some smaller ports and passages then the lines you are using.

[Mettler]

Yeah I'm not gonna use any adaptors or anything now. Going to draw up & laser cut some custom plates with -12 fittings welded on, will keep all diameters at 16.15 or greater.

[450Z]

Here a couple of pics showing how I did it. At this point I was tired of working on the car and did not bother running an oil cooler yet. I will run off of where the oil filter is and go out the front.I hope the pics get put in the message (first attempt)

[450Z]

Lets try this again.........................

[Kevin Johnson]

You need to pay attention to sharp bends in the routing of the hoses and construction of passages. They can cause big pressure drops.

Well I measured the I.D. of the inlet and outlet from the oil pump housing to the filter housing, and the holes are 16.15mm.

After speaking to a couple of hydraulic engineers, and my own bosses who are also engineers, it appears everyone unanimously agrees that a reduction in diameter at any point is where a bottleneck will occur and backpressure will build up from.

As far as I'm concerned, I wouldn't run anything less than a -12 fitting now... not even -10 has a large enough I.D. for my liking... it's abundantly clear now.