VW ABF 2.0lt 16v Engine Build Planning

[Georges Fonso]

Hello All!
First of all, I’d like to wish everyone a happy new year, above all with good health and, of course, with lots of success for all of your ventures.

I’d like to have your opinions and, hopefully, experience, on the engine project I’m about to start, hopefully around February...
The engine is a VW ABF 2.0lt 16v 150Ps, as used in VW Golf Mk3GTi et al. It will be installed in my 1986 VW Golf Mk2 GTi and face double duties, as a road/ trackday car.

Some vital stock engine stats:
--Max Power: 150Ps@6400rpm
--Max Torque: 17,8kgm (129lb.ft) @5000rpm
--Bore x Stroke: 82.5 x 92.8mm
--Compression ratio: 10.4:1
--Compression chamber: hard to describe, basically a 4-valve wedge/pentroof “hybrid”? It is inclined in relation to the block face, inlet valves are at about 40degrees off horizontal reference plane, whereas the exhausts are at right angle to the horizontal, i.e. their heads are face-to-face with the piston crown. The spark plug is centrally mounted. I include some photos taken from various internet sources, since I find it a bit hard to illustrate in writing. – GC, if you think that conflicts with copyright policies, please advise and I will remove at once
--Valve size: 32mm inlet/ 27mm exhaust
--Connecting rods: 159mm center to center.
--Piston Pin: 21 x 60mm
--Stock crank is fully counterbalanced (eight couterweights), and of forged steel construction.
--Main bearings journals are 54mm dia and big ends 46mm
--Piston rings are 1.2 / 1.5 / 2 mm
--With no clearance the camshafts are about 254° duration, with 10,76mm intake lift / 10,73mm Exhaust. Timing figures at 1mm lift are 1-38 / 39-1

The concept is to build a decent long engine and, initially, utilize some existing “power parts” from my 1.8 16v engine, to keep budget and setup time within reason.
My first target is 200 crankshaft HP with a 8.000rpm redline (stock redline is 6800rpm, i think). Ideally, I’d like the bottom end to be usable for further upgrade to throttle bodies, EFi and hopefully 9000+rpm – but that’s another story, not to be considered at the moment

So, existing parts are:
--Piper “Ultimate Road” cams. Intended for Hydraulic lifters, they are timed 29-65 / 66-30, i.e. 274/276 deg with 11.00 / 11.43mm lift respectively, 108deg full lift both
--Janspeed 4-1 exhaust manifold, custom made 55mm o.d. exhaust with two straight-through silencers
--Complete Dellorto DHLA45E carb setup. I have lots of stuff to set them up properly for the 2-litre once it is run in (emulsions, jets, 36mm through to 41mm chokes, alternative rampipes etc), and I already have them running on the 1.8 with 38mm chokes.
--MBE 957i mappable ignition ECU
--MSD HVC Ignition box and HVC Coil
--Magnecor KV85 ignition leads
--Schrick finned and baffled alloy oilpan
--Adjustable timing pulley, adjustable inner cam sprockets (in this engine the timing belt drives the exjaust camshaft, and this, in turn, drives the intake via a short chain)
--Oil cooler installation featuring Mocal 19-row 330mm wide core and 75deg oilstat, -12 oil lines

New engine planned spec, open to discussion and advice:
--Mild knife-edging of crankshaft counterweights (trailing and leading edges), dynamic balancing
--Lightweight 228mm (G-60 style) CroMo flywheel (appr. 4,5kg)
--4340 H-Beam conrods, possibly Wossner or Arrow
--0.25mm cylinder boring/ plateau honing (in order to remain eligible for 2-litre classes in trackdays)
--Wossner forged pistons 12:1 C.R.
--Total seal piston rings, gapless 2nd ring configuration
--Crank scraper from fellow CGRE forumist Kevin Johnson, along with VW TDi crank splash shield
--New OEM oil pump (classic twin gear design, 36mm wide gears)
--Balanced auxiliary shaft (on the 16v its only use is driving the oil pump), new shaft bearings
--Glyco trimetal main and big end bearings
--ARP hardware throughout the engine (main caps, head studs, rod & flywheel bolts)
--Fully ported and polished cylinder head
--New valve guides
--Schrick valves intake and exhaust
--Schrick valve springs, steel retainers and valve locks
--New OEM hydraulic lifters
--OEM Goetze gasket kit (it includes 83.5mm MLS head gasket and viton seals)

And now to the project’s “dark spots”:
-- I think my exhaust system will be a bit marginal for the new engine. Current manifold primaries are 39mm i.d., about 60cm long. I consider a Golf Mk3 Kit Car style ex. Manifold, with 42mm i.d. primaries instead of the Kit Car’s 45mm i.d. primaries. Primary length will be a bit longer, around 65cm, and collector outlet will be 60mm o.d. (57mm i.d.), same as the rest of the new exhaust. For the rest of the exhaust I am considering a 5-litre “expansion chamber” about 30cm downstream of the collector, and two straight-through silencers, as big as they can get, mostly for reasons of exhaust loudness. Your views on this layout?
--Previous incarnations of this engine in 1.8lt and 2.0lt form (KR/PL/9A engine codes) used 28mm exhaust valves. Are they to be preferred? If so, can they be installed by enlarging the existing exh valve seats, or shall I be replacing them? In that case, what sort of seats to use?
--I am considering the main bearing girdle from Eurospec Sport (see attached pic). I like the concept but feel unsure of its actual merits for my application. Any experience/ views on this?
--What sort of head flow/ dimensions should I be after for my application? Apart from that, what sort of flow is this head capable of and with what sort of compromise, if any?
--The intake ports show (by eyeballing, at least), a great bias of flow towards the left intake valves (as seen from the port opening, with the gasket surface facing downwards). Is this a feature to go along with the stock EFI inlet manifold routing, or is it also contributing to some sort of intake charge swirl? I think the combustion chamber shape lends itself to such a concept. Can/ should it be tampered with?
--Can the VW crank be considered reliable at this sort of revs and power?

