What Head Gasket?? what notch?? ***now updated***

[rixy]

hi peeps, im going to be putting another head on my 1.9TD ABL engine over the next week, in my spare tiime. But what i wanna know is, which head gasket do i need to order??

The engine has never had the block re faced, and as far as i know, the head has not been skimmed, and is currently flat, so will not be skimmed??

But what is the difference between notch's??

im guessing they r diff thicknesses to make up for compression differences etc.

So what one do i need?? Would going with a 2notch one be a safe bet? And if the compression is slightly higher / lower than it should be, will it hamper performance and economy?

[theman53]

The only right way to do it is to measure piston protrusion if they are like the 1.6Ls and I think that they are. The notches are different thicknesses and affect the quench and starting ability of the engine. You can take whatever gasket was on it before and put it on the engine, but without measuring you really don't know. If you then have problems that would be the first place to check, so just measure and get the correct one.

[rixy]

so how do i measure the protrusion to work it out?? can you tell me please??

also, how do i measure the exisiting one, or is there a mark or something i gotta look for?? may be a stupid question, but is it actually "notched" to the number it should be, i.e 1notch, 2 notches or 3 notches??

i have some vernier guages, socan measure pretty accurately i should imagine, and yes, you are correct, when turning engine over, the pistons do protrude from the block.

[theman53]

You can measure a couple of different ways. One is with a dial indicator and the other is straight edge and shimms. The idea is you use the deck as a zero reference and then move the pistons to the absolute TDC and then measure. Take that number and go to the bentley (which I don't have in front of me to give you exacts) and it will tell you the acceptable range for each notch/hole gasket.  
The notches or holes are on the front of the head gasket. There is a tab that has 1, 2, or 3 notches in it. I searched the FAQ and didn't see a writeup on this, but I didn't look to hard. I will also use the regular search now to see if I can get an exact on the measurements.

[rixy]

excelent, so i need a set of feeler guages or smilar to use as shims?

how do i know absolute TDC? just roll the engine over to roll over point,and check it on all 4 pistons? then average it? this will be moreaccurate i should think??

cheers for ya help, i'llwait for the exact measurements, nice one :-)

[theman53]

feeler gauges is what I meant here is a thread that you can see some holes in head gaskets. I am still looking.
http://vwdiesel.net/phpBB/viewtopic.php?t=10211&highlight=piston+protrusion

[theman53]

Here is the one I was thinking of.
http://vwdiesel.net/phpBB/viewtopic.php?t=14956&highlight=piston+protrusion

[rixy]

ok, cool,what unit is the measurement for protrusion taken in?? mm or thou??

[theman53]

The last link has info on both units of measure. Did you see the holes? Also if this is your first one imagine me yelling at you because it is caps
TURN THE ENGINE OVER BY HAND WHEN YOU PUT THE TIMING BELT BACK ON.
It is most important. You will know if there is valve contact and won't destroy your head...and won't have to do it all over agian.

[Dakotakid]

NO, you do not "average" the protrusion. You go with the largest value/the most protrusion and THAT is your determinance in selecting which gasket.

[rixy]

ok, cheers, i gathered that from reading the links posted by theman53.

i have read and think i understand whats gotta be done. will let you know the results.

[rixy]

hello, i have measured the piston protrusion on all 4 cylinders,and the largest measurement being 0.966mm, and the rest all being very close behind it, but smaller protrusion.

So by my calculations, i make that a 3notch head gasket.

Is this correct ?

Does any1 know what the usual piston protrusion is, or does it vary so much? Does mine sound correct?

what do ya think peeps??

[79rabbit4dr]

largest measurement being 0.966mm... 3notch head gasket.

Is this correct ?

You should be able to find it in a bentley for your model year. I'd seriously consider ordering one if you don't already have it (reasonably priced used on amazon is where I got mine). I went through these same questions and posted some pix in my thread about it. My motor is a '81 1.6L NA so it might be a bit different. Here is the thread anyway;
http://www.vwdiesel.net/forum/index.php?topic=17027.0
You'll be most interested in the pix on page 1 (current gasket) and page 3 (measurement to notches chart). If the piston protrusion on a 1.9TD calls for the name # of notches as a 1.6, then yes, 0.966mm = 3 notch gasket (see pg 3 pix). But I don't know if they are the same.

My Bentley covers "Rabbit/Jetta Diesel Including Pickup Truck and Turbo-Diesel '77-'84."

Hope that helps! Good luck!

[Vincent Waldon]

Here's what our very own FAQ has to say:

http://www.vwdiesel.net/forum/index.php?topic=6741

mod: fixed link.