speedyxjs
|
| posted on 3/3/09 at 06:07 PM |
|
|
Broken camshaft bolt
When i was putting the engine back together on Sunday, one of the camshaft bolts snapped.
I have looked everywhere and cant find another one and the only set i can buy is for the whole engine (a bit extreme for just one bolt.
At the risk of looking like an idiot, i would like to know if i can do without it.
The picture below is a rough sketch of what the brackety thing looks like. There is a camshaft bolt on one side of the cam and a head bolt the other
side so it would still be held on.
 
Rescued attachment untitled.JPG
How long can i resist the temptation to drop a V8 in?
|
|
|
|
|
BenB
|
| posted on 3/3/09 at 06:09 PM |
|
|
Can't you take out one of the other bolts, measure it up and get a replacement. A bolts a bolt after all is said and done.
I personally wouldn't risk running without it in place, especially when you've got more valves than most to bend!!!!!
|
|
|
speedyxjs
|
| posted on 3/3/09 at 06:10 PM |
|
|
Where can i get a replacement made up?
How long can i resist the temptation to drop a V8 in?
|
|
|
dinosaurjuice
|
| posted on 3/3/09 at 06:14 PM |
|
|
its probably a stretch bolt. there not usually the kind of thing you can get made up. if it was me i would risk running without it. that head bolt
will be taking most the stress.
i dont like to give risky advice... so probably best to source another...
|
|
|
iank
|
| posted on 3/3/09 at 06:15 PM |
|
|
Are they a special size/shape, or are they stretch bolts?
If they're not I'd replace with a high tensile cap head (12.9 probably) of the same length.
If they're stretch bolts I suspect it's best to replace them all as an engine set.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
|
|
|
owelly
|
| posted on 3/3/09 at 06:22 PM |
|
|
Given the size of the bolt and the siting of the head bolt, I'd be running without it. But it's easy for me to be brave with your
engine............
http://www.ppcmag.co.uk
|
|
|
BenB
|
| posted on 3/3/09 at 06:23 PM |
|
|
If it's a stretch bolt then realistically you shouldn't be re-using them anyway!!!!!
|
|
|
speedyxjs
|
| posted on 3/3/09 at 06:28 PM |
|
|
What is a stretch bolt?
How long can i resist the temptation to drop a V8 in?
|
|
|
thunderace
|
| posted on 3/3/09 at 06:37 PM |
|
|
quote:
Originally posted by speedyxjs
What is a stretch bolt?
type it into google 
|
|
|
thunderace
|
| posted on 3/3/09 at 06:38 PM |
|
|
its a camshaft post bolt
|
|
|
r1_pete
|
| posted on 3/3/09 at 06:39 PM |
|
|
quote:
Originally posted by speedyxjs
What is a stretch bolt?
A bolt which when torqued up stretches slightly to keep the components tight. The manual usually specifies torquing up and then angle tightening a
further xx degrees.
|
|
|
jollygreengiant
|
| posted on 3/3/09 at 06:44 PM |
|
|
If the its the smaller cam bearing bolt and into an alley head then I doubt it would be a stretch bolt. Just go to a local (GOOD) bolt supplier with
another one as a pattern and replace it. It will cost you pennies. It will be there to make sure that the cap is properly lined up before the head is
fitted.
If its one of the main head bolts then buy a new set because they will be stretch bolts and you should be able to source them from a good
engine/cylinder head repair workshop. If you have taken the head off then you will need to buy a new set of head bolts anyway.
Beware of the Goldfish in the tulip mines. The ONLY defence against them is smoking peanut butter sandwiches.
|
|
|
speedyxjs
|
| posted on 3/3/09 at 06:46 PM |
|
|
Its not a head bolt. Its much shorter. How can i tell if it is a stretch bolt? All the others went in fine, Its just the one that broke.
How long can i resist the temptation to drop a V8 in?
|
|
|
*davies144*
|
| posted on 3/3/09 at 07:13 PM |
|
|
i bought my chassis with this already done to it but all the other chassis ive seen have a different support? and i cant find any thing in the
book!
 
Rescued attachment steering column support.JPG
|
|
|
flak monkey
|
| posted on 3/3/09 at 07:16 PM |
|
|
Measure it up and buy a set of new ones from a hardware supplier. If you cant get them I can get you a for them from my supplier.
Cheers,
David
Sera
http://www.motosera.com
|
|
|
mediabloke
|
| posted on 3/3/09 at 07:25 PM |
|
|
It's tempting just to replace the bolt that snapped, but I'd err on the side of caution: if one has snapped, probably better to replace
the set regardless (leaving the head bolts alone, of course).
Agree that the head / machine shop will be able to source them. Always worth getting on first-name terms with them.
Francis.
|
|
|
britishtrident
|
| posted on 3/3/09 at 07:42 PM |
|
|
Hold on guys -- reality pill time.
Nearly all stretch bolts can be re-used --- the not re-using because they turn in toffee thing is largely an urban myth.
In any case if is a stretch bolt it will say in the WSM ---- camshaft bearing cap bolt is unlikely to be stretch bolt.
If it were me I would just use a cap head bolt (allen screw) -- as you can be sure it will be suitable high tensile grade.
|
|
|
iank
|
| posted on 3/3/09 at 07:52 PM |
|
|
quote:
Originally posted by britishtrident
Hold on guys -- reality pill time.
Nearly all stretch bolts can be re-used --- the not re-using because they turn in toffee thing is largely an urban myth.
Indeed, but if one stretch bolt of a set has snapped (over torqued or whatever) what are the chances of the others still being fine? - I think
I'd err on the side of caution (depending on what they cost).
As you say, in this case it's probably just a regular bolt and can be replaced by something good quality of the same size.
[Edited on 3/3/09 by iank]
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
|
|
|
jollygreengiant
|
| posted on 3/3/09 at 11:33 PM |
|
|
On the diameter of bolt it is likely to be to bold down the cam caps, it is most unlikely to be a 'stretch' type bolt (these bolts are
tightened to literally 'just' below the elastic limit of the bolt, i.e. the point at which it starts to stretch, hence the term stretch
bolts) as it would most likely pull the threads out of the alloy head, unless steel inserts were fitted.
Hence take one bolt down to your local bolt suppliers to use as a pattern and they will match it for you.
J.D.
Beware of the Goldfish in the tulip mines. The ONLY defence against them is smoking peanut butter sandwiches.
|
|
|
BenB
|
| posted on 4/3/09 at 11:55 AM |
|
|
Yup. Like I said it's likely to be a standard bolt in which case any old bolt supplier will sell you a new one.
You can re-use stretch bolts in the same way you "can" re-use some interference fit fluid fittings but you shouldn't and if it all
goes pete tong and kills the engine you feel a bit silly!!
You can tell if it's stretch partially from the description of how to tighten it in the Haynes book of lies. IE if it just gives torque figures
its normal, if it gives "torque to X then give Y degrees more it's likely (but not definately) stretch.
|
|
|
