thf944

So I was wondering what type of oil does everyone use for their air-cooled? I use Mobil 1 in my turbo Golf but I'm not sure if synthetic is alright with such an old motor. What's everyone's experience? I was told by a local air-cooled VW guy that 20-50 conventional would be good. It gets pretty hot in the summer here (Denver) and the winters are usually mild.

For reference, I have a '74 but the motor is a '73 1.8 on carbs.

skl

I use Mobil 1 in the newer cars but never used synthetic in the older cars as I figure it would leak like a sieve. I don't drive the 914 really hard anymore so I've been using a Valvoline high mileage multi-weight that seems to be doing fine. With a pretty basic engine like we have in the 914's, I guess it isn't rocket science... as for 10-40 or 20-50 I'd watch the oil pressure and temp under different loads. I mounted oil temp and oil presure VDO gauges were the ash tray used to be- works great.

Rotten Robby

Research says that you should use an oil with a higher zinc content. Search L&N Engineering and then snoop around the pages until you find his research on oils in flat tappet engines.
Several come to mind, some dino oil, some synthetic. Brad Penn which is the old Kendall GT, and Royal Purple. There are also zinc additives that you can put in to bring up the content in newer oils.
Apparently, the zinc content in the older oils was wearing out catalytic converters so the change was recommended by some govt. agency. It's all in the research...

skl

I do remember hearing about the Zn issue- thanks for reminding me. We sure don't need to worry about cats with these cars thank God!! (guess some of the late ones in California did have cats??)

Matt Romanowski

Brad Penn is supposed to be the old Kendall when it was green. I still don't understand why people think tthat 20 year (or more) old oil technology is so good.

I run either Amsoil or Valvoline synthetic. No leakage problems.

Jay Gratton

I run Amsoil 20w-50 in my 1.7 and it doesn't burn it or leak it. It is not as loud either not that I run the syn. oil too! I might switch to 10w-40 in the cooler months if it gets into the 40's or less though. Also, if the engine is a '73 it is a 1.7 and if the engine is a '74 it is a 1.8 so you know. Keep asking questions if you have them and enjoy the ride.

mikekoozmin

The critical component in the oil choice has been noted and proven to be ZDDP (Zinc dithiophosphate) which is an anti-wear component that remains free flowing in the oil until enough heat builds up to break the oil film. Then the ZDDP reacts and sticks to the surfaces to reduce wear. It doesn't prevent wear, just reduces it. The flat tappet engine in the 914 likes the high ZDDP content oils. Brad Penn 20/50 "Racing" oil happens to be one of the more commonly used since it has the "required" amount of ZDDP for wear prevention in our 914s. I believe Amsoil has oils that are high in ZDDP content too, as does Valvoline. You can use anything, but using the proper viscosity oil with the proper additives for the engine type will prolong the life of the engine.

thf944

What's a good way to tell what motor I have? Can I tell by a serial number?

BTW, I appreciate all the responses. I've been doing some reading and this helps a lot!

Matt Romanowski

Check out this link. It has all of the engine types.

http://www.tunacan.net/t4/reference/case.htm

mikekoozmin

This one is kinda cool too. It has engine/trans numbers corresponding to chassis numbers. This way you can see if the engine/trans in your car has a probability of being original to the car.
http://www.bigporsche.com/history914w.htm
I like the one Matt posted because it has engine numbers original to VW chassis as well as the 914.

skl

Interesting links guys- I know the engine in my '71 is original because I've had it since new. I've known the '73 since it was a year old so assume everything is OEM in that too but will check out these links.
Thanks!

skl

As for the oils with higher Zn- wonder how to find out which ones are available at local parts places like O'Reilly or NAPA etc without having to send away for it...

mikekoozmin

Yer local parts stores will likely have Royal Purple but if you find a buggy speed shop in your area they will probably carry one of the zinc rich oils.

Matt Romanowski

I could be wrong, but I don't think there are any bug shops in Iowa.

I think the oil thing is overinflated. Anyone have first hand experience with problems? I'm only heard of far off stories.

mikekoozmin

Yep. Chunked lifters, flattened cam lobes... and such... without it. It can get ugly. Never had this issue with the zinc rich oils (unless I did something else wrong). I'm no expert. As a matter of fact I am just a hobbyist and not even a pro at that but I have been tooling around with the flat tappet engines for about 25 years so I have had my share of mishaps. Most (if not all) of which were my fault. I didn't learn quick so the scrappers and parts hounds loved me.