Lotus Elan and Lotus Elan Plus 2 Forums

JonB wrote:Edit: Oooh by the way, you'll perhaps notice from the picture that the cooling system full of water. I thought it had a proper water / anti-freeze mix but nooooo...! So I will put that right toutes suite!

That's what comes of letting Wiggy near it!

Jon

I just poped out to mine as it stat housing is off. It looks like perhaps 1/2 inch of threat would be in there at best. 10 or so mm in modern day speak.
I still think you can get that out by filing flats and removing with socket or ring spanner. Abit of penertration and shocking may help with some heat when you can.

JonB I think you need some good luck, if you didn?t have bad luck you?d have none at all!

For this type of broken bolt / stud I tend to hammer it repeatedly on the end with a not too big hammer to try to shock it loose in the head. I?d then warm the alloy head in the area with a gas torch, nothing as fierce as oxyacetylene as you don?t want to damage the alloy. I?d use small stilsons to grip the stud if possible or if necessary file flats on it for a better grip. If that doesn?t work file it down so that you can see the diameter of the bolt, centre punch the bolt and gradually drill it out, have a helicoil set to hand if you drill it too big so you can refit a standard size bolt. Should be unc into the alloy. Good luck!

Jon,
I feel your pain, soon you will be ready for the comfort of the dark side



It could be as soon as tomorrow.... May the fourth be with you!

At least it's an easy one to heli coil if needed. I have done both mine with great success.

Steve

Alan

Is that yours?

Another plus 2 project?

pauljones wrote:Alan

Is that yours?

Another plus 2 project?

No Paul, just bait for Jon, I feel him strongly through the force and await his presence in the dark side of black top Zetecs ( it?s Star Wars day tomorrow....May the 4th.... geddit?)

I?m actually looking at building/ rebuilding an original Elan.

Jon,
The process of welding an M8 or M10 nut to that bolt stump will no doubt loosen the corrosion and make it an easy job to remove. Filing it flat into a square would work as well. All of the Twincam engines are at least 45 years old now, it?s hardly surprising that there are problems when doing routine maintenance, most other cars would have been in the great scrapheap after 10 years. Sympathetic and innovative fettling is required, therapy and self medication is advised on occasions.

Another option would be to grind it off flush with the head, centre punch accurately, and progressively drill the stump out, starting with a 5mm bit. As it's not a blind tap, it should free out and turn with the drill before the threads are reached.

I tried about 5 times to weld a nut onto it but failed. I think my welder is knackered. It would not feed the gas through at the right rate.

I then attempted to drill the nut from the top and use a pin to lock it. It failed.

Finally, I drilled the stud and tried the extractor. No joy, and now it's sheared right off. At least the extractor didn't break.



I am officially "screwed" (geddit?) now, I think.

I need professional help. Do I need to take the head off now? I can't drive it to a garage.

Jon,
OMG!

Thats not good, You now need a very good set of cobalt drills and a lot of luck along with a good tap set.

Opps

You need to be very carefull with a drill. As its in that state now you could try a small drill bit as deep as you dare try to keep it centered. Then open the drill hole little by little ( song) You may get to the point where its easier to extract. I think when its out you need to clean those threads or even,if its possible, go next size up.
Lots of patience required now i think.

Alan,

You are a tease.

Can drill out and Helicoil if I knew anything about them, but the problem now is it's already off centre.

I could use the cover as a template to keep the drill centred, though.

I suppose if it was easy it'd be much less fun - right?

Daughter's prom in 6 weeks.... and it's not my fault this time, I had to take the cover off to renew the leaky gasket.

Gah...

I warn you now. He does swear a little!

https://youtu.be/fqZYgReuywM

His other videos are very entertaining and interesting. The Heating up a bearing in a microwave clip was illuminating.

vincereynard wrote:Be very careful with the welding. I've done this before, the heat can alter the bolt to the strength of toffee and all that happens is it shears off flush with the head.

Well there's a surprise!

You only have 2 options now Jon. Try and drill it yourself or lift the head and take it to a machine shop. I would advise the second.

But providing you can make a good guide and get the first hole reasonably central it should be easily possible to drill it out. The thread does not go in very far.

I don't remember whether Snap-On or MAC supplied my set of left-hand drill bits. So often, when drilling out a bolt or a stud, it will catch and the LH drill bits tend to back out the offending part.

I believe my original Elan had normal steel bolts retaining the T-stat housing and were corroded much as your's are. I don't remember where I got them, but those bolts were replaced by brass studs. I may have made them from brass rod on my lathe. I will be building the engine for my FHC later this year and it too will be fitted w/ brass studs.

Roger