Date: Mon, 17 Jun 1996 22:58:03 -0700
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: ddes@anet-dfw.com (David Schwarze)
Subject: Re: More questions as the rebuild progresses.
At 12:15 PM 6/17/96, thorsland@bigvax.alfred.edu wrote:
>Last weekend I removed all of the cooling tin and fan housing along with the
>exhaust system. I am now down to the heart of my bus and everything has gone
>very smoothly. The reason for my engine removal is to fix the low compression
>found in cylinders 3 and 4. They were running about 60# each while th
>e right side cylinders (1 and 2) were up around 130# each.
>Here are my weekly questions, please feel free to answer as many as possible:
>
>1. Do I need to have any work performed on the right head while I am working
>on the left one or can I just leave it alone since the compression was good.
Depends on what you're doing to the left one. If you're replacing it, the
casting could be different, which could change the compression, which would
make the engine unbalanced. If you find the valves or guides need to be
replaced, the right side is probably bad too and you should do them both.
>2. Should I throw in new rings all around?
I would recommend not touching the bottom end unless there is a problem.
Rings don't generally wear out unless the engine has been abused (such as
run for years without an air cleaner). Be careful that the cylinders don't
fall off once you have removed the heads. It's tempting to turn the crank
with the heads off but don't do it. Wire the cylinders to the block to be
safe. I bet you will find the cylinder head is the source of the loss of
compression on the left side. I'd fix the head and put it back together,
unless you want this to turn into a month long, four-figure $$ project. If
there wasn't smoke belching out your tailpipe under heavy throttle, leave
the rings alone. IMHO.
>4. How difficult is it to pull the gas tank out? My bus is a '77 2L FI westy.
I wouldn't try it with the engine in, even though some say it can be done.
It was enough of a pain with the engine out. It's not too bad of a job,
but it's a dirty one.
>6. It seems like it should be fairly easy to put the exhaust back on whilt
>the engine is in the bus. Is this true? (remember '77 FI 2L westy).
Bingo. I don't know why anyone would ever install/remove a type IV engine
with the exhaust attached. It's just plain silly. One bump in the wrong
place during install and you mess up your exhaust studs or worse. Not to
mention it adds 50 lbs to the weight of the engine that you are trying to
maneuver around.
>7. What is the best method for cleaning grease/oil/dirt from the cooling tin.
>How about the partially disassembled engine block?
Most people seem to use gunk or something similar on the block, although I
hate to introduce that stuff into the environment. Better might be to
spray it down with carb cleaner while it's sitting in a pan, then recover
the carb cleaner and take it to be recycled. Most places that take oil
also take carb cleaner, brake fluid, and transmission fluid. Take the tin
to a machine shop and have it hot-tanked. You'll be glad you did.
>
>8. Once I get the head off is there any obvious things I should look for as
>possible trouble spots (that caused the low compression)?
Look for cracks in between the valves (especially exhaust) and the spark
plug hole. Carbon will hide them. Best to have the heads cold-tanked
(don't hot-tank aluminum - it will mess it up) so you can see the cracks
better. Heads that have been run too hot (i.e. most of them) will have
cracks. They can be welded. Also pull the valve springs and check the
guides for wear. Lift the head of the valve off the seat a little and try
to wiggle it. You should not have more than a few thousandths of lateral
movement. If you do (again, likely) the guides should be replaced. If the
guides are worn and the heads cracked, consider replacing them with some
Mark Stephens rebuilts. Stay away from GEX rebuilt heads - they are junk.
Stephens only charges a few $ more anyway. If you re-use your old heads,
replace all of the exhaust studs and loctite (blue) those bad boys in
there. Make sure your spark plug threads are clean and not stripped. Try
to avoid installing helicoils - they are unreliable. If you get rebuilt
heads make sure you specify no helicoils in the spark plug holes. That's
about all I can think of - hope it helps...
-David
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David Schwarze '73 VW Safare Custom Camper (Da Boat)
Dallas, Texas, USA '73 Capri GT 2800 (Da Beast)
e-mail: ddes@anet-dfw.com '87 Mustang Lx 5.0 (13.986@100.81)
http://www.anet-dfw.com/~ddes '93 Weber WG-50 (Da Piano)
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