This has most likely been covered many times but I'm new so here goes. I have a 1966 with original engine and the original manual that was conveniently filled out by the original owner. All numbers match. The original Owner's Manual states that the B18D engine valve lash should be .020-.022". Everywhere I look it says valve lash should be .016-.018". I did see a Volvo bulletin dated 1965 that does state that the clearance should be .020-.022". What should I believe?

The engine has a Weber 32/36 DGAV carb but no other mods. I currently have the valves set at .020" but it's a touch noisy. Any help?? Thanks.

Don
1966 122s
1971 Marcos V6

Tighten them down and see what happens. I set mine to 0.018 on the advice of the board, but I have heard of people running 0.016. I still have noise (valve recession or some other valve issue), but my engine is pretty much trash (and I am putting together a HP B20, so I've not worried it).

Craig

I had my valves tighter at first and found it idled nicer and easier at lower rpm at the looser setting. Tightening up the valves essentially makes the cam "hotter" because the time on the lobe is longer. Your overlap increases. This is fine for spirited driving or racing but causes a loss in fuel economy.

Unless you have a replacement cam that was ground for a specific lash.

Mike!
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Mike!

Recession makes the clearance smaller.
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George Downs Bartlesville, Heart of the USA!

Hi George,

When I get the B20 built I'm going to redo the B18 for fun and see what's wrong with it internally. I don't know if the valves have recessed (which would tighten things up as you indicated) or if I have some other issue. I've had a consistent ticking with this engine since I've had it. When I set the valves (and I used the 9's method to make sure the lifter was on the base circle of the cam) they were all over the place - and it did get quieter. I took Phil S's advice and reset the valves using his method - didn't change. I also looked very closely for a broken valve spring etc...but found nothing. So there is something valve-train related that is not quite right.

Craig