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Discussion Starter #1
Okay, so I got my new (rebuilt) head last night and checked the valve clearances after installing (not fully torquing the "keepers/caps/whatever" though) the cams. I got everything snug and flush without a full torque (trying to save stress on threads.

Anyways, I checked all the clearances and it looks like things are SUPER loose... I followed the Alfa Bible's procedure and here are my measurements:

Intake:
  • #1 - 0.026
  • #2 - 0.024
  • #3 - 0.028
  • #4 - 0.029

Exhaust:
  • #1 - 0.029
  • #2 - 0.035
  • #3 - 0.024
  • #4 - 0.030

I forgot to measure the shims last night (d'oh!)... but will do that tonight. These seem pretty **** massive to me. I found the feeler gauge that "felt" like it was the clearance, not the biggest one I could cram in there. Is it normal when going to a freshly rebuilt head to be that much different from a stock one? Should I put the cams back on the old head and measure them to see if they were in spec? The cams and followers look good. Pretty much a mirror-like finish on the wear surfaces.

Also, does anybody know the proper clearances for a Bosch L-Jet spider? Are they correct on this site?: http://www.alfacentro.com/features/valve/index.html
 

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Did they recut the valve seats and/or replace the valves? Either way I would expect that the valve clearance would change. Nothing really unusual. You will need to do as Pat says and measure the shims (and tappets as well). Hopefully you have a shop (perhaps your rebuilder) that has shims that they will exchange. Dean Russell did that for me here in Michigan. Good thing because I kept changing things and needed to re-shim.

Here is a simple shim calculator based on .019" exhaust and .017" intake. You change them as required.

View attachment Valve Shim Calculator R0.xls
 

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Discussion Starter #3
Okay... awesome! Thanks for the sanity check! I bought a remaned head from Centerline, so I get to buy new shims I guess. :)
 

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As I said, you should check local Alfa shop (assuming there is one) or your local AROC chapter- they may allow you to exchange your shims for their shims for free. At least our guy here will do that. Also, you might be able to swap some of your own shims around.

Lastly, I have some extra shims. If you post your size and I have them I would be happy to swap with yours.

Godd luck!
 

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Discussion Starter #5
Awesome!

Somebody should create a website for shim exchanges... hrm... alfashimexchange.org (and .com) are available! :D

/sooo not volunteering :p
 

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Awesome!

Somebody should create a website for shim exchanges... hrm... alfashimexchange.org (and .com) are available! :D

/sooo not volunteering :p
We could have a "Sticky" thread for it, in the engine rebuilding forum. No need for a separate site. Great idea!
 

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The motorcycle (Honda ST1100/ST1300) internet 'club' I belong to (no officers, no dues, no rules) has a 'shim kit' that we circulate to members. It has a plastic box with assorted shims, feeler gauge, & even a video of the valve clearance check/adjust procedure (the engine is a DOHC V-4 - 4 valves/cylinder - 4 cam shafts & 16 valves in all).

Whoever needs the kit posts a 'need it' email and the current holder mails it to the needee. Thus one only pays postage one-way. It is all on the honor system but has worked well for a couple of years or more.
 

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Discussion Starter #9
Awesome idea! :)

One question I do have... do you measure the entire size of the shim, or from the inside of the "button" part to the top?

I've only done this on my honda dirt bike before. :)
 

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You need to measure the thickness of the top of the cup-shaped shim. So, you would measure the shim from the inside to the top.


On a related note, does anyone else grind their shims to make them thinner by a couple of thousandths when needed? Is there a problem with this?
 

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Discussion Starter #11
It says in the Pat Braden book that (to paraphrase) "in a pinch you can grind a shim down using #600 sandpaper and a piece of glass"... so I assume it's okay.
 

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It says in the Pat Braden book that (to paraphrase) "in a pinch you can grind a shim down using #600 sandpaper and a piece of glass"... so I assume it's okay.
Oh yeah....maybe that's where I got the idea!!:eek:
 

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Discussion Starter #15
Well, that one would be okay... I just want to see if anybody else out there has one they use and like before I go buy this one and hope it fits inside the cup.
 

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You need to get a micrometer. I use a 0-1/2" for valve shims but a 0-1" will work just as well. A vernier caliper will not work for valve shims.
 

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please torque down the cam mounts before checking the clearance. the valve springs push up and can open the gap if its not tight.
cliff
 

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Discussion Starter #20
good call... anybody recall the torque spec on those? :)

btw, for anybody who's interested, I elevated the head on two pieces of wood to protect the valves from pushing into my workbench. I used a 7/8" open box-wrench to rotate the cams and it worked great!
 
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