# OBDI vs OBDII ABA engines



## tdogg74 (Mar 1, 2002)

Joint effort by me and Jeff.









*The difference in the top end is as follows.*
*Throttle body:* 
-OBDI had a dashpot while OBDII does not.
-OBDI has the external ISV (idle stabilization valve)
-OBDII has the TPS (throttle position switch) integrated eliminating the dashpot and ISV.
-OBDII has a different throttle bore shape than OBDI to increase air velocity at lower rpms.
*Intake manifold:*
-OBDI has the external ISV attached to the exterior of the upper manifold.
-OBDII has vanes immediately forward of where the individual ports begin in the upper manfold. Lower manfilds are identical for both OBDI & II.
*Camshafts profiles:*
OBDI camshaft measured @ .050" 
Advertised Duration: Unknown 
Duration @ .050": 211*/212* 
Valve Lift: .400" 
Lift @ TDC: Unknown 
Centerlines: 113.2* / 113.8* 
Lobe Center: 113.5* 
Valve Timing: -7.7/38.7 - 39.8/-7.8 
Valve Overlap: -15.5* 
OBDII camshaft measured @ .050" 
Advertised Duration: Unknown 
Duration @ .050": 210*/210* 
Valve Lift: .417" 
Lift @ TDC: Unknown 
Centerlines: 110.8* / 109.2* 
Lobe Center: 110* 
Valve Timing: -5.8/35.8 - 34.2/-4.2 
Valve Overlap: -10*
Pic of OBDII stock cam next to a Techtonics 276* & Techtonics 288* camshaft:








*Valve springs:*
-OBDI came stock with dual valve springs capable of lifts of .450" of lift. 
-OBDII came stock with single valve springs capable of lifts up to .432". 
- And a link to why you need to upgrade with high lift cams over .432" http://forums.vwvortex.com/zerothread?id=4696004
OBDII valve spring assembly:








*Heads*
-OBDI & ODBIII heads are interchangable.
-OBDI had provisions for EGR (exhast gas recirculation)
-OBDII heads had SAI (secondary air injection) attached to the exhaust manifold
-Stock OBDI intake ports flow better than OBDII.
-OBDII intake ports were designed with shrouds immediately before the valve guide. This was to reduce intake noise and redirect the A/F mix to the top of the piston for increased efficiency. These shrouds became a hinderance at high rpms.
-It is important to note that during the 1995.5 and 1996.5 model years, there was sometimes a mix and match of parts. Some cars came with OBDII heads with OBDI valvetrain parts, ect. There is a ghost head out there. It's the OBDII "German" head. It has large OBDI ports, single valve springs, no spring seats, and smaller JH sized spring seat bores. If you see a head that has "germany" stamped on the back and single valve springs, please IM me, as I've had a lot of experience with these heads and can save you a lot of headaches when it comes to modifying them. 

Here is a pic of a (ported) OBDI next to a stock OBDII intake port:








Here are cut-away shots of an ABA head:
















