Head Bolt Torque on Bolt Removal
#11
10-09-2012, 07:20 AM
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Thanks for everyones feedback on my question. I thought I better follow up. Drowssap was right. The machine shop said that the heads were badly warped and they felt that would account for the big variation of the torque across the 10 bolts on each side. They took 0.018 off which was near the limit of what they thought could be done on these particular heads. They also made me some 0.04 shims for the rocker arms to get the valve geometry correct. Tom.
#12
10-09-2012, 07:25 AM
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It is common for them to be uneven - but 20lb seems ridiculously low. Typically they will be anywhere between (approximately) 75 and 200 lb ft to remove.
As to why - well, probably the last garage didn't do it properly is the easiest answer. Perhaps they forgot the second angle rotation sequence? Why not make things better this time around and junk the stretch bolts and replace with a quality engineered solution - a set of ARP 124-4003. This way all torques will be equal when you install them, and all torques will be equal when you remove them. There are just too many variables with the bolts, studs are guaranteed more consistent.
As to why - well, probably the last garage didn't do it properly is the easiest answer. Perhaps they forgot the second angle rotation sequence? Why not make things better this time around and junk the stretch bolts and replace with a quality engineered solution - a set of ARP 124-4003. This way all torques will be equal when you install them, and all torques will be equal when you remove them. There are just too many variables with the bolts, studs are guaranteed more consistent.
Anbody have any comments on this? Thanks. Tom
#13
10-09-2012, 07:54 AM
Baja
Your reading one post from someone who had trouble with them. Just about every re-builder on the other side of the pond uses ARP stud with no problems.
If you read his post in depth he had to have his intake machine, the block has helicoils and he also says that the stud hit his aftermarket exhaust.
So you not taking about a stock out of the box block he is dealing with it has obvously been machined before probably decked a couple of times.
usually when you see a manifold that has to be re-cut to sit on the head properly, it is because the the block and heads have been decked either a couple of times or a whole lot.
I see in your next post that you too are going to use a helicoil, all the more reason to go with the ARP's, by using studs you eliminate to tortional stress on the bolt hole or in you're case the helicoil. Jmho
If you read his post in depth he had to have his intake machine, the block has helicoils and he also says that the stud hit his aftermarket exhaust.
So you not taking about a stock out of the box block he is dealing with it has obvously been machined before probably decked a couple of times.
usually when you see a manifold that has to be re-cut to sit on the head properly, it is because the the block and heads have been decked either a couple of times or a whole lot.
I see in your next post that you too are going to use a helicoil, all the more reason to go with the ARP's, by using studs you eliminate to tortional stress on the bolt hole or in you're case the helicoil. Jmho
Last edited by drowssap; 10-09-2012 at 11:38 AM.
#14
10-09-2012, 12:54 PM
Pro Wrench
#16
10-12-2012, 12:57 PM
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....Why not make things better this time around and junk the stretch bolts and replace with a quality engineered solution - a set of ARP 124-4003. This way all torques will be equal when you install them, and all torques will be equal when you remove them. There are just too many variables with the bolts, studs are guaranteed more consistent.
First, do the studs get in the way of installing the heads when the engine is still in the vehicle (2001 DiscoII)? It's pretty tight at the back near the firewall on both sides.
Second, anybody got any last minute observations or experiences on using or not using studs before I order them? I sure like the idea of torquing nuts instead of bolts but I tend to go stock in the guts of the engine. Stiuds is going to wild side for me.
Thanks. Tom
#18
10-12-2012, 05:55 PM
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I've been reading the posts over at discoweb.org. Lots of good skinny on the issue of bolts or studs. A little embarrassed to say you can ignore my first question in the previous post as to whether studs can be used with the block still in place. Sure studs can be used with the engine in place. Just put the gasket and head in place and then insert the studs. Duh!
Still a tough call on which to use. Cost is not a factor for me as both are reasonable. Either is reuse. First priority for me is to avoid that dreaded feeling on the last 90 degrees when the breaker bar all of sudden is way easier to turn. Second is getting it done so it will last the longest time. I don't want to pull the heads on this thing for a bunch of years. By them I will have forgotten all the fun I'm having in 2012 with these bolts or studs.....
Still a tough call on which to use. Cost is not a factor for me as both are reasonable. Either is reuse. First priority for me is to avoid that dreaded feeling on the last 90 degrees when the breaker bar all of sudden is way easier to turn. Second is getting it done so it will last the longest time. I don't want to pull the heads on this thing for a bunch of years. By them I will have forgotten all the fun I'm having in 2012 with these bolts or studs.....
#19
10-12-2012, 06:00 PM
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I'm not so lucky. I was able to remove that specific bolt with a 3/8" socket knuckle joint on a slight angle, an extension all connected to a 3' breaker bar. Used the same approach on the installation of the new bolt. Just needed 2 guys....one to hold the socket on and knuckle straight and the other to work the breaker bar.
#20
10-20-2012, 10:37 PM
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I am working on a head job on my 2001 Disco II, got the heads back and working on getting the bolts torqued back down. I am having troubles getting to the lower rear head bolts. I am using a 1/2 in drive with a universal joint, but everytime I go to torque it, the socket comes loose. Any tips on how get that torqued down?