Oil plumbing

This is in some respects similar thinking to the larger/longer boost piping furphy where it's regularly thought, and even stated that it "takes time to fill the larger volume"!!
Like your boost will take time to "travel' the length of the pipe. Even allowing for compressibility of air, this argument holds no water. Pressure at one end of the pipe is pressure at the other end!
Things like oil filters and coolers tend to stay mostly full of oil.

When dealing with oil, your talking for all intents and purposes (intensive perpahsez) of an incompressible fluid.

When you think of it, there is a lot of potential in an oil pump and id say it would take a lot longer to initially lift the oil out of the sump, up an empty 14mm pipe circa 300mm long than it would to pressurise a system of 3mm holes that terminate in several thou restrictions at 80 or 90 psi cold.

Id predict the slow lift of oil pressure when cranking would have more to do with the previously mentioned lifting of oil up the strainer tube at low cranking rpm. Can also be heavily influenced by gear lobe and housing wear.
Is why you grease an oil pump on assembly to suck the oil up the tube faster.

I do get the TT setup thinking. Cool the oil when it actually demands it.
However, a decent thermostatted full flow setup will outperform it to buggery and be a really helpful aid especially with respect to warning the oil as quickly as possible.

To that end, i will be using a water to oil heat exchanger. The beauty of this setup is that not only does the water extract excess heat but it assists in heating the oil from cold since the water temp increases far faster that oil temp.
Furthermore, the cooler can be placed anywhere and this removes pesky airflow restrictions from in front of radiators.
Win-win!

E

 

Tas that may be so but on the Supra we didn't have oil coming out the turbo feed until at least half a dozen cranks of the engine. Admittedly again this turbo feed was up high.

But yes thinking about it further the filter will have an anti drain back valve, and the cooler will be still full, so if anything it would still be momentary.

I'm not convinced on the whole 'oil is too cool' issue though. At what lower temperature point does the oil being 'too cool' cause problems for the engine?

 

Isn't that the whole point of warming up? Get oil up to temp? If so, why would you want it to drop back down again?

 

Being too cold is two problems, it effects viscosity and hence reduces flow through smaller oiling ports and you're more likely to be diverting flow through bypass/relief valves, and if the oil isn't getting over ~80C it wont boil off condensed water or blow-by contaminants properly.

 

I don't understand or agree with this. To make boost you must compress air. A 1lt volume system will compress much faster than a 5lt volume system.

Same with oil pressure. If you have an empty hose and turn the water on full boar, it takes time for that water to run out the other end at pressure.

Sure pressure might be the same at either end at any point in time (ie after 1 sec the pressure in a 1 litre volume system might be 10psi 'either end', but after 1 sec in a 5 litre volume system it might only be 5psi - yes completely wrong numbers but for illustration). Pressure doesn't exist at either end until the volume is filled.

 

Again, how many people sit and wait for their oil temp to reach 80degC before moving above idle? Has anyone actually even timed how long this takes?

Also if you're running the correct viscosity oil (5W30) in our climate is viscosity really going to be such a big problem at lower oil temps?

 

It's not about not using the engine you just don't put full load on it in those conditions, I don't know anyone that waits for full temps before moving but I don't know anyone that runs it out to redline taking off after a cold start.

The difference in viscosity between 25C and 100C is about 10-fold for a 10W30 oil and 4-fold for 0W-30 so you want to be at least kinda close to temp. The curve of viscosity vs temp is different for any given oil based on stocks and modifiers used and proper synthetics are better than mineral in that respect but it's not a moot point yet. Surely your pressure gauge would show you the difference in viscosity (since flow is basically constant at a given rpm) at cold start vs up to temp, mine goes from 80psi at 15C to 15psi at temp with 15W40 (Run in oil) at the moment.

 

Yeah mines about the same.

But my point is are our cars once up to running temp actually running an oil temp that is too low in the first place? And if so, why? Again this tells me money is being spent that doesn't need to be spent.

