# ABA head on 1.6 high compression block, need to lower compression ratio



## Shaggy (Jan 20, 2000)

I need an option to lower the compression ratio with an ABA cyl. head/1.6 high comp. bottom end combo. The 1.6 is currently at 225psi average compression. 

The aba's main oil drain is going to have to be decreased in size making it impossible to bolt up an aba head spacer straight up. 

Can head spacers be built up, ground down, then decked flat safely? 

Trying to avoid double stacked 1.6 gaskets if it's even doable. Not sure what else to do.


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## antichristonwheels (Jun 14, 2001)

You can get a thick gasket cut by cometic. 

What happenned to the head you had on it?


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## Shaggy (Jan 20, 2000)

Ditchin the carb stuff for FI. Have to keep up with the mk1 vr6s of the world. 

Thanks for that.


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## WaterWheels (Aug 14, 2005)

Shaggy said:


> Ditchin the carb stuff for FI. Have to keep up with the mk1 vr6s of the world.


 I guess a lot depends on what you mean by "keep up". Everyone knows there is no substitute for size, all things being equal a larger engine will win (sooner or later). But I would think if short stop light races are what you are refering to, those Dells should do real well if everything is tuned correctly. With the 8v you will be lighter in the front for what should be better handling and acceleration possibily too. If the engine is set up with the side draughts correct, it should leave the VR6 behind at least for a short time until it's size takes over. By then the next light should be red and you have to stop anyway. Don't get me wrong, fuel injection is a good thing, but just swapping over to fuel injection is not going to increase anything, except your fuel milage maybe. In either case it has to be set up good, FI or the carbs, for you to play with a much larger engine. The VR6 will have the torque advantage.


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## Jettaboy1884 (Jan 20, 2004)

I'm just wondering why go through all the trouble of running a crossflow head on a 1.6 block? Is it a combination of parts that you had available, or did you specifically pick this combination? 

Reason I ask is because technically you can get more power from a properly built counterflow head. And although I understand it is not preferable to have the carbs above the exhaust, there are solutions for the heat soak as well. 

Not knocking your setup at all, just wondering. Probably worth mentioning that I've secretly wanted to build a balanced 1.6L with a built solid-lifter big valve head and ITB's... With a short ratio trans and a light car, I bet it would be a LOT of fun... 

Anyhow, throw up some pics (if you can) of your setup. I'm interested in seeing the carbs, and coolant hose routing... 

*Edit* Just re-read that you're going FI. What are you planning to run?


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## Glegor (Mar 31, 2008)

Shaggy said:


> I need an option to lower the compression ratio with an ABA cyl. head/1.6 high comp. bottom end combo. The 1.6 is currently at 225psi average compression.
> 
> The aba's main oil drain is going to have to be decreased in size making it impossible to bolt up an aba head spacer straight up.
> 
> ...


 if the center oil drain on your block is not the same size as the ABA oil drain, then you have a 1.5D block.. im sorry! 

im going to go check an aba, and 1.6D gasket right now to make sure the center oil drain holes ARE the same size..


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## Glegor (Mar 31, 2008)

only oil drain that isnt the same size/same location is the drain specific to the hydro lifter heads.. 

and that only needs to be threaded and plugged.. 

i just looked at 1.6D head gasket, and ABA head gasket layed over each other.. 

if you want a head that bolts straight on, maybe look into an early GTI head? 

and i too, would think the Dell'ortos will do a better job then the EFI.. provided the dells are tuned good.. 

those things have some potential to flow some air! there almost as good as ITBs.


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## Shaggy (Jan 20, 2000)

Glegor said:


> only oil drain that isnt the same size/same location is the drain specific to the hydro lifter heads..
> 
> and that only needs to be threaded and plugged..
> 
> ...


 The block is a 1.6. I was going off of what I've read and have heard about in the past in regards to making the main oil drain smaller. Apparently there have been issues with seeping without narrowing the passage down. The extra drain is being taken care of via a countersunk npt plug. 

Will look into the sizing of the gaskets and how the aba head lays over the 1.6 when I have it apart later tommorow. 

