needturbo6

has anyone had any problems when reusing old head bolts on OHC motor,
or had their head go too "soft" to be used

READ THIS it says bi-metallic enges have special head bolts.....

the head on my EB got done a while ago and all origanal head bolts were used except the broken one which was replace with an AU one i think? so am curious to know if i should replace them at a later stage

whats ur opinion

SiX_iN_a_RoW

the head bolts stretch once torqued to specs and will most likely bottom out before actually reaching the required torque setting if re-used. I'd be replacing them

__________________
Lets go find that Hotdog tree I planted

Lowered EF Futura
Black Steelies ( too cheap to buy proper mags )

INJECTED250

WHAT.. you only replaced 1 bolt thats crazy... if a mechanic done it id have a real go at em.. trade price is 1.90 per bolt for au ones.. if one snapped didnt u think the otheres will for 25 od bucks worth of bolts i carnt belive people still dont doo em

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EB FALCON
98 T5 gear box (was auto)
Wade 977b cam
3.7 lsd
AU bottem end
ELXR6 ported Head
PH4480 Pacemakers

needturbo6

yeh it was actually my brother 14 years experience (tranny rebuilder tho) and also done a worked at a couple ford dealers, usually does a top job, ill have to ring him and ask him to be certain, though im pretty positive he only replaced 1 bolt, ill giv him a blastin if he did....

can i just take out the head bolts and replace em with new ones?

SPHELL

IMO I wouldn't worry about it mate. I've done 4 head swaps and only used new bolts once and they had a terrible head design and rounded off easily so I got rid of them and used the original ones again. Most recently I put an EF head on my EA and used the old EA bolts from one of the wrecks me and Sunny got. Obviously you shouldn't use the bolts if they have corrosion on them (which i've seen sometimes) but generally I think changing the bolts is over-rated.

INJECTED250

Chainging bolts is not over rated. THe head of the ea-el bols snap of without warning there a faulty bolt, the head of this bolt can go into youre timing gears and fuk ya motor has happend before. Never seen an au head bolt snap, and ive done 40-50 head gaskets, seen heaps of ea-el ones, most common cause of gasket fault is the head bolts shitten em selfs

THe design of the au bolts is fine if u are using decent tools and keeping the socket square on the bolt, a good single hex impact socket is fine. This has been covereed many times so its up to u

__________________
EB FALCON
98 T5 gear box (was auto)
Wade 977b cam
3.7 lsd
AU bottem end
ELXR6 ported Head
PH4480 Pacemakers

needturbo6

would it be ok then, to replace the head bolts without having to machine the face and replace gasket?

EDXR8

If you change them, you wiould probably want to do head gasket too. If the engine is stock, the head bolts should be ok but they will cause the head gasket to blow sooner than if they were new bolts as the torque will not be up to specs.

No one should really reuse TTY head bolts. It is widely known that their torque values on reuse are not accurate and they are also more likely to break. They are not expensive to replace either.

SPHELL

why wouldn't the torque be up to spec? Surely if you had a used bolt and torqued it to 120Nm then it's torqued to 120Nm....same as if you torqued a new bolt to 120Nm, then it's the same. I know the bolts stretch but they aren't going to tighten themselves once they are in.

INJECTED 250 - since u've done some many heads, you might know....are the EA-EL bolts different in construction (not just looks) to the AU bolts? I heard they were and that AU bolts should definately not be re-used but EA-EL was ok.

EDXR8

It's not about the torque it's something to do with clamping force. I am no expert on this but I believe the bolts stretch as they are torqued down and the stretch is calculated into the final torque values. Not totally sure on this but it has been debated on alot of forums so a google search should answer this better. Also, the torque specs for the I6 are not given, they say something like torque to xxNm then turn a futher 3/4 of a turn (can't remember the exact specs). This method would take into account the correct stretch of the bolt and the clamping force it will provide.


Other way around. EA-EL bolts are Torque-to-yeild and should not be reused. The AU' bolts are not so can technically be reused if in good condition.