Date: Mon, 6 Sep 2010 23:02:18 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Should I rebuild the bottom end? Questions & photos.
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re
These are
almost a torque to yield and leakage at the top of the cylinders means the
studs no longer maintained enough tension to keep the heads down under
pressure.
How do you figure ?
the studs and nuts are not like regular torque to yield fasteners...turn to
a certain torque, then two more 90 degree turns say.
they just go to 37 ft lbs , and that's it.
and ...that's such a very low figure ..
I can't imagine there's much actual tension load on the studs, not compared
to normal engines anyway.
the do twist, for sure ....springy even , kinda weird.
the only 'danger' I've seen with them is breaking off at the bottom from
corrosion.
and I'm sure it's smart to replace the cyl head studs, just never found the
need myself.
there's not a huge amount of force going on , compared to normal engines.
If it was say 100 ft lbs ..or 60 ft lbs plus two 90 degree turns sure ...
but not at a plain ole 37 ft lbs.
those tiny crack like appearing lines on the block flat spots next to the
rod ..
I don't think those are real cracks.
and ....now I'm starting to think 2.1's might be weak or shaky in the bottom
end ..
I know of two with pretty bad noises in them and cam bearings or cam gear is
suspect so far ..
both are on rebuilds , one with maybe 20K on it, one with 30K .
and I have another 2.1 ...just a 'mystery' engine someone gave me, so
figured I'd try it out ..
it's been rebuilt before ....
just has a noise in it, not lifters.....cam or crank related and more like
cam perhaps,
so ..given all that ..
maybe it would be a very good idea to split the cases ..
see what you really have in there.
there's on engine ..from a very clean looking van, not that many miles ...
even had a tow bar like it had been towed behind an RV ..
so I was tempted to put in just rings and do the head ..
( it was a diesel ) ...once I got inside the engine ...'everything' was
tired.
so ...if wanting to 'feel safe' driving down the road in the future with
that engine ..
you'll probably feel much better if you go through the bottom end too.
that'll be interesting !
Scott
www.turbovans.com
----- Original Message -----
From: "Dennis Haynes" <d23haynes57@HOTMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, September 06, 2010 9:01 PM
Subject: Re: Should I rebuild the bottom end? Questions & photos.
>I would suspect that maybe there are also some oil pressure issues leading
> to the pump being replaced. I have done head-gasket replacements on
> engines
> of this mileage with some success. Yes, Vanagon connecting rods can and do
> fail along with the cam shaft and cam bearings. But I would not just say
> that at 150K a rebuild is in order unless there are some other
> considerations.
> Were you able to determine of the combustion leak was due to the cracked
> head? If due to loose heads you may want to replace the studs. These are
> almost a torque to yield and leakage at the top of the cylinders means the
> studs no longer maintained enough tension to keep the heads down under
> pressure.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Tom Lambas
> Sent: Monday, September 06, 2010 6:35 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Should I rebuild the bottom end? Questions & photos.
>
> My '86 Vanagon has 178k miles on the odometer. The PO had headgaskets,
> oil
> pump, one head (used), a couple of lifters and a rocker arm assembley
> replaced. Test drive seemed fine, and I bought it. Well , it didn't take
> long before I had overheating issues that I ultimately found to be exhaust
> gasses blowing into the coolant. Pulled the heads, one was junk with a
> crack between the valves. I had the good head and another head rebuilt and
> pressure tested. I've pulled the barrels and pistons, and I am wondering
> whether to rebuild the bottom end, or not. Side play on the connecting
> rods
> seems normal. I can't feel any play when I push/pull toward or away from
> the
> crankshaft. I'm also wondering if it's normal for the core to show what
> looks like fine cracks on the solid area to the left of the connecting rod
> (see photos). Wrist pin wear looks minimal and the pistons look pretty
> good, but I'll probably replace the pistons.
>
> *http://tinyurl.com/39a3yso*
>
> Thanks for any advice,
>
> Tom
