Car Analogy

How to tell torque setting of a fastened fastener? Really not possible to get an accurate figure for that. Torque wrench measures accurately only when fastener is being moved. The amount of torque required to begin to loosen is greater than torque it was fastened to.

To confirm torque you could loosen then retighten.

If you can locate an old school beam type torque wrench, you can get some idea of torque without really loosening or tightening the fastener, but it won't be entirely accurate.

Slowcrash_101

Head bolts are torque to yield. There is no torque value, they can be reused if they're within spec. Basically you measure the thickness.

There is an initial torque spec, then 2 more 90 degree turns, 3 if you're using new bolts. If I had to guess it's like 140ft lbs.

The importan part is doing the bolts in steps so everything tightens down evenly. You only get 1 shot to tighten down the head gasket.

starchland

Equally important with removal as well. If the head is flat, don’t touch it.

s2kyee

Machine shop inspected, C3 valve obviously shot but seats on their way as well. Recommended doing all exhaust valves, seats, and guides. Said warp was minimal at 0.002 and could be milled at 0.003.

Should I just replace the burnt valve and let it ride? C2 and C4 held perfect compression.
Do I need to mill at 0.002 warpage?

They want $800 :/

Thanks guys =)

Billman250

I promise you at .002 the cylinder head will conform to the engine block.

The amount of cylinder heads I have milled during valve work is the same as the amount of shifters I have greased in order to improve shifting.

0.

This is S2000 specific and does not apply to all engines with .002 variation.

s2kyee

Thanks Billman. Do you think I should request OEM parts? Should I just do the valve myself? It would be considerably cheaper. C1 was only off 8-10% PSI on 100PSI test. 2 and 4 were 99% (leak down)

Car Analogy

How bad is the seat? I'm wondering if new valve then lapping all of them wouldn't be satisfactory. Then you preserve the factory 4 angle valve job, and factory seats.

The guides can successfully be replaced, they just have to pressed in the correct amount. Then new oem seals for good measure.

Then everything actually wrong with head is corrected, and risky things with lower success rates avoided.

s2kyee

I'll ask the shop if they can be lapped =)

Car Analogy

Lapping is an easy diy btw

s2kyee

Anxious to get out and drive as the weather is beautiful (Utah). Shop said the exhaust valves were pretty worn (~160k miles on the engine, so I can see that). They were planning to machine the intake side though.

I'm going to use new bolts and a new head gasket, any tips to getting the block surface clean (solvents, chemicals, etc)?

Really appreciate it guys =) I'll post some pics when I get the head back