*The difference in the bottom end is as follows:*
There are only 2 different blocks that the ABA could have... squirter or non-squirter. There is only one way to know exactly what's in there, and that's to take the oil pan off and LOOK.
Generally speaking, squirter blocks are the way to go if you're building a performance engine, however, I've used both for pretty intense buildups and I can't say I've noticed a difference.
There are a variety of internal combinations that you may find as well, but let me preface it with a couple ABA LAWS.
All ABA's have forged rods
All ABA's have cast pistons
All ABA internals are interchangable
That said, lets get down to the whole OBDI vs OBDII debate.
The general rules are...
OBDI - forged crank
OBDII - cast crank
But, knowing VW, there is a lot of gray in the middle. The only ones i can say for sure I've never seen deviate from the rule are 93-94 OBDI and 98-99 OBDII. Everything in the middle is hit and miss. Forged cranks are stronger than cast, but the power yeild difference is much lower than people think, only about 35-50lb/ft.
The earliest ABA's also tend to have a full metal windage tray that forms the oil pan gasket, later ones had a little splash guard that snaps onto the oil pickup, the full metal tray is perfered.
There are also 3 difference sets of pistons you may find. They are also hit and miss, so the only way to tell for sure is to at least inspect them through the spark plug holes or remove the head. There is a smooth dish piston. These are generally OBDI "German" blocks, but they also made their way into later "mexican" and "brazilian" blocks. The later OBDII engines had what I call castle pistons. They look similar to the smooth dish, but have little castles that stick up on the front and back and also have a deeper dish. I assume the reason is to better direct the combustion downward but narrowing the combustion chamber at TDC. There are a handful of the elusive "unicorn" pistons out there as well. I have a set that I pulled from a "brazilian" block and they are a mix of the other two but slightly a-symetrical like a VR piston. Not sure what the reasoning was for them, but they clear a 16V head rather nicely.
Of the 3 pistons, for an ABA, I can't see either of the common ones making any difference, but I go with the smooth dish for because they seem to offer slightly more clearance for a large cam and decked head with large cam lift. For an ABA/16V build, the rare ones or the smooth are the more ideal.
/thread



_Modified by tdogg74 at 9:26 AM 4-6-2010_


----------



## pedrosan (Feb 6, 2005)

*Re: OBDI vs OBDII ABA engines (tdogg74)*

Awesom writeup http://****************.com/smile/emthup.gif 
I have a 96 1/2 golf. ill need to go check if the head says germany on it


----------



## 20B_envy (Mar 16, 2006)

You just cleared up a LOT of my block questions. I'm sticking to my OBDII block for my ABA16vT just because I already have it. I might swap out the crank when I change the pistons, but the rods are all forged already so that saves about $6-700.
What do the unicorn pistons look like? Do we have any pictures of the different pistons?


----------



## independent77 (May 23, 2003)

*Re: (20B_envy)*









castle piston








smooth dish piston


_Modified by independent77 at 9:06 AM 6-7-2008_


----------



## jerrymic (Apr 19, 2007)

*Re: OBDI vs OBDII ABA engines (tdogg74)*

praise the many various gods of the many various religions (unless you're an atheist, then praise the many laws of physics) the OBDI vs. OBDII threads should finally end...


----------



## Josh1581 (Feb 27, 2005)

*Re: OBDI vs OBDII ABA engines (jerrymic)*


----------



## JonVWluver (Mar 29, 2005)

nice write up...


----------



## Daylight Bombings (Oct 23, 2008)

*Re: (20B_envy)*

bump so its not archived and in my watched topics


----------



## wantacad (Apr 4, 2003)

*Re: (Daylight Bombings)*


_Quote, originally posted by *Daylight Bombings* »_bump so its not archived and in my watched topics









same here.








A friend of mine built up a 16vT with a OBDI block and wound up bending a stock rod and a few other things, when he got a new motor it was a OBDII. One thing we noticed was the OBDI rods were a little more beefy.


----------



## Chapel (Jun 23, 1999)

*Re: OBDI vs OBDII ABA engines (tdogg74)*

also, the OBD2 Throttle body has to be flipped for Mk2 installs, the OBD1 throttle does not.


----------



## MkIIIJetta94 (Aug 4, 2007)

*Re: (wantacad)*

I have a German OBDII head for sale right now. It was a pain in the ass to mod, I had to have the bores for the springs honed for the dual stages to fit. http://****************.com/smile/emthdown.gif VW needs to make up their mind


----------



## victorpires1985 (Aug 30, 2008)

*Re: (MkIIIJetta94)*

I have a 96.5 Jetta.. Manufactured in march, assembled in mexico. It's an OBDI (Damn I hate it when performance parts web sites say that a 96 is OBDII







) I'm gonna check if it says Germany in the back. Might make me feel better lol


----------



## rado1234 (Apr 21, 2006)

*Re: OBDI vs OBDII ABA engines (tdogg74)*

Awesome write helps me out a lot!


----------



## Pitsy (Oct 27, 2007)

*Re: OBDI vs OBDII ABA engines (tdogg74)*

Probably won't stop the newb questions, but at least we now have a place to send them. Great write-up.


