installing 1.9 head on 1.6 TD block

[16V-Sauger]

yeah, they tried to calculate how they could rise the cr. the aaz heads rechamber shall be 0,002L or 2ccm bigger than that from the 1.6l

so they discussed to use a 2 hole headgasket instead of the 3 hole they were using. also they wanted to deck the head down until the valves were equal in hight to the rest of the head.

[chrissev]

http://f23.parsimony.net/forum49387/messages/165941.htm

sadly only in german

read it (understand some german cause I lived there for a year and went to school there).  They basically say that they compared the prechambers in both the 1.9 and 1.6 heads and at first sight they appeared identical however when they looked closer they noticed that the prechambers in the aaz head were 5mm deeper into the head.  They say that this gives the aaz prechambers around 2 cubic centimeters more volume than the 1.6 prechambers.  They then thought about planing the head till they flattened the indented area between the valves and figured that would get them 1 cubic centimeter, but they decided it was too much effort.  They then decided to use the thinnest head gasket instead of the thickest, and found that this would get them 3 cubic centimeters less space, and it would more than compensate for the bigger prechamber.  So they decided to use the two hole head gasket.  They end the post by saying that they still have to check whether if they use the two notch gasket there will be enough room so that the pistons don't hit the valves.  

Various people then answered this post stating that the original posters had made mathematical errors, and that in reality they would only get around 0.4 cubic centimeters less volume with a 2 notch gasket than they would with a 3 notch.  

The main problem that everyone in the thread seems to agree exists is that a 1.6 motor with a 1.9 head on it would be hard to start in cold weather because of lower compression.

I'm not sure if I agree that 2 cubic centimeters is a whole lot.  The head that is on my car right now has cracks between the valves (in the usual spots where the 1.6 heads always crack) that probably hold a cubic centimeter of air, and it still starts at -20 degrees without a block heater.

Dave:  what head gasket are you using on your 1.9/1.6 engine combos?  Have you ever measured compression on your engines?  I have a 3 notch metal gasket I was planning on using, but might exchange it for a two notch now that I know about this bigger prechamber issue.

[16V-Sauger]

your german should be very good  :shock:

[chrissev]

your german should be very good  :shock:

it was, back in 1997 when I was there.  I went to U of Freiburg.  Haven't read it or spoken it since then so it's a bit rusty now.

[935racer]

I use the 1.9 metal layered gaskets, I just use the right gasket for the deck height. I haven't had any issues with the cold start thing but it doesn't get THAT cold here I think its way too cold here but yeah never goes much below 0 celcius. I am just a whiner cus I grew up in la mesa and el cajon

As far as pre cups go, there is a thread on here where malone posted soem info and pictures and measurements I gave him regarding the different pre cups available. I thinkt he thread was titled" IDI there is a future" Think redrotors was the original poster.

[chrissev]

just looked at the measurements, the head gaskets are different by 1.57mm thickness in the two notch and 1.61mm thickness in the three notch, so .04mm difference.  It appears that the posters who answered the original poster are right, there is not too much to be gained by using a thinner gasket.  Also the 3 notch gasket can apparently be used on engines with piston protrusion of between 0.91mm to 1.02mm meaning that if you used a 3 notch on a 0.91mm piston protrusion engine and also on a 1.02mm piston protrusion engine, you would have 0.11mm less space on the 1.02mm piston protrusion engine compared to the 0.91 piston protrusion engine.  If that guy on the German forum was right, then if he can get 2 cubic centimeters less volume from a difference of .04mm then there is almost a 5 cubic centimeter difference in volume between the two engines I mentioned above, but VW prescribes the same head gasket for both of them.  Obviously then 2 cubic centimeters more volume is not an issue.  I think I am wasting my time with thinking about this.  2 cubic centimeters more space is not enough to worry about.

[dieseltim]

I am not sure how well it will work for all of your uses, but it will translate most things I tryed. If this link doesn't work you can find babblefish at Altavista.com. Just copy and drop in the www or words you want translated.
http://babelfish.altavista.com/
Dieseltim

[samuraikid]

I just finished my 1.9td head on to a 1.6solid block. and it makes amazing power! and I used the 1.9 injectors and they worked fine on the 1.6 hard lines? and I used the 1.9intake with the 1.6 exuaust and the k24 turbo. every thing went pretty smooth

[mkosem]

good times!  pics?

[samuraikid]

what kinda pics u want?remember it is in a samurai) :p

[chrissev]

what kinda pics u want?remember it is in a samurai) :p

done a compression test?  I'll be doing one on mine once I get the head on it anyway but just interested if you have any numbers.  I think I'll take pics of the whole operation with my digi cam.

