Date: Thu, 28 Nov 2013 11:09:16 -0800
Reply-To: Scott Daniel <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel <scottdaniel@TURBOVANS.COM>
Organization: Cosmic Reminders
Subject: Re: off with her heads
In-Reply-To: <CAFnDXk2mjeqpvno2aN8CphPVnvEzc4H3z3vrGzX3wHzZrcH0sw@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Ditto.
On 11/28/2013 7:09 AM, Jim Felder wrote:
> I have to question this advice, or at least advise looking into it further.
>
> I think that honing cylinders is standard practice when fitting new rings.
> While there may be exceptions (Porsche 911 silicon-impregnated cylinders,
> cylinders that still have enough roughness to seat rings and especially
> soft or otherwise compliant rings come to mind). Honing is at most going to
> remove a few tenths of a thousandth. You would have to be at it all day to
> hone out what ordinary tools could even measure if you are doing it right.
>
> To not hone a cylinder that is receiving new rings is to take an
> unnecessary risk.
>
> Jim
>
>
> On Fri, Nov 22, 2013 at 11:36 PM, Dennis Haynes <d23haynes57@hotmail.com>wrote:
>
>> See below!
>>
>> Dennis
>>
>> -----Original Message-----
>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
>> Tom Carchrae
>> Sent: Friday, November 22, 2013 4:50 PM
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: Re: off with her heads
>>
>> Hi All,
>>
>> I got the bolts fixed and the heads vacuum tested by the machine shop (if
>> you are in Vancouver, Alec's
>> https://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 internet.
>>
>> I really don't believe in honing the cylinders much. You need to measure
>> carefully. It is easy to remove a few thousandths quickly and you will end
>> up with an engine with piston slap noises. I am even seeing (hearing) this
>> with engine rebuilt with the new knock off cylinder kits.
>>
>> 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.
>>
>> Machining the tops of the barrels requires a lathe and someone who knows
>> what they are doing. The lathe and the chuck needs to accurate. I have
>> probably replaced more cylinder sets due to top damage or bad pistons than
>> cylinder wear or bore damage. You can try cleaning the tops using a very
>> flat surface and a fine grit emery. If you can see or feel the scratch I
>> wouldn't use the cylinder. Not only does the top of the cylinder have to e
>> near perfect, the two of them side by side have to be perfect together.
>> Hylomar is a good sealant to use on this gasket and the O-ring.
>>
>>
>> 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).
>>
>> If you're going to work on your van at some point a good floor jack is a
>> must. Get it over with and get one. Look for one with a large saddle.
>> Preferably a removable saddle so that tranny adapters and stuff can be
>> fitted.
>>
>> Tom
>>
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