Super long oil lines - Pressure drop possibly an issue?

[trdee]

Sigh..... EGTs are good. Timing map is good. AFRs are good. I have my air intake in the side vent and realistically the side vent is too small for a decent sized cooler anyway (didnt I say I've looked at all the options already?).

Oil temp problems are a well known issue on turbocharged adubs, this is something that nobody else seems to have tried before and I would like to have it as a possible option for future consideration if it's doable.... so lets stop going sideways and just look at my original question please When I want to discuss options for mounting my oil cooler or using a water to oil core I'll make a thread for it.

[knightrous]

Give up, your going to fail j/k

Use water to oil cooler, but use water system from your water to air intercooler system? Should be cooler then engine coolant temps.

[Sammich]

.... so lets stop going sideways and just look at my original question please

listening to OP is for sissies.

[fixeruperer]

have you tried, hooking the a/c back up and mounting the oil cooler inside, to a dedicated a/c vent ? then just blow cold air through it ?
maybe install an engel fridge in the car and mount the oil cooler in there ? that might work. tried that ?

but im sure as its such a problem, there is going to be heaps of answers on how to fix it.

good luck champ.

[trdee]

ways to get banned #1347782: pissing off a moderator in a tech thread, especially when it's his tech thread....

[dnegative]

You wont have any issues with pressure loss but running a cooler so far away is less than ideal I would think, its a lot of hose to prime. Shame you cant set it up as a bypass cooler

[fixeruperer]

get off your high horse.

your dad own toymods or something ?

if you ban me, you can give me back my $50 i sent for membership weeks ago, that still hasnt been activated yet. dont worry about the odd few dollars here and there into the toymods account. seeing as im such a bad member.
just coz you got a problem with me man. ive done nothing wrong.

[andrew_mx83]

You wont have any issues with pressure loss but running a cooler so far away is less than ideal I would think, its a lot of hose to prime. Shame you cant set it up as a bypass cooler

this man brings up a good point, esp with a sandwich plate type deal. you dont want to end up with a system where you have to crank for ages to get oil pressure then add spark for it to actually fire (i reckon my dry sump system will end up like this)

you could probably get a 7m-gte bypass setup to fit, but it restricts you to a 3/8 line to the cooler and all the other downsides of a bypass cooler.


edit: if oil flow to the cooler is thermo controlled, and you mount the thermo bit up the engine end of the car it would negate the issue of lots of line to prime (when cold anyway).

[trdee]

fixeruperer; take a chill pill... and for the record i have nothing against you but this is the tech section and i am quite within my bounds to take action if people keep taking threads off topic

dneg; yes priming could be an issue but only after an empty fill imo. once the lines are full they are going to flow as soon as you start pushing oil further upstream.... again with something like 4m of oil lines in the current configuration I am seeing no pressure drop or startup pressure issues. The first go did take a while to get pressure but once those lines were filled it has always pressurised same as a normal setup on startup..

andrew; the oil cooler has an inbuilt thermostat, i could add an inline one upstream to bypass the length of the lines but if there are oil flow issues then that will only make them worse once the thermo opens, with the problem happening at who knows how many rpm and load rather than just on startup...


now this is the kinda discussion i wanted to be having

ill try calculate some pressure drop figures with the numbers thechuckster gave me when i get back from gym...

also, i would imagine a lot of those articles talking about removing restriction from the path of the pump are to do with high revving 4As (which are well known for killing oil pumps once the revs start to get up there). I wont be revving this past 8000rpm...

[dnegative]

If the lines stay charged then your sweet, if you have oil draining back and being replaced with air then it becomes an issue. You also have to consider that with a front mount oil cooler you effectively make your engine extremely vulnerable. A small leak or a rock through the cooler and by the time you realise it could be game over. You would want to be running steel hardline all the way to the front.

[thechuckster]

gut feeling only, but i think you'll loose a lot of pumping effort (and thus reduced flow & pressure) thru shifting the oil so far forward and then back. All the dry sump systems scavenge-pump to an open head (to the big reservoir directly or via a cooler block to it). The pressure pump then sucks from that reservoir to lube the engine. Each pump only uses half the overall length of piping. Asking a single factory pump to do both is going to be risky.