----------



## godoveryou (Apr 1, 2007)

*Re: OBDI vs OBDII ABA engines (Pitsy)*

You said that the head were interchangeable, but the OBD1 head has EGR provisions and OBD2 has SAI. How does one block off the EGR provision and allow the OBD1 head to use the SAI?


----------



## dubswede (May 21, 2006)

*Re: OBDI vs OBDII ABA engines (godoveryou)*

thank you for this. 
anyone point me in the direction of readings about the interchangeability of intakes, needs for ISV (removal of them), etc.? 
I have an obd2 jetta, want to buy a golf sport obd1 and swap my motor in it...i assume i'd just do so but would have to use golf's intake and wiring.
I need to read more. having a hard time finding it.

thanks again for the great info at the top. http://****************.com/smile/emthup.gif 

edited for clarifying the golf is OBD1, good lord.


_Modified by dubswede at 1:48 PM 11-23-2008_


----------



## godoveryou (Apr 1, 2007)

*Re: OBDI vs OBDII ABA engines (dubswede)*

As long as the Golf is an ABA, everything from you ABA Jetta will swap onto that ABA Golf since they are both OBD2, I know that. Spare OBD2 motors can be had up to a 01 Cabby as far as I know (maybe even later). It's when we start playing with OBD1 and OBD2 ABA Parts interchangability that I have questions. I'd hate to find out I had to wel shut a port on my new ODB1 head to make it work on my OBD2 motor.


----------



## dubswede (May 21, 2006)

*Re: OBDI vs OBDII ABA engines (godoveryou)*

thanks, edited due to my weak mindedness.


----------



## godoveryou (Apr 1, 2007)

*Re: OBDI vs OBDII ABA engines (dubswede)*

I can't remember what the original post said now, but that may have been my misreading as well.
Tends to happen







Mid-day on a Sunday, my mind goes a tad bit numb.


----------



## minimort (Feb 21, 2008)

*Re: OBDI vs OBDII ABA engines (godoveryou)*

I have an ABA from a 95 jetta. How can I tell if it is obd1 or obd2 just by looking at it?


----------



## dubswede (May 21, 2006)

*Re: OBDI vs OBDII ABA engines (minimort)*

the throttle body and whether or not it has an isv on the upper right side of the intake mani.

but afaik, it is 'cause it's a 95.


----------



## ShadowConspiracy (Feb 8, 2007)

*Re: OBDI vs OBDII ABA engines (dubswede)*

http://****************.com/smile/emthup.gif


----------



## kylekocsis (Aug 23, 2007)

*Re: OBDI vs OBDII ABA engines (ShadowConspiracy)*

i have a 94 golf that has the motor still in it, i also have a 97 complete spare aba motor thats obd2, i basically am going to use the golf as my beater, i want to build an all motor aba 16v for my mk2 gti 16v thats my main car and were all my moneys at so thats my baby, i want to know wat i need to do to the 97 motor to make it work in the golf so i can use the 94 aba motor as my build up since that seems to be the better of the two motors for a performance build for my mk2 (correct me if im wrong), i also already have a 16v head for it. some people also said to combine the two motors and make one beast one, using the 97 block and all the 94 internals but i kinda dont wana have to build two motors because i do need both cars to run. any help would be awsome thanks alot


----------



## jungle (May 6, 2002)

*Re: OBDI vs OBDII ABA engines (kylekocsis)*

so which of the oem cams would yield better performance? I know the differences are slight....but oem parts can be had for next to nothing. 
I have seen different compression numbers between the two, is that because of the "castle" on the pistions? The bore & strock numbers seem the same. If that is the case the odbII pistons would be prefable.
Lastly, will the block & head between a mkIII & mkIV swap back and forth? Again i know the bore & strock #'s are the same. The mkIV has 10:1 cr, not sure how they get the extra ~0.4 - 1.0 bump, if it is just a thiner head gasket of piston design.


