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Date:         Sun, 7 Apr 2002 10:29:35 -0700
Reply-To:     Karl Wolz <wolzphoto@WORLDNET.ATT.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Karl Wolz <wolzphoto@WORLDNET.ATT.NET>
Subject:      Re: Boston Bobs tale of an engine stripper or .19  Main bearing
              info             was Flickerin oil light on 85 auto
Comments: To: Robert Donalds <bostneng@FCL-US.NET>

Bob,

Great article. Only problem is you never answered the original question about oil viscosity!

I've been advised to never use multi vis oils (yes - a long time ago) and also that modern low vis oils are not the best for the relatively low tech vw engines we use. The chart in the owner's manual does not go above 100 deg F., and I live in Phoenix (land of 110 - 115), so I use 30 weight in the winter and go to 40 weight in the summertime. I use Valvoline Racing Oil exclusively.

Your comments on out of round journals and related OP problems tend to go hand in hand with my use of the 40 weight.

Comments?

Thanks,

Karl Wolz

----- Original Message ----- From: "Robert Donalds" <bostneng@FCL-US.NET> To: <vanagon@GERRY.VANAGON.COM> Sent: Sunday, April 07, 2002 9:33 AM Subject: Boston Bobs tale of an engine stripper or .19 Main bearing info was Flickerin oil light on 85 auto

Mike wrote

My 85 westy is a new one to me. my first wasser at that. it's got 168,000 with 75,000 on a rebuilt engine. My first oil change is coming up. Can anyone suggest a particular oil and or viscosity for use during the hot summer months?

Mike and fellow vanagon types

In my time I have taken a couple of 1.9 engines apart and I would like to share with you some of the things I have seen and learned. Most 1.9 engines are pretty tired by the time I get them in fact they are mostly turned in cores in exchange for fresh rebuilds but some come from stripped vans that had other problems. The one thing that is consistent in all 1.9 engines is that the crank bore in the case are out of spec. The specifications for the crankshaft bore size and the amount bearing crush is not listed in any book I have seen. This leaves allot of room for a judgment call based on past experience or advise from others and lack of other options. Some would tell you that if the bearing sits in the web and seems tight then that's OK and if the engine does not bind when you tighten the case bolts then you are good to go. Now we are getting to the difference between going threw an engine and rebuilding an engine. As I said not knowing the specs makes the job a little tricky so in order to understand the intent of the manufacturer I have looked back at some of the older engine specs to see if there is any details that we can use to interpret the intent of those who designed the WBX engine. The type 2/4 engine and the bug engine do have specs for the case bores and wear limits listed in the without guesswork book. The without guesswork book was handed out to techs as they went threw the dealer training programs back in the sixties and seventies. As it turns out there is some good info we can use to determine the intent of the designers of the WBX engines. First the nose bearing is the same on all flat 4 vw engines since 1961 right threw to the 91 WBX engine. The size of the bore for the nose bearing is 50 mm to 50.03 mm. and the wear limit is 50.04 mm. The next thing I noticed is that the Main bearings bore sizes are all in round numbers. Yah got to love those Germans need for order and straightforward simplicity. The two middle main bearings bores are in fact the same size on the bug main bearings bores as they are on the 1.9 WBX engine and that is 65 mm. with a wear limit of 65.03 mm. The type 2/4 main bearings bores are the same bore size as the rear main WBX bearing no big surprise! ( no its not the same bearing ) The rear main bearing bore for the type 2/4 engine is 70 mm with a wear limit of 70.03 mm. With all of that in mind we can now go back and look at the WBX block and use these dimensions to determine the condition of the used 1.9 cases. The next dimensions we need to determine if the case is in useable condition is the actual size of the bearings and then we can do the math and determine the bearing crush IF ANY!!!

At this point I am going to repeated the statement I made at the beginning of this rant. The one thing that is consistent in all 1.9 engines is that the crank bore in the case are out of spec. With that said I can tell you that the new OEM 1.9 bearings I still have on the shelve (no they are not for sale so don't ask) are 3 ths or .12 mm larger than the main bearing bore specs I have listed above. So with all this we can do the math and see that the case crush on the bearing is intended to be between .002ths. And .003ths.

When the bearings do not have the proper crush or the bearings are loose in the block as is the case with older high mileage WBX engines and with engine that have just been redone rather than rebuilt then the engine will have low oil pressure at warm idle.

Measuring the WBX block to determine the size of the crank bore can't be done without a good bore micrometer and a lot of practice. The other thing I has noticed is that the case halves tent not to bolt together as intended. The WBX block has two locating pins as do all VW air and water-cooled flat 4 engines this is done to hold the block in place so it can be machined and so the halves will return to there machined position when assembled. Over time the case halves do shift you can in fact feel the shift at the parting line when a used case is bolted and torqued together without any bearings in place. The case shift is commonly .002 to .005 ths. at the parting line and this can vary from end to end. I have tried to use a block of wood and hammer to align the halves as I bring the case halves together before I align bore with limited success and have had to developed tooling do get the cases halves back where they belong in order to align bore. This is important because when the case is not properly centered the cam bore and oil pump bores will be permanently misaligned by the new bearings in the nice round holes for the main bearing once we align bore the crank bore. One other note about used 1.9 blocks is that the thrust surface takes a pounding and the new main bearings can be loose and the case needs a thrust cut. You bug types might remember that the bug blocks commonly needed the thrust cut to keep the rear main bearing from moving.

Now that I have told you all this great info on 1.9 cases and bearings I need to tell you that the nice folks at Kolbenschmdt have not produced Main bearings for the 1.9 WBX engine for the last 3 years. There has been no news from across the big pond as to when they intend to make a production run if ever. The demand has not diminished so a few brave soles have started making 1.9 rear main bearings and using the bug bearings for the other mains bearings. I at first did not want to use these custom made bearings for fear of the dreaded unknown. As time went by and fellows like Jim Digennaro former editor of limbo needed main bearings we got brave and tried a set or two more than a year ago and now many more sets and the engines are still going strong with no signs of any oil pressure issues.

I have also in the last year made changes to my boring bar that allows me to align bore and thrust cut 1.9 .20 and 2.1 engine blocks and I now offer these services hear at the engine exchange. I also stock 1.9 main bearings in most common dimensions and I have also had made 20 and 40 over and thrust cut bearings for the discrimination engine builder.

Be aware that with some aftermarket bearing the tolerances are not what they should be and the bug bearing set aren't much better so measure measure and remeasure and remember that they say about assuming

All rights reserved

Bob Donalds

Boston Engine Exchange

The Engine Exchange Deluxe

http://www.bostonengine.com


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