[Vwdiesel] Head gasket choice?

[Brian Decker]

Being a turbo engine a little lack of compression won't hurt except perhaps with starting. I took a few thousands of the top of a set of turbo 1.6 pistons and built a VW 1.6 turbo engine it ran fine just a little hard to start. It had I figured about 19 to 1 compression ratio.


-----Original Message-----
From: Vwdiesel [mailto:vwdiesel-bounces at vwfans.com] On Behalf Of Ralph Meyermann
Sent: Thursday, April 16, 2015 4:30 PM
To: Andrew .Libby
Cc: VW Diesel Group
Subject: Re: [Vwdiesel] Head gasket choice?

Block was only cleaned, bored and honed, the hybrid turbo should make up the compression difference. Also purchased some ARP head studs for this adventure On Apr 16, 2015 6:16 PM, "Andrew .Libby" <libbybapa at gmail.com> wrote:

No need for fancy tools a straight edge across the piston and feeler gauges on both sides (to find the higher side) is plenty good.

Given the new pistons and the too small protrusion, am I right in assuming that you did not have the block head gasket surface machined?

If you don't have the block skimmed you will be slightly lower on compression but only slightly.  You are not terribly out of spec on protrusion - not as bad as running a 3-notch when a 1-notch is spec'd and there are plenty of those running around.  The one time I placed myself in the same situation I disassembled and had the block skimmed, but we each make our own choices.

On Thu, Apr 16, 2015 at 4:08 PM, Ralph Meyermann <ralphmeyermann at gmail.com>
wrote:

> I have new 1mm oversized kolbenschmidt pistons bottom end is fully 
> assembled, I  measured with a digital caliper on #1 cylinder parallel 
> with wristpins to  eliminate piston rock. Kind of lacking some 
> precision tools due to cost of parts including new nearly complete kolbenschmidt head.
> On Apr 16, 2015 5:59 PM, "Andrew .Libby" <libbybapa at gmail.com> wrote:
>
>> Have you accurately measured the piston protrusion at TDC for all 4 
>> pistons?  In order to do so you must clean all carbon or foreign 
>> matter off piston crown and engine deck. You then take the largest 
>> protrusion reading and use the appropriate head gasket that matches 
>> that protrusion.  If you are accurately measuring 0.5mm as the 
>> highest piston I would be a little concerned as that is less 
>> protrusion than fits even the skinniest 1-notch gasket which calls 
>> for 0.66-0.86mm (2 notch = 0.87-0.90 and 3 notch = 0.91-1.02).  The 
>> given spec readings make me wonder what you are supposed to use if 
>> the protrusion is o.865mm or 0.905mm.  :-)
>>
>> I have found that the wristpin is moved toward the crown typically 0.010"
>> per oversize in order to accommodate machining the engine block head 
>> gasket surface.  Did you fit new pistons without having the 
>> headgasket surface skimmed?
>>
>> If your tallest piston protrusion is 0.5mm is there any chance the 
>> rods are bent?
>>
>> The 1-notch gasket seems to be particularly hard to come by.  It is 
>> part # 028103383BH (2-notch is suffic BJ and 3-notch is BK).  Looks 
>> like you have the correct part although I'd probably disassemble the 
>> bottom end and have a little skimmed off the block.  For future 
>> reference or anyone else who is reading, if I am replacing the 
>> pistons, I measure the protrusion of the old pistons, measure the 
>> wrist pin to crown height on both old and new pistons and then do the 
>> math so that I can tell the machinist exactly how much to skim off 
>> the head gasket surface without multiple trips to the machine shop or 
>> multiple times assembling/disassembling the bottom end.  I have done 
>> so on several engines and the piston protrusion has been exactly where I wanted it each time.
>>
>>
>>
>> On Thu, Apr 16, 2015 at 3:28 PM, Ralph Meyermann < 
>> ralphmeyermann at gmail.com> wrote:
>>
>>> Hi Volks! Currently assembling my AAZ and my pistons seem so come 
>>> .5mm out of the hole. I bought a factory head gasket from my local 
>>> vw dealership.
>>> It
>>> is a 028 103 383 BH DE. Is this thick enough? All I have is my 82 
>>> diesel westy Bentley and all my $$$ and then some has been spent on 
>>> parts. Your help is greatly appreciated. Thanks!!!
>>> _______________________________________________
>>> Vwdiesel mailing list
>>> Vwdiesel at vwfans.com
>>> http://www.audifans.com/mailman/listinfo/vwdiesel
>>>
>>
>>
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