Pre heating oil - pre pumping oil - before ignition
 

Any one doing anything along these lines?

Seeing as most engine wear is done on start up and then in the first 5 or so cold minutes.
I drive arround like a vicar for 10mins untill the oil temp is at least up to 80deg
Then never give it full beans utill 85-90deg

Conversely modern good quality oil coats everthing when cold.

Anyone have any mods - that pre heat the oil or pre pump it into the right places?
Or a waste of effort for any benefit

Interested in your views guys

I'm sure you remember Tim from tonbridge might be worth pm'ing him on 22B (hid id is "Slooby") as i know he has a pre-start pump or even better asking this question on 22B.

Or i could always put it on there for you which will save you registering.

Hope your well BTW as havent heard from you in a while....

Hi Baly mate.
Yep just been real busy and havent really touched the scoob at all.
Will be about in early July and will probably visit Harvey.
Yes I remember Tim and guessed he was Slooby. I just lurk on there every now and then :)
Stick the question up on 22B and see what happens.
Done any more on the house yet. PM me if you want.
Steve

The Canton accusump pre pumps oil before startup

http://www.accusump.com/accusump_units.html

i dont even drive the car for the first 5/10mins, i let it idle and normally set off when it's settles down to normal idle..

also dont take it over 3k revs in first 20mins of driving..after this 5/10min idle..

suppose i can with it being a weekend car and it only goes out when i want fun..

Posted on 22B for you Steve, i will PM you a bit later as i'm just about to finish work and head home.

Home and car both gather dust at the mo :lol1:

Your even more anal than me :)
I used to let it idle for 5-10mins like you.
Mine is forged (pistons, liners ect) and knocks like a good un when cold. I now wait probably about 2-4mins and wait for the knocking to die away and then I drive it very slowly way under 2k revs and use my temp guage to work out went to start giving it some.

As the pistons are lose when cold and i expect oil gets past them I also want to get the engine working ASAP and get warmth into then, safely, ASAP.

Harvey's got some good experience of this, and it's something I'll look further into when I have a clear deck. One of the things I'm thinking of is feeding an oil pressure sender into a spare analog input on the ECU so, firstly, during startup it will delay fuel and ignition until there's a set amount of pressure, and secondly so that limp mode or, in extreme circumstances, engine cut could be instigated if there's a drop while the car's being driven. It's also easy enough to lets the engine rotate on the starter for a little longer before lighting up.

However, all that said, there's a reason why we have good multigrade oils nowadays. Cold performance is much, much better than it was three or four decades ago and to be honest you're probably better off driving the car slowly than just leaving it idle while your oil warms up.

Given the above I would suspect the main opportunity for wear, on a standard-ish Subaru engine, comes within the first handful of seconds of startup as flow and pressure are establishing. Harvey's observations on the car with the superfluous cooler were interesting in this context. Increasing the volume of the oilways resulted in that engine taking much longer to generate pressure.

As above you'd probably be better driving round slowly than doing that

Interesting reply Splitpin. Keep me posted as to if you get the time to putting your plan to test. As it is first 10 seconds of building flow and pressure I am interested in. When I vist Harvey I will also see what he thinks.

Agree totaly about driving it around slowly rather than letting it idle, which is why I now do this, as soon as the inital piston slap has died away.

Kenlowe (sp?) used to make a water heater, that would obviously warm the whole engine, it was designed for winter use, and adds a fairlump of weight IMHO.

dunx

http://www.kenlowe.com/pre-heaters/cars/whatwill.html

I looked into the Accusump a while back- the electronic one that goes off at 20 psi or so seemed to be the one to get, but I ended up getting a baffled sump as oil starvation was my main concern.

They fit Accusumps on the new Exige I believe, and a few Caterham track cars use them.

Prelubing is just an added benefit from them, and if you dont have a baffled sump, not a bad solution for oil starvation was my conclusion from research. Seemed simple to fit too, especially if you already have an oil cooler.

I think for the UK pre heating the oil is a bit annal but in Scandinavia, Russia, Hungary and elsewhere, where temps regularly drop below -20C both cars and trucks have water heaters but the purpose is to keep the oil viscuos at these low temperatues. At truck stops they have mains power points to hook up the heater plugs in the water jacket. I think in Scandinavia you can actually buy new Saab and Volvo cars with self contained heaters and most new trucks have these but powered by deisle.

What I would suggest you do is fit a switch to your fuel pump supply. If the car has been stood for a few days or over a particularly cold night which we only get rarely you can crank the engine with fuel pump off and when you see full oil pressure switch the fuel pump on and start normally. Depending on the engine this will involve cranking for 5-15 seconds.

There are a lot of cars out there fitted with oil coolers but they have no oil temperature guage. This makes no sense to me. Classics generally do not need oil coolers. New Age generally run 5-10C high and all 2.5 tuned engines I have had anything to do with run a clear 10C more oil temperature than a Classic 2 litre.

I think cranking without firing from cold on occassion has to be worthwhile. No doubt it knocks hell out of the starter and battery but I have never had to replace the starter.
Next time you do a cold start, just observe how long after starting it takes to achieve oil pressure and if you do not have a pressure guage, get one fitted. I use the Racetech combined oil pressure temperature guage. Very neat, attractive and compact. Two important bits of information from one 52mm hole. Also you will be surprised how long it takes for the oil to get to working temperature and during cold slushy winter days some cars are still not at working temperature after 20 miles of suburban use.

Makes interesting reading,this.
I am in the prcocess of buying a Spec C,from Litchfields.This has oil temp and oil temp gauges.
What should the pressure gauge read,on start up and when it is warm?
What pressure is deemed,too low?
Also,what temperature do you recommend the oil reach,before you can "use" the car?
Thanks a lot,for your time
Chris

Pressure (this is what mine does)
Well at idle 40psi ish under load 90-100psi dropping to 80psi when the oil gets hotter.
Basically anything very low is alarm bells time. Pull over and turn the engine off ASAP.

Temperature
Drive with kid gloves to 80deg
Drive moderately working the engine more to 90deg
90deg and over cane the c_ap out of it.

I personaly back off at 110deg

(edited in light of Harvey´s post below - 125deg is a safe limit)

Some people with coolers fitted see below 90 as a working temp

Basically 80-85degrees is the temp which for me is the dividing line between carefull driving and giving it stick

2.5s tend to runner hotter than 2.0

I'd wait till it sees 70 degrees, and the "stat" opens at 88 degrees, so I'd almost never get to "drive" it...

I wouldn't worry till you pass 120 degrees, I only ever managed 115, but fitted a cooler anyway.

All IMHO, ( <400 bhp 2 litre New-Age )

dunx

That's unnecessarily cautious too. 120-130 is the area to start paying attention to it. At the lower level anything about 70 should be okay for most engines. As above we're talking about modern multigrade synthetic lubricants here not caster oil.

so rather than letting it idle i should drive it slow? i just found when cold you tend to rev higher to like 2.5k/3krpm

if i let it idle for 5 mins it comes down and i can drive it under 2.5k no probs without accidently having to give it more gas as it's jerky..

Start engine, drive off. No boost and 2500-3000. When oil is cold tickover and running pressure is far higher by as much as 40psi/nearly 3 bar.
As oil starts to flow round engine water will warm up first and Subarus are amongst the fastest warming cars on the water side. After a few minutes at 2500-3000 up it to 3500 and keep to that until you see the oil up to the 70s and gradually increase load revs and boost. Basically I drive to keep oil pressure down below a certain level so as oil warms, pressure drops so I increase revs slightly maintaining up to the pressure I do not wish to exceed.
Classics typically cruise at 84-86 C oil temp and NEW Age or 2.5 perhaps as much as 10C more.
Unless driven very hard Classics won't go much higher than 105C but New Age and 2.5 can go over 100 regularly past 110-115. When on track I come in if I ever get to 125C. This is on a car at well over 500 bhp. The oil manufacturers all state that the temp limit is 140C and all VAG and Porsche I have seen that run oil temperature guages as standard, even the very old quatrosof the 70s and 80s all had the red line at 140C.
Water should normally be mid 80s and a common cause of high oil temperature is a blocked water radiator causing water and oil temperatures to increase.

Oil pressure drops as the oil warms. So on start tickover may be 4 or 5 bar, mid 50s to 70psi but hot it may be down under 2 bar. Signifigantly below 2 bar is a cuase for concern eg1.5 bar 22psi. Subarus run generally at full oil pressure beyond about 2.5k rpm and this can be as low as 60 psi just over 4 bar up to over 6 bar 90psi. All very approximate.
It is a sudden drop in normal oil pressure or a risw in normal running temp that should be of concern.
Obviously on hot days the oil will run a bit hotter than on cold days.
Changing oil viscosity/type results in different temps and pressures.

I remember Performance Car saying that you shouldn't unnecessarily sit stationary, idling after immediate start up (for all cars). Can't recall a scientific reason though.

Don't be anal - just drive "normally" off-boost until you get up to normal coolant temp i.e. to 83+ deg or so. That's what I do (takes c.3-4miles) before even thinking of hooning. I have no oil temp/pressure gauges.

So far, no issues in c.30 months on my Zen-rebuild.......

ok no worries, so a question for those with guages as i dont have any, how long does it usually take a on a normal british day to get to full operating temperature? i normally wait for 30mins/10miles.. is that too long?

Thanks very much to all who replied.:thumb::thumb:
Really useful information.
Chris

15+ mins seems to be the time the coolant temp get to normal i.e. 83+ C in Spring-type weather.. So 30min should be okay for winter.

Anybody used one of these? >> https://www.subarugenuineparts.com/p...products_id=64

^+1, excellent post. It's the sudden and unexpected drops in pressure that are usually the clearest telltale signs of problems. And, as a minor side point, while that dual LCD temperature/pressure gauge is neat, the one advantage analog gauges have is that the typical driver is more likely to notice sudden fluctuations on a needle than changing numbers on a small LCD screen in the corner of the eye.

Yeah that's fine, just drive the thing. If as you say it's "jerky" when not allowed some time to idle, that suggests an issue with the engine's mapping (i.e. cold start parameters), or, possibly, a dodgy coolant temperature sensor that could/should be addressed.

Short answer: get some gauges! Long answer: None of us knows how long your particular car takes to warm up, especially without knowing whether it has the standard modine/etc. or not. It's also an obvious fact that it'll warm up a hell of a lot quicker on a day like today, with 23-25C ambient temperatures, than it would have when there was snow on the floor in January/February.

Assuming you have a standard oil system, you are likely to find in practice that the coolant temp gauge is as good a guide as you'll need. As that needle reaches its normal running position, your coolant is in the 80-85 bracket, likelihood is that your oil temp won't be more than 10 degrees or so behind. Waiting half an hour before driving the car fully is more than a little cautious.

There's also no need to stick religiously to 3000rpm until your engine is fully "hot". The OE temp gauge on the dash on most cars doesn't start to move until the temperature's above something like 50C. As such, when you see the coolant needle start to move, you can regard the engine as "warming" and progressively give it a bit more until it's settled in normal run position.

Baly: That's an interesting find, wonder where it connects. Biggest issue with someone trying that in the UK or Europe though would be that it's a 115 volt device and so would need a transformer. Unless of course Subaru do a 220/230 volt version as well.

I whole-heartedly agree with that!

They get to temp in astonishing-quick time - defo the quickest of the 13 cars I've owned to date...

thanks for the advice splitpin, and i drove it today without letting it idle and it was fine, it's just as soon as you lift the clutch the revs drop on cold idle easier and stalls, a bit of gas and its fine :)

Good find there Baly. When time permits I will look in to that not because I think it is necessary for the UK but more out of interest.
Thanks for that Splitpin.
As regards warming up times, all the Subarus I have owned have reached water temperature very quickly, over 80 deg.C. within 2 miles in a 30 zone but oil temperature typically takes 10 miles to reach 80 C. and on a cold wet slushy Winter morning I can drive to Middlesbrough, 17 miles away and oil temperature might only be 70 C.
Generally I work on the basis of 10 miles to full oil temperature but by that time I will be cruising gently at 3500 rpm. Thereafter it can go up to 4000 or 4500.

In summer with weather like this its not needed as much really as the ambient temp is suffiecent. Just allow sufficent oil pressure and a bit of temp to get in engine then lay off boost for first X amount of miles on your journey. It will warm up a damn site faster driving under 2k for 2 - 5 mins than sat there idleing. Each to their own though. In regard to start up oil pressure mine usually takes 4 - 5 seconds to crank which i think builds oil pressure more than enough if you have a healthy oil pump and clean oil and filter. Although i will be changing the oil pump on this engine rebuild for a better unit.

harvey: how would you go about fitting a switch yo the fuel pump supply?

i mena how would it be wired up? could i do it myself?

https://www.scoobynet.com/showpost.p...&postcount=174

^ Post #172.

If you're up to some simple auto electrics and have the simple tools you'll need to do it properly, almost certainly. If you're not sure, probably better left to someone who is.