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
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