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Tue Nov 23, 2004 6:27 pm

I need a rundown on align boring...

I understand the principle and need for it - just need some help on terminology! Typically I would replace a case before going this route, but its the original to my car and I hate to part with it for a mexican/brazilian case!

A few shops had quoted this, looks like it should be around $50+shipping or $100 locally. However, the shops seemed to require different things? One guy wanted me to me to bring in the crankshaft? Another wanted me to send in the oversized bearings to measure diameter and thrust? Why would I need to do this? Shouldn't we be able to send in the case, measure, and bore accordingly and then order bearings that will fit? I explained that I didn't order bearings yet, because I was waiting to see what size was required.

All of this came from reputable shops, so it appears that I need a lesson in align boring before I make any decisions. Any advice you guys can give would be appreciated!

Tue Nov 23, 2004 7:13 pm

Here's a few old threads, more out there if you search.

I'm sure some others will respond as well.

http://www.thesamba.com/vw/forum/viewtopic.php?t=61649&highlight=align

http://www.thesamba.com/vw/forum/viewtopic.php?t=73453

Wed Nov 24, 2004 3:29 am

First of all, thank you for not referring to it as "line boring" :wink:

The local shop that does all my align boring charges me $40 per case, and I also purchase my bearings from them. I've been there when he does it, and he checks the fit of the bearings to the case after it has been bored. The guy who wants the crank may want to take the extra step of checking the fit of the bearings with the crankshaft installed, hence the reason for the higher cost. When you do have the case bored, make sure that the shop stamps the size of the bore on the front of the case.

Wed Nov 24, 2004 1:19 pm

you typically have to bring in the crankshaft to have it checked for straightness and bearing size, in case it's been machined before... you will want to get the correct bearings from the shop that does the align boring, no confusion that way.

the case will probably have to be decked at the jug bore as well, do you how to tell if that is necessary? you'll probably have to pull the head studs anyway, sears has a decent stud puller.

you will also have to do a crack inspection, you sure don't want to pay to ship a cracked junk case.

i believe that rimco does their align boring on a machine that's about the size of a small car... i wouldn't want it done on anything less, a bad align bore can ruin a case.

Wed Nov 24, 2004 8:26 pm

The above is all good advice. Most shops use a boring device that attaches to a hand drill, and the job can be satisfactory IF the operator knows what he's doing, and IF the boring bar is not worn, and IF the front and rear case openings (which are used to position the cutter) are not distorted. After getting an unsatisfactory job from my local shop, I now send all my cases to RIMCO to be bored. I do have my local shop check for warpage first, however, as I lack the tools to do that myself. RIMCO will also machine the cylinder seating surface so that it is smooth and perfectly perpendicular to the crank centerline. Many small shops cannot do this. And most used cases need it. They can also run a cutter thru the cam tunnel to make sure all bearing bores are perfectly round and parallel to the crank. And they can check your lifter bores for wear, and sleeve any that are loose.

Unless you have complete confidence in your local shop, I would not take a chance with an original case. Send it to the experts.

Wed Nov 24, 2004 10:10 pm

This happened to me once when I tore down an engine. When I reassembled the engine, I thoroughly degreased the threaded hole in the case and the case saver (still stuck to the stud), then I sprayed Loctite Klean 'n Prime on case saver and into hole in case. Then I applied red Loctite and screwed stud/case saver back into case. That was a year ago, and there have been no leaks or other problems.

Since this is an original case, you may not want to risk it. Why not have RIMCO install new case savers when they do the other work?

You need to apply some sealer (I like Gasgacinch or #2 Permatex) on the studs when you install them into the case savers to prevent leaks. Maybe a PO used red Loctite on your studs!

Thu Nov 25, 2004 12:19 pm

Hello everyone.

There are so many ways you can do the align boring on the VW case. The trick is knowing how to do the cut accurately. It is all a big machining challenge. A few will shine and a few will suck on this one. :lol:

RIMCO uses a bar mounted on centers in a fairly large lathe (the size of a car is right)...not exactly classy. The tips on the bars are DeVlieg toolbits...adjustable. The bar is mounted on centers, so the case is independent from the boring bar and rides on the "V" ways of the lathe. The problem with this set up is that if the lathe is worn on the "V" ways, there will be a "dip" and you ride on this dip. Thefore, holes that are cut will not be round and will NOT be in a straight line, since the bed will follow the warp on the ways. I have tried this set up too. I was not too impressed. It is not wrong! But this set up depends heavily on good unworn machines.

Second, you can do it also on a Rottler or Kwik-way boring bar set up for align boring. This does a nice job with very straight holes and round too. You just have to do the #4 main separately. With this set up, the bar is also independent from the case. Orientation of the holes in the case could be a problem. But the bar is long and it will do one straight cut all the way through. This depends heavily on orienting the case accurately and squarely before the cut. I have a Kwik-way also, and I use it mainly to bore Type1 for Type IV 411 mains setup. It does a very nice job.

Third one is a bar mounted on outboard bearing supports with feed mechanism by a drill....this is the TruLine set up. THIS IS MY FAVORITE. This is MORE accurate by a distance than the "lathe set up". The bearing supports are on each end of the case. And if these bearings have a tolerance of 5/10,000 inch or better, they will produce nice round holes that are TRUE to the case end holes. This is the simplest, most well- thought out align boring machining for the VW...ingineous! And all it takes is a drill. Thank you Hank.

Also, the tool has a lead-screw feed mechanism just like a lathe..so it will do a nice fine, smooth finish....almost mirror finish! You can check out the pics of this finish in my Ad...Machining in VA.

You should not need the crank for align boring a case. What for? Straightness of the case align bore check? Ridiculous. IF THE HOLES ARE ROUND AND IN A STRAIGHT LINE W/ BEARING CRUSH, WHAT IS WRONG? That crank should spin nicely, right?

