Date: Mon, 17 May 2004 10:45:03 -0400
Reply-To: ROBERT DONALDS <donalds1@VERIZON.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: ROBERT DONALDS <donalds1@VERIZON.NET>
Subject: Re: How my engine rebuild is going
Content-Type: text/plain; charset="iso-8859-1"
Doug wrote
>I am having all 4 exhaust seats replaced in the practically new AMC heads.
The seats have receded really far into the >head for some reason. There is a
shop here locally that can do all 4 seats for about 60 bucks. I have
another guy who >is going to do the valve job and seat the keepers properly
as AMC does not do this. I had to purchase new exhaust >valves because the
keeper grooves were practically worn away from improperly installing the
keepers. There seems >to be a problem with keeper fits these days on new
heads, the valve stem keepers bottom out against each other >before making
full engagement on the valve stem grooves, so there is slop between the
keeper and valve and it >wears. You need to check this if you buy new head
as well as the valve grind which will typically not be 3 angle >grind but a
flat 45 degree on the seat which is incorrect.
The exhaust valve seat recession can be due to higher than normal combustion
chamber temps. This can be from lean mixture or sustained high speeds over
4k for long periods of time. The other thing that pounds the seats out is
low valve spring pressure and you pointed out that the keepers had ridden up
on the valve stems. This change in retainer height lowers the spring
pressure. The reason is not that the keepers are not correctly fit this
allows slop between the keeper and the valve but that the valve stem is to
soft so the loose keepers take there toll. the reason for the sloppy keeper
fit as you call it is so that the valve can rotate and this prevents uneven
valve end, stem and face wear. Trimming the keepers is the cure for a soft
valve stem but it stops the rotation and does lock the keepers into the
valve but makes it less likely that the soft stem will wear as fast.
The AMC valve job is a little wide but if you narrow the seating surface the
valve will widen the seat on its own in short order because the seat is to
soft for a narrow seat surface.
When I put in new exhaust seats I use the same seats that I use in my
propane applications expensive very hard but not heat treated this applies
to my big valve WBX heads also. I have even tried to use an exhaust seat
with a larger ID but that ruins the flow of the exhaust port.
>I am going to use copper coat on the metal head gaskets and put it all back
together. Anybody know of a larger oil >pump for the vanagon? We used some
pretty big ones on the bugs in the old days I think the 2.1 could use more
oil >circulation.
the copper coating is not needed of you maintain the proper cylinder
(Coolant) temps
My preference for oil pumps is a nice minty OEM used pump they fit the case
better they make better pressure hot and cold plus the hydraulic lifters
don't need more pressure than they have the engine is set up that way for a
reason. The larger pumps interfere with the rear engine support.
have the cam reground and buy new German lifters. I see that there is a
aftermarket solid lifter kit BUT I don't now of any solid lifters that work
for more than a few miles before they wipe the cam out
going faster miles an hour with the radio on
I remain
Bob Donalds
http://www.bostonengine.com
all rights reserved
----- Original Message -----
From: "Doug in Calif" <vanagon@ASTOUND.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, May 16, 2004 1:25 PM
Subject: How my engine rebuild is going
Well,
This is my 2nd waterboxer I am rebuilding and I have to say the 1.9s are a
little more basic and more familiar to the air cooled engine folks.
I pulled my 2.1 out of my 89 bluestar because it had a catastrophic metal
headgasket failure and left me stranded 300 miles from home.
After flying down to San Diego to purchase it last August, it only made it
to the grapevine hill outside of LA before it gave out.
Its been parked in my backyard ever since. I would occasionally go out and
sit in it on nice mornings and have a cup on the very slick flip out table,
listen to the radio and pretend it was a running vehicle.
Well, now I have the engine out and torn down all the way. I had the rods
checked and they are fine, I polished the crank and have installed new main,
cam, and rod bearings. I made the mistake of putting the #3 bearing on the
crank backwards, as the oil holes are only on the left side of the case and
the outer locking tabs have to be on the bottom. (oops). Had to pull the
gears back off and turn it around. The other mistake I made is I did not
carefully remove the lifters and sort them so I could place them back into
their respective bores. How important is this? none show any wear really.
Should I purchase new ones? Anybody do what I did and have their cam go
flat in short order?
Other than that, I decarbonized the pistons, broke the glaze on the
cylinders and have cleaned up everything.
I am having all 4 exhaust seats replaced in the practically new AMC heads.
The seats have receded really far into the head for some reason. There is a
shop here locally that can do all 4 seats for about 60 bucks. I have
another guy who is going to do the valve job and seat the keepers properly
as AMC does not do this. I had to purchase new exhaust valves because the
keeper grooves were practically worn away from improperly installing the
keepers. There seems to be a problem with keeper fits these days on new
heads, the valve stem keepers bottom out against each other before making
full engagement on the valve stem grooves, so there is slop between the
keeper and valve and it wears. You need to check this if you buy new head
as well as the valve grind which will typically not be 3 angle grind but a
flat 45 degree on the seat which is incorrect.
I am going to use copper coat on the metal head gaskets and put it all back
together. Anybody know of a larger oil pump for the vanagon? We used some
pretty big ones on the bugs in the old days I think the 2.1 could use more
oil circulation.
The end play shims were incorrect on this motor when I tore it down, it is
supposed to use the newer style thrust washer and the late shims, it had the
late thrust washer but 1.9 shims in it. So I am going to have to find the
late stuff to set it up correctly.
Other than that it looks like a runner, it may have been a GEX motor from LA
as it had some buttons JB welded to the heads and case and had writing all
over the back. The case also was painted silver, arghhh!, fortunately I was
able to get most of the paint removed. If the heads had run the way they
were set up much longer I think one of the exhaust valves would have worn
all the way through the keeper and I would have sucked an exhaust valve into
the engine.
Looking forward to getting the blue star back on the road again. This will
be my first vanagon with AC and our summers gut up into the 100s so it will
get a good test.
Doug
