Itinerant Air-Cooled

I just completed the first valve adjustment on my bus by myself. In the past Colin has been watching over my shoulder.

Data is indicated in number of turns backed out of adjusting screw before contact is felt (from 1.5 turns in last year). Here are the results:

No. 1 - exhaust 1.75
intake 1.5

No. 2 exhaust 1.0
intake 1.0

No. 3 exhaust 1 5/8
intake 1 3/8

N0. 4 exhaust 1.5
intake 1.5

How concerned should I be with No. 2? Last year when I did it with Colin, I had number 1 and 2 mixed up. No. 1 was not at TDC when I started. So I had to reset to TDC, but it was too late to get any real data. I think I did no. 2 correctly, but may have been slightly flustered at that point. So I am not sure how accurate it may be.

I am planning a big trip next week. Am I heading for trouble if I embark with these numbers on the no. 2 cylinder?

Thank you.

I wouldn't worry about it when your just starting to get a feel for adjusting hydraulic lifters.

I was totally confident in my adjustments being 1.5 turns past first contact and when Colin checked them I was way closer to 1.25 turns past contact.

Until you are certain that you have a good feel for where that point is - just log it and check it again after your trip.
Start adjusting them more often BTW, until your totally confident that they aren't changing. There's nothing wrong with adjusting hydraulic lifters at every oil change, even if they say you don't HAVE to.

Alright, thanks. I will settle down and just keep an eye on things. It's just that I have these recurring nightmares that Colin is telling me I have valve stretch or horrors, seat recession.

Like Chris said, I wouldn't worry too much about it first time. If you notice a trend over several adjustments then you should start looking into the reasons why.

There is one other source of reduced post-lash adjustment that isn't often mentioned: valve adjuster wear. If you look at adjusters that have a few thousand miles on them, they'll have wear patterns from where the swipe across the valve tip, which increases valve lash (or decreases post-lash on hydraulic lifter engines). When you then re-adjust the valves, you end up orienting the adjusters at a different angular position, which sets up a new wear path on the adjuster. Eventually you end up with an adjuster that has a faceted look.

It is a good idea to check the business end of your adjusters once in awhile. Any that start to get pitted or spalled should be replaced. Don't go cheap on the adjusters. Cheap adjusters are most likely not heat-treated, and I've seen many reports of ones with a tiny little nub on the rounded tip. I had one set that wiped themselves into uselessness in less than 100 km, leaving tiny shards of low-quality steel in my oil. Genuine VW ones are the way to go, IMO.

After yesterday's valve adjustment, the bus seems to have lost some power. Prior to the adjustment the ride seemed quieter, smoother and had plenty of power when asked.

Next on my list was the AFM adjustment. Should this take care of it? I know that Ratwell says that you should adjust the air fuel ratio after a valve adjustment. Is this what he is referring to?

I did retime the engine after he valve adjustment.

did you retard the timing from where it was? Timing has a huge impact on power output.

It dawned on me as soon as I posted this that I forgot to replace the vacuum hose on the distributor. That should make most of the difference.

I am reading over Colin's AFM procedure and will adjust from there as well. I will be heading cross country in a few days and Colin suggested I run slightly rich rather than the slightly lean that his detailed procedure outlines.

aopisa wrote:It dawned on me as soon as I posted this that I forgot to replace the vacuum hose on the distributor. That should make most of the difference.

Indeed it will.

aopisa wrote:I am reading over Colin's AFM procedure and will adjust from there as well. I will be heading cross country in a few days and Colin suggested I run slightly rich rather than the slightly lean that his detailed procedure outlines.

Good idea.

Here are a few other tips:

1) Don't drive with the radio at full volume. Keep at least one ear tuned to the sound of your engine.
2) Check your oil at every stop for fuel. Check your engine temp then as well.
3) Drive sensibly and take your time.

Have fun on your trip. Tim