TR7 cylinder head removal

[Howard_B]

Can anyone point me in the direction of a decent guide to removing a very recalcitrant TR7 head. I have a substantial specially made TR7 head removal tool but the head is fighting back.

Plenty of tension has been applied combined with lots of pentrating oil and its still not moving (well it has been there for 40 years so its not in a hurry.)

Thanks

Howard

[johnnyj]

Hi Howard. I'm afraid I can only point you in the direction of Roger Williams' book, but if you have a substantial head removal tool then you're bound to have read it already. It's here, just in case https://www.waterstones.com/book/how-to ... 1904788249

I think the best advice will come from the absolute gurus on this site.

Good luck!

John

[Beans]

If it doesn't want to move with a special "head honcho" it is time for patience
I removed a rather recalcitrant head many moons ago with simple tools, but with the engine out of the car!
To achieve this I placed the engine at such an angle that the angled studs were vertical (the bolts were easy to remove)
Than I used some kind of putty around the studs to create a small bowl which was filled with penetrating oil (nuts and washers removed).
I filled these every morning when I went to work and gave the studs a few sharp taps with a hammer.
When I got home in the afternoon I would try the locked nuts method to try to release the studs (more hammer taps and penetrating oil)
After four (4!) weeks all studs were removed without damage to the head ...
Good luck

[Stag76]

Vinegar is better than penetrating oil.
It dissolves the oxide that has built up between the steel studs and alloy head.

[Howard_B]

Hi Beans,

Engine is out of car and the "head honcho" is doing a good job. The bolts have been removed and its the studs that are causing the problem.

My mechanic had been trying for about one week now, so I need to warn him that it may take little longer than that & will suggest he uses your idea of putty to make a little reservoir.

Stag76 - I haven't heard of using vinegar for this, but if the penetrating oil fails will give it a try

Thanks guys

Howard

[Stag76]

Some people have had success by turning the engine to BDC on No.1 Cylinder,
filling the cylinder with Rope, turning the engine to compress the rope and lift the head,
then repeating on No.4 Cylinder.

If you are using double (lock) nuts on the studs, try turning them clockwise first, then anti-clockwise,
as this has been said to help break the corrosion.

There was a tool made by Sykes Pickavant that was a thin metal tube with saw-teeth on the bottom.
This was a snug fit over the stud, and was used to saw/drill the corrosion from between the head and stud.

The Acetic Acid in vinegar will dissolve the Aluminium Oxide that jams the studs...eventually.
WD40 etc. will coat and protect it.

[FI Spyder]

What Stag said.....and Beans. Patience is key. Haven't thought of vinegar although I've used it to remove rust so I'd try that. I have seen a head where the stud was so forcibly turned that the you could see the aluminum in the head swirling around the stud. The head was ruined but the owner was replacing it with a Sprint head so he wasn't too concerned. Goes to show that patience trumps brute force.

[Hasbeen]

I found the best way to remove the head was to remove the studs.

They have a screw driver slot in the top, give it a try.

I found with my current 7, 3 studs screwed out with a screw driver.

3 others with locked nuts.

All bar one of the remainder came out with a nut welded to the stud. One of these broke the first light weld, but came with a more serious weld.

The last one sheared, but allowed the head to come off. It was then removed with a stud extractor.

I found there was no corrosion, absolutely NO corrosion between the studs & the head. I believe it was jamming because the studs were not straight & we were not pulling it straight off the studs.

Once started the studs would screw out by screw driver, & infact most by fingers. I believe the difficulty in removing them is that they bottomed tightly in the thread in the block, locking as if with a lock nut.

To avoid this happening again I used bolts instead of studs, so they couldn't lock in the block. However I have not removed the head again, or those bolts, so I can't guarantee this as a cure.

It may help to stick your tongue into your left cheek, & bite on it reasonably hard. No it won't get the head off, but may reduce the amount of foul language emitted.

Hasbeen

[Howard_B]

Hasbeen

Thanks for your recommendation:-

"It may help to stick your tongue into your left cheek, & bite on it reasonably hard. No it won't get the head off, but may reduce the amount of foul language emitted."

I just passed it on to my garage and they agreed that it was the best advise ever recieved on TR7 / Stag head removal

Cheers

Howard

[Cobber]

The thing about removing the studs before trying to remove the head is that your only fighting one stud at a time, which is always going to be easier than fighting all the bastards at once!

[sonscar]

I seem to remember a line in the Haynes manual"using a suitable screwdriver unscrew and remove the studs"3 of mine did this,one took several days and the last stayed in place whilst I removed the head by rope in the cylinder repeatedly turning the motor and tightening the nut.Was it fun?it wasn't, even my car at the time belonging to my son.Have fun Steve.

[jeffremj]

Perhaps the last option is to use a wedge to lift the head away from the block. We did this 25 years ago on a 16V Sprint. There was slight damage, but not deep enough to affect the head gasket function. This lifting allowed us to remove all but one stud which, in the end, we had to hacksaw - the head was lifted enough to get a blade in between the head and block. The machine shop pressed out the offending item and skimmed away the slight hacksaw scratches.

[Beans]

... I seem to remember a line in the Haynes manual"using a suitable screwdriver unscrew and remove the studs" ...

Sometimes you are lucky

[Howard_B]

Success at last - with the aid of the head removal tool we freed three studs and managed to move the head sufficiently to cut the last one off. The remains came out of the block without any problems. but the part in the head will need to be pressed out. Thanks for everyone's advice.

While the engine is out and the head is off I am considering what, if anything, else should be done to the engine. Its done just over 100k miles (160k Km) of which 40k has been during the last ten years in my ownership. Since I plan to keep it on the road for as long as possible, I would appreciate any suggestions.

Oil pressure currently is just under 50 when cold dropping to about 25 on tick over when hot. When I had the oil pressure gauges fitted in 2010 the pressures were about 55 & 35 but some of the fall may be down to different oil.

Aside from the cylinder with the burnt valve the compression test was good and the car burns very little oil (during the 10CR & RBRR runs which involve about 2000 miles of serious driving in a few day it doesn't need topping up) & the power output was very close to the original specification (confirmed by max speed on an Autobahn). Unless it was rebuilt in the first few years of its life, where my records are incomplete, the engine is totally original.

Currently my thoughts are:-
1) Replace the main bearings & grind crankshaft if necessary to match.
2) Change timing chain (and check gears for wear - I had these replaced after I purchased the car)
3) Retain existing pistons - there are very small lips in the cylinders which can be honed out.

Thanks

Howard

[johnnyj]

Success at last - with the aid of the head removal tool we freed three studs and managed to move the head sufficiently to cut the last one off. The remains came out of the block without any problems. but the part in the head will need to be pressed out. Thanks for everyone's advice.

While the engine is out and the head is off I am considering what, if anything, else should be done to the engine. Its done just over 100k miles (160k Km) of which 40k has been during the last ten years in my ownership. Since I plan to keep it on the road for as long as possible, I would appreciate any suggestions.

Oil pressure currently is just under 50 when cold dropping to about 25 on tick over when hot. When I had the oil pressure gauges fitted in 2010 the pressures were about 55 & 35 but some of the fall may be down to different oil.

Aside from the cylinder with the burnt valve the compression test was good and the car burns very little oil (during the 10CR & RBRR runs which involve about 2000 miles of serious driving in a few day it doesn't need topping up) & the power output was very close to the original specification (confirmed by max speed on an Autobahn). Unless it was rebuilt in the first few years of its life, where my records are incomplete, the engine is totally original.

Currently my thoughts are:-
1) Replace the main bearings & grind crankshaft if necessary to match.
2) Change timing chain (and check gears for wear - I had these replaced after I purchased the car)
3) Retain existing pistons - there are very small lips in the cylinders which can be honed out.

Thanks

Howard

Hi Howard

Great to hear that you got the head off at last.

I am doing a similar job to you and had to consider what to replace, and in the end opted for re-shimming the cam buckets, changing the core plugs etc. On the block side I bought a re-ground crank with bearings, thrust washers etc to suit (as one "kit") for about £90+VAT. Can't remember where from exactly, might have been Revington TR or TD Fitchett - if interested let me know and I will dig out the invoice. It seemed like good value to me.

Cheers

John