Oil for air cooleds in AFRICA

[Haans]

To the ghurus out there?

1st,...I do know thereare sharper pencils in the box,.....and less sharp too,.... so for me and rest here is the question

Happen to stumble on the "thread" on another forum,.....shoptalkforum.com and pages of discussion on the"correct" oil to use

Now what I got is this,......oil pressure is just the measure of resistance,...so far so good!
Oil breaks down when overheating,.....ok I'm still with them !
The better flow rate the better this cooling process works !,.....still makes sense ??.
Now in my world of air cooling I was led to believe,....you use a SAE 30 or 40 ,...and a diesel engine oils,....BECAUSE it keeps it's "properties" better

Keep in mind that we only have 2.5 litersof itto play with so to speak !!!

These guys are telling me to use a 10W40 or even better 5W20/30 oil!!!!!!,.....to aid the "flow" too enhance the cooling properties,..and due to lower tempretures,...it will keep the lubricating propertie !

This all seem to make sense,....BUT,......what about our SA conditions ?,........yes we all cutour teeth on good old SAE30 !!!!!!

I am very keen to heary your opinion !!

Regards. Haans

[Merlin]

If you're running in a new motor, Castrol GTX.

After that, Castrol EDGE (fully synthetic) 10W-60 SN.

Period.

...whilst we're at it:

Deep sumps (with lengthened collectors) are great... Save your motor in the bends.

Unleaded 95 with valve additive (Valve Ease or Valve-Guard)

End of story.

[Riaan.N]

I have been reading up on what people said about which specific oils to use and the one thing that is a problem is that with the ever changing legislations and demands from car manufacturers, the oils also have to change. So if oil X was the go to oil 5 years ago, it is not to say that oil X will still be the same today, if it is still available. There might have been changes to its formulation some where along the line that does not make as good for the unchanged application anymore.

So, although there are many threads about which oils are good, one has to also keep in mind when it was good and check the specifications then and now to ensure that it is still fit for purpose.

The other issue is that some of answers/responses are biased due to personal opinions/preferences.

[Tony Z]

Now what I got is this,......oil pressure is just the measure of resistance,...so far so good! viscosity is a resistance to flow. Pressure is pressure.
Oil breaks down when overheating,.....ok I'm still with them !
The better flow rate the better this cooling process works !,.....still makes sense ??.wrong, it is this mentality that sells bigger, unneeded oil pumps which aid overheating
Now in my world of air cooling I was led to believe,....you use a SAE 30 or 40 ,...and a diesel engine oils,....BECAUSE it keeps it's "properties" better

Keep in mind that we only have 2.5 litersof itto play with so to speak !!!

These guys are telling me to use a 10W40 or even better 5W20/30 oil!!!!!!,.....to aid the "flow" too enhance the cooling properties,..and due to lower tempretures,...it will keep the lubricating propertie !

This all seem to make sense,....BUT,......what about our SA conditions ?,........yes we all cutour teeth on good old SAE30 !!!!!!

I am very keen to heary your opinion !!

Regards. Haans

I've done a fair amount of looking into it over time. I even sent off an oil sample to test the properties.
I pretty much run Shell Rimula R4X 15W40 exclusively at the moment and always recommend it. It has ZDDP up in the 1250ppm range which is exactly perfect for our engines. The second oil I had good success with was GTX Diesel 15w40 but I didnt have this one tested.
The general Run now is to avoid the new SN oils like the plague. SL or if you can find it, SJ oils have the correct anti wear packages for us.
As for flow rates and cooling.... you need to understand that the VW cooling system is not temperature regulated, it is pressure regulated. So when the oil warms up, the pressure drops and the oil is then routed to the oil cooler. Very simple. Problem is that many companies sell larger oil pumps to improve cooling by moving more oil through the cooler at higher speeds and many people believe this to work, but the reality is that the bigger oil pump increases the pressure which reduces the cooling until the oil is so hot and thinned out that it finally goes to the cooler. By this time the damage to the oil is done. But hey, if they market it this way and get people to believe it, then they can sell external coolers and more products... their marketing people did a good job.
A thinner oil (10W40) with a stock pump drops to "cooling" pressure at a lower temp and this then keeps the oil much cooler than a 20W50 with a bigger pump.
BTW, the stock 26mm oil pump is oversized for the engine already, so you can afford to use a thinner oil. Provided all your tolerances are still within spec. I even once built an engine with a 21mm oil pump which is still running on Rimula R4X without any issues. This wasnt a stock engine, but a higher performing unit that doesnt have overheating or oil pressure problems.

I used to use Edge 10W60 and futron 20W60 before I really put some thought into understanding the cooling system.
Also, consider that most people recommend the 10psi per 1000rpm rule. Food for thought here - on Angrrr (one of the most expensive aircooled engines in SA) I run a stock 26mm oil pump. I removed the stock cooler due to it being pressure regulated and thus useless when turning rpms well above stock. I have a thermostatically controlled oil cooling system now. Anyway, I run Mobil 1 0W30 oil, plumb this through an oil filter and about 1.5m of 1/2" oil hoses before it returns to the engine. I still get more than 10psi per 1000rpm when cruising around normally.

[73type2]

Whew Tony! I thought it was "end of story" as per a previous post. Should I change from running SAE40 on my stock engines?

[Tony Z]

definitely
SAE40 is thick when cold, so you get more pressure and less flow, which equates to less protection.
10w40 is as thin as a 10 when cold but as thick as a 40 when warm so you get better protection when the engine is cold

[acpaterson]

I saw the innards of a few engines when I was getting my motor done by Andreno, and he showed me a Shell Motor vs other brands.. It was interesting to say the least. The Shell motor looked half as old as all the other motors, metal was much cleaner etc.

Shell 15W40 is the only oil I use these days.

regards

Al

[Haans]

Contributors,.....there is nothing more I enjoy more is to light a fire on this forum !!!, and then accept however difficult it is,......I am not thesharpest pencil!!!!

Then again sharp enough to join a forumsuch as this !!!!

Thank you to all,..and to those that will still contribute !!!!

It looks like the Shell 10w40 seems to be the in thing for now !

I willreturn to this issue again,...and study the contributions again!!

THANK YOU! Very interesting

Haans

[retrovan]

Agree with all said above, but want to add one thing, as Tony said, temp. in an aircooled is not regulated, and as all modern oils are made for antifreeze cooling systems, they know their oil will not run hot.

The only Oil that has high temp ability is the Diesel oils, thats why I use 10W40 Diesel oil and do not burn my oil.

Herman

[Riaan.N]

On the subject of oil, what gearbox oil is ok to use...what specific product?

I read a thread where GL5 75W90 is advised even thought it might not be safe for yellow metals. Is a GL4+5 oil then better?

[sean]

On the subject of oil, what gearbox oil is ok to use...what specific product?

I read a thread where GL5 75W90 is advised even thought it might not be safe for yellow metals. Is a GL4+5 oil then better?

Do not use the GL5 spec. A basic EP90 GL4 gear oil is available. Castrol also sells a 80W90 in GL4 spec. I found this to be the best one.

[XXXNEL]

Delo 400 MGX --- -15W-40 -high in "zinc". I run it in my 327 corvette V8, 1993 Isuzu 280TD, Bedford RL and Beetle

[64 Notchback]

Has anyone heard of or used products called Royal Purple and Belesta?.

[Haans]

Are you speaking a foreign language ?

Haans

[64 Notchback]

???? Me
No never sir