----------



## akabigmike (May 2, 2003)

travis,
i just scored a full obd1 swap...whats the highest duration cam i can throw in it..before i need to change the valve springs and what not...


----------



## Jay-Bee (Sep 22, 2007)

*Re: (akabigmike2)*

I/m pretty sure i've heard him say ~.440" is the max to try with the stock/single springs.
I don't know what kind of lift the dual OBD-1's can support but it's a decent amount more than the OBD-2 ones.


----------



## gti8684 (Nov 29, 2008)

*Re: OBDI vs OBDII ABA engines (tdogg74)*

Great write-up http://****************.com/smile/emthup.gif


----------



## Zorba2.0 (Jan 28, 2005)

*Re: OBDI vs OBDII ABA engines (gti8684)*

haha, thats my melted piston http://****************.com/smile/emthup.gif 
That piston came from my 97'. I also melted a castle piston from the 96' j-yard motor I swapped in. I was cornfused when I saw two different piston types from motors only one year apart.


----------



## tdogg74 (Mar 1, 2002)

*FV-QR*


_Quote, originally posted by *akabigmike2* »_travis,
i just scored a full obd1 swap...whats the highest duration cam i can throw in it..before i need to change the valve springs and what not...


OBDI duals can handle .450" lifts.


----------



## Issam Abed (Feb 12, 2004)

*Re: FV-QR (tdogg74)*

ABA's are only good for the blocks and cranks


----------



## tdogg74 (Mar 1, 2002)

*FV-QR*

The amount of truth in that hurts. Heads are _crap_.


----------



## Dave's89GTI16V (Feb 8, 2000)

*Re: OBDI vs OBDII ABA engines (tdogg74)*

I need to swap a OBDI engine into a OBDII configed chasis what do I need to consider? Will it work? Just swap intake & exhaust manifolds?
Tks, Dave


----------



## luv2exl8t (Apr 11, 2008)

*Re: OBDI vs OBDII ABA engines (Dave's89GTI16V)*

excellent information 
ABA's are only good for the blocks and cranks 
X2


----------



## jungle (May 6, 2002)

*Re: OBDI vs OBDII ABA engines (Dave's89GTI16V)*

some of the sensors are different...


----------



## Unit01 (Dec 26, 2008)

This deserves a standing ovation.


----------



## 8vlove12 (Jan 8, 2008)

i have a 95 gti trying to figure out if im obd1 or obd 2


----------



## ps2375 (Aug 13, 2003)

*Re: (8vlove12)*

Most likely OBDI, there should be s label under the hood stating what emission standard it is certified for.


----------



## Ventooo (Nov 26, 2008)

*Re: (ps2375)*

hej I wanted to know where the obd1 had the scan tool port because my 1995 jetta has the scan tool port in the same place as my friends 1997?


----------



## ps2375 (Aug 13, 2003)

*Re: (Ventooo)*

All the mkIII's have the port in the same place.


----------



## Ventooo (Nov 26, 2008)

*Re: (ps2375)*

o my bad


----------



## 2low4fathoes (Apr 25, 2006)

*Re: (Ventooo)*

that helps alot with my rebuild. i was not sure what bottom end was in my 97 when i bought it. i knew the car was a clean project car before but was not sure on all of the specs. i now see that i have an obdI block. plus when i got an 94 block from the bone yard to start parting for a head rebuild; i then needed the rods and pistons from it, i knew i was getting better parts for my rebuild. i was not sure in the crank but now im safe to say that it is the better of the 2. thanks








just need to get my head stuff checked all out before i slap it together and get a compression test.


----------



## dustinwassner (Apr 4, 2009)

*Re: OBDI vs OBDII ABA engines (jungle)*



jungle said:


> so which of the oem cams would yield better performance? I know the differences are slight....but oem parts can be had for next to nothing.
> i am also curious which of the cams are better?
> awsome writeup
> 
> ...


----------



## tommyjunior (Apr 2, 2004)

*Re: OBDI vs OBDII ABA engines (tdogg74)*

If I wanted to convert an obd1 engine to obd 2 it could be accomplished by swapping the harness and the intake tract(including throttle body)? I would also need to add a second o2 sensor. Am I missing anything?


