shim size

[petree777]

i have a quick question. can you get any smaller shim size than 2000 or is that as small as it gets. because i checked my lash and i couldent even get a 0.0015 feeler through some of my intake valves. can i get any smaller shims or dose it need a valve job? or can i use smaller lash caps. this is not a stock motor the sho shop put together this motor so i dont know what was done to it.

 

[sdpatt]

The gap you measured was 0.0015 inches I assume. To determine the thickness of shim that you would need you will have to remove the existing shim, read the thickness number off the shim and calculate the required thickenss to get the shim with the required specification. I always use the metric measure on the feeler gauge sinze the shim thicknesses are indicated in mm.

Regarding the measurement, you have to ensure that the lobe of the camshaft is at least 90 degrees away from the shim. Ideally, it would be pointing directly away from the shim to make sure that you are measuring the gap at the heel of the cam lobe.

The calculations below are from my valve gapping worksheet, which I would be happy to email you if you PM me a valid email address.

Intake
1) Gap - As Found
2) Nominal Gap 0.20mm
3) Old Shim
4) Reqd Shim [1-2+3]
5) Shim Installed
6) Gap - As Left

Exhaust
1) Gap - As Found
2) Nominal Gap 0.30mm
3) Old Shim
4) Reqd Shim [1-2+3]
5) Shim Installed
6) Gap - As Left

Gap specifications:
Intake 0.15mm < gap < 0.25mm
Exhaust 0.25mm < gap < 0.35mm

Shim thickness indications:
ex. 2000 = 2.000mm, 3250 = 3.250mm, thickness increment = 0.025mm

 

[petree777]

i understand all of that. i pulled the shim out and it 2.000 mm shim with a valve lash of 0.0015" with that shim in there. do they make a shim smaller than 2.000 mm?

 

[LOUDSHO92]

They do not.

I had a simialir problem due to a poorly ground cam, so I took out the lash cap and put in a thick shim to make it work.

 

[petree777]

what do you mean take out the lash cap? the whole ting or just put in a smaller cap? thanks for all of your help

 

[SHObill]

Because you prob have staged cams there is a lash cap sitting on top of the valve stem under the bucket the shim sits in. Either get a thinner lash cap or remove lash cap & go with a thick shim to get the tolerance correct.

 

[LOUDSHO92]

If you have a SHOShop cam then some might not be ground right (My set and another I installed) and it was teh rear intake cam. With the cams you put a lash cap on the valve stem to make up the difference due to the grind. I would remove the lash cap and get a few shims around 2900-3200 and see what it takes to make it right.

 

[petree777]

yea there shoshop cam and they were put in by them to. is only on like 4 lobes and i think mostly intake. ok i will do that and let you know. thanks for your help

 

[AREA 91]

If it makes you feel any better, I had to have custom sixed lash caps made for my +40's. I'll be damned if I could get the clearances correct. I tried them on 2 different engines first. I know they work now!