[zooky08]

what does every body torque there head bolts to, the gasket kit ive got said 75nm, but i think 75nm is way to tight, i snapped a bolt trying to tighten it up

[Built4thrashing]

You need to put a washer under the bolt head and make sure it is well oiled. do them up in stages. not just straight to max tension.


B4T

[ck13488]

Make sure it's newton meters not pound feet

[zooky08]

there oiled and i did them in stages. it snapped on the last stage which said on the paper 75nm. my torque rench doesnt have nm, so ive got to convert it

[Jester]

somethings wrong then cos zook head bolts arent that tight, fresh bolts used? are you sure of your conversion? are you sure of the accuracy of your torque wrench?

[shakes]

A little rude but did you convert it right?

I don't have a manual handy but I know with toyota 4a engines the head bolts are meant to be one use only due to the fact they stretch... Assuming sierra's are the same could your bolts possibly be old, stretched beyond limits and bottomed out causing it to snap?

[shep]

i thought that they are about 60flb

[Ben_Sierra]

My Sierra FSM says 63-70Nm or 46-50lb-ft.

[zooky08]

yes im pretty sure i converted it right, ive got a conversion chart. the bolts are fair new, there not rusted or nothing, i looked at a manual i have nd its said only 68nm (50flb), the paper i got with the vrs kit said to do them up to 75 (56flb), which coursed the bolt to snap

[Blueberry]

by fairly new, do you mean they've been used before. if so thats why they snapped, headbolts are a one use item.

[zuk85]

Blueberry wrote:

by fairly new, do you mean they've been used before. if so thats why they snapped, headbolts are a one use item.

have to agree with the man here. And the other post of when u tighten them the first time, they stretch. So they snap the next time they are tightened to same setting.

[coneykid]

Yeah the tensions are right. Mine are at 76nm. The 12ht I just rebuilt was 145mm.

[zooky08]

were can i get new bolts from as in 1 or 2 days, can i just go buy high tensile bolts the same thread and length or do they got to be the same bolts

[Jester]

dont mess about like that get the real thing and get quality, you guys seem to have zooks everywhere up in qld so i reckon youd be able to get some easy

[zooky08]

i would get them from a another sook but you said there only a one use item, so ill have to get some of suzistore

[steak_knife]

zooky08 wrote:

i would get them from a another sook but you said there only a one use item, so ill have to get some of suzistore

Not on all eng's, there is such a thing as a stretch bolt but i'm 99.99% sure these ole thing's don't use em..

[zooky08]

this is for a g16a engine and the head is of a g13ba btw, not that it makes a differents i dont think, suzistore dont have them

[jonno_racing]

g13 are re usable. only head bolts that are done in degrees are one use. that came from both a engine reco place and 00zuk.

gti are 75nm id asume g13a the same.

[want33s]

Blueberry wrote:

by fairly new, do you mean they've been used before. if so thats why they snapped, headbolts are a one use item.

In some cars they are not re-useable but in Zooks it is fine to use them again.


I would be looking at a non compressible substance in the bottom of the bolt holes causing the bolt to bottom out before reaching full torque.


Clean out all the holes.

[atari4x4]

are the heads 2 different heights & are the bolts to long?

[zooky08]

the bolts have came out of the engine before. ive just got a full rebuild, the block is sand blasted and clean, so no dirt or any thing in the holes

[Built4thrashing]

zooky08 wrote:

the bolts have came out of the engine before. ive just got a full rebuild, the block is sand blasted and clean, so no dirt or any thing in the holes

Dont assome this ever.

My old motor was sand blasted and then pressure cleaned and the sand that got left behind destroyed a full set of bearings. I have also come across stud holes full of oil that can cause the head bolts to hydrolic and snap off. kinda line bottoming out.


check the depth of the head stud hole and use compressed air to blow the shit out.

B4T

[zooky08]

i gave the block a good blow out, including all ten holes i even shoved the nozzle down the hole and then gave it a blow out once more, it was only the second bolt that snapped. first one went to 75nm just though, then the second one snapped, it just kept getting tighter and tighter, was much tighter then the first one i did, maby was the torque rench not clicking wen it was ment to?

[ajsr]

holding the touque wrench in the wrong spot???or bumped it out of spec?

[zooky08]

i had one hand on the top of the head and the other at the end of the handle, torque rench has a lock on it