11mm or 12mm Head on a 1981 (pick-up) 1.6 n/a?

[Greenthings]

Is there a way to tell which 1.6 mechanical head/block (11mm or 12mm) before pulling head? It was made 6/81. Has the star-bit bolts, not socket types. # 068 103 373 F  2BR  made in Brazil.

[theman53]

If it has the triple square bolts I would think it would be a 12mm head.

There has never been a standard VW casting # reference to say yes or no to any of them. When I started on this forum that was the info I was after and asked if we could put together a casting # and letter reference for the FAQ. That was when we figured out that some were 11mm some were 12mm and there was no definative answers other than check and see. That said generally the one with the F at the end is usually a 12mm.

[Rabbit on Roids]

but, ive seen 1.5s and early 1.6s with gasser head bolts in them. triple square. and 11mm. being an 81, i would think it would be an 11mm from the factory.

[Greenthings]

Thanks for reply...I figured I (would have to) wait till lifting the head. Another important question? Does anyone know the mpg drops when going to over-size piston and rings. Do you think it would be a couple of miles per gallon "Loss" for each increase in scale of "over-sizeing"?

[Powered by Spearco]

As far as milage, I think your spliting hairs. Lets say your getting 44 mpg, if board out to next size up, maybe 1-3 mpg differance, if that 

Your still getting great milage due to being a diesel.

 I mean, does it really matter that much?

[Greenthings]

Yeh...I'll be splitting hairs for a while making shure I keep the mileage in the 40's. I see so much performance mod and re-build stuff, on here, with-out much mention of the mpg losses. 40-50 mpg(goals) is the only real reason I drive these noisy, huggable, rattle-boxes. Let's get some Anti-Gravitational Mods going soon people !!!

[maxfax]

An '81 is supposed to be 11mm, but we all know how that goes..  Check your block code..  It's stamped on a flat spot on the block right at the top of the deck between the #3 and #4 injector..   This can be a pain to see.  Engine code CR or CK (sort of like a short abbreviation for crack) would be 11mm.. CK would be a 1.5 engine..   IF you do happen to have an 11mm engine read this http://www.vwdiesel.net/forum/index.php?topic=21948.0..

I doubt that an overbore is going to make a noticeable difference in your mileage..  The nifty thing about these old rattle traps is that no matter what mods are done to them, a light right foot will still yield you incredible mileage.. 

[Rabbit on Roids]

An '81 is supposed to be 11mm, but we all know how that goes..  Check your block code..  It's stamped on a flat spot on the block right at the top of the deck between the #3 and #4 injector..   This can be a pain to see.  Engine code CR or CK (sort of like a short abbreviation for crack) would be 11mm.. CK would be a 1.5 engine..   IF you do happen to have an 11mm engine read this http://www.vwdiesel.net/forum/index.php?topic=21948.0..

I doubt that an overbore is going to make a noticeable difference in your mileage..  The nifty thing about these old rattle traps is that no matter what mods are done to them, a light right foot will still yield you incredible mileage.. 

true story, i still got almost 50 mpg in my rabbit if i stayed out of the boost.

[Baron VonZeppelin]

When you say made in 6/81 - I'm guessing you mean the Body.
Not the block and/or head.

IF it is/were the Original CR engine, it "probably" would be 11mm with 6point-allen head-hex head bolts. The 12 point/triple square would indicate 12mm. But take note of RoR's posting about gas bolts in a Diesel, also.

Engines also get swapped from time to time along the way.
Another problem is the CR code was used on 11mm and 12mm 1.6 NA 81-82, maybe through 84. So the CR block code is not definitive on that.

What is (as far as we know so far) supposed to be a definitive on that - is the block ID casting on backside (firewall side). If it has 1.6 or 16 casted in raised numbers - it is 11mm.

If it has 1.6D or 16D casted in raised numbers - it is 12mm.

I recently had similar dilemma as you, with my 81 Truck.

Was supposed to be an 84 or 85 TD engine in Truck. For the price, I grabbed Truck without fine tooth inspection. All exterior TD garments are 85. Engine turned out to be a CR code. With an aged Reman'd sticker remnant. oh well, it runs

So was it crap-pile original CR 11mm that had been reman'd, or 82-newer CR 12mm replacement reman'd ?
Valve cover revealed 12pointers - block reveals 1.6D on backside.
So it should be 12mm CR.
But its going to come out and get a real TD longblock.

Other significa-insignifica from engine:

Block:
code # CR
1.6D - on back side
068 103 011 Brazil - on front side

Head:
068 103 373 B     WWO     H
1-7-10
Germany
Single oil return
12point / triple-square head bolts

* The 1-7-10 was deciphered from circles on head. I 'believe' that is 1981 July 10 date. Making at least the head an early production 1982 unit. 1982 body production began in August 1981. Engines are cast and built month(s) ahead of bodies.)

* Being my engine is a reman'd unit - it could be hodgepodged pieces aka 82 head 83 block etc... It seems odd it has a Brazil block and Germany head ... idunno.

* With yours being such a late build - it "could" have "possibly" gotten the 'new' 12mm engine assembly when built.

* I can't find any cast or stamp markings on Blocks that would indicate a date - or a VIN - on any of my VW's - so far. The stamped numbers after/before the block code stamping are the engine unit number (EUN). You would have to source the original VW billing invoice or dealers copy of invoice (not window sticker) to be able to match that number to prove defacto if it is the original engine in these Mk1/Mk2.

If all that got fuzzy or was too much reading ... lol
Just check firewall side of block for 1.6 or 1.6D
Its all we got short of pulling a head bolt and measuring it.

  





  

[Baron VonZeppelin]

An over-bore will probably increase your mileage - after break-in.

1.9's get same or better MPG as our 1.6's

[Rabbit on Roids]

is it weird to have german and brazilian parts on the same engine? an ABA gasser i picked up recently, the block is made in mexico, and the head is german. i thought that to be a little weird. and i think it came like that from the factory. the headgasket was original VW/audi and had a date on it. date was some time in 1995.. so that leads me to think it came that way from the factory. just thought it was a little odd is all..