Date: Fri, 22 Nov 2013 16:55:32 -0800
Reply-To: Tom Carchrae <tom@CARCHRAE.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Tom Carchrae <tom@CARCHRAE.NET>
Subject: Re: off with her heads
In-Reply-To: <528FEB75.4080107@turbovans.com>
Content-Type: text/plain; charset=ISO-8859-1
Thanks Scott, much appreciated.
That is an interesting number (3.5mm) to know about checking how far the
the cylinder goes into the head. I was a bit concerned about doing any
machining in there and changing the step-distance/deck clearance/etc. I
think I might just get the heads back and keep cleaning them by hand and
see how it looks when it is all clean. My friend suggested a bit of
seafoam will help the carbon, I had given it a good rub already with brake
cleaner, but some of the carbon didn't want to move.
Thanks for the jack offers, sounds like a handy thing to have lots of!
I'll probably borrow one from said friend above.
I'm pretty sure there is an oil leak on the clutch end of the engine, and
the van does this terrible shudder thing if you let the clutch out too fast
(the engine nearly jumps out of the van - not stalling though), so I had
been tempted to look at it. I'm not keen to keep heading down the hole
though, would like to finish this before Christmas when I'll be freezing my
knuckles off.
Tom
On Fri, Nov 22, 2013 at 3:40 PM, Scott Daniel <scottdaniel@turbovans.com>wrote:
> Hi Tom,
> I always hone a barrel or cylinder if I'm putting in new rings.
> I have rarely seen much of a ridge build-up at the top of the
> barrel/cylinder, though you can read lots of warnings about it. I think I
> had to ridge-ream one or two engines out of dozens and dozens of engines
> I've re-ringed.
>
>
> Many machine shops are not set up to remove material down in a hole in a
> head, like at that metal sealing ring surface.
> Keep in mind that if material is machined off that surface.....an equal
> amount needs to be taken off the flat surface of the head, to preserve what
> I call the Step Distance.
> ( which is not always exactly right - and to check that, I put the bare
> head on with the compression metal gaskets...
> and measure the outer gap, where the rubber gasket goes. I aim for 3.5 mm
> there. Usually they are ok ..
> I have seen a few that were off, including a head that sits on the barrels
> somewhat tilted ...
> though that's rare. )
>
> A floor jack is so useful ..
> and fairly decent ones are not expensive these days ...like at HF ..some
> of their stuff is OK. Under 100 bucks and countless uses.
>
> I would probably concnetrate on getting the engine and cooling system all
> happy first.
> And after that ..
> if inspecting the clutch seems in order ...I'd pull the trans to get at
> the clutch. Lot easier than pulling the engine.
> A floor jack really comes in handy for that task.
>
> If you were local I would even offer you one .
> I find so many tools that people just 'leave laying around' ....not
> joking either. I got two fine floor jacks out of an abandoned Ford Escort
> station wagon left behind my rented shop. New property owners had it
> towed away, and the jacks would have ended up in recylced metal if I didn't
> grab 'em. That gives me a total of about 5 floor jacks.
>
> Scott
>
> On 11/22/2013 1:50 PM, Tom Carchrae wrote:
>
> Hi All,
>
> I got the bolts fixed and the heads vacuum tested by the machine shop (if
> you are in Vancouver, Alec'shttps://plus.google.com/103170149757334342065/about?hl=en - they were
> helpful and seemed pretty fair). All good, and my 1984 NLA
> thermostat/water-pump housing is saved from the snapped bolts... for now.
>
> How important is it to hone a used cylinder. The internet seemed full of
> opinion on it. I remember Dennis saying to carefully remove the carbon on
> the top, but honing to help the "piston rings seat' (I am replacing the
> rings) did not yield any clear answer on the great interent.
>
> I had also asked them if they could clean up/smooth the surface area under
> the compression gasket (where the head mates with the cylinder) and they
> said they were not sure how to do that properly, but they had called around
> to some other shops to ask and suggested I take it there (which I totally
> respect them for admitting that). I am considering doing this myself -
> there is no major damage. The worst is a small scratch from the (first and
> only) use of a screwdriver to remove the compression gasket - the rest of
> it is just carbon crap.
>
> I am considering removing the engine to check the clutch, although I don't
> have a floor jack and the engine is really high up from the ground (van is
> up on blocks). I might try the winch method, or just leave it. Common
> sense tells me I should check the clutch while I am in this deep (how deep
> is the rabbit hole...). And I'm sure I'll my sanity will thank me when I
> put the piston rings on (without removing the pistons).
>
> Tom
>
>
>
>
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