Head bolts

[oblark]

As I`ve taken a few 5 cylinder engine apart and now have a quite a few sets of used head bolts.

One set I`ve got was only on a engine for 300 miles.

I`ve compared the length of all the head bolts and they are all the same length.

I now they are stretch bolts or are they ??? or just a marketing thing to get people to buy new bolts every time the head is removed ???

[960kg]

I would of thought it obvious that seeing as all your bolts are used then they have stretched to the same length `cos of the same torque tightening!

I would seriously buy a new set for your new engine otherwise you may regret it!.........also while your at it measure a new bolt...

[oblark]

I would of thought it obvious that seeing as all your bolts are used then they have stretched to the same length `cos of the same torque tightening!

I would seriously buy a new set for your new engine otherwise you may regret it!.........also while your at it measure a new bolt...

I will buying a new set for the ME7 engine and I`ll be comparing them to the used sets I`ve got to see if they is a difference in length

[jamesy12345]

I will buying a new set for the ME7 engine and I`ll be comparing them to the used sets I`ve got to see if they is a difference in length

Those used bolts have had a hard life!



From my car, exhaust side

[Dangerous Dave]

I re-used mine on the 850 (didn't really get the new bolt thing back then). The first time I had no problems.

The second time I tried to re-use them one of them snapped leaving 2cm of the bolt in the block. Fortunately I managed to get a socket on the broken bit and undo it then fish it out with a magnet tool.

So yeah, it's iffy re-using them once, twice you're probably gonna lose

Oh and there was definitely a difference in the length compared to the new ones

[graemewelch]

To check.if theyve streched put a vernier on the should of the bolt. Me personly id just get some 12.9 cap heads.

[jamesy12345]

I re-used mine on the 850 (didn't really get the new bolt thing back then). The first time I had no problems.

The second time I tried to re-use them one of them snapped leaving 2cm of the bolt in the block. Fortunately I managed to get a socket on the broken bit and undo it then fish it out with a magnet tool.

So yeah, it's iffy re-using them once, twice you're probably gonna lose

Oh and there was definitely a difference in the length compared to the new ones

my bolts were original & never been disturbed as far as I know. Two of them baked into the exhaust side of the block so snapped on the way out

[Sweep]

I'd never ever re-use head bolts.

[oblark]

The set I removed from the ME7 engine I had to lay the engine on it`s side and stand on the engine, they where £$%&ing tight and where the orginal bolts.

[partsforvolvos.com]

don't re-use them , just go for new.
I cant find a spec on the length for you in my data books.
all of the models that you can re use state the length there, and what is ok or not.

[t5 pete]

Ive reused head bolts on my own standard engines but with this one ive just built running a fair bit more power I fitted new but did a caliper test on both used and new and they were the same

[T5frankie]

i'm sure you can get stretch and non stretch bolts

[Dangerous Dave]

The set I removed from the ME7 engine I had to lay the engine on it`s side and stand on the engine, they where £$%&ing tight and where the orginal bolts.

Oh yeah they're tight, I had to brace the engine against something solid using a barbell bar wedged into the water pump hole