The bearings have a tolerance too in size like anything that is mass-produced. The variance is not that big. A bearing crush of 0.002-0.0025 should be plenty. You will not need the bearings by the side too.

Just remember, the finish on the align bore has to be round and very smooth to seal the bearings. You will need this for your oil pressure.

$50 align bore? This is like having one of your kidneys taken out for $50.

A beautiful linebore should be $100 - $125.

Decking the case bores should always be done. You would have to blueprint the case and find out where the crank is more prominent in the case. There will be a "tilt" too for the mains...it can go left or right from the back to the front with respect of the parting line. The trick is reproducing this tilt on the milling machine when you deck. THE IDEA IS TO HAVE THE CRANK AXIS LINE CENTER (NOT THE CASE PARTING LINE) EQUI-DISTANT FROM THE CASE BORE DECKS. So..when you install the pistons and cylinders, the deck heights will be almost all the same....if the crank and rods are all in order.

Good luck, man.

Thu Nov 25, 2004 1:11 pm

#4 is a Porta-Tool Lineboring bar. It bores all 4 journals at once with pre-set cutters. I think it does a decent job and it has a hydraulic feed that is powered by a hand drill. The speed of the feed is controlled by the RPM of the drill. It also will thrust cut a case to any dimension that you want. It's a decent tool that has been used by many people in the VW industry . I've personally been using mine since 1979 and haven't had any compaints. I also check my cutter settings on a regular basis. It centers on the Flywheel seal area and the snout by the pulley end of the case. One drawback is that if your pulley end is worn it can give you a crooked bore. I try to seat in the flywheel end first to avoid this problem. Tim

Thu Nov 25, 2004 1:40 pm

why did vw stop doing align bores and replaced the case when i worked as a dealer mechanic in late 60's to mid 70's??? if you know the answer then you know my opinion on align boring,line boreing and whatever you call it. make sure to redo spot face in oil pressure area also. the piston distorts it.

Thu Nov 25, 2004 1:45 pm

I guess that is the 4th alignbore tool....Porta-Tool. I own one too, but I have never put it up to service cases. It makes a nice stroker clearancing tool though.

It is a hydraulic feed. So for light cuts it is fine. But for 0.020 inch deep and cut of 4 different holes at the same time is a LOT of drag for hydraulic. The bar is 1 inch versus the 1.5 inch TruLine.

Sometimes the Porta-Tool will jump and give lines and very rough surfaces. The tool bits are mounted on round pieces of aluminum and pushed on a bar and secured bya set screw. There are just too many things to move around to give an accurate cut.

The hydraulic-fed Porta-Tool will not do a cut as good and as smooth as the lead screw-fed TruLine.

All I am saying Sparky is have you ever thought of upgrading to TruLine?

If you have used one, you will appreciate what I mean.

I have fellow in Nevada sending me a TruLine to get rebushed and trued...accurized.

regards Sparky.

NSR.

Thu Nov 25, 2004 3:06 pm

bill may wrote: why did vw stop doing align bores and replaced the case when i worked as a dealer mechanic in late 60's to mid 70's??? if you know the answer then you know my opinion on align boring,line boreing and whatever you call it. make sure to redo spot face in oil pressure area also. the piston distorts it.

Lineboring is a demanding chore already as it is. Finding the right people to do it is another chore. Lineboring anything has been done for years in the past before the VWs. Doing it accurately is the key....which I do not think $50 will cover.

But what do you do if you end up with a full-flanged 88mm stroked crank with all mains to 411 size (Type IV)? How are you going to install that in a new case? or an old case? I can tell you that case is linebore city if you want to play around with these huge cranks.

You do these 411 mains in ONE set up only...no going back for seconds. That boring bar does not move until the process is done. That is how you put straight holes in a VW block. The Kwik-way is the one for this job or other boring bars like it. These are not cheap either...around $8500 for a new bar. I was lucky to find mine cheap with table and all...SWEET. You know my Christmas came early.

regards. NSR.

Thu Nov 25, 2004 5:18 pm

stress relief of case? fretting of mating surfaces of case? so far no mention.

Thu Nov 25, 2004 8:29 pm

bill may wrote: stress relief of case? fretting of mating surfaces of case? so far no mention.

Fretting?

Well...let us see. You just eyeball the case and see if you want to reuse it. We are VW folks. We use that thing until it blows up. :lol:

We shuffle pin the case. We stroke it and drive the hell out of it. It is all fun.

It would be nice to buy all new parts all the time. But we all know that is not the practice.

I do not know about you, but I do not buy a new case everytime I build. I like the original cases somehow.

But that is just me. :roll:

Sat Nov 27, 2004 8:26 pm

No beef on the case saver issue? I thought someone would have something to add on this issue? I wish I could remember where I heard that removing the case savers and trying to reinstall them was BAD - BAD - BAD!!!

Also, what is a thrust cut? I know it has to do with the front bearing saddle, but thats about it... Once again, usually I prefer to use new cases on rebuilds. First time on this whole align-boring thing... Anything else I should be aware of?

Sat Nov 27, 2004 11:11 pm

it has to do with low oil pressure, and will redone hi mileage case give life of new case.adding a larger pump because oil pressure is lower on rebuilt case is a band aid approach.

Mon Sep 24, 2012 12:56 am

i watched on web this video of Rimco machine shop.
http://www.youtube.com/watch?v=d-oMfB-pYbg&fea...playnext=2

how does them do? it looks that they have various bars,that are fixed on lathe. they have "centers" that appear sealed ball bearings in front and rear of the case , and feed should be the one of the lathe, where case is (is?) fixed.
it is now well clear from the video.
Can someone explain better?