7003 fab - aka "iron maiden"

autokunst

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As some of you know, I've been on a quest with heads lately. And as I tear them down, I am finding that the having the right tools will make my like easier. This has led me to BMW special tool #7003 - aka the iron maiden.

As seen here, it is what the blue manuals prescribe to remove the cam.
31000003_z.jpg


The trick is, you need to release/depress all of the valves simultaneously to allow the cam to make a clean getaway. Others have managed to circumvent the 'maiden by using a series of screwdrivers and wires. I considered this, but didn't feel it was as easy nor safe as just making my own tool - especially if I plan to do it more than once. At a minimum I imagine performing this operation at least (4) times. Two heads, disassembly and assembly. Following is a high level documentation of my build.

I may have overbuilt it. The frame is composed of 3/8" by 2" bar (~9,5mm by 50mm).
20211226-iron maiden 01.jpg


Tacked the frame.
20211227-iron maiden 02.jpg


And welded. Not my best work, but should be plenty strong enough for this tool.
20211228-iron maiden 03.jpg
20211228-iron maiden 04.jpg


Then on to fabricating the "fingers" I used 1/8" by 3/4" bar (3mm by 19mm). Note the rounded edges - they become quite elegant later in the build.
20211228--iron maiden 05.jpg


Color example from an original BMW tool - found on the forum, maybe from @restart ?:
color example.jpg


And here it is all painted. This is Rustoleum "Maui Blue" color - pretty close to the original photo. It's a little too clean at the moment.
20211231-iron maiden 06.jpg


Here it is sitting on the head. The fingers engage the valve adjuster wheels.
20211231-iron maiden 07.jpg
20211231-iron maiden 08.jpg


As the rockers are depressed, they rotate. The rounded edge of the fingers fit beautifully in the concave sections of the rocker arms.
20211231-iron maiden 09.jpg


I polished the end of the fingers to they won't mar the surface of the valve adjuster wheels.
20211231-iron maiden 10.jpg


Arrow marks the front.
20211231-iron maiden 11.jpg
20211231-iron maiden 12.jpg


I will use (4) seperate bolts - not the head bolts - to operate the tool.
 

stphers

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Very well done, just a word of caution, we had this at the 3 different dealerships that I worked at and saw more than one tech, bend 2 or more valves using this tool. As you tighten down the tool and the valves get opened, they can hit each other and bend does not take much best to rotate the adjuster to give max clearance on each valve and watch carefully as you tighten the tool down

Thanks, Rick
 

autokunst

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Very well done, just a word of caution, we had this at the 3 different dealerships that I worked at and saw more than one tech, bend 2 or more valves using this tool. As you tighten down the tool and the valves get opened, they can hit each other and bend does not take much best to rotate the adjuster to give max clearance on each valve and watch carefully as you tighten the tool down

Thanks, Rick
Thanks for the tip, Rick! I've already rotated all the adjusters to max (or min). But will definitely keep an eye on the valves as they open.
 

autokunst

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I have a vintage tin snips - I think it was my father's uncle's originally. I cleaned it up and painted it when I was around 15 years old (about 4 decades ago) and it still looks good today. Sure, it has some scrapes and scratches - even some chipped paint. But no corrosion. I applied the paint on the 'maiden a little too heavy, but it will cure out and be just fine. I may even have to stencil the side of it - HA HA:
iron-maiden-logo.jpg
 

Fritzie

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Very nice tool. I ounce made also an iron maiden. During the fabrication I learned how to dismantel the cilinder head without the use of an iron maden.
 
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deQuincey

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some advice

i found really surprising the tight contact that the valves make when you press them (despite of course increasing valve gap to maximum before proceeding)

the fact is that to avoid the top of the cams you do not need as much pressing as what you need to let the two central supports to pass through the intake rockers numbers, 2 and 4

1653982795997.png


as you can see in the picture, in the way out (orange arrow), the highest elements are not the cams, but the two central supports of the camshaft arrowed in green, that interfere with intake rockers number 2, and 4
funny enough, when the supports pass behind the mentioned rockers the camshaft falls a bit and the rest goes very smoothly

during the process i checked the contact between the valves below, at the begining there was no contact, you reach contact but you can still turn them with your hand, but you are still unable to remove the camshaft, you have to go a bit farther to be able to remove it, just make it in small increments, and go continuously testing it
 

Jon B

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what is the use of the wooden piece that can be seen here arrowed n green?


View attachment 141845

The 7003 tool was also used to compress the valve springs, for the removal or installation of the springs and valves.
The wooden piece kept the valves in place as the springs were being compressed.

The image below is the earlier version of the tool, from the Spezialwerkzeuge Katalog '71, complete with the valve spring compression lever...

DSCN3117.JPG
 

deQuincey

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The 7003 tool was also used to compress the valve springs, for the removal or installation of the springs and valves.
The wooden piece kept the valves in place as the springs were being compressed.

The image below is the earlier version of the tool, from the Spezialwerkzeuge Katalog '71, complete with the valve spring compression lever...

View attachment 142062


oh, that‘s it
thank you so much
 
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