Valve clearance Ugh

[Erich Z]

Ok so a few things here:

1. I ordered a valve feeler gauge kit from Snap-on at the advice of someone here, but only two sizes are somewhat applicable - .0275 or so, and .07 or so. Probably should get a better set huh? Any recommendations?

2. All my shims won't allow the 0.0275 feeler gauge in. Am I doing something wrong? I'm using the gauge with the lobes pointing "up"

3. I rotated the engine with no shims in, didn't read that it was a bad idea til just now. How bad is that mistake?

[doctorgonzo]

Ok so a few things here:

1. I ordered a valve feeler gauge kit from Snap-on at the advice of someone here, but only two sizes are somewhat applicable - .0275 or so, and .07 or so. Probably should get a better set huh? Any recommendations?

2. All my shims won't allow the 0.0275 feeler gauge in. Am I doing something wrong? I'm using the gauge with the lobes pointing "up"

3. I rotated the engine with no shims in, didn't read that it was a bad idea til just now. How bad is that mistake?

Most people on here (including me) seem to use one that only goes to .04. If .04 won't fit (if .03 to .08 is spec) I change the shim. Too loose is better than too tight. Too loose might be a tad noisy. Too tight will burn your valve. If .0275 won't fit, it needs to be changed. It wouldn't be THAT unusual for all to be out of spec. 6 of mine were the first time I adjusted them. For all you know the PO never even did it once. That being said if they are the flat blades make sure you don't have two stuck together, easy to do.

[Steve]

I have not looked at the Snap-On catalog, but isn't FOUR decimal places for feeler gauges a bit extreme?
I have seen that with some of the smallest inch feelers, but not metric.

One other question to ask...that .0275...is that inches or millimeters?
If that is inches, that is way too big, and should never fit. (A .00275 would be near max, but it has to have that extra zero.)
If it is millimeters, that is just below minimum clearance, and you will need to change all your shims.

The same question would go for the .07.
If that is inches, you had better hope it won't fit.
If that is millimeters, it is near the maximum clearance of .08.


Not sure if the 450 engine requires the lobes in any special position, but my guess would be that as long as the lobe is pointing somewhat away from the valve, it should be OK.

Rotating the engine without shims risks scratching the cams. Get shims in there quickly, even if they are the wrong sizes, so you don't scratch them any more. Inspect the edges of the lobes to see if anythng has flaked off where it hit the edges of the buckets. If you don't see anything wrong, you may have gotten lucky.

.

[chef1366]

I'm putting together a 450. When you get it sorted I'll be picking your brain.

[Nessism]

I'm putting together a 450.

Joining the circus?

[BassCliff]

Try apples to apples

Hi Mr. Eric Z,

In order to avoid any confusion, I bought a metric feeler gauge set. It starts at .04mm and goes up in .01mm increments (.04mm, .05mm, .06mm, etc.). Keep your SAE gauge far away from your metric bike. I don't even like thinking about .001 inches to .003 inches as the clearance values. I'd much rather use .03mm to .08mm. I know my set goes down to only .04mm, but if that doesn't fit then the shim is getting changed anyway. I got mine at the local Pep Boys auto store for $5.

As you have found out, it's not a good idea to turn your motor with the shims out (could damage your cam lobes and leave metal shavings in the top of your motor). Check a clearance, pull out that shim, check the shim size, put it back in, check the next one, etc, until you are done. Then you will know what clearances you have and what size shims you have. Then you can juggle a few between valves and end up buying only one or two to take care of the valves that need the smallest size shims. The clearances tend to tighten up over time.

Hopefully one of the 450 guys will verify this, but I think you should point the lobes up when measuring. You've only got 4 valves there. Keep us informed.

Thank you for your indulgence,

BassCliff

[Steve]

but I think you should point the lobes up when measuring.

What has me curious is...which way is "up"?

Do you mean "up" as in away from the valve or "up" as in pointing toward the ceiling?

.

[Erich Z]

I am pointing them away from the valve, basically.

I really think all the tutorials here ought to mention that you shouldn't rotate the engine with no shims in it. I read them many times and saw no mention of that, and saw mention of exchanging shims from valves so thought it was fine. Took some digging here to find out I was wrong.

It may seem like common sense to some of you, but to someone like me who has never messed with any of this before, well, we need to be guided rather specifically.

[chef1366]

Joining the circus?

Uh yeah. If they will have me.