SC Twin Kam Engine build

[Fanfaniracing]

Hi Folks

As mentioned some day last summer I am building a very special Twin Kam Engine using a Conversion Kit from Specialist Components.

Here I would like to part my experience and obstacles with this build.

After sourcing all Parts, I sent the Block, Crank with Rods and Pistons, Flywheel, new Main Caps and shizzle to the machine shop about a Year ago.

Unfortunately they were to busy and nothing happened for a year...

As i have a bit time at the moment, they allowed me to do all the work myself as much i can.

So the adventure begins...

[Fanfaniracing]

First task was to close all the Holes in the Block as the Block and Head will be Dry decked and get an extrenal Oil feed.

As the Holes were not all perfect round, they had to be reamed to get a good surface to seal properly.

next step was to turn the right Plugs on the late. the plugs I turned, were 0.03 - 0.05mm biger than the holes I reamed. I also turned them conical from 0.2mm under the top of the Plug.

After all Plugs were machined, I glued them in the Holes using Loctite.

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[mk1]

I look forward to following this thread. Rich & I started doing one years ago, but never got round to finishing it.

Will be nice to see the build through to the end.

[Fanfaniracing]

Thanks for your interest!

Its along way to prepare such a Block to accept the BMW Head. I think this was the main reason why my machine shop did not start...


Next step in the build was to close the Stud Holes that were no longer used. The three Studs in the middle of the front of the Block remain.

I took some 12.9 Bolts with I then just cut close to the Block with a cutting wheel.

Then i had to face grind the Block a first time to get all the Bolts and Plugs flush with the Block. Just enough to not grind to much of the Block and getting a even Surface.

Now with the grinded Surface I could fix the Template with the three remaining Studholes and a bit of masking tape to fix it properly.

Next was marking the Centers of the new stud holes so I knew where to drill. I made this step on the milling machine, so the stud holes were straight for sure.
pre drilling, drilling and taping the thread. and nada: all Bolts were straight. (hopefully in the right position... )

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[Fanfaniracing]

Sorry for the wrong order of the pics...

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[mk1]

Look like lovely quality instructions & template from John @ SC.

[Fanfaniracing]

As with the DOHC it should be possible to Rev the Engine a bit higher. So i opted for a bit a Special Crankshaft.

But a Good Crank alone brings nothing if the Crank Cabs are not up to do the Job.

So next was to positioning the new Cabs, drill the two additional Treads for the 4 Bolt Main Cab.

The new Bolts were a bit to long and had to be cut down by 5 respective 8 milimeters.

Also I had to measure the Step of the trust washers and grind the Main Cab to the right height. the are talking in hunderedth of millimeters...

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[Fanfaniracing]

Here some more

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[Fanfaniracing]

Look like lovely quality instructions & template from John @ SC.

Yes Mark. The Booklet and Template with came with the Kit are very easy to understand and make Steps very short.

[Fanfaniracing]

After the Main Cabs were all in Place, it was a goo idea to check Gearbox clearance. This would avoid bad surprises once the Gearbox is build up...

I had just to grind a bit on the Timing cover side of the Gearbox.

The MED Cab Set fitted surprisingly good in the Gearbox Casing!

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[Fanfaniracing]

Next was to give the Block the Bore it needed.

Bored out 0.10mm under the final size. the rest will then be honed out.

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[Fanfaniracing]

Final step this Day was to Line Bore the Main Bearing Bore of the new Cabs.

The Material of the Cabs was so tough, that the needed to solder a very hard cutting Steel to the Head of the Milling machine.

After this operation the Bore will also be honed to the right diameter.

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[Fanfaniracing]

Nice Surprise when I got home in the evening.

The Head came back from SC.

as I was unable to find someone here who was willing to weld the Water Canels and stuff and rebuild the Head, I decided to send it to Specialist Components for a rebuild.

The Head looks very well machined and clean. so will go next time for a pre fit.

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