Actually, thinking about the whole debacle I decided to do some quick calcs for the 9A.... Data collected: Bore: 82.5mm Stroke: 92.8mm Head vol: 45cc Piston valve cutout vol: 1cc Piston block protrusion: 0.65mm Compressed head gasket: 1.5mm Using this data I actually come to the 9A being 10.8:1 which when searching around, is what most places quote. Gurds
aye later 9a/6a had abf head and zaust cam, the inlet cam is still lame but a lame version of the abf inlet cam rather than lame version of the kr inlet cam there is actually a good faq around somewhere which covers all the head castings for the 16v and which engines they were fitted to and at what times etc.
10.8:1 was the number i had in my head from somewhere for abf.. found this on tinterweb just now. from here> http://guy-croft.com/viewtopic.php?f=13&t=1274
Some of that doesn't seem right Bill. I am pretty certain that ABF's were: 150 PS (110 kW; 148 hp) @6000 rpm 180 Nm (130 lbft) @4600 rpm 10.5:1 Compression
Guy Croft!!!!! haven't heard that name in a very long time, use to get my UNO turbo and 8V twin cam heads from him back in my fiat days. ABF is 10.5:1 and 9a 10:1 from autodata. Which is more than likely wrong.
I have the proper vw engine repair manual, shows as: bore 82.5 stroke 92.8 cr 10.5:1 110kw @ 6000rpm 180Nm @ 4500rpm intake opens 1deg before TDC intake closes 30deg after BDC exhaust opens 39deg before BDC exhaust closes 1deg after TDC
9A Capacity 1,984cc Bore 82.5 x 92.8mm Ouput 136bhp at 5800rpm Compression Ratio 10.8:1 Maximum Torque 132lb/ft at 4400rpm (179Nm) (Corrado owners manual '92-'95)
its exactly the same engine as what you get in the uk corrado/passat. 9a is a 9a is a 9a. But yeah, 9a is a detuned engine no matter where you buy it
Interesting topic coming up here of the actual OEM compressions for the 9A/6A etc. When I was compiling this OEM outputs thread, I kept tripping over 10.8:1 references, aswell as 10:5:1, and settled for 10:5 for now. Could this be due to the later ABF head appearing on later versions? There are definitely early and late 9As in appearance (the 2 different block breather {metal then plastic}/oil take off designs {extra hole at the top} exist on 9As), and alteration of later heads would suggest a further makeover to allign the engine with the features of the ABF and taller blocks in general. This post perhaps points again to why we see 10.5:1 and 10.8:1 ? (Btw, may require a thread split in due course).
Interesting this topic of CRs. Even I thought the all 2.0 16v engines of this kind where 10.5:1 I have the 9A engine code as, 10:1 for North America applications, 10.8:1 for European applications, I do not know what effect the later post '94 051...D head would have on this as these have the same cc as the early type. A deeper dive shows engines ACE and 6A to be 10.5:1 and the AAL South African 16v KJet to be 10.2:1. Assuming all test machines where reading the same for homolgation, then we have torque for all of the above peaking at 129lbft to 133lbft. This matches what has been seen on the machine that was used in the comparison for STDish vehicles. What is brought out by discussing the result of the tested 9A MK2 and refering to the spec of the STD KE Motronic engine, is the vehicle in this test seem'd to hang on to torque much longer than if it where standard. This is why the bhp measurement peaked higher than the rest. Bearing in mind that the cal is only 85% matured, my expectations of what it should achieve when further developed with the benefit of the dyno, seems to be plausable.
would the metal head gasket make a significant difference to the cr? the early 9a/6a were fibre and later ones were metal abf ones. they did the same thing on the mk3 2.0 8v as well... classic cgti thread hijack chris maybe we could split all this cr discussion out into a new thread, I know how you like doing that. plus maybe you could add one of them tables that you love as well
These threads are what make CGTI what it is! Seems funny that VW list the 9A as having different compressions depending on the market - you would assume that it would have a different engine code as VW seem to like changing engine codes for the slightest little difference... Metal HG is an interesting thought. I always thought even though it was thinner, it "squished" to the same size as the fibre ones? Probably wrong, and somebody is guaranteed to know in this thread lol. I find it odd how many different quoted figures there are. I think the 136 bhp vs 134 bhp can be attributed to 136 PS equalling 134 bhp and the 132/133 lbft just being different rounding from the Nm conversions perhaps?
it may well be the bentley is wrong, it has been in the past though very rarely. even etka lists the wrong power for a mk2 valver!
where did VW get the 139bhp for the KR in the golf versus 136 in the corrado and Passat??? It's not down to inlet manifoilds as late mk2's had the same as the Passat and Corrado, and they all had the same exhaust manifolds, downpipes, cams etc. In theory then a 42mm inlet 1992 mk2 16v should be 136bhp. Marketing, minor production changes, VW's testing of engine batches, all sorts of factors affect the figures quoted. Reality is most VW engines of this era varied wildly when new anyway, there were good and bad ones off the transporters, purely from manufacturing tolerances