General: Valve Clearance Adjustment.

[sleek lemur]

Yes, sorry for all the qns. I was having trouble finding the specific clearances for the B20E is all. Actually, just after posting, I did find this useful PDFVolvo Engines Specifications B4B till B30.pdf

[c1800]

No worries on the questions.

Here’s some more info that might come in handy.

http://www.vclassics.com/archive/index.html

[sleek lemur]

Wow! That's a useful link! Thank you.

[northNH]

Originally Posted by lancsclassics

From a technical standpoint both put the cam on the base circle so the valve clearance should be at a maximum.

Decades ago I was shown a simpler way of doing this by a legendary old Volvo mechanic:

—Turn engine correctly to line up 0° on crank pulley with front cover indicator;

—One set of 4 valves (either 1,2,3 and 5 or 4,6,7 and 8) will now be fully
closed i.e. max clearance/max loose; which set you do first is irrelevant;

—Adjust those 4 valves that are all equally max loose; order irrelevant;

—Correctly rotate engine once/360° to again line up 0° at the crank for the 2nd set of 4 now totally loose valves.

—Check your work at 0° through two more full rotations;

—Done

Using feeler gauges I’ve actually compared this method and it’s results with all the others mentioned and have never found one where the valve being adjusted was “free-er” to rock (i.e. “cam on base circle”) prior to adjusting than any other carefully executed method. And that’s the key. And this is quite simpler.

Doing it this way since for all that time I thought the motors ran strong, lasted long and sounded happy.
And I know so did plenty of that long-gone old guy’s satisfied customers.

Contrary experience? I’m all ears, err, screens...

[Ron Kwas]

nNH;

That method seems simple indeed...it, and the RoN method are based on the fact that the Cam base-circle is circular in 3 of the four quadrants (Engine Strokes), so Rocker clearance can be checked and adjusted at any one of them...

Another trick I developed was to narrow down my 0.016" feeler gauge so that it wouldn't bridge any wear gap and result in larger gaps than specified...like so:


Cheers

[northNH]

Indeed, that’s a finer point, well worth illuminating...

I have and sometimes use an older set of “go-no-go” feeler gauges.

They look like normal ones but they’ve been manufactured with a taper that varies 2 thou” along their length, so the pertinent ones taper from 0.016-0.018”, .018-.020”, .020-.022, etc...

Bet they’re still available; you may like ‘em.

Using the two-full-turn valve adjustment method I described and these tapered feeler gauges, one can do a complete accurate valve adjustment while waiting for a long red light to change. 😉

Best regards...

[sleek lemur]

From the various methods, this seems like both the simplest and most fool- (ie me) proof. The comment that the valve is in the correct position 75% of its journey makes me wonder how any method can give a better result than any other. Why not simply go for the quickest and simplest?

The books say that the clearance can be set with the engine hot or cold. How can that be, if the metal has been expanding and contracting with heat? My local expert says to do it hot.

[Derek UK]

Volvo says warm or cold. That is not the same as hot or cold. If you've been out for a drive, leave it for an hour or two before doing the job. Should then be "warm". It's usually much more convenient to do it cold. If you've just driven the car out of the garage it is still "cold". Letting it tick over for 5 minutes and the thermostat has opened gets it into the "hot" range. If you have ever checked the tappets with the engine hot you'll know it's not a comfortable place to be.

[Ron Kwas]

sl;

"how any method can give a better result than any other."...it can't...as I say: ...many roads lead to Rome...it just depends who's driving the chariot...!

Adjustment... "hot or cold. How can that be"...easy...EVERYTHING in the engine is of the same material, unlike iron blocks with alu heads, (and pistons not withstanding, but these don't affect Valvetrain clearances) ...so everything grows and shrinks proportionally with temp.

Cheers

Edit: ...and as Derek mentions, a hot engine is not such a fun thing to work with...

[sleek lemur]

How dare you describe my lovely Volvo as a chariot!?

Thank you both for the explanation of the difference between warm and hot. "Red face imoji".....