Need some valve shims

[malcantry]

Im almost finished building my block and now im to the point to where i need some damn valve shims, I found some through sam but theyre 15$ a piece! I think im going to need... 10 or 12!

anyone know where to buy some of these damn things?!

 

[BRIAN_MP5T]

The dealer

 

[Installshield 2]

I got mine recently through Rosenthal Arlington Mazda, near DC...which shipped for free and had them around $8 a shim...thats a dealership though, and prices change based on their current inventory...

here you can find the part numbers, and there are many cars (not just Mazda) that use 27mm adjustment discs...so you can source them from other dealerships if you can't find the right size...

http://forum.miata.net/vb/showthread.php?t=471599

and the dealership:

http://parts.arlingtonmazda.com/

the sizes are the physical thickness of the shims...you need to measure your clearance with cams installed FIRST...then measure the thickness of the shims once you remove the cams (they pop right out of the lifters easily)...the problem is there is no 'factory' set adjustment shim, only 3 of my 8 exhaust shims were the same which were what came with the car...so after you have your lash figure and know the shim that was currently making that lash...you have to buy the right shim that will bring the lash back into spec...its not hard, just needs organization...write everything down and be sure and use a good digital mic to get figures to at least .00X"...

 

[pbarton14]

What will happen if the shims are just thrown in there without measuring

 

[Installshield 2]

^^if you don't know the shim thickness that is giving you a measured lash...you'll have no idea what the 'new' lash is...too tight and you'll burn up the cam journals and/or head, score the lobes, and destroy the shims/lifters possibly...too loose and you can crack the shims and possibly the cam lobes, as well as make all kinds of noise...if its only slightly loose, worst case would be valve float...giving high rpm problems (engine power will just plummet as if fuel was cut)...

so its not something to really mess around with...harbor freight has decent enough mics for $10...and as long as you take your time and write stuff down, its impossible to screw up...

 

[pbarton14]

So lets just say when I had my engine rebuilt and I bought shims from the junkyard so the shop that did it could measure the,m and get the ones that fit. What if they didn't? I've been having a power issue ever since I had them rebuilt it. Sorry for the thread jack .my idle and afr are both ok, but I do hit the cut here and again at 5500

 

[Installshield 2]

I would hope they did it right, as its not a difficult thing to do...but you never know...

It takes 15 minutes to check it yourself...you need a lifter 'feeler' gauge from a parts store, which is cheap...its just a little tool with about 15 different metal slides that fit under the cam lobes when the nose is point straight up...and each slide is marked with a thickness...and you simply fit the thickest slide in you can, and thats your lash...

so you simply take off the valve cover, get the splash shield off on the passenger side so you can get a wrench on the crank pulley bolt...remove the spark plugs so its easy to crank the engine by hand...and just start writing down your lash for every single valve...ONLY turn the cams by turning the crankshaft clockwise, DO NOT turn the cams themselves by any means...you'll load up the timing belt incorrectly and it could easily skip a tooth (usually on the crank sprocket, and you'd never know it)...so just make a diagram on a piece of paper of all 16 valves, and start with which tappets you can access, and move the crank pulley bolt clockwise to change lobe position on other tappets...when you have all 16 written down, you're finished...

lash with stock cams should be .010 to .014" iirc, both intake and exhaust...this may not be your problem, but again...if it is too loose you can get some float that will dramatically mess up higher rpm...if your lash is not correct, the job is no longer simple...as you'll have to get the cams out and then measure the shims that made that lash...and order new replacements to fix it...