Please verify my shim calculation

[Walle]

I would appreciate if someone would look through these numbers for me. I'm not very experienced.

All valve clearances were tighter than my smallest 0,05mm feeler, so I used a 2.05mm shim for these measurements.

The blue is what I think I need, calculated for a final clearance of 0,05mm.

• Should I go down 1 size for all for a 0,10mm clearance?

• Is it likely that these tight valves have suffered any damage?

• Will a valve adjustment result in more power, or is it merely to prevent valve damage?

Here are my current shims, all of them too thick.

1ex 2,60
2ex rubbed off number, but measured to around 2,5
3ex 2,60
4ex 2,55
1in 2,30
2in 2,55
3in rubbed off number, but measured to around 2,2
4in 2,25

thank you, Jesper

 

[Steve]

The numbers you have entered as "final shim" are very confusing and should not be there yet.

For the exhaust valves, they appear to be the ones that were in there when you started.

For the intake valves, they don't agree with what was there, so I don't know what they are.

More details will be in my answer to your PM.

.

 

[BassCliff]

Hi,

It looks like most of your clearances are in spec already. You probably will not notice any increase in power from adjusting your valves. You will notice easier starts, shorter warm-up times, and a smoother running engine. Yes, valve adjustments also prevent damage to the valve. Personally, I would not swap out a shim on a valve that has .05mm clearance, .04mm, yes. Keep up the good work.


Thank you for your indulgence,

BassCliff

 

[Steve]

It looks like most of your clearances are in spec already.

Read it again, Cliff.

All valve clearances were tighter than my smallest 0,05mm feeler, so I used a 2.05mm shim for these measurements.

We already have a PM session going, so it should be under control.

.

 

[BassCliff]

Hi Steve,

I must admit that I'm still using one of the older versions of your spreadsheet.

But I see only intakes #1 and #4 as being too tight at .02 and .025mm. Am I reading it wrong?

EDIT: Oops, I now see decimal points in the wrong place.

I'll shut up now.

This is me, not saying a word.

Completely silent.

Absolutely quiet.

Thank you for your indulgence,

BassCliff

 

[Steve]

Thanks, Walle, you have just uncovered a flaw in the spreadsheet. :clap:

Apparently I have not provided the correct adjustment for really LARGE differences when using a checking shim, as you have.

I will make those corrections and start sending out updates.

.

 

[Steve]

OK just checked the math on the spreadsheet.

The math is just fine, I just hit a limit on the size of the "IF-THEN" statement that determines the desired shim.

The problem is that I can only go for SIX levels with the way the formula is set up.
Walle chose a shim that is TEN sizes too small, so it only suggested the six sizes that it could.
The good news is that if he checks the clearance after putting in the suggested shims (as he should), he will still find a large clearance and a new suggested shim size.

OK, the bottom line: Don't use a "checking shim" that is more that SIX SIZES (0.30 mm) smaller than what you have in the bike.

.

 

[Steve]

EDIT: Oops, I now see decimal points in the wrong place.

I'll shut up now.

This is me, not saying a word.

Completely silent.

Absolutely quiet.

Here ya go, BassCliff, JUST FOR YOU:

.

 

[Steve]

Hi Steve,

I must admit that I'm still using one of the older versions of your spreadsheet.

No excuses, fine sir.

I sent your copy of v4.2 on 27AUG2010.

.

 

[BassCliff]

No excuses, fine sir.

I sent your copy of v4.2 on 27AUG2010.

.

Yes, one of these days I'll figure out how to use Excel well enough to import 4 years worth of data from one version to the other.

Thanks for all that you do.


Cliff

 

[Walle]

Thank you both for your time. I just wanted a shim to measure from, and had no idea what shims was hiding inside the engine, so I told my dealer to grab the thinnest for me. Didn't mean to sabotage anything :-#

I'll be back with more questions later this week - when I start playing around with the Carbtune pro, which hopefully soon arrives from England. I'm having so much fun in the garage these days

 

[Steve]

Walle, there was no sabotage detected.

You just uncovered one of the limitations of my spreadsheet

I have now changed the wording in the instructions to explain that limitation.

For such a small change, it's not worth sending out 452 copies.

Any new ones that go out will automagically have the new instructions.
If anyone wants the updated version, let me know via e-mail.
Please let me know that you are requesting an update to a version that you already have.

.