Does the Shinano key have enough room to add a ring spanner so you can pretension that 30% with some 11/2" GI then hit the gun?? Hold the GI at 10oclock as if it lets go you have a bit of time to dodge it

That sounds like an excellent idea to me......never tried that but seems smart

The bolt heads are Torx 50 and OK, none of the heads were damaged just the bits I was using. I have a T50 impact bit on the way so that will get them out and new bolts are on the way from UK and I am taking it easy because my back has decided it doesn't want to play ball this week.
All I'll be doing is robbing a valve from the spare and putting it in the head that came off the engine.
If I welded to the grade 10.10 bolts they would probably break at the weld.

Well I am now regarding this as a bit personal. I recieved the impact torx50 socket and the impact gun just didnt work as I have tried before and the damn bit bent on the very first bolt I tried to undo so now it either drill it out which will put all sorts of crap through the engine or used dynamite. I can't get any sort of grinder in at the head of the bolt.

I'm sorry to hear that rick. Some things that happen are beyond explanation.

10.10 cant be welded to generate heat down to the threads without risk of fracture below the weld site can it be frozen? or will it result in the same stress point. can you warn it and flood it in penetrine and let gravity do what it does in the shed overnight, the cold should help it head south, after bending the bolt 30% the thread is sure fixed in, if you drill it it still gets hot, either way you end up with a stud in the block and a way of getting the head off, as the only thing holding it on is the bolt heads? not the bolt shaft. that help?

5 minutes ago I just shagged my 3rd drill bit on one of the bolts that I have already got out just to see if it will drill.
Thing is the bolt heads are fine. To be quite honest I have never come across a bolt that is so resistant to being removed.
All the bolts that have come so far have no sign of corrosion on the thread and they are oily when they do eventually come out and are not bottoming in the thread so I dont know what is holding then in there. Heat directly onto the thread would probably do the trick but how is another story.

You probably already know this but, after a failed attempt at a drill job sometimes, I find that the old bit somehow Glazes the surface of the area trying to be drilled and the new drill bit will just kinda slide over the surface ruining that bit as well.
How reasonably sure are you that you have the very best industrial cobalt bits to attempt this? I can't see from here what type of failure you experienced when you say "shagged" the bit.
Any chance you could get a dremel in there with a grinding stone to just rough up whatever bore hole you may have, then try another new bit?
I'm tempted to go out in my junk pile and get a head bolt from my old K100 engine and try to drill it.....just to see what's happening there. Maybe I'll try it tomorrow.

I got the drill bit to bite in but only just and then it work hardens the metal and being 10.10 that makes it real hard.
I have a new snap on bit coming tomorrow at least if it snaps or twists they replace it without question. Couple of mates in the trade still have said that they are the only tools worth having now. One said that even Stahlwille is not worth having now.
Its sort of become a personal crusade for me. All I want is to take 1 exhaust valve out of the head and put it in the other head and go for a ride. I didn't really expect all this *^#(^ crap.
I can feel a beer coming on.

Probably would have been another option for me to send you a few exhaust valves out of a scrap head I have laying on the bench.
I'm trying to wrap up a deal with "TacKler" in Brisbane to ship him a final drive. I was going to send Blakeley's handlebar end bolt in TacKler's box to Brisbane, then he was going to send it on to Blakely, but Blakeley already found a source there.
Tackler has been a bit slow getting back to me on closing up the deal.....but if he does & you have a friendship there with him, it's possible he'd be willing to accept a couple of valves for you????? Then send them to you via local post? I know the time span is a long way out for you from here - through him, but if we can set it up, I'll just donate the best 3 (Exhaust?) valves I can find in this head???
As for the drilling. I assume you are proficient, probably more than I????
I might remind you that slower speeds might be better and a good quality Machinist grade cutting oil can make a huge difference. (No WD-40.....lol) No other kind of lubricant can be substituted, it has to be cutting oil.
Seems as if I remember that it's like high in sulpher or something.......smells like %$#^......really makes a drill bit BITE
I don't have any, but I do have some good cobalt bits and I'm gonna try drilling one of those bolts just for fun tomorrow. At least if I can't help, I can then have some "sympathy sickness" for you.......lol. Sorry I can't fix the back pain.
PS: Looks like he's only a fast 2 hour ride from you on a K????