----------



## redzone98 (Jun 10, 2004)

*Re: OBDI vs OBDII ABA engines (tommyjunior)*

probably easier to grab the complete head / intake from the OBD2 engine as an assembly..


----------



## tommyjunior (Apr 2, 2004)

*Re: OBDI vs OBDII ABA engines (redzone98)*


_Quote, originally posted by *redzone98* »_probably easier to grab the complete head / intake from the OBD2 engine as an assembly..

But then I would have to upgrade the valve springs, and I don't want to get into that. Just need to know if anything else is required to swap to OBD2.


----------



## redzone98 (Jun 10, 2004)

*Re: OBDI vs OBDII ABA engines (tommyjunior)*


_Quote, originally posted by *tommyjunior* »_If I wanted to convert an obd1 engine to obd 2


_Quote, originally posted by *tommyjunior* »_
But then I would have to upgrade the valve springs, OBD2.

why are you going from OBD1 to OBD2 anyway?


----------



## mk2zach (Nov 7, 2007)

*Re: OBDI vs OBDII ABA engines (tdogg74)*

Will be using this soon. Just wanted to put it in my watched topics and really thought it needed to be back up.


----------



## tonythayer (Apr 3, 2006)

From this thread: http://forums.vwvortex.com/showthre...erman-head&p=67333370&viewfull=1#post67333370

"95 is obd1...german stamped is typically obd1. since it came with the throttle body, the easy way to tell is if the throttle position sensor is built into the tb or if it can be removed. if the tps can be removed, then it is obd1."


----------



## RAINWAGEN (Sep 25, 2008)

What would I need for 150-200hp out of a aba16v turbo set up what internals should I run. I need help choosing fueling ,turbo ,cams ect.... also what trannys do u guys recommend cuz I'm trying to get a parts list so I can figure out cost


----------



## The Big V (Jul 11, 1999)

great writeup! :thumbup::beer: tdogg74 thank you for all your TECH writeups as well!!! it's nice to have a reliable resource to go to. 

to *ADD* to the differences. late ABA models (specifically-- early '99 mk3-01' mk3.5 cabrio) OBDII have some sort of heater/sensor and vac line (going to throttle body) addition to the intake tube coming off the MAF/airbox. part # is 1HM 129 627F for reference or ETKA. 











*please keep content pertaining to the thread everyone!!! just make your own thread with personal questions etc and keep this for clean reference


----------



## Prof315 (Jan 5, 2009)

RAINWAGEN said:


> What would I need for 150-200hp out of a aba16v turbo set up what internals should I run. I need help choosing fueling ,turbo ,cams ect.... also what trannys do u guys recommend cuz I'm trying to get a parts list so I can figure out cost


 Stock internals will be ok at that level, just be careful with the tuning. Cast pistons melt easier than forged ones. 

As far as the rest goes. Megasquirt for engine control, 30# injectors, stock cams, and a tight trimmed T3 turbo ought to get you where you want to be. 10-12 psi should be all you need. Tranny.... 02A/02J period.


----------



## Old Windy (Apr 1, 2009)

:beer: Great information. Anybody has the part number for the castle pistons?


----------



## ADeHelian (Oct 1, 2009)

hey guys, I had a couple questions I was hoping you could point me in the right direction. I just crashed my OBD2 gti with an awesome running engine and a sweet gli close ratio trans :facepalm:, so needless to say I want to keep that duo, but the only donor cars I can find are all OBD1. What all would be involved with taking out the OBD1 engine and trans and swapping in my OBD2 engine and trans. I've already decided i'll need to swap the ecu, cluster, engine harness. But what else would I need to swap. Also I noticed while reading you said that the interals are all interchangable, so would I just be able to take the forged crank out of the donor car (assuming its in good condition) and slap it in place of my cast crank? thanks in advance. :thumbup:

