Date: Tue, 2 Oct 2001 22:07:01 -0400
Reply-To: Kenneth D Lewis <kdlewis@JUNO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Kenneth D Lewis <kdlewis@JUNO.COM>
Subject: Re: B. Bobs 2.1 main bearings info
Content-Type: multipart/alternative;
Bob;
Many thanks for that. Is it feasable to install the bearings and
torque down the case to arrive at clearances by subtracting the crank
journal size from the bearing I.D.?
Good Luck and Drive Safely
Ken Lewis
86 Crewcab,60 356
http://Neksiwel.20m.com/
On Tue, 2 Oct 2001 15:51:56 -0400 Robert Donalds <bostneng@FCL-US.NET>
writes:
Fellow vanagon types and so forth mores
With all the talk about main bearings color codes I think I can clear
the air on this subject. It has been suggested that the difference in
size of the blue verses red is .004 ths. The measurements I have taken
show that the difference is .00025 ths. that turns out to be a 1/4 of
.001ths. Why they would bother to make two different bearings sets with
so small a clearance change baffles me. The clearance for the main
bearings is important and hard to measure I have spent thousands to be
able to do this accurately every time. Plastagauge is nice but not the
cure for knowing the clearances of the main and rod bearings and it has
let me down to many times.
I have never found the case measurements or the bearing clearances
listed for the1.9 or 2.1 engines and I am not going to offer them today.
what I will say is that I have found the need to align bore most 1.9
blocks. the reason is they loose the crush on the bearing over time In
layman's terms the hole is to big.
As for the 2.1 block some are fine and some need to be align bored and
there is only one way to tell. That one way is with a top of the line
bore gauge and a couple of hours to get the block clean at the mating
surface and bolted together. I can say that if the middle bearing web is
out of round then it needs to be align bored the other thing you need to
know is that the crush is greater on the 2.1 main bearings because they
are a thinner walled tri metal design bearings.
The clearance for the main bearings to the crank on the # 3 and # 4
bearings is .002 to 004 ths. as taken from the type 2 Bentley book yes
its a different engine but the basic requirements of main bearing
clearances are the same and the journals dimensions are also the same.
the # 2 splitshell bearing is not the same in the WBX 2.1 engines as the
type 4 or the 1.9 engines. the type 2 book says the min clearance is
.0012 ths to .0035 ths. As for the WBX 2.1 I would not want any less than
0015 ths on this split bearing to be safe. The # 1 bearing next to the
flywheel calls for .0019 to .004 ths I have found most cases with
bearings installed to measure close to the high limit of new spec. the
wear limit is .0074 ths. WOW
As for the rod bearings I like my rods to have .0015 ths between the
rod bearing and the crank journals the type 2 book lists .0008ths to
.0027 ths as the new spec this is for both the 1.6 and the 2.0 air cooled
engines.
I have recommended not reusing the 2.1 rods over without having the
bolts changed and resizing the big ends of the rods
I just finished and test drove my 84 westy to the transporterfest in
brookline MA.
with a stage 3 2.1 big valve engine
I'm really pleased with the increase in power. I had some concerned
about the injection system but the exhaust gas tests showed everything is
a go. I did have to back off the main spring for the air door in the air
flow meter to get the mixture set right. The mixture adjustment was much
more sensitive than any I have seen I think the big valves are the
reason. The flow bench showed a 20% increase in air flow threw the heads
at all valve lifts we tested.
Because of the past shortage of WBX main bearings I used a set of used
main bearings in this engine with no problems the clearances where right
where I wanted them and no oil light at hot idle
my new web page with lots of updates and head flow chart specs for the
big valve engines is almost ready and I will keep you all posted
as always all right reserved
hope this helps
Bob Donalds
Boston Engine Exchange
http://www.bostonengine.com
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