Short blocks, then tall blocks, then short blocks - what was that all about then VW?

Bump

(ignoring diesels)


From 136mm rods / 220mm block height*

(EG engine)

to

144mm rods / 220mm block height*

(DX engine)

to

159mm rods / 236mm block height*

(ABF, 2E, AGG, ADY)

to

144mm rods / 220mm block height*

(1.8T engine)

< aka: complete about turn >

to

150mm rods / 220mm block height*

(AKL crossflow 8v)


* = crank centreline to deck.


References:

http://www.clubgti.com/forum/showthread.php?t=222440
http://www.clubgti.com/forum/showthread.php?t=230780
http://www.clubgti.com/forum/showthread.php?t=220777


Engineering gurus, your explanation please!

 

Those engines do not all use the same stroke, or pistons with the same compression height.

 

Well indeed!

I think the best thing to do would be to revise this with a table!

Engine|Stroke|Rod length|Compression height (OE) EG|80.0mm|136mm|40.7 +/- 0.1mm EV|86.4mm|144mm|33.3 +/- 0.05mm KR|86.4mm|144mm|34 +/- 0.1mm ABF|92.8mm|159mm|31.6 +/- 0.1mm 1.8T|86.4mm|144mm|32.6 +/- 0.1mm AKL|77.4mm|150mm|? So we can see the direct comparabilty.

Forum joiner is on double time this evening

 

More data for your table internet chippy.
http://www.clubgti.com/forum/showpost.php?p=2057159&postcount=94

 

Hmmm, slight differences on the low area measurement

But the basic gist is the smaller 77.4mm crank allows the use (gain?) of space to put a longer rod in. Without that, the top of the piston would be huge, huger than the EG.

So next question is where have VW used the 77.4 before, and what rod & compression height did they have?

A: http://www.clubgti.com/forum/showthread.php?t=228971

So it's been around since '84.... but presumably with 144mm rods for a good ~ 10 years first?

 

My little 16v apprentice is beginning to show positive signs. Stick in and one day you may become worthy of wearing the 8v badge of honour.

Those slight discrepancies in heights are still close enough to prove the point.

 

Positive signs indeed, but the audience has missed the question!

77.4 cranks ran with ?144mm rods and monster piston heights from 1984 => ?

 

Certainly to the early 90s with roccos and mk2 golfs with 1595cc engines.