Question: What valve spring shim thickness do I need for my setup? I don't have access to a valve spring tester or Comp Cams until Monday and I want to get it done this weekend.

Cam:
Gross valve lift: (I) .510 (E) .540
Duration at .006 (I) 290 (E) 307
Valve timing Open Close
At .006
(I) 37 BTDC 73 ABDC
(E) 90 BBDC 37 ATDC
At 108 Intake Center Line
Duration at .050 (I) 229 (E) 245
Lobe Lift .3400 .3610
Lobe Seperation 112.0

Valves are the factory length.

Springs: 26918-16
Installed: 130 LBS @ 1.800"
Open: 318 LBS @ 1.200"
Spring Rate: 313 LBS/IN
Coil Bind: 1.085

I've got spring seats with a .570 guide

Here are the 3 different spring shim thicknesses they sent me:

1) .015 x 1.437
2) .030 x 1.437
2) .060 x 1.437

Thanks guys, hopefully I can get a concrete answer without having to wait till Monday.

 

Measure to 1.800. Measure ALL of the installed heights. Some may require different shim combinations to get to 1.800.

 

For such a critical aspect of an engine (coming from a guy who's had more than one valve train fiasco - not from install height, however), you're best off doing it right with a valve spring height micrometer.

Just my .02.

Ryan

 

do you have any other kind of measuring tools that have reasonable accuracy? (down to .001") theres other things you can do in the event you dont have a barrel mic handy, although its the best way imo.

 

I just talked to my buddy, and we're going to buy a valve spring height micrometer to be on the safe side. As 96speed, and my buddy said: Valve spring installed height is very important. If its under the installed height, the valves might float. If its over, coil bind might be an issue.

Thanks guys!

 

You don't need to be accurate to the .001" for your case, the shims only go as low as .015" so that is your requirement. Buy a 6" steel rule at the hardware store, it should have .010" incriments on it, that will get you close enough.

 

oops got a bit sloppy with the typing earlier .010 is what i meant.

 

How do ya know ya need shims????

 

Bingo . I'll guess at this one: You don't know unless you measure!

Good choice Kain. Like Machinist said, you don't have to be perfect, but its nice to know exactly where they are setup up for reference.

Ryan

 

GOOD guess.
If he did the math between coil bind(usually around 1.100),installed height(1.750 for stock heads),and lift(?) he should be able to tell if he has room to run it.