Date: Thu, 24 Oct 2013 15:43:13 -0500
Reply-To: Jim Felder <jim.felder@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jim Felder <jim.felder@GMAIL.COM>
Subject: Re: off with her heads
In-Reply-To: <52698384.7000109@turbovans.com>
Content-Type: text/plain; charset=ISO-8859-1
No, "barring." Baring might get him arrested, especially if he were driving
around doing it in a Vanagon.
Jim
On Thu, Oct 24, 2013 at 3:31 PM, Scott Daniel <scottdaniel@turbovans.com>wrote:
> HI Angus ..
> on the 'bar thing'..yeah, Angus turned me onto what you meant.
> The word you wanted was 'baring' .
>
> On the rings ..I find that compression rings go in fairly easily ..
> it's the oil rings that are a tight squeeze sometimes.
>
> One way to gauge piston ring and barrel wear is to remove an old ring
> from that piston,
> put it in the barrel and measure the end gap of the ring, then compare
> that to spec.
>
> You'll likely find pretty 'good' wear.
>
> I forget how many miles on your engine ..
> and it's always .."Do I just fix what's really broken or worn badly ? ..
> or do I go further ?
> And ....once you do 'this' ..then might as well do 'that' too ..
> and it just keeps growing that way.
>
> Need to draw the line somewhere ..
> it's tempting to do new rings and rod bearings ...
> but then you might as well do X too ...........etc. etc. etc.
>
> yes, the right forward cylinder is # 1 .
> VW has used that numbering pattern in their oppossed fours since about
> 1950, if not before that even.
>
> here's a neat trick ..
> when you are adjusting your valves, turn the engine backwards to get to
> each cylinder on compression in turn ...
> that it's 1, 2, 3 , 4 . Confirm which cylinder you are on by dist
> rotor position .
>
> If anyone is interested in rebuildable 1.9 core waterboxer engines ....I
> have about 6 and don't want much for an assembled short block.
> You can make a 1.9 DH code engine into 2.1 by putting a 2.1 crankshaft
> in it.
>
> Scott
>
>
>
>
>
> On 10/24/2013 8:08 AM, Tom Carchrae wrote:
>
>> @Scott:
>>
>> Thanks for confirming about the valves. I'm not entirely sure which ring
>> it is, I'll go and have a closer look today. Btw, I didn't adjust
>> anything
>> with a bar - bar was meant as a synonym for 'except'. I am pretty sure it
>> is cylinder #1 (it is the closest to the passenger seat).
>>
>>
>> @Dennis;
>>
>>
>> On Wed, Oct 23, 2013 at 10:50 PM, Dennis Haynes <d23haynes57@hotmail.com>
>> **wrote:
>>
>> Please take this as training.
>>>
>>
>> I do take it that way - mistakes are the best teacher, so they say?....
>> but
>> still enjoying learning and working on it.
>>
>> I also very much appreciative of all the time and insight you, and others,
>> on the list are so generous with.
>>
>>
>>
>> At the point that compression test was taken
>>> that engine should have been taken out of service and further evaluated.
>>> All
>>> the cylinders are down and the one with 60 psi indicates a failure. If
>>> you
>>> had an emissions test program it should have failed. The catalyst is most
>>> likely shot. More concerning is while that cylinder was down the
>>> remaining
>>> three had to work harder to compensate.
>>>
>>
>> That is the strange part - it passed the emissions test fine, not even
>> close to failing. The mechanic who did the compression test also thought
>> it would be a problem. So, I don't understand how that works, except
>> perhaps that Vancouver's AirCare is a farce - one that they are ceasing to
>> operate next year.
>>
>>
>>
>> This often translate to increased
>>> wear on the rod bearings. The oil contamination from unburned fuel
>>> doesn't
>>> help things. Before taking the engine a part a leak down test would help
>>> to
>>> diagnose if you had a valve or a ring problem.
>>>
>>> This is was my most expensive lesson. I took it to a mechanic, and
>> asked
>> him to do a leak down test, and to look at the compression problem. He
>> reported back that he had got the compression back up by adding racing
>> lash
>> caps. I recall asking him about the leak down, and got back 'fine', and
>> 'it holds pressure', and so on. It is clear from what you're saying that
>> I
>> should replace the valve adjusting screws, not just pad them with lash
>> caps.
>>
>> Shortly after that, he changed the expansion cap, and I started to get a
>> really expensive series of coolant explosions. Then I drove the van
>> across
>> western canada, with a few incidents, although after I changed the
>> pressure
>> cap to another one I didn't have any more explosions - just coolant backup
>> behind the plate, and it was fine for an entire leg of the journey home.
>> Each experience made me want to fix it myself more - the last incident
>> was
>> taken care of while we stopped for lunch (the first involved a tow truck,
>> waiting around for a day, and a crappy patch on a hose).
>>
>> Anyway, all that is now water under the... no, coolant under the van? har
>> har. sorry, sorry... groan-worthy.
>>
>>
>>
>> Now that the heads are off there are some easy checks you can make. Put
>>> the
>>> spark plugs in and set the heads with the combustion chambers facing up.
>>> Fill the chambers with some light liquid like WD-40 or even carb cleaner.
>>> You will find leaking valves real fast.
>>>
>>
>> Thanks. I'll give that a shot before I dig further into the valves. I
>> saw
>> a video of someone doing that, but it was on a different type of engine.
>>
>>
>>
>> The exhausts should not be ground.
>>> If the seat are cut or the valves ground the stems should be shortened
>>> and
>>> the springs shimmed to compensate. This is to maintain spring pressure
>>> and
>>> rocker geometry. Adjusting screws should always be replaced. If the valve
>>> guides are worn it is likely time for new heads. These are a heat the
>>> head
>>> to 400 and cool the guides in liquid nitrogen fit. Otherwise they tend to
>>> go
>>> in off center and the seats will need a lot of cutting to compensate.
>>>
>>
>> ...and I though the spring tool was going to be fiddly.
>>
>> They are newish AMC heads, no pitting (aside from some crowbar scratches).
>> I think they were done 5-10 years ago according to the receipts log, but
>> I'm not sure both sides were done at the same time. I've read the bit
>> about the AMC valves being terrible. I'll do some more reading up on how
>> to check those (aside from WD-40 test)
>>
>>
>> Back
>>
>>> when VW rebuilt these heads they almost always ended up drilled out and
>>> fitted with oversized guides. A lot of labor. Make sure the intakes get
>>> the
>>> oil seals. ETKA does not show them but they should be there. I have a
>>> bunch
>>> in stock. They will keep oil from getting sucked down the intake guides.
>>>
>>> and that would help prevent the valves and cylinder getting filthier?
>>
>>
>>
>> You need to remove that carbon ridge at the top of the cylinder. The new
>> top
>>
>>> ring can get broken hitting it. If honing the cylinders remove as little
>>> material as possible. A few more thousandths and you will have an engine
>>> with piston slap noises. With the cylinders out at least measure the rods
>>> for play and bearing wear. The rods and bearings can be replaced without
>>> splitting the case, (this sucks but do-able).
>>>
>>> I've been reluctant to pull any more cylinders out until I try getting
>> one
>> back on.
>>
>>
>> Good luck,
>>
>>> Dennis
>>>
>>
>> Thanks Dennis - very much appreciated.
>>
>> Tom
>>
>>
|