You sure those aren't inches....?

 

unless my eyes are not working properly, yea.

 

 

There was a 3 to the left of the decimal, but I left it out for simplicity.

I haven't checked clearances yet because cams were out when I received it back from the machine shop. my plan is to measure shim sizes, then put it all together and measure clearances, use the shims I can and order the rest.

I was using the click ****, but the issue is I would close both pins together, set to 0, then measure shim size, close it again and it would not go back to 0 (off by a few thou)


to everyone: Hold off on further posts till I measure with calipers.

 

My caliper Is showing the micrometer to be correct.

 

Ah! Leaving out the 3 is what totally confused me, those numbers make sense now. The biggest gap between any two on the same side is 0.1mm, which is only about 4% of the total height. Mazda sells them in the range of 2.8mm to 3.4mm, yours are all between 3.05 and 3.25.

I've never used a micrometer to measure shims, because it's a lot more fiddly than digital calipers. More accurate, yes, but quality digital calipers are sufficiently accurate for this.

--ian

 

ok. Well in that case, I shall proceed.

 

Did anyone attempt to hand grind them? I've had difficulties measuring consistent values because of this, otherwise they should be very easy to measure consistently.

 

 

I has issue my dudes. I cant fit the smallest spec feeler gauge shim (.011) between the cam and the shim on cly 1 (right), 3 (both), 4 (right) on the exhaust side. And on the intake side, .007 wont fit under any of them. wtf. halp.

 

Take a picture of how you are measuring.

 

both intake side

 

lobe is suposed to be straight up, no?

 

even if I hold them straight up, no difference.

 

Here are the clearances. Super tight. But it makes sense because I had the valve guides and seats replaced. So the valves are sitting up slightly higher.

 

On the cams I've checked the base circle doesn't vary much, I've never been able to measure a difference in clearance between 90, 180 and 270 degrees from max lift.

(edit, now I see the info on seats). Are they original valves? Who put the seats in?

Generally machine shops that do valve jobs will grind down the tip of the valve so that they fit with the existing shims, rather than buying new ones. That's not really a great DIY-in-the-garage kind of solution though.

--Ian

 

his comments above indicate it's been rebuilt with new guides/etc

 

If you can't get the clearances right by swapping the shims. Measure your final clearances and bring that info to the machinist, then he can cut the valves for you. All pretty normal stuff.

 

And you want to do rod bearings on a BMW?

 

I dropped your numbers into my valve shim spreadsheet. All the gaps are too small right now, but if you swap shims around you can probably get by with only needing to buy 4 or 5 new ones. They're $7 each from Mazdacomp, dunno what they cost at a dealer.

http://www.codrus.com/misc/valves-george.xlsx

(I recommend double-checking the specs & measurement numbers before buying stuff)

--Ian