engine oil

[Svejk]

I'm new to VW ownership, though I like to point out that I grew up in the 70s in a '64 split window bus—complete with hippie flower decals all over the exterior. Anyway, I purchased a '75 Riviera last summer and had Mitchell's do some work on it. When I asked him for an engine oil recommendation, he said plain old 10w-40 year-round; what do you guys think? And should I use synthetic or non? Thanks for any help.

[CustomVW]

I never use multi wieghts in air cooled, due to their head temperature. Aircooled engines run at anywhere between 250-300F, which will burn most conventional multi wieghts, and leave that lovely black tar everywhere.

all conventional oil, is based on a 30wt oil. They add modifying packages, to change its properties into other oils, ie 10-40, 20-50, etc....

the package cannot take the heat, but the oil usually can. so the package burns.

I run straight 30wt all-year round, the only exception would be the use of a synthetic, whihc, does burn off, but not the same way.

Summary, if you don't wanna spend lot's of coin on synthetic, go to Pacific petroleum, and ask for their 30wt tractor heavy duty oil.

[jengel451]

The "rule of thumb" is 10psi of pressure for every 1000rpm. From cold to warmed up.

The great oil debate is far reaching and never ending. There are some very good papers out there you can research. I've spent a bit of time on it this year and have basically thrown out a lot of prior assumptions at this time.

Right now, in my bug, i'm running 0w-30w Synth Blend. Straight 30 when the engine was warming up, was way too thick, I think I was pegging around 40-50psi at idle, you can actually do damage that way as the pressure relief valves are dumping oil before the bearings. I only used the straight weight during break in with Zinc additive. Also, you don't want to have your engine oil above 250, the stock system, if everything is intact and running right, will run below that.

BTW, My built 2276 has come down around 15 degrees to a constant 200 degrees (without my ext fan running). (220ish on a 90+ degree day) now that i've found the oil that works for me, I went through a couple different weights. (I also have a thermostat for my cooler, that will keep the oil at ~180)

Here are some links. Do you're own research and come up with what works for your particular engine.


http://www.lnengineering.com/oil.html

http://www.aircooled.net/gnrlsite/resource/articles/synthoil.htm

http://www.widman.biz/uploads/Corvair_oil.pdf


Here's a long one but a GREAT read:
http://www.ferrarichat.com/forum/faq.php?faq=haas_articles

[shakajava]

In the last few years I use synthetic for just about everything. Everything seems to just run smoother and cooler. I put it in my VWs, Volvos, and lawnmower. I think my cars shift better and idle smoother. Just my opinion.