Align bored and Thrust cut any good for mild motor

cal63look

Ok case is an as41 freshly checked out from the machine shop, cylinder mating surfaces leveled and resurfaced .040 thrust cut and .020 line bore. Would this be OK for a mild 1776-1835??

The Noof · Samba Member Joined: January 25, 2005 Posts: 4346

Properly done, align bored case is fine for that purpose. I used a case that was .5mm on the o.d./1mm on the thrust for a turbo application and it is holding up fine. As long as the machine work is good, you won't have any issues.

1432 · Posted: Sat Jan 06, 2007 9:51 pm Post subject:

If properly done a line bored case is good for all applications.

nsracing · Posted: Mon Jan 08, 2007 7:45 pm Post subject:

AMEN!!!

Thank goodness. Finally. Some sense of direction.

Nater · Samba Member Joined: June 19, 2006 Posts: 493

They have only been align boring cases for ......what 40 years?

gt1953 · Posted: Tue Jan 09, 2007 6:28 am Post subject:

I do not see a problem with what has been done with your case...while you are at it make it full flow.
_________________
Volkswagen: We tune what we drive.
Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.

72 type 1
72 Squareback
({59 Euro bug, 62, 63, 67, 68, 69, 73 type ones 68 & 69 type two, 68 Ghia all sold})

EZGZ · Posted: Tue Jan 09, 2007 7:06 pm Post subject:

in 1993 I thought I would freshen up a running 1776.

It turned out to be 4th over on main and thrust.
I bought a cheap welded counterweighted crank that was .020 over.

I threw some .100 shims under the barrels which brought the compression down below 7 to 1.

I put that engine in service in a manx buggy, then a sandrail and then on the street. I gave it to my son to run the beegeezus out of it in a bus. That POS is still screaming today and leaks from every seam.

I think the trick was to keep the compression down.

You don't have anything to worry about.
_________________
64 custom Ghia, 66 Bug, Sandrail, Barrien tub

cal63look · Posted: Sat Jan 20, 2007 6:21 pm Post subject:

Ok bringing back up this post, i received my bearings from the guy i bough the case from today and they are mahle ext- .50 int- std. are these the correct bearings??? I put the rear in to see how it fits i think thust is correct bearing isnt loose but snug if i push it in.

Please help are these correct bearings?? I have the specs in my first post.

Ace · Samba Member Joined: July 07, 2003 Posts: 1903

propflux01 · Posted: Sat Jan 20, 2007 10:03 pm Post subject:

1432 · Posted: Sat Jan 20, 2007 10:51 pm Post subject:

[quote="cal63look"]Ok bringing back up this post, i received my bearings from the guy i bough the case from today and they are mahle ext- .50 int- std. are these the correct bearings??? I put the rear in to see how it fits i think thust is correct bearing isnt loose but snug if i push it in.

Please help are these correct bearings?? I have the specs in my first post.[/quote]

With your case +.020" and your crank at standard size your bearings should be +.05mm, std, + 1mm (os .040" thrust). be certain thrust bearing is a 'snug' fit in it's saddle, with the thrust bearing in position in the 1/2 case you should not detect any movement when wiggiling the exposed half of the bearing.
Tip, when final installing your crank in one case half, use the opposite 1/2 shell of the center main to straddle the crank (center main journal) when the two halves contact each other (or very close to contact) you can be confident that all bearings are aligned properly with their corresponding dowel pins. During pre assembly (always a good idea) when the case is torqued, with crank only, it should spin easily with no more than finger tip pressure as well as move freely front to back.

1432 · Posted: Sat Jan 20, 2007 10:56 pm Post subject:

What about heat and stress. An align bore doesn't do anything to correct this.[/quote]

Any problems related to heat or stress should be evaluated and addressed prior to any machine work being done on the case.

Ace · Samba Member Joined: July 07, 2003 Posts: 1903

MackB · Samba Member Joined: January 15, 2006 Posts: 21

A properly done align bore should be good for any application, but one must make a reasonable judgement as to if the case is fit to be reused, and having it done by a reputable company with proper tools such as rimco, will ensure that the tolerances will be perfect and problems such as low oil pressures will not be a problem.

propflux01 · Posted: Sun Jan 21, 2007 6:30 pm Post subject:

1200RS · Posted: Tue Feb 13, 2007 2:29 pm Post subject:

vwinnovator · Posted: Tue Feb 13, 2007 5:32 pm Post subject:

GregZA · Posted: Wed Feb 14, 2007 1:41 pm Post subject:

I'm curious to know exactly how you check for warpage and where?

I am assuming that you are not just talking about ovality in the housing...

keifernet · Posted: Wed Feb 14, 2007 1:44 pm Post subject:

GregZA · Posted: Wed Feb 14, 2007 1:51 pm Post subject:

Okay so we're talking about warpage of the mating surface of the case halves?

Back in the day they used to standardize casings by facing both halves and align boring the main housings and reaming the cam housings, then you still had to remachine the oil pump housing.

Not really worth all the effort, especially considering the trauma that a case needing all this done would have been through but it was once common practice here. (South Africa)


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