[type53b_gtd]

I installed a 1.9 head on a 1.6 MF (hydro)  block  last spring in my '84 Scirocco and I put about 16,000km on it over the summer.  I used 1.6 injectors.

The 1.9 head definitely flows more air than the 1.6 (I have been using an AAZ KKK turbo for several years) and it was necessary to adjust the pump fuelling to accomodate the extra air.

I do experience a very poor idle when cold, including smoking.  The bottom end is well worn (to many 000km's to count, including several re-rings) and I believe this coupled with the extra cc's in the 1.9 head result in the cold running issues.  Block heater helps reduce the smoking at startup.

I'm hoping to do a compression test before proceeding with any bottom end work.

Drew

[chrissev]

I installed a 1.9 head on a 1.6 MF (hydro)  block  last spring in my '84 Scirocco and I put about 16,000km on it over the summer.  I used 1.6 injectors.

The 1.9 head definitely flows more air than the 1.6 (I have been using an AAZ KKK turbo for several years) and it was necessary to adjust the pump fuelling to accomodate the extra air.

I do experience a very poor idle when cold, including smoking.  The bottom end is well worn (to many 000km's to count, including several re-rings) and I believe this coupled with the extra cc's in the 1.9 head result in the cold running issues.  Block heater helps reduce the smoking at startup.

I'm hoping to do a compression test before proceeding with any bottom end work.

Drew

re: poor idle when cold:  my jetta right now has a rebuilt block (not re-ringed, done properly) with around 70k on it and it smokes and idles poorly if I start it when it is below -5 outside without a block heater.  It'll start down to -23 without a block heater (that's the coldest I've ever tried it) but it'll idle crappy and make tons of smoke till it warms up.  So I am used to the smoke and poor idle.  Diesels seem to be like that regardless of how much compression they have.  I'm hoping the slightly bigger pre-cups and the extra space in the 1.9 head gasket don't add too much volume.  The valves are also slightly bigger and you are right about the intakes, they are shotgun right to the valve port, and they are way bigger than the 1.6 head intakes.  When I get my 1.9 head put on this spring (soon as it warms up, it's -12 right now, too cold to do the job, I don't have heated facitities) I'm going to double the turbo boost to around 22psi and then play with the fuel screw.  Right now it has the crappy 1.6 fibre head gasket and I'm pretty sure I'd blow it if I put more boost in, it is already leaking some coolant from the back from when I overheated it last summer (hehehe).  

Anyway, great to hear that your car starts when it is cold out.  That is all I need really.  If it smokes, that is fine.  I don't care.  As long as I don't have to push it down the road and pop the clutch like I used to do with my 79 diesel rabbit that didn't have enough compression to start when it was below -5 outside.

[mkosem]

what kinda pics u want?remember it is in a samurai) :p

Pics of the install.

--Matt

[type53b_gtd]

re: poor idle when cold:  my jetta right now has a rebuilt block (not re-ringed, done properly) with around 70k on it and it smokes and idles poorly if I start it when it is below -5 outside without a block heater.  It'll start down to -23 without a block heater (that's the coldest I've ever tried it) but it'll idle crappy and make tons of smoke till it warms up.  So I am used to the smoke and poor idle.  Diesels seem to be like that regardless of how much compression they have.  I'm hoping the slightly bigger

If your diesel smokes excessively and idles poorly at cold temperatures then either timing, compression, or glow plug system are not within spec.  I've driven IDI diesels for 15 years and they only do that when something's not right.  Some white/blue smoke is to be expected, along with a lower idle, but the symptoms I experience with the 1.9 head (and what you're describing with your engine) are misfire symptoms.

pre-cups and the extra space in the 1.9 head gasket don't add too much volume.  The valves are also slightly bigger and you are right about the intakes, they are shotgun right to the valve port, and they are way bigger than the 1.6 head intakes.  When I get my 1.9 head put on this spring (soon as it warms up, it's -12 right now, too cold to do the job, I don't have heated facitities) I'm going to double the turbo boost to around 22psi and then play with the fuel screw.  Right now it has the crappy 1.6 fibre head gasket and I'm pretty sure I'd blow it if I put more boost in, it is already leaking some coolant from the back from when I overheated it last summer (hehehe).  

The D shaped intake ports are a definite improvement, but the valve size is the same as the 1.6 TD head that I was running before -> in fact, I used the same valves when rebuilding the 1.9 head.