I’m open to all sorts of input on the subject, please let me know what you think of it! Is there anything you would add/ omit/ modify or change in the above spec? Is my 200BHP target realistic, or should I slow down in order to avoid disappointment? What sort of power curve should I be expecting?

I really appreciate your interest in such a long post.
Many thanks in advance!

Georges Fonso

[Acki]

Nice post :)
Some friends of me drive fast VW's. They always said the ABF engine is the worsest 2l engine VW ever made.
They often use the KR or PL engines. The heads of KR and PL shall be the best.
I think the KR inlet camshaft had a longer timing than the PL.
But you use other camshaft, so it's only a information for you.
Exhaust valves are sodium filled. But it give a KR head with bigger channels then other. In remember te headnumber 027?! I can ask my friend when you need something about this.
My friend prefer Audi blocks because the have better rods. Hartmann Motorsport had sold them years ago as motorsport conrods.
You can install it plug'n'play. That's the best on the VW/Audi engines.

For the hydraulic lifts you can buy lighter lift from Dr. Schrick. For high revs you need this or you install mechanic lifts.
Bearings the turbo guys often use Audi RS2 bearings or G60. But the RS2 shall be the strongest.

When you need Wössner pistons I can help you. I have seen in UK they are very expensive. Don't know why?!

[Georges Fonso]

Hello, Acki!
Thank you very much for your input!
I think the KR/PL vs ABF "theory" lends itself to some common misconception/ urban legend. True, as they come from the factory, the KR/PL heads have larger cross-section throughout their ports and they also have bigger exhaust valves. Is that really significant when you are going to do porting anyway? What I see as significant in relation to the ABF head is that the floor of the intake ports is more curved, in a way extending the port's short side radius upstream of the valve seat throat, thus giving more options for efficient porting and smoother curvature of the ported SSR. Also, the ABF has a slightly modified (improved??) combustion chamber (obviously, the combustion chamber photos I've posted are from KR/PL), featuring two small "bulges" either way of the spark plug hole, located between the inlet and exhaust valves. They are said to have been put there by VW in order to optimize inlet valve discharge at lower lifts and to prevent excessive incoming charge spillage towards the exhaust at TDC valve overlap. Some expert input and first-hand experience on the above would be duly appreciated!
Anyway, the ABF head is what i have at hand anyway, along with the block, and I don't want to take my old KR engine apart -- you never know when a spare long engine can prove handy, even though i have high hopes for the new engine spec's ability to hold itself together at 8krpm... ;)
Conrods are to be changed anyway, I shall take no risks there. I like the peace of mind of forged rods and, since I read GC's comment on I-beam strength vs H-beam strength I've started fancying designs such as the one from Pauter Machine -- anybody ever tried those?
OEM hydraulic lifters are dirt cheap and VW p/n 050 109 309 H are lightweight, almost comparable to Schrick lifters, at half the price if you get them from the aftermarket, e.g. from INA (which also makes them for VW in the first place).
Bearings... As a matter of fact, the bearing shape and dimensions are the same across all 827 4-cyl blocks and, of course, the 5-cylinder sibling, the difference being the quality chosen from the factory. RS2 bearings and G60 bearings are trimetal, same as Glyco, Vandervell, ACL and perhaps others in the aftermarket. Glyco is my favorite brand, with Vandervell/ Floquet Monopole the second best, even though this is more a matter of personal preference I suppose...
Thank you for your offer to help with Wossner, I really appreciate it. I work very closely with the importers for Greece, so the pistons are not a problem.

Once again, thanks a lot for your advice!
Best regards,
G.F.

[Acki]

I have bought Pauter conrods. Looking very nice :)
The turbo drivers always said they made differences between G60 and RS2 bearings.
Hmm I can try to speak with my friends about the ABF engine.
The 2nd picture from the head I would prefer. But maybe GC can tell you more. :)
But why you don't use DCOE carbs or a programmable injection?

[Georges Fonso]

Acki,
Fuel injection is a no go at the moment, and I will certainly agree with GC's views on mappable EFi when not carried out the way it should. I believe Dellortos will give me the power i want and, on top of that, I am quite familiar with them, have lots of spares and accessories, so why not continue capitalizing on this quite substantial investment? Plus, they sound great too, FWIW anyway... I don't think they lack anything compared to the Webers, and I find their five progression holes a handy feature when you deal with a "touchy" engine which will inevitably be driven in traffic from time to time.
Programmable ignition, on the other hand, is something the engine will most definitely need since the standard distributor has no advance mechanism and the K-Jetronic ECU cannot be mapped in this respect, well at least nobody seems to even care trying to modify it. I also have the ignition components already, therefore it's the obvious solution. It should also be a neat installation as well, since the ABF block has a built-in 60-2 crank trigger.
G.F.

[RedLexus]

On the Club.gti forum , there's quite a lot of info on this engine . I plan on dropping one into my MK1 Golf , KR's and PLs etcc are all well and good , but the ABF is much newer and easier obtainable .