Re: Type 1 twin screw supercharger build / 9 yrs later I'm back at it

Alexander_Monday · Post by **Alexander_Monday** » Tue Nov 04, 2025 4:58 am

Boy did I underestimate how hardened the pizza steel is.
I fought milling it this weekend and ended up tearing up the hub gear in my 6" rotary indexing table from vibration.
Lesson learned, my little lathe / mill just isn't up to the task and I should not have forced it to do so.
Picked up a new gear yesterday and ordered a 1/4" X 18" 6061 aluminum disc to machine.
Also, just finished up the 4th brass lifter sleeve when I heard a pop / sizzle and shut the lathe motor off.
There was definitely an electrical smell, and I suspect a capacitor gave up the ghost.
Didn't have time to check it out, but I found my LCR meter and will test them when I can this week and hopefully rebuild the rotary table.

Alexander_Monday · Post by **Alexander_Monday** » Tue Nov 04, 2025 5:02 am

Oh, I also picked up a Wiseco 39-6079 W6079 nylon flexhone brush to plateau hone the cylinders.
And in big news for me, my custom camshaft is supposed to be delivered today by UPS.

Alexander_Monday · Post by **Alexander_Monday** » Tue Nov 04, 2025 2:58 pm

Post by **Piledriver** » Tue Nov 04, 2025 4:46 pm

Nonstd checking clearance makes it difficult to compare to anything...

Alexander_Monday · Post by **Alexander_Monday** » Tue Nov 04, 2025 5:25 pm

I hope to have my cam profiler back to working this weekend and I will have the full profiles.

Post by **Piledriver** » Tue Nov 04, 2025 11:54 pm

Groovy, curious what comes up.

Alexander_Monday · Post by **Alexander_Monday** » Sat Jan 03, 2026 8:04 pm

Piledriver wrote: ↑Tue Nov 04, 2025 4:46 pm Nonstd checking clearance makes it difficult to compare to anything...

Remade the hardware of the cam profiler to get stable readings.
Now using modified lifers with aluminum inserts for 4 digital dial indicators.
Mostly done with the software.
What checking heights do you want to see the data at?

Been awhile since I posted, but here is what I've been up to.

Got the degree wheel done, although I did go to aluminum after snapping too many 1/16" carbide bits.
I was a little skeptical, but the bubble is readable to about 1/8 degree.

Took a Comp Cams 4798 crankshaft socket and lathed the ID out to VW type1 and used a 6mm HSS bar with an angled end to cut the 3/16 keyway to 6mm.
Also drilled and tapped another hole further out for the set screw to clear the case.

Today I checked the cam for clearance.
Since it is on a little over 0.9" base circle instead of the 1.2" that the other cam was the lobes clear the crank.
I had to get out the die grinder in 4 places for minor removal by the middle bearing and just behind the thrust bearing for lateral rod clearance.
I got the short block together and started to check rod to cylinder and piston to valve clearances but found I need to take just a smidgen out of the cylinder stud holes toward the cylinders for the 10mm studs to alaign with the stud holes in the heads.
Will work on that tomorrow and hopefully get the rocker arm geometry set, and the head studs and pushrods cut to length.
If I'm lucky I might have time to degree the cam.

Post by **Piledriver** » Sun Jan 04, 2026 6:50 am

Progress is good.

Happy new year!

Post by **Piledriver** » Mon Jan 05, 2026 6:29 am

The only two "standard" advertising/check clearances I'm aware of for cam profiles are 1mm (euro std) or .050" (more or less US standard)

These were intended to get past the ramps on the profiles and provide some kind of comparative basis for cam selection and advertising. Also works as a reference for dialing in... sometimes check values like you got on your cam card were used simply for dial in.

Alexander_Monday · Post by **Alexander_Monday** » Mon Jan 05, 2026 12:53 pm

Yesterday I didn't get as much done as I had hoped, but made progress.
Got the head studs cut to length in the lathe.
I took the die grinder to the stud holes in the cylinders and elongated them in towards the cylinders for the 10mm studs to line up in the heads.
It didn't take much grinding with a burr and then a sanding roll.
I also plateau honed the cylinders with the Wiseco soft nylon honing brush.
(This was a suggested by Brian Salter @ Salter racing)
It made them noticeably smoother to the feel with a fingernail.
Plateau honing is supposed to make break in quicker, improve ring seal, and less metal particles during break in go into the oil.

Before:

After:

EDIT: Looks like I need to raise the rockers a lot according to pictures I found on the wayback machine since these are the old style rockers.
Good thing I did not cut the pushrods.
Got the rocker arm geometry set.
Pauter instructions say to center at mid lift.
That is what I did, but the adjuster is supposed to be in line with the pushrod at mid lift.
Because the old CB street eliminators were ordered with the "LS1" spring package they got 0.100" longer valves and add the lash caps and you cannot get both a roller centered and the adjuster in line with the pushrod.

The Brian Salter style level degree wheel works great!
No pointer to have to attach and adjust.
Center the bubble and it is as accurate as your eye can guess 1/8ths of a degree.

But.......If you look closely Dumb Ass got his B's and A's backwards, so BTDC and ABDC are marked AT and BB etc.
Knowing that makes it simple to read, but if I could kick myself I would.
I also wish I would have made a jig for the stamping so it was uniform.

Max lifts with "loose 0" were intake 0.568", exhaust 0.571".
This means that the Pauter "1.40" roller rockers are actually 1.48 at max lift.

I did not have time to cut pushrods, but the adjustable pushrod is set.

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