Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[omega3000]

Ok so can you , or should i say would you re-use stretch bolts for the head  Old old mate says he has always re-used with no problems 

[bored bigyin54]

Ok so can you , or should i say would you re-use stretch bolts for the head  Old old mate says he has always re-used with no problems 

i have been told never reuse mate

[omega3000]

Ok so can you , or should i say would you re-use stretch bolts for the head  Old old mate says he has always re-used with no problems 

i have been told never reuse mate

Would be interesting to see who has re-used them though , old old mate has re-used them for years and never had any fail ever 

[andyc]

Depends how lucky you feel but for thirty odd quid is it worth it. Its not that the bolt may snap but if the bolt has already been torqued to its yeild point your not going to get the same clamping force by doing it again it will just startn to stretch the thread.

Worst case would be a snapped blot in the block or the head may start to lift

Cheers
Andy

[Webby the Bear]

shouldn't reuse them steve. we were told its a definite no no at school... obviously though im sure, like your mate, people have done it

[omega3000]

Im not going to re-use mine when i get round to taking the head off , just this old old bloke says you can  Dont fancy doing the stem seals and cam belt kit for it to go pop 10 miles down the road 

[bored bigyin54]

Im not going to re-use mine when i get round to taking the head off , just this old old bloke says you can  Dont fancy doing the stem seals and cam belt kit for it to go pop 10 miles down the road 

better safe than sorry mate

[Rods2]

I know somebody that did this when repairing a blown head gasket on a Landrover and the gasket went again within days, where the head was not clamped properly. Cost more to do the job twice, than the extra cost of the bolts first time. 

I would imaging a cam stretch bolt failing at speed would make a bit of a mess of the valves. 

[dbug]

Im not going to re-use mine when i get round to taking the head off , just this old old bloke says you can

Perfectly ok for "old style" head bolts that were not stretch bolts, but just torqued - probably the "old bloke" has got himself a bit confused.

I would not re-use stretch bolts on a cylinder head

[Marks DTM Calib]

Ok so can you , or should i say would you re-use stretch bolts for the head  Old old mate says he has always re-used with no problems 

Hes an idiot then

Years and years ago, when headgasets were copper and heads iron, the heads werwe often held on with monster studs or bolts, these could be re-used adn often required re-torquing after a number of miles.

Now we have alloy heads and composite or multilayer metal gaskets.

These use a high tensile bolt which is angle tightened to the point where they 'yield', at this stage they actualy go to a stage where they are elastic and apply a sprung clamping force.

The benefit is that it maintains a constant pressure to the gasket across the full temperature range and does not require re-tightening.

They cant be re-used as once they have passed the point of yield they cant be re-tightened to achieve the same.

So, in summary, old setup means re-torquiing (a git of a job on a OHC setup) after a number of miles and a compromised clamping force on the gasket. New setup means fit once and forget plus a better more consistent clamping force.

[sdwall]

+1 

[omega3000]

Ok so can you , or should i say would you re-use stretch bolts for the head  Old old mate says he has always re-used with no problems 

Hes an idiot then

Years and years ago, when headgasets were copper and heads iron, the heads werwe often held on with monster studs or bolts, these could be re-used adn often required re-torquing after a number of miles.

Now we have alloy heads and composite or multilayer metal gaskets.

These use a high tensile bolt which is angle tightened to the point where they 'yield', at this stage they actualy go to a stage where they are elastic and apply a sprung clamping force.

The benefit is that it maintains a constant pressure to the gasket across the full temperature range and does not require re-tightening.

They cant be re-used as once they have passed the point of yield they cant be re-tightened to achieve the same.

So, in summary, old setup means re-torquiing (a git of a job on a OHC setup) after a number of miles and a compromised clamping force on the gasket. New setup means fit once and forget plus a better more consistent clamping force.

 

Understood Mr DTM  Incidentally whilst searching for a head set turns out the engine code looks the same as the old calibra 2.0 

[Marks DTM Calib]

Later 16V calibras used the ecotec lump as per that in the Vectra.

I use Trechii for bits (good for head gasket and bolts) plus genuine camcover gasket, O rings and exhaust manifold plus inlet manifold gaskets. Re-use the cam seals.

[omega3000]

Later 16V calibras used the ecotec lump as per that in the Vectra.

I use Trechii for bits (good for head gasket and bolts) plus genuine camcover gasket, O rings and exhaust manifold plus inlet manifold gaskets. Re-use the cam seals.

Not bad £31 for the full Trechii head set inc bolts valve stem seals too