Cylinder head removal - so near yet so far

[simon hubbard]

Dear all

On Saturday i took the plunge, the engine bay went from looking like this ..........



to this.........



I need to change the head gasket and i will change the water pump and timing chain at the same time.

The reason for the title is that with my limited experience and the help of a friend we managed to get as far as removing all the bolts and suds - except one.

One of the studs came out as we undid the nut the other 3 came out after locking 2 nuts together and turning the stud out with much effort. The cente one does not want to budge. And no matter how hard i try and tighten the nuts together they still turn, but of course not with the stud.

Having thought about possible ideas i wonder if anyone has any other suggestions. I asked before and someone said to weld the nuts onto the stud, but i dont have this sort of equipment.

Can you apply some heat to the stud? Will a little heat make any difference, i am concerend about using my little blowtorch with all the fuel, oil etc around the area.

Could i araldite the nuts, tighten them, let it dry and then try?

Or is it a question of stick with it?

If anyone has any other thoughts or ideas it would be much appreciated.

Thanks in advance

Simon


TRR676R Speke Built 2.0L Tahiti Blue TR7
1969 Mk2 Vitesse Convertible
1997 Rover 800 Vitesse Coupe

[Marko]

i took mine of with an impact screwdriver. but it will be simpler to find someone to lend you a welding machine or to weld it for you.

[nick]

I had one brake off during removal, so be carefull. Even if you can get enough torque on it you may end up snapping it. I suggest constructing a bath around the stud and fill it with penetrating oil. Then walk away for a few days. I did this and was finally able to get the broken stud out.

nick

[Rich in Vancouver]

If you can break the head free from the gasket/block you may be able to rotate it slightly, enough to break the grip on the stud.
Be careful doing this though. Too much force can damaga the head.
If you can wait soak the stud as described above.

1975 TR7 ACL764U

[Nightrunner]

Some thoughts:
1) As Marko suggested, an impact driver might help. They are not terribly expensive and good to have in the toolbox. Also some pentrating oil and time as others have said.
2) You have to decide what you plan to do with the timing gear. One way is to remove the timing cover, gear and tensioner. The deal is that the tensioner is a ratchet mechanism that takes up slack. So you have to reset the tensioner to give you enough slack to get the chain back on when you reassemble. If you are careful you can unbolt the cam gear and keep enough tension on it so the tensioner does not move. I used to tie off the cam gear with heavy bungee cord so I didn't have to remove the timing cover when I removed a head. On the other hand, depending on mileage, it might be a good idea to inspect the chain guides and tension pad for wear; not to mention worn chain/spockets.
3) Since you only have the one stud left, can you not get the head 'unstuck' from the gasket and pull it right over the stud? Or is the fire wall in the way? Its been a while since I've done this and I don't have a TR7 nearby to look at.
4) I also recall the early head bolts/studs were soft and prone to stretch and allow the head to warp [too] easily if overheated. They sold an uprated head bolt set. Don't know if its still available. If you are so inclined you can swap in high grade bolts for those studs too but it takes some careful fitting.

Good luck
Scott

[aeroshadow]

In my engine the studs all came out but one. It was seized in the head not the block. ( differential metal corrosion).
The penetrating oil may help, its worth trying, but it didn't work for me, after a week of soaking.
We finally resorted to wiggling the head from side to side, and with sheet steel protecting the block and head, we drove in wedges, bit by bit, working towards the offending stud. This pushed the head up, not much, but just enough that the stud could be very carefully hacksawed through between the head and block.
We never bothered to try and get the stud out of the head since we had a spare head. If that weren't the case the head would've gone to the local machine shop to get the stud out.
This was a shade tree way to do it, but it worked okay. I believe the idea came from a forum search.
Alex

[aeroshadow]

I should add that we tried the impact driver, with double nuts.No luck, the nuts turned. Then we welded a nut onto the end of the stud. No luck, the stud broke.
As I recall there was just enough of the stud left to weld on another nut. Once again the stud broke.
That's when we found/thought of the wedges.
Alex

[john mc nulty]

Hi Simon
Ihave the same problem ended up just putting the engine in the corrner of the garage and started to work on a V8 that I had to replace it in the future.

[Nightrunner]

Wow! Definitely a testimony for using anti-seize compound on reassembly. Or switching to bolts.

[Rich in Vancouver]

I tried carefully wedging the head off the block-no movement.
Then I put a piece of 2x4 alongside the manifold and beat on it with a BFH which cracked the head and made it scrap.
With the head written off I tried wedging it apart again, this time more agressively and managed to break it free.
I wish I had thought of aeroshadow's hacksaw idea.

Rich

1975 TR7 ACL764U

[simon hubbard]

Many thanks for the suggestions, i am going to make the "bath" and leave it to soak for a week or so. I am not in a hurry to get it done, i wont be in time for the National Weekend, as i wasnt for Stoneleigh - so it will have to be next year!!

I am also going to clean up the engine bay and paint things whilst so much is out of the way.

I hope to be able to provide some good news with some progress.

Simon


TRR676R Speke Built 2.0L Tahiti Blue TR7
1969 Mk2 Vitesse Convertible
1997 Rover 800 Vitesse Coupe

[Mowog73]

Could you put some heat (propane torch) to the head at the location of the stud? Expanding the aluminium slightly may break the rust bond between the head and the stud.

Better to burn out than fade away

[lennorthall@btinternet.co]

I had the same problem with my Stag engine except I had 2 studs stuck. I used most of the suggestions above but with 2 broken studs I needed to do something drastic. As it happened I had an ingot of aluminium about 1/2 inch thick by 2" deep and 8" long. I placed this against the head face where the inlet manifold sits and hit it with a big hammer, hard, many times. Eventually it moved and I cut the studs as described above.
The head was cleaned up and refitted with no problems.
Good luck.

[bmcecosse]

Is there any merit - in a an otherwise perfectly good running engine - in taking these studs out from time to time, one by one, - and refitting them with a smear of copperslip or similar ?

[76Triumphtr7]

I had a bolt in a transmission once that wouldn't break loose and then we eventually broke it and were left with a stud. Steel and Aluminum just don't like each other. We ended up using map gas and oxygen on a torch and heating the bolt (not the aluminum) until the bolt started to glow red it took about 10-15 mins of heating then we hit the bolt with a hammer 3 times, 5 mins later we sprayed it with PB Rust Buster, came back a half hour later and it unscrewed ridiculously easy. Also with an mg the head was stuck to the stud I undid the valve train and cranked the motor using compression to break the seal between the block and head then I wiggled the head left to right until it slid off the stud. Just be careful not to mess up the timing chain in the TR7.

1976 Tr7 Coupe
1980 Tr7 Convertible