Off center they are, that is how they all end up with those circles on the tops and bottoms. The be spinning man.
Not sure it you have the specs from a Bentley for the 1.6D but they are as follows:
Engine cold the intakes should be between 0.15 - 0.25 mm (.006 - .010 in)
The Exhausts should be between 0.35 -0.45 mm or (.014 - .018 in)
Engine Hot Intakes 0.20 - 0.30 mm or (.008-.012 in)
Exhausts 0.40 - 0.50 mm (.016 - .020 in)
From the timing belt to center they are EIEI Then mirror that IEIE to the trans side of the block. This is the EIEI OH! rule to remember. I have seen several sets of pistons so far that were rounded out by the valves and I think it was due to the wrong sequencing on the valve clearances. Or the wrong head gasket.
For newer valves and such I go a little to the wide side and as valves seat they come towards the middle of the range.
They very much do wear into the bore in the head. Volvo does it. We have trouble with the lifter carrier in the M96 Porsche motors with it often. That and the lifters suck, but that's another story.
Be glad VW hyd lifters aren't a hundred bucks a pop.
And the carrier is like six.. Each.
I've been known to use a brake cyl hone on lifter bores in redblock Volvo's to get them to spin freely through there range of motion.
Air cooled, I do not believe what you are saying. Do you have a bentley or some manual to back it up? IIRC our manual lifters never touch the cam, the lifter has the shim and the bucket deal on top of it, then the cam IIRC.
yea, like i said i havent had a mech head engine for more than 10yrs, i dont have my bentley with me, iirc shims can be swapped. but im skeptical of that as any other lifter combo (in any other vehicle i know of; mech/hydro lifters) you cannot swap a lifter off the lobe its been running on.
lifters do rotate in bore as cam lobe is slightly on an angle and rotates lifter. if i recall its to promote a consistant, even wear pattern.
So those massive boxes of shims they sell for like 225 bucks are just a bunch of little paperweights? Seems like the design was meant to allow swapping as wear and rebuilds occur. Thus changing the initial distance of the space between shim and cam lobe. I have not had issues moving the little slugs around. But then I do live in the PNW where they are common place.
Air cooled, I do not believe what you are saying. Do you have a bentley or some manual to back it up? IIRC our manual lifters never touch the cam, the lifter has the shim and the bucket deal on top of it, then the cam IIRC.
yea, like i said i havent had a mech head engine for more than 10yrs, i dont have my bentley with me, iirc shims can be swapped. but im skeptical of that as any other lifter combo (in any other vehicle i know of; mech/hydro lifters) you cannot swap a lifter off the lobe its been running on.
lifters do rotate in bore as cam lobe is slightly on an angle and rotates lifter. if i recall its to promote a consistant, even wear pattern.
No, they are dead flat, offset which is why the last a long time even with crap LE oils. Even my cave man 6.2 Chevy lets you freely swap lifters around, as do all roller cams I've seen