-Adam


----------



## Fizzo20 (Mar 29, 2010)

So a few questions for you guys: 
*First off, regarding my ABA block* 
I was told it's from a 97, it has the smooth dished pistons and no oil squirts... obd1 or 2? Which one is better? Are there any codes on the block that'll help me find more info about it? 
*Secondly, ABA 16vt build* 
I wanna run somewhere between 300-400 hp and imagine stock internals will melt/blow. Are at least the stock forged rods sufficient for that @ ~25psi? If so, would there be a risk of bending them? Also would a forged crank be better? 
*Lastly, MK2 jetta coupe* 
I have a 1986 Jetta Coupe that I wanna swap this ABA 16vt into, what would be needed? 
What would an approx cost be for all this? $3000? 4? 

Thanks so much for the write up and any help I can get.


----------



## mizzuh (Oct 13, 2010)

from what I've read, the obd1 motor is "better" to some extent. intake manifold has no baffles, forged crank, oil squirters, dual rate springs, and a "simplified" timing belt guide. as far as pushing 300 hp. its possible on the stock bottom end. but the 10 to 1 compression ratio is whats going to kill you if you put boost behind it. you are looking at around 13.5 to one (give or take a few due to altitude and fuel rate) compression @ 5psi of boost. 

havent read enough build threads to tell you what the aba motor itself can withstand, but ive built enough cars to know the baseline of what to expect...start building from the ground up. or do a swap. 

ps. x2 on the awesome write-up


----------



## Fizzo20 (Mar 29, 2010)

mizzuh said:


> as far as pushing 300 hp. its possible on the stock bottom end. but the 10 to 1 compression ratio is whats going to kill you if you put boost behind it.


 I thought stock ABA pistons/rods yield an 8.5:1 CR with the 16v head which is perfect for boost. Is this wrong? Cause then I'll probably go JE or Wiseco pistons with IE rods ($800-$900 :banghead


----------



## mizzuh (Oct 13, 2010)

ah, didnt fully read your post. I thought you were using the full aba 8v. not sure on the 16 valve head swap. 

so to sum up everything i said, with your new info included......i dunno. lol.


----------



## ride4life154 (Jan 18, 2011)

*Obd ii - obd i help*

I have a '97 Jetta OBD II. I just bought a motor from a '95 jetta OBD I. What all do i have to do to throw my OBD I in my '97?


----------



## FATANG!! (Aug 21, 2007)

mizzuh said:


> *from what I've read, the obd1 motor is "better" to some extent. intake manifold has no baffles, forged crank, oil squirters, dual rate springs, and a "simplified" timing belt guide. *
> 
> havent read enough build threads to tell you what the aba motor itself can withstand, but ive built enough cars to know the baseline of what to expect...start building from the ground up. or do a swap.
> 
> ps. x2 on the awesome write-up


First off, this is awesome, x10 on this write-up

I don't know about the Timing belt guide (because I never got into that on an OBDII), but the rest of it I can, my car is a last quarter 1994 build date, and I had always wondered why my brother's car was a 2.sl0w when I drove it, but mine will turn it's nose up at the.phrase. The only place it falls on power is 3300-3900 rpm, does pull, but the power is even and not on the increase.

It has all of the OBDI parts for sure (I've been checking slowly but surely), the only things I'm wondering about, since I don't want to pull the head off, is how do I find out which piston is which through the spark plug hole?

For instance, what exactly would a unicorn piston look like (a picture would be killer), or because of the build date (Mexico btw) would it automatically be smooth dish, or are the "castles" easily visible and it's not a big deal to figure out, like the pictures with the head off? 

Also, I've been searching around my engine, and the forum, but I can't seem to find where exactly the "Germany" is supposed to be stamped if I even have it .

Lastly, if I go with an adjustable cam gear for my OEM cam, am I going to have trouble because it's different than most other ABAs? For instance, will the gear not fit, or because of the valve overlap, will I have interference problems sooner when advancing the cam? Or does the decreased in lift compensate for this? I'm thinking of advancing it about 4 degrees or less.

Once again, great write up, it should be required reading.


----------