[trdee]

Dneg, why would it make my engine more vulnerable than a leak anywhere else? Oil pressure is going to drop off at the same rate regardless. Granted there is more hose that can fail, but it is all very well protected under the underbody plastics as I have demonstrated with my WTA hoses showing no signs of damage after a fair bit of street and track driving for a while now.. hardline is stronger yes, but it cant be pushed up into all the nooks and crannies to protect it like i have done with the flexible WTA hoses, so even though it's stronger, it will be more exposed. Plus hardline work hardens if you fuck with it too much, and is generally a bitch to work with if you are going to play around with the arrangement of it more than once.

And yes you are right about the oil priming. Placing it under the engine lid or in the side vent would actually present more ongoing problems with oil priming as it would drain back unless a check valve was installed. Whereas lines going either to the front or back of the car remain low enough that this doesnt happen. That's why my current setup doesnt have startup issues...

Chuckster; Being a positive displacement pump flow rate the extra resistance shouldnt affect the flow rate of oil (i think??). However it will put more strain on the pump and result in more parasitic loss etc etc. How much more though is the question... it could be a lot, or it could be marginal. I think this is the biggest issue as I honestly have nfi how much more strain I am putting on the pump if I do this, but i cant imagine a few metres of hose adding THAT much resistance.

Gonna do some calcs with those figures from earlier on now. brb

[masterofsinanju]

Car. AW11
Engine. 4AGTE
Problem. Inadequate oil cooling

With the crapass packaging that is the AW11, it is near impossible to have a decent oil cooling solution. One method I am considering is to run lines up to the front of the car and run the oil cooler up the front like a normal car, where the cooler will get a nice faceful of fresh air. The only thing is I am worried about the length of the lines (they will be somewhere around 6-7metres all up) and whether they will cause pumping issues for the oil system.

Even with my current rear mounted setup the car still has some 3-4 odd metres of oil lines and pressure seems to be unchanged to when there was no oil cooler on board, but if I could get some better educated opinions that would be good.

Cheers.
Vito.

The remnants of some first year hydrology/chemistry and physics classes tell me you will lose some pressure if only because of the increased surface area in the additional pipes. If you have no pressure loss with 3-4 m of line I would take a guess that the loss even with double the amount of lines would be negligible.

The problems then lie in the variously identified weaknesses of having lines running up and back.

I'm not experienced enough to offer opinion on whether such a system would actually work in the real world but I can't see any reason for it not to (theoretically). Any way you could run the same length of lines out to a cooler without running them on the actual car? Stick a fan in front to simulate some airflow and see what temps and pressures you get? That way you don't have to hack into your car until you have some assurances it works.

Also, for what it's worth, on the face of it your points about front mounted cooling make sense. It's the first point of contact for your car and without access to a wind tunnel, you'll be hard pressed to identify other air flow rich areas without a lot of trial and error.

I love the car and was disappointed to see how track day panned out. Hope you don't let it bum you out too much.

EDIT: Dneg knows his hydraulics. I'd take his advice over mine, it is at least based on practical experience. Still, I can't see it going wrong (didn't see my car catching fire under Melbourne until it happened either )

[trdee]

Haha thanks sinanju. Yeah I was trying to recall my old fluid dynamics brain back from the mothballed engineering sections of my brain, gonna try have a go now....

So assuming a flow rate of 45l/min at 8000rpm we get roughly 12 gallons per minute at 8000rpm
Looking at the table i provided earlier that means I am getting somewhere around 0.5psi pressure loss per foot.
Overestimating 8m of hose gives roughly 26 feet.
As a result, at 8000rpm i have a pressure loss of roughly 13psi at 8000rpm

Someone wanna check my calcs?

Either way that sounds like a bit of pressure loss. But being a positive displacement pump, the flow rate of oil through the lines should always be the same no? And thus that means that the pressure on the bearings themselves shouldnt change, so this "pressure loss" calculated above is more a measure of the extra strain the pump has to overcome, does that make sense? My brain is hurting lol



Anywho, If I'm not retarded and it is just a measure of strain on the pump rather than "real" pressure loss that I would see in the engine, then that is ok, as people shim pumps up a fair bit more than that kind of pressure difference without issue anyway.

[dnegative]

Dneg, why would it make my engine more vulnerable than a leak anywhere else?

Two big lines snaking the length of the car with more fittings, hoses and a dirty big cooler up front pretty much turns your whole car into a vulnerability compared to confining the cooler to the engine bay etc

Hardline is definitely the way to go over hose, its just as easy to bend (only SS and copper really suffer from work hardening imo), is always going to look neater than hose and it will take a pothole hit without fucking it too badly.