Itinerant Air-Cooled

I just took my heads apart to check for cracks,nicks heat,etc..Surprizing they look pretty good.I did have good compression so I was not to worried MUCH? One thing I did notice was there were no valve stem seals,no "o" at the top of the valve or a rubber cap at the head base were the valve guides come thur the head..Am I missing something here.The bus ran good and didnt seem to smoke.Question...Without valve stem seals would'nt the oil leak past the valve and down into the head causing some problems??...THANKS for any info givin.....jrbo

VW air cooled engines don't use/have them.

karl wrote:VW air cooled engines don't use/have them.

Is that because there are side mounted heads and not mounted flat to the block surfaces...just courious....

Early VW engines had them. Then they were discontinued. The valves angle upward so we don't have to worry about draining rocker area oil through the guides. BUT, engine vacuum and exhaust pressure does allow both a fair amount of oil to get into the intake tract and get contaminated by soot with high mileage engines.
Colin

Amskeptic wrote:Early VW engines had them. Then they were discontinued. The valves angle upward so we don't have to worry about draining rocker area oil through the guides. BUT, engine vacuum and exhaust pressure does allow both a fair amount of oil to get into the intake tract and get contaminated by soot with high mileage engines.
Colin

Thanks Colin, I just wanted to double check before the engine goes back together......THANKS for the info....jrbo =D>

An amusing and instructive entry on Bob Hoover's blog about valve stem seals for aircooled VWs:
http://bobhooversblog.blogspot.com/2006 ... seals.html

Wow!
This has been a topic I never knew about until my search for answers to an abnormal oil consumption I have experienced with my pancake engine. My search led me to oil pressure issues and oil levels dropping due to several possible issues including worn out valve guides...which then led me to valve guide seals.

I only recal seeing one engine with these seals-
I am really interested in knowing what I could do as a probable solution to my engine that burns up oil (20w 50) at a very high rate...my last experience being about 4litres on a 651Km highway journey. It was so bad, I had to spend a night parked in a gas station waiting for the morning sales to start (the guys only sold fuel through the night...other things had to wait for morning)

Amskeptic wrote: ↑

Sat Aug 16, 2008 5:19 am

Early VW engines had them. Then they were discontinued. The valves angle upward so we don't have to worry about draining rocker area oil through the guides. BUT, engine vacuum and exhaust pressure does allow both a fair amount of oil to get into the intake tract and get contaminated by soot with high mileage engines.
Colin

So what do high mileage engine drivers have to do to aid the matter? Of my whole experience with the air cooled Vw engine, this has been my greatest nightmare/disappointment. Kindly advice.
Thanks.

4 litres! I'd say your rings are shot or you are leaking oil everywhere.

ktk833 wrote: ↑

Tue Apr 25, 2017 1:07 pm

Amskeptic wrote: ↑

Sat Aug 16, 2008 5:19 am

Early VW engines had them. Then they were discontinued. The valves angle upward so we don't have to worry about draining rocker area oil through the guides. BUT, engine vacuum and exhaust pressure does allow both a fair amount of oil to get into the intake tract and get contaminated by soot with high mileage engines.
Colin

So what do high mileage engine drivers have to do to aid the matter? Of my whole experience with the air cooled Vw engine, this has been my greatest nightmare/disappointment. Kindly advice.
Thanks.

Your situation is an anomaly that suggests you need repair. You may need to get new valve guides. You may need rings, even if the exhaust seems clear. A properly assembled and healthy VW engine does not burn more than a quart maybe in 1,000 miles.
Colin

Hi.

Thank you for your response. I decided to do a complete cylinder head job. I'm still on the same as i am sourcing for valve guides (which has proved a challenge). I'll update on the same soon as done

do not try to do the valve job yourself. The valve guides will not be exactly concentric with one another. The seats have to be ground. In addition I doubt if you have the experience that is required. Air cooled VW heads get more abuse than about any other daily driver head. You'd be smarter to just replace them with a new set from Len Hoffman if you want something reliable. If you want something inexpensive but not nearly as good or reliable as a new head send them to Adrian at Headflow Masters.

My background includes being a machinist on all kinds of engine heads. That said even I would not attempt it without the proper equipment which likely will include a TIG welder to fix all the cracks. Bus and Vanagon heads really get beat from the heat.

BTW you might check your PCV valve to see if it has perforated. That can cause excessive oil consumption on some engines.

ktk833 wrote: ↑

Sat Jul 01, 2017 4:25 pm

Hi.

Thank you for your response. I decided to do a complete cylinder head job. I'm still on the same as i am sourcing for valve guides (which has proved a challenge). I'll update on the same soon as done

If you see drenched combustion chambers and pistons when you take the heads off, do pistons and cylinders too! It's easy enough.
Colin