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

Posted: Wed Apr 02, 2025 5:54 pm
by Alexander_Monday
Holy cow, almost 0.006" new?
That is over D × 0.0025.
I'd be sending them back, unless it was pro stock or top fuel.

Made a lot of aluminum swarf tonight.
Guess what they are:



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

Posted: Thu Apr 03, 2025 3:55 pm
by Alexander_Monday
Wow, Speedway Motors doesn't mess around shipping, got the King CR 803XPN SBC small journal narrowed rod bearings today!

So nice when something measures exactly as advertised:
(I only opened the first package of 8 and all except 1 which was 0.0620")



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Vs the Mahle CB-610A bearings:



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This will give me 0.0017" clearance with 1.9991" journals which is D * 0.00085.



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Unfortunately, I will have to make a jig to take 2mm off one side of each bearing.
Can't have my cake and eat it too, but my bad since they are advertised as 20mm wide while the Mahle's are 18mm wide)



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

Posted: Sat Apr 05, 2025 8:57 am
by Alexander_Monday
Designed a jig to narrow the bearings on the lathe.
3D printing it now.
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Re: Type 1 twin screw supercharger build / 9 yrs later I'm back at it

Posted: Sun Apr 13, 2025 1:31 pm
by Alexander_Monday
Jig worked really nice in the lathe.
Just a touch of chatter because it is plastic.

Before:



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After:



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I have another printing that is narrower to use to relieve the edges.

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

Posted: Sun Apr 13, 2025 1:39 pm
by Alexander_Monday
Alexander_Monday wrote: Wed Apr 02, 2025 5:54 pm Holy cow, almost 0.006" new?
That is over D × 0.0025.
I'd be sending them back, unless it was pro stock or top fuel.

Made a lot of aluminum swarf tonight.
Guess what they are:



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BTW, the big aluminum jigs I made awhile back are for this:
(Not ready for that yet, but I have the jigs made)



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

Posted: Sat Apr 19, 2025 12:22 pm
by Alexander_Monday
Cut down SBC small journal rod bearings before clean up in narrow 2nd jig



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After file and stones to clean up



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

Posted: Sat Apr 19, 2025 12:35 pm
by Alexander_Monday
Decision time.
Should I measure end play with tension on the crank or not?
What is acceptable for a flanged crank?
I have seen .005 to .008 preferred and .010 to .014 preferred.
This is a street warrior engine, not a drag race only engine.
Crank installed with Brad Penn assembly lubricant and case nuts tightened.

End play with 1/4" wrench turning big screwdriver against crank away from Flywheel end



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Let tension off



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Holding tension toward flywheel end



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Let tension off



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

Posted: Mon Apr 21, 2025 3:05 pm
by Alexander_Monday
From Mark Lawless:
"Your thrust measurement is right on the money."

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

Posted: Thu Apr 24, 2025 9:31 am
by Alexander_Monday
BTW, Pat Downs sells HP SBC small journal rod bearings already narrowed.
If I would have known, I would have bought them from him.
https://shop.patdownsperformance.com/products/bearings

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

Posted: Sat May 03, 2025 1:19 pm
by Alexander_Monday
Long story short, the conversion stub axles rub on the inside of the trailing arm.
Putting a 30mm x 44.5mm x 0.5mm shim I found between the inner bearing and the inner race for the seal stops the rubbing.
I want to put 2 on each side but only found 3.
They were in with my VW saved stuff not used.
Anyone know what they are actually for so I can get more?



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

Posted: Sun May 04, 2025 10:40 am
by panel
Kinda look like swing axle washers that fit behind the seals.

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

Posted: Sun May 04, 2025 10:47 am
by Alexander_Monday
Are they that thin?
Someone else suggested the same.
Funny though, never had a swing.

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

Posted: Sun May 04, 2025 11:24 am
by Alexander_Monday
The second side took 2 to stop rubbing so I decided to use 2 for it and 1 for the other side.

Stub axles changed, freeway flyer out and KCR "best parts type 1" unboxed.


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

Posted: Sun May 04, 2025 5:28 pm
by Alexander_Monday
Didn't get as far as I hoped, but transaxle installed, Bowden tube adjusted, shift coupler hooked up, stub axles installed.
CV's & axles another day, this old man is beat after lawn work, mowing, and working on this.



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

Posted: Sun May 18, 2025 12:29 pm
by Alexander_Monday
Is this normal radial play for brand new parts?
It is total play for both sides.
The slop appears to be in the EMPI axle splines.