valve shim question

[stevejames3]

i had to take my cams out to replace my shortblock and i moved from a garage to a shop, and in the process a few of the shims got mixed up and one got lost. i can do the whole, put the shims in rocker arms, and bolt the cam down, see if there to tight or too lose with a caliper gauge. but my problem is i dont know the clearence. the fsm doesnt tell me what size the gap should be. it only hase the sized which to my knowledge are .25 dif in each cyl. can anyone clear this up. even if i just know what size each cyl. should have in it i can just measure it with the mico meter and put them in the proper spots. also its a redtop sr20.

[sr20-thoj]

i would like to know this also...

[180fan]

Looking at the records for my rebuild, the numbers are all less than 0.025mm clearance. Use a feeler gauge.

[UK-SRi]

25 micrometer clearance??

zer...ote=1#http://forums.nicoclub.com/zer...ote=1#

Mike

[180fan]

you got it

[stevejames3]

what are the links for?

[stevejames3]

i talked to someone at heavythrottle and they said because the rwd redtop has hydraulic lifters it doesnt matter what size they are as long as the shims are the same size on each rocker. can anyone agree or disagree with this?

[UK-SRi]

I tried to put in an astonished smiley, but it seems broken on Tiger OSx.

zer...ote=1#

mike

[Dori Dori]

i talked to someone at heavythrottle and they said because the rwd redtop has hydraulic lifters it doesnt matter what size they are as long as the shims are the same size on each rocker. can anyone agree or disagree with this?

The shims are there to keep the rockers level - they have nothing to do with the hydraulic lash adjusters (lifters are for pushrods).

[FAST-DATSUN]

Yes it to keep the rocker level and from breaking at high rpm's the need to be with in .001 of the other valve. you use a special tool and a dial indicator to set them see the US service manual for the SR20 Sentra to get the procedures...It does mater!!!!!!!!!!!!!!!!!!!!!!!!

[Dori Dori]

^I did intend to get the point across that yes, it is important to shim the rockers.

[stevejames3]

im saying each rocker had 2 shims. as long as they are the same size. there good. but from rocker to rocker they can very is size of like .025. as long as each rockers shims are the same size.?.?.?

[180fan]

they will vary in size but the distance from the top of the rocker arm to the cam at the far side (opposite side of the cam lobe) must be 0.025mm or less.

[LonnieP]

In order to shim the rocker arms you need to rent the shim tool kit, you can do this from matt at http://www.importintelligence.com , the kit contains a plate and dial indicator, along with hardware to attach it. to measure the clearance you will install the guide on the proper valve stem, refer to manual because it matters which side has a shim and which has a guide, (guide=slotted looking shim, used for keeping the rocker arm in place) mount the plate and put the dial indicator in the center of the guide and zero it, now move it over to the other hole and push the dial indicator down, the amount that it moves is the thickness of the shim that you need. (order shim from dealer for 92 se-r "sr20de")You are making up for possible variation in valve stem install height. there will be instructions included in the kit, it is a revised version from the one pictured in the manual and looks nothing like it.