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[Ewan]

Hi, anyone know why new cylinder head and camshaft sprocket bolts must be used? Never used to be the case. Local VX dealer quoting ludicrous £s as usual. Cheap Ebay ones any good, and dare I risk puting the old ones back? I bet they'd be OK.

[RobG]

Hi, anyone know why new cylinder head and camshaft sprocket bolts must be used? Never used to be the case. Local VX dealer quoting ludicrous £s as usual. Cheap Ebay ones any good, and dare I risk puting the old ones back? I bet they'd be OK.

I bet they won`t. Cylinder head bolts "stretch" on the final torque

[tunnie]

Hi, anyone know why new cylinder head and camshaft sprocket bolts must be used? Never used to be the case. Local VX dealer quoting ludicrous £s as usual. Cheap Ebay ones any good, and dare I risk puting the old ones back? I bet they'd be OK.

I bet they won`t. Cylinder head bolts "stretch" on the final torque

Yup, remember doing father T's 2.2, they don't have torque up tight & then its + 45 degree's or something. I would not want to put that kind of strain on used head bolts!

[Andy B]

....
I bet they'd be OK.

you'd probably get away with it, but as RobG says, they are stretch bolts and are designed to be used just once because as the name suggests, they stretch when you tighten them. If you use them again, you've no idea how much they will stretch again.
I reused the head bolts on her Hyundai with no apparent problems.  :-/ :-/
Best to replace them. 

[Jimbob]

trechhi is a known good seller on ebay for head bolts 

[Elite Pete]

trechhi is a known good seller on ebay for head bolts 

As Jimbob says Trechii on Ebay are good and a fraction of the price of genuine ones.

[cem_devecioglu]

I had the same question this summer.. they were not found easily (cyliner head bolts) .. I talked to 3 different mechanics.. All of them said if the gaskets not done before nothing will happen .. They re-use them frequently and not encountered any problem.. But they must be properly torqued as much as possible according to book values..

ps: but if they are easily accesible for you no reason not to use new..

[Marks DTM Calib]

The issue is that the head bolt is designed to be tightened past the point of yield to where it is stretched. At this stage it applies effectively a sprung load which ensures a constant clamping force over the entire operating temp and pressure.

The tighteneing is 25nm plus 90 deg, plus another 90 deg and plus a further 90 deg and the potential for an additional 15deg (which is the tolerance).....which is F-tight and on the final 90 deg you often feel them yield!

But, once stretched, thats it, you cant get them to the same state with the same clamping force.

The cam bolts you can get away with as they are not actulay tightened to the point of yield.

[Ewan]

That's great, many thanks everyone. I think I should change my user name to cheapskate.

[Marks DTM Calib]

Give these chaps a call.

http://www.trechii.com/

Good quality and well priced.

[Ewan]

P.S. Actually, I'm surprised to hear about that about the cam bolts. The ones on mine were on unbelievably tight. I expected them to shear when I undid them.

[Marks DTM Calib]

P.S. Actually, I'm surprised to hear about that about the cam bolts. The ones on mine were on unbelievably tight. I expected them to shear when I undid them.

They are angle tightened but not to the point of yield 

The head bolts are MUCH tighter

[cem_devecioglu]

most manufacturers dont recommend either they are yield bolts or not.. however , many people re-use them without problem (I have also re-used on another car) .. but personally if they are handy I wouldnt risk and buy new..