Headbolts

by **Alpineandy** » Sat Jan 13, 2007 1:51 am

peterg wrote:only changed them on the k-series because it had had some serious abuse and several rebuilds/head gaskets already.

The K series is about the only engine that really should have it done everytime. I've heard of sooo many problems with them.

by **clee** » Sat Jan 13, 2007 10:30 am

simontaylor wrote:
clee wrote:But.......................... would you use the 2.8 lower tensile bolts Fek it only one way to find out
You like DATA ????
http://www.roymech.co.uk/Useful_Tables/ ... rength.htm

lee, if you understand all of that, then I think you know the answer to you question!

The numbers are quite simple .The first is it's strength in Newtons ,8 is 800 ,10 is 1040 .The second bit is when it starts to stretch as decimal/percentage ...........the 8 will deform @ 80% of 800, so 640 and the 10.9 @ 90% ,940 .

by **peterg** » Sat Jan 13, 2007 2:18 pm

Yes the k-series can be a bit of a 'mare! I blew up my first one at Knockhill in some style....flames the lot! What was interesting is that it carried on running on 3 cylinders afterwards (meaning I could drive it onto the trailer), but when I dismantled it to look the piston in the cylinder that blew had completely gone and the rod was going up and down on its own!!! The intake and exhaust were full of atomised piston!
The 3rd K-series I had (not built by me.....by Janspeed) self destructed in similar fashion at the same event 2 months after I had sold the car to someone :twisted:

by **simontaylor** » Sat Jan 13, 2007 2:51 pm

Ooooo, I do like to learn something every day, now I know.

by **clee** » Sat Jan 13, 2007 6:54 pm

The headbolt part # for the Z7U,Z6W and Z7X are the same :roll:

Turbo don't come in to it.............................My new bolts are ZNJ, Z7W EAGLE etc ......................I fink they'll do fine

by **peterg** » Sat Jan 13, 2007 6:56 pm

I'm not sure anyone cares!!! :lol:

by **clee** » Sat Jan 13, 2007 7:01 pm

Fine

Fek-off then :!:

You got that lump runnin yet :roll:

by **simonsays74** » Tue Jan 16, 2007 12:02 am

simontaylor wrote:"A real professionals opinion would be welcome though" you'll have to wait see what "simonsays"

the prv head bolts are non stretch type.

normally a good mechanic will mark the top of the bolt with a single centre punch to signify that they have been re-used.

after that you would be best to use new bolts.

go to you local engine gasket supplier for new bolts.