The reason for going with the xflow head is for the room it provides for the turbo and manifold out back, and the ease of use with plumbing and the short runner intake.


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## ps2375 (Aug 13, 2003)

Why not switch to a later 1.8 block? The head will then bolt on w/o mods. (or an ABA block) They all fit into that bay just like the 1.6.


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## Jettaboy1884 (Jan 20, 2004)

Shaggy said:


> The reason for going with the xflow head is for the room it provides for the turbo and manifold out back, and the ease of use with plumbing and the short runner intake.


 
That's a very good reason to go crossflow. :thumbup: Counterflow is much more of a pain to work with in that regard. 

And as a previous poster stated, why not go with an ABA block so you get the oil squirters (among other benefits) or at least go with a 1.8L 

Internals for the 1.6L are not nearly as common or easy to find as the 1.8L and newer...


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## Shaggy (Jan 20, 2000)

This bottom end is in good shape and rust free. It's a tough standard to live by up here in Toronto. 

I've had more than enough opportunities to obtain full aba's or rebuildable bottom ends but I've decided to reuse this block since there's no reason to be putting more money into this build as it sits. 

The D block already just may be a TD block and would have the oil squirters in it in that case. Still have to tear into this thing to determine whether or not it has any funky aftermarket bits in it, but it ran super strong on the carbs and certainly didn't feel like a little 1.6.


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## Jettaboy1884 (Jan 20, 2004)

Ah.. I didn't realize you are located in Toronto. That may (or may not) make for some different information because I for one, had assumed you were in the US and asking about an early Rabbit/Scirocco 1.6L 

What's the engine code of your 1.6L and what year/model did it come from? 

Do you have any pictures?


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## Glegor (Mar 31, 2008)

if it has 12mm head bolts, you guys are gonna have to modify the heads you run for the bigger head bolts.. 

gassers and early diesels run 11mm bolts, later diesels run 12mm bolts.


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## B4S (Apr 16, 2003)

Shaggy said:


> This bottom end is in good shape and rust free. It's a tough standard to live by up here in Toronto.
> 
> I've had more than enough opportunities to obtain full aba's or rebuildable bottom ends but I've decided to reuse this block since there's no reason to be putting more money into this build as it sits.
> 
> The D block already just may be a TD block and would have the oil squirters in it in that case. Still have to tear into this thing to determine whether or not it has any funky aftermarket bits in it, but it ran super strong on the carbs and certainly didn't feel like a little 1.6.


 So...going to sell your carbs?  
/end vulturing. 

Same reason I'm sticking to my digi-1.8, it's been reliable, makes great power, and is more trustworthy than any of the ABAs that I've been offered over the years. Southeastern Canada puts strange strains on engine parts, thanks to the salt .


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## Shaggy (Jan 20, 2000)

B4S said:


> So...going to sell your carbs?
> /end vulturing.
> 
> Same reason I'm sticking to my digi-1.8, it's been reliable, makes great power, and is more trustworthy than any of the ABAs that I've been offered over the years. Southeastern Canada puts strange strains on engine parts, thanks to the salt .


 Yep, I'm with you, I think ABA's are great reliable stout motors but not without knowing their history or being from sourthern ontario originally. :laugh: 

So got the head off of the block tonight and it's happy time. 

She's got flat top pistons, not stock diesel parts. 

It has an 82.5mm bore, 38mm intake valves, and 33mm exhaust valves. Cross hatching is still clearly visible in all bores and there is about 8mm visible of carbon deposits below the deck height. 

edit. oh yea, the carbs are for sale.


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## Glegor (Mar 31, 2008)

Shaggy said:


> Yep, I'm with you, I think ABA's are great reliable stout motors but not without knowing their history or being from sourthern ontario originally. :laugh:
> 
> So got the head off of the block tonight and it's happy time.
> 
> ...


diesel pistons are flat on top too.. or do you mean completely flat, no valve reliefs or anything?


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## Shaggy (Jan 20, 2000)

Glegor said:


> diesel pistons are flat on top too.. or do you mean completely flat, no valve reliefs or anything?


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## ps2375 (Aug 13, 2003)

Now that you have the head off, you can cc the head and block to figure actual CR.


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