I just discovered, I can't help with the valves. Mine is a 2 V, Yours in a 4.
I do have 1 more hairbrained idea. You have half the bolts out, correct?

Ok, assume for a minute that because those bolts are out, you have lost all that clamping force from them. Maybe the head has even more torque now on the remaining bolts because they are carrying the clamp pressure of all ten bolts....hence they would be stuck tight. Kind of in a bind?
Maybe you could lube up the ones you took out with lots of anti sieze and put them back in as tight as you dare. In theory, they would pull the head back down, relieving some of the stress on the five that are not yet out. After they're all back in, then heat the one you're working on as much as you dare, the heat should make that bolt minutely longer. Then give it the maximum heave ho & see if it pops loose??????

WE often have to pull them back down on some of the 6cyl fords but the head of the bolt turns quite easily on the head its the thread at the base that is the problem.
Any way I will see what happens tomorrow just keep a look out for a mushroom shaped cloud to the south west and then you will know it didnt come.

I think you might consider my idea even though the top does turn. It could be equally helpful on both ends (if at all)

Well I got a new snap on bit today and with mt reverse tension wrench I tried to crack the remaining 4 bolts.
I got to 150ft/lb and decided that I just dont want to destroy one more good tool and heav decided to attack the things with a diegrinder and tungsten burr then a stone if that dont work. I have been stuffing around for two weeks now and I cant just wait any longer as there are other things that also have to be done to it after the head comes off.

I'm sorry it hasn't worked out for you. I did not get a chance to see if I can drill these bolts today.
I would bet if you had my 700 ft/lb, Ingersoll 1/2" drive impact wrench running on a fat air hose with 175 psi of air pressure, it would rip those right out or break the heads off. Even with the "spring" you describe in the bolt shafts,
The impact wrench (with high speed, many beats/per minute) is still your best option. With A double hammer wrench running at big air pressure, the second beat will hit the bolt before it has had time to spring back.
I would even go so far as to run some air tool oil through the wrench just before attempting.
Can I assume that you did not reinstall the other bolts to lessen the clamp force?
The Snap on tool is fully warranted, I guess you are aware of that. Maybe the heads are too buggered already to succeed?
Could you shoot me a picture of the head with the location of which bolts are in & which ones are out????
I'm pulling for you, Rick.

I have just finished cutting the heads of two of the bolts and they are lose and just screw out by my fingers. Threads are clean as and lightly oiled.

Well done!

Ahaaaa, good going rick. 3 to go????

Good work Rick....keep screwing.

How can a stud flex by 30% and not let go and when its head is cut off just unscrew by hand?????? Sheeesh

what the !!!!!!!

good luck with the rest

Got the rest out today and just as I took the head of the damn die grinder fell into the ports and took some of the humps and bumps out.
All I really did was match the ports to the inlet stacks, they were fairly well matched but one can always improve on mass production.
I can also feel a set of 1200 cams comming on too.

RicK G wrote:Got the rest out today and just as I took the head of the damn die grinder fell into the ports and took some of the humps and bumps out.

Well that was damn careless of ya, hope you sent the polishing mop in there after it!!! lol

I will be sure to polish all the rough bit.
Actually I am not a big believer in the polish finish for ports but a 180 -200 grit finish works very well and is much easier to do.

yeah i heard similar from some top race prep guys rick ,,,they maintain that anything above 400 grit is getting too smooth

its on my plans list

There seems to be 2 schools of thought on that. The v.fine blast effect a la golf ball dimples
or the high polish .... sh1t off a chrome shovel.

RicK G wrote:Got the rest out today and just as I took the head of the damn die grinder fell into the ports and took some of the humps and bumps out.
All I really did was match the ports to the inlet stacks, they were fairly well matched but one can always improve on mass production.
I can also feel a set of 1200 cams comming on too.

No real damage though, huh.....just nicks & scratches?
Do you have the good valve installed in the other head, now?

Well done \Rick...keep at it.

I am going to do a head up and set up the 1200 cams while it is on the bench which is a heap easier than doing it on the bike.
The 1100 dont have shims and the whole bucket is the adjustment so to change a bucket its cams out each time and if I want to take a couple of thou of the stem its easy.

Exhaust ports I like real smooth, intakes are better a bit rough.