 

When you say 'our cars' are you referring to mine, yours or Zs in general?

 

In general, and I guess I'm talking to anti more than anyone else in this thread lol.

Why spend money on things that just aren't necessary is my point.

 

the purpose of the thermostated plate is to get engine warmed up quicker .

it opens between 75 and 80 degrees .

my operating oil temp sits at 90 degrees on idle.. hit a 100 degrees under WOT but quickly comes down to early 90's in minutes on idle
pretty efficient

without a thermostat it would take longer to warm but still sit at the same operating temperature.

Anti ,the sandwhich plate only flows 10an in/out so 12an isn't needed .


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Did you test how long it takes to warm up before and after fitting the thermostatic sandwich plate?

Mine stock with the bigger cooler warms up pretty much in line with water temps.

Anyway each to their own. I just don't see why this is such a big issue.

 

The stock system is good for stock cars being driven on responsibly(ish) on the street, it doesn't really kick in unless you give it a hit and actually run it over 3krpm so you can cruise around town and it should be somewhere from the water temp to maybe 20C over and if you get spirited it gives some added cooling.

When you wind the boost up to 20psi or start working the car hard you need to deal with a bunch more heat, Anti's car isn't exactly stock and will probably cop some punishment from time to time and it's easier to design the cooling system while everything is in pieces than put it together and figure out whether or not it's over heating and have to pull it apart again.

Me and Anti are attempting to have cars that suitable for both street duties and working hard but achieving that versatility is tricky. Basically brings me back to my first post, with my system I'm thinking about just having a ball valve to switch oil flow to the cooler on and off based on what I'm doing, lots of cooling on the track with temps from 90-100C and no cooling on mild days when I'm driving to the shops.

 

No but my water gets to 80 first as I have a larger sump.
I have 8 litres of capacity with coolers so it would take significantly longer without.

 

Not sure what your problem is with the thermostated plate? It is an only beneficial addition. Most people don't wait 'til their oil temp is up to 80, no, but warming the oil is part of warming up. It'd take bloody forever if that oil was running full stream though a massive after market cooler from the get go.

I'm quite surprised you're not concerned about running your oil temp too low. Fists is right, I'm redoing everything and am looking to put it together in the optimum set up.

Rob, what plumbing set up are you running? Z1 style but with two coolers in a series?

 

Black Beast: In case you haven't read through all our babbling 'Z1 style' runs the factory cooler feed line back to the sump through a restrictor rather than blocking it off or switching to an NA tree.

 

I honestly don't see what the big issue is. A couple of minutes warming up is all I've ever done. I've never ever been concerned with the oil temps being too low on my street cars or my race cars, and I don't know anyone who races that does. Again though that's just my thoughts. The only oil temps I'm concerned about is if it gets too hot.

 

I run the GREDDY plate with NA TREE and twin 19 row coolers in series.
the drivers side cooler is actually hotter than the passenger side to touch after a run so it works quite well.

it runs hot enough on the street and wont run too hot on the track.
90 -110 .




you aren't going to get a better (optimum) set up than this (with a FMIC )

http://www.aus300zx.com/forum/showpost.php?p=1411520&postcount=581

(edit: the 4th pic is the power steering cooler )



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I never give my race engine a "big" rev (race start for instance) unless I have minimum of 45-deg C in the oil.

I had an uncle who was in the Air Force in WW flying Kittyhawks and he told me that the LAC would bollock any pilot who en****erated any of "his" engines with a big-rev on cold oil. The LAC always said he got up 2 hours before sparrow fart to warm-up engines properly to make sure the oil had plenty of heat for when they came on duty just before first light and any pilot on readiness had to start/run the engine every 20 minutes to keep heat in the oil so they could start and go fork-off at WOT and not spin his bearings.

Cold/thick race oil (even fully synthetic) has massive oil drag ............ in my new car, I will have an oil tank heater fitted because we are going to run it to tight-ish clearances and I am even thinking of a water heater to get some heat into the block before engine start.