Valve clearances on built block
 

Hello,

I am currently assembly an IAG stage one block with my machined heads by IAG, as well.

I have the LH heads on my block, and I checked the valve clearances after i torqued down the cam caps.

Intake: .08mm, .13mm, .08mm,.08mm

Exhaust: all .18mm

The OEM specs on the shop manual are:
Intake .10mm- .15mm
Exhaust .20nm-.25mm

A bit confused. I know that the shims/buckets need to be change but i dont understand how the labeling for the shims are.

UPDATE:
okay so i have figured it out. thanks to @NoHaveMSG and @bobel. I wanted to give some updates and try to simplify to process. this isn't a guide, this is just some tips or pointers or anything that i didnt know beforehand about valve clearances for FA20s. @bobel's thread should have most of the info there.

You need to change the shims to the correct value. There are numbers of the side of the shims that correspond to the thickness they are.
To get your correct valve clearances, you must time the motor and crank it a few times. Reason being, if you have heads that was machined at all or the valves that were replaced, the valves won't be seated in their final position until you crank the motor a few times. I did this without the motor being timed, and the clearances changed the next day by 0.2mm+/-. After i timed the motor and cranked the engine, the clearances would stay the same.

After you get your measurements and shim numbers, in the service manual, there's formulas to use to determine what shims you need based on the clearances and the numbers on the side of the shims.

Intake formula
A =B+(C - D) x 1.54

A - what shim # you need
B - what shim # you have
C - valve clearance you have
D - target valve clearance

Example) A=2.36 + ( 0.06 - .15) x 1.54

B - 236 shim i have , so it means 2.36mm
C - .06mm of clearances on that valve
D - target of .15mm clearance

A= 2.36 + (-0.09) x 1.54
A= 2.36 + (-0.1386)
A= 2.2214
A= 222 shim required for .15mm clearance on that valve.

Exhaust formula is the same but you multiply by 1.69.

Exhaust formula

A= B + (C - D) x 1.69


Edit 2: i assembled everything properly up to the cams and cap caps. I didnt apply silicone to the cam caps when mocking up to check clearances. Just to be clear.



Edit 3: just in case someone wanted to see what measurements and shims i got. 2nd numbers and mm are what i got after final valve checking.


Lh
Intake
1:236 .06mm. ——2.22 ——222 — .14mm
2:236 .05mm—— 2.206——220 —- .15mm
3: 226 .11mm—- 2.1984——219 —- .15mm
4: 23?: .02mm—- 2.0998—-209 —- .15mm

Exhaust
1: 220 .18—-2.0817——208— .25mm
2:220 .18mm— 2.0817—208—-.25mm
3: 224 .16mm —2.0879–208—-.25mm
4: 224 .15mm— 2.071—207—-.25mm

RH
Intake
1: 231 .10mm—-2.233—223 @ .14
2: 230 .11mm—-2.2384–223 @.15
3: 234 .12mm—-2.2938–229@.15
4: 232 .11mm—- 2.2584–225 @.15

Exhaust
1: 223 .17mm—-2.0948——-209 @ .24
2: 226 .18mm—-2.1417——-214@ .24
3: 228 . 13/14mm—-2.0772-207 @ .25
4: 224 .14mm——2.0541—-204 only @ .24

https://www.ft86club.com/forums/showthread.php?t=138753

It's hard to see, but the shims SHOULD have markings on there, just difficult to see. You need the right lighting or a good flashlight.

Yea thanks, ive seen that. Ive also seen another thread about a user on the site that had my issue and went with the shims that gave him intake ~.15mm and exhaust ~.25mm

You measure your valve clearance, then you
Can measure shim thickness with calipers. Then add/subtract shim thickness to get the correct clearance.

So if you want .15mm but you have a valve that measures .10mm. You measure the shim and it is 2.45mm. That means you need a 2.40mm shim. You can’t just use the shim thickness from somebody else’s build and call it good.


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Thanks to @NoHaveMSG, i got to this point.

Ill time the motor tomorrow and to check what shims are needed.

Timed and everything is spinning how it should.

Checked all the clearances and they were different from the clearances checked without timing and rotating the crank a few times. I did another check today after rotating the crank another few times to check if they were similar or the same and they were.

I checked the clearances when I first bolted on the block and next day after that. They were at different clearances, i did another check and they were off again.

So it seems to be going the same way as the results in this thread.

https://www.ft86club.com/forums/showthread.php?t=139082
Valve jobs or new valves or even machining of the heads will have the valves not seated fully yet. You need to make sure they have seated properly. The way to do that is cranking the rotating assembly. Since the clearances havent changed much or at all, it seems that the valves(hopefully) have seated and given me an accurate measurement.

Now got my measurements and have ordered the shims i need.

After you get your measurements and shim numbers, in the service manual theres a formula to use to get exactly what shims you need based on the clearances and the numbers on the side of the shims.

Intake formula
A =B+(C - D) x 1.54

A - what shim # you need
B - what shim # you have
C - valve clearance you have
D - target valve clearance

Ex) A=2.36 + ( 0.06 - .15) x 1.54

B - 236 shim i have , so it means 2.36mm
C - .06mm of clearances on that valve
D - target of .15mm clearance

A= 2.36 + (-0.09) x 1.54
A= 2.36 + (-0.1386)
A= 2.2214
A= 222 shim required for .15mm clearance on that valve.

Exhaust formula is the same but you multiply by 1.69.

Exhaust formula

A= B + (C - D) x 1.69

Here is the tiny numbers on the side of the shims. They are extremely hard to see and i walked around the garage/outside til i got a good shot of those numbers.:bonk:
It says 224 btw meaning 2.24mm

It is possible for the numbers to be worn off because i have on that says 23. Theres no shim thats just 2 digits. The numbers are barely visible and theres so sign of the 3rd digit so im guessing.

today I've gotten the shims i needed and assembled everything up to the timing. And everything holds around .15mm intake and .25 exhaust. There were a few exceptions that were .14mm and .24mm but thats still good enough.

Subaru part numbers and what shim they are. this is not all of them, these are the ones i have found myself.

13218AK970 - 207

13218AL060 - 216

13218AL020 - 212

13218AL080 - 218

13218AK950 - 204

13218AK960 - 206

13218AK940 - 202

13218AL030 - 213

13218AK930 - 200

13218AL070 - 217

13218AL120 -222

13218AL170 - 227

13218AK990 - 209

13218AL190 - 229

13218AL040 - 214

13218AL130 - 223

13218AL150 -225

13218AL200 - 230

13218AL090 - 219

13218AK980 - 208

Mad respect for you gear-heads.

Just went through figuring this stuff out, was a real headache. Nice to have it documented somewhere!!!

This is why i updated the thread with any useful info in the simplest terms. It does show this stuff in the service manual but those sometimes make no sense or maybe im too dumb to understand.