Torque setting w/ TODA MHG

[AE092]

Currently having the head fitted with a TODA 1.0mm head gasket with reinforced head bolts from Japan, wondering if anyone knows what the correct torque setting would be for the metal head gasket?

[70XIN]

It doesn't matter what brand of head-gasket it is, it matters what bolts you're using :)

If it's those allen-key type reinforced bolts from japland, then they just use standard 4AGE torque settings.

[ke70dave]

though it depends if they are those torque to yield as well, or not.

"apparently" the standard 4age bolts are one use only, though i reused mine and its still going 2yrs later....

i would be trying to find specific instructions for the bolts, as the standard toyota 4age settings are for standard toyota bolts, which mr ae092 doesnt have.

[Skylar]

You've done stress/strain and young's modulus right? You do realise what happens to the metal when you tighten a torque-to-yield head bolt?

[ke70dave]

yer i kinow whats going on, and i only found this out after i put them back in. and at the time i needed the car back together ASAP so it was a bit rushed.

4age manual gives a length that the bolt should be (exhaust side is 108mm and intake is 90mm), sais "if any of the bolts dont meet them, replace"

soooo maybe i got lucky and mine are all in spec, or they are in spec good enough to seal for the last 2yrs or so.

[AE092]

It doesn't matter what brand of head-gasket it is, it matters what bolts you're using :)

If it's those allen-key type reinforced bolts from japland, then they just use standard 4AGE torque settings.

Exactly the ones' I've got and called a few 4AG shops and they told me to use the stock torque settings as well. 29nm + 2 x 90 degree passes.

[Javal]

yer i kinow whats going on, and i only found this out after i put them back in. and at the time i needed the car back together ASAP so it was a bit rushed.

4age manual gives a length that the bolt should be (exhaust side is 108mm and intake is 90mm), sais "if any of the bolts dont meet them, replace"

soooo maybe i got lucky and mine are all in spec, or they are in spec good enough to seal for the last 2yrs or so.

I had a set stretch on me tonight. 4AGE factory headbolts are torque to yield and should be replaced every time. Factory torque settings is 3-stage: 29nm then 90 degrees, then an additional 90 degrees.

[AE092]

I had a set stretch on me tonight. 4AGE factory headbolts are torque to yield and should be replaced every time. Factory torque settings is 2-stage: 29nm then 90 degrees.

Sure? I've read elsewhere is 29nm then 2 passes of 90 degrees

[Skylar]

Yah, two passes.

[70XIN]

Just to entertain people's curiosity, this is what happens to a rod bolt (torque-to-yield) that's been done up once or twice too many. The stretch is awesome!

http://img696.imageshack.us/img696/8363/torquetoyield.jpg

[Skylar]

Haha, necking followed by rupture. Sweet.

What are they off Seamus?

[Javal]

Sure? I've read elsewhere is 29nm then 2 passes of 90 degrees

Correct, actually. The specs book I have has stage 1 and 2 on one page, then rolls over to the next page for stage 3.

Good catch. I'll edit my old post to reflect this.