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75 Twin Spark Engine Head Removal Tool

Posted: Tue Oct 01, 2019 1:15 am
by MD
I realise that this is not a universal topic of interest in marketS where this engine is not prevalent. However, where they are available whether due for wear or upgrade reasons the head needs to be removed, the process is usually accompanied by a lot of frustration.

After working on the last engine for 3 days to try and coax the head off the block studs, it was decided to simply make an appropriate tool to force the head off.

The tool is made from 12mm steel plate. 4 Bolts engage the spark plug sockets. The six camlock studs are also engaged. the function of all bolts is to form a solid anchor to the head when separation pressure is applied.

The applied pressure comes from 10 x M10 threaded high tensile bolts that press directly onto the head studs. This pressure causes the head to move away from the block and eventually completely off it. The process during the final stages is aided by suspending the entire engine by the head anchors from an engine crane or a hoist arm.

Naturally copious use of penetrating fluid is obligatory as is a gradual pulling up process to be able to monitor the parallel upward movement of the head. Failing to do so will result in binding up of the head into the studs. Excessive applied pressure could strip the spark plug socket threads and pull out the camlock studs.

SO IF YOU MAKE ONE TO USE- GO GENTLY BENTLEY !!!

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Tue Oct 01, 2019 10:05 pm
by 75evo
You have a lift at home, that’s cool.

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Tue Oct 01, 2019 10:39 pm
by MD
No not at home.
It is at my light industrial dedicated Alfa workshop.
It is only small but I spend a lot of time there particularly now as I have started my new race car project which will be a 75.

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Wed Oct 02, 2019 1:04 pm
by MD
Couple more perspectives..

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Wed Oct 02, 2019 1:06 pm
by MD
..

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Wed Oct 02, 2019 9:28 pm
by 75evo
Love it! Very ingenious. But I'm guessing the bolts have to all be turned slowly and equally.

I think JK would be really proud of you and send you a friend request on Facebook.

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Thu Oct 03, 2019 10:12 am
by Jim K
If you weren't such a cheap-ass, you'd find a DECENT used TS engine to buy, instead of the crapola you got! Then, you wouldn't need them medieval bullshit puller tools! :roll: :shock: :| :wall:
And stay away from my fb!

Jim k.

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Thu Oct 03, 2019 10:04 pm
by 75evo
Aha! This is where you are wrong. It's a combo pusher and puller tool :mrgreen:

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Thu Oct 03, 2019 10:41 pm
by Jim K
Whatever you call it, its a tool for cheapskates! He doesn't mind spending big on lipsticks and high heels, but tools.... :mrgreen: :wall:

Jim K.

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Fri Oct 04, 2019 12:28 am
by MD
Cheapskate ?? !! That's a low blow. Not much of a creative descriptor either.
I got a feeling you're running low on go-go juice along with whatever talent you had that just seems to travel down your left leg while the gaseous components filter through your shorts quietly without you ever realising it. If it wasn't for the passengers in the pensioner bus you're commuting in progressively diving out the window for some air, there would be no hint of your internal decay at all. Tragic really and you in your prime as well-like how bad can 93 be anyway.
I 'm gonna go easy on ya today but I will say this much. I am never gonna lend you my tool. Beg all you want.

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Fri Oct 04, 2019 6:20 am
by Jim K
Never going to lend me your tool? As if you can find it, hahah! Have you even figured out a use for it yet -besides trying (in vain) to pump your brains out? :oops: :lol:

Jim K.

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Fri Oct 04, 2019 12:58 pm
by MD
Stop hi jerkin' my post and just send Zeefa his olive oil will ya, you tight bum. :wall:

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Wed Oct 09, 2019 3:04 pm
by KevinR
We used to hang these engines for days suspended over old tyres and just spraying WD40 down the bolts. Sometimes you would here a massive clonk in the night :)
The last engine ( nord) we could not split heads off no matter what even with a few bottle jacks .... Engine went to the bin !
Maybe spark erode the front and back studs to start off with ? Easier if some one made the "tool" !

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Fri Apr 23, 2021 2:12 am
by MD
Totally like that tropical jock itch or its brother, the toe jam, I'M BACK !

So here I is to tell you the rest of the tale of push/pull head removal tool. Now this could take a zillion words or just one short You Tube video but I am reluctant presenter.

I think you will find the sequential photos are self evident. The main thing to keep in mind is the use of R12.5 rated threaded rod and nuts. Anything else will simply strip the threads due to the pressure involved.

The key objective here is to rescue the block and the head. If pistons and rods get damaged in the process, well, they can readily be replaced. Liners may or may not survive. Mine did.

I hope this post finds you and yours in good health.

Re: 75 Twin Spark Engine Head Removal Tool

Posted: Fri Apr 23, 2021 2:15 am
by MD
more to the story...

Essentially it is a very slow and long winded process. Each bolt at the top has to have an equivalent number of turns at the bottom. The turns should be restricted to 1-1.5 turns per sequence. The bottom push rods locate on the piston wrist or gudgeon pin. Before you start, remove the spark plugs and wind some rope into the cylinder enough to cover the piston crown. This is to cushion the piston from the head so as not to damage the head.
DO NOT BE IN A HURRY. A really hard stuck head may take days to inch forward but it will come off.

The pattern for the holes to the bottom plate are transferred from the crankcase turned upside down on it and marked.