Thread: Head Bolts Won't Shift

Nothing for it but to keep trying, they ARE very tight, after 20Nm they are tightenend again by 2 lots of 90degrees

I always fit them back on using the early bolt tensions, 50, 70 and then 95Nm .

JC

dont use an oxy a hot air gun will be enough if you can get one with a restrictor nozzle try to keep it aimed at the bolt as tightly as you can. 20 minutes per bolt should be enough to let you get it.

Ive had to resort to 5 foot of breaker bar before today. Best thing is IF they snap the heads off it doesnt matter once you get them all freed or broken off you can lift the heads off and then multigrip the shanks out as the tension on the threads is gone.

IF they still hold after that you can weld a socket to them and get a more direct drive and IF THAT shatters off you still have room to dremel the shank flat then drill it down the center and go for easy outs.

AND when that fails you can then drill the whole thing out and go the helicoils.

Dont ask why I know this.

And when you put them back use nickel anti-seize on the entire shank of the bolt. Before this, get one of those expanding wire brushes used on valve guides and thoroughly clean the bolt holes in the heads and run a tap and die over the threads.

Well the heads are at last off. I bought a new 16mm ABV 1/2 inch drive single hex impact socket, put it on a Sidchrome 18 inch breaker bar over which I placed a 5 foot long water pipe. With my son standing on the block on the garage floor I managed to undo all but two of the 20 stretch bolts. On the two remaining bolts, both outer ones on the same head, the socket just kept slipping round the bolt head when heavy force was applied.

I had to resort to cutting and grinding the heads of these two remaining bolts off with a grinder. Unfortunately this messed up the washer platforms a bit so I'll need to get some alloy welding done to build these back up.

I would have thought that it should have been "Captain Airwrench " to the rescue. I luuurve mine for Pinion seals etc. Maybe this is why it is recommended that a thread sealant be used on assembly ie to stop corrosion. I couldn't figure out why at first as all the bolt holes are blind, and do not enter the water jacket. Used Holden sealant. However being a good soldier I obeyed and the bolts all came out easily on my next head change. Regards Philip A

you could try that Freeze Spray in an aerosol can, that's suppose to release tight bolts.

or an impact driver, has come in handy many times for me

never tried it on head bolts though

I had to resort to cutting and grinding the heads of these two remaining bolts off with a grinder. Unfortunately this messed up the washer platforms a bit so I'll need to get some alloy welding done to build these back up.[/QUOTE]

G`day , they can be fun at times .

The single hex impact socket and more muscle was certainly the right move .

If you have the problem again , i`ve found the easiest way is to drill the head of the bolt .
Use one you have out as a guide as to how deep and the diam needed .

The bolts a loss already but nothing else needs to be repaired .

Cheers