another oil question ~ go with it....

on another thread discussing cooling it was mentioned running without thermostat meant the engine warmed up slower and didn't maintain a constant temperature this it was said meant the oil didn't circulate as well which would aid in faster engine wear, so based on this theory what are the pros and cons for running thinner oils? last year i ran the cheapest mineral grade i could find 20/50 i think? where as this year after much thinking i'm on semi synthetic 10/40, i know less than zero about oil but if indeed it does help cooling or movement around vital parts quicker then what would be best?.

 

Don't go for thinner oil in an aircooler. 20W50 is fine, if you've got an oldish engine. 15W40 as well.

A thermostat just helps the engine warm up quicker from cold, which is when most wear takes place. Once it's open, it's open, like a watercooler.

Aircooler engine temps bang all over the place, depending on whether you're tootling, hammering down the motorway or climbing a hill. A thermostat won't have any effect on this.

Stop worrying ...

 

so are you saying 10/40 is thin then? someone on here and i forget who now claimed that it was perfect to use as oil technology had come on since mineral days, as i say i don't know what the numbers mean and i'm not worried just interested.

 

My engine builder insisted that I used Brad Penn oil for the breaking in (300miles) and then change to more Brad Penn 20-50 for normal running. He told me this was the best for aircooled and why risk using cheaper oils on an engine that is likely to cost 3K. The oil cost £30+vat and postage from Stateside. A lot of people run Morris oil which is £25. I can't see the point in buying tesco's own to save £10. Also I don't know any better and generally do as I'm told. I am thinking about changing to the Morris stuff, as I can buy it locally.

Anyone else using Brad Penn or Morris?

 

Rick, Im running a semi synthetic 15W40 as I seem to remember it ticked alot of the boxs and was judged as a resonable all rounder. Just dont mix your oils either use a mineral or synthetic oil and stick with it...

 

cheers so far, i'm still no nearer my original question though......we're nearly there but..... why are thin oils bad - if they are, and is 10/40 classed as thin..... the oil change frequency matters not one bit to me, last year i did just over 1000 miles and changed it, this year will be the same plus or minus 500 miles.

 

^or this, not taking the P, but it's all down to oil film stability through the range of operating temps.

http://www.substech.com/dokuwiki/doku.php?id=engine_oils

 

oooohhh that requires reading when i'm more awake, cheers chaps.

 

i have spent more than a few hours looking into oils
first of all, type 1 engines. beetles buses whatever. these do not have oil filters. they have a strainer and thats it. mineral oil is preferred in thes as its thicker and retains the dirt etc in the oil itself. larger bits are are caught in the strainer.
type 4 engines, call them what you will. these have a spin on metal canister oil filter so dont need the same properties in the oil as the type1. autodata lists 15w40 for these engines.
personally i have run 10w40 for 3 years with no issues. this is my choice and if it goes tits then its down to me. semi syn oil has better cleaning and cooling properties, doesnt need to be changed every 3 months and is fairly cheap.
i wouldnt say 10w40 is particularly thin, but you make your own minds up.
i am not telling people to do anything as the oil debate will continue for ever. do what you feel is best for you and your engine

 

cheers aussie bay, typed in a way i can understand when tired..... and it has a disclaimer too so i'm happy to leave the 10/40 in for now if someone else has used it for a while

 

^ now thats a fair comment

 

I love this place, Its like playing chess with the old boys down the park in summer time!

Thin oil will ******* out of every orifice.

Ref the thermostat 'problem. Yes, thermostats fail in safe mode. So, not having a thermostat is not a major issue, it takes the engine longer to warm up a bit - not a major deal. If you don't have a thermostat fitted you should never let your van tick over and warm up. Get in, start the engine and drive drive drive.

But...

If your flaps are missing, then you have an issue, because the air has to be channeled to cool effectively. Remember, remember remember, these engines are

OIL COOLED

The air cools the oil. It does this by being channeled through the oil cooler. Some of it cools the heads and cylinders but most of it cools the oil. If it doesn't get channeled to the oil cooler the oil doesn't get cooled and it doesn't cool the engine effectively. The problem with a CHT gauge is that if you don't have all of the correct tin in place the air will get blasted over the top of the engine and down onto the heads. Therefore a CHT gauge will show a reduced HEAD temperature, however, you could, and most likely will, see increasing temperatures elsewhere in the engine, namely the bits that need cooling by the oil. This will likely cause it to go bang in a rather spectacular fashion, probably with a rod welded to the crank and sticking out the side of the crank case.

I might have said it before, I work for a materials testing company. My sector is aerospace. As such we do a host of testing for the primes, Airbus, Rolls-Royce Boeing Pratt and Whitney, Nasa et al.

We make sure that aircraft are certified and stay in the sky where they belong. We don't just break and smash metal and composite. We also test fuels and lubricants, before they get used, during use (called condition monitoring) as well as after use.

We test oils and fluid which have been in jet engines and what we are looking for is the break down of fluids, but also engine wear. We also test car engines, gas turbines and wind turbines.

I used our service when I built my engine. I though 'good enough for Rolls-Royce good enough for me'

The mineral oil I was using (halfords cheapo) showed no break down in the oil quality, and minor wear in the engine (they count the percentage of particles)

With some pretty spanking computer wizardry they can run some simulations which would show the effect of different oil grades on MY engine based on wear.

The crazy haired mad Swedish scientists told me that the mineral based oil I was using was made for the engine - they couldn't run an effective simulation running different grades which would show similar results.

I use Halfords, whatever floats your boat

 

^^You sound like you may even understand some of the stuff in the link I posted. ???

You may even read it. If you do can you explain it to me?

 

i've come to the conclusion that sometimes ignorance is bliss, i make the mistake when i get involved with a scene/manufacturer to try and learn stuff just because i'm interested in having knowledge, i'm not really bothered about using this knowledge in a practical way 'cos i'm lazier the older i get, when i was 20-30 i loved it if summat broke and i could tinker for england, now in my 40's i find checking the washer fluid or oil level a chore.... i learned a lot about landrovers but that took me 20 years, in the 10 months of having a vw oil/air cooled van i have never known so many differing opinions and found so many bodges that are accepted as "the norm" by some or rideculed by others, one thing is for deffinate if my engine does go bang the only way another aircooled will go in is if it's cheap, other than that i'm going diesel and water cooled.

 

When Rudy drank more oil tahn petrol see got the cheap stuff now think it might be but sure what really as shes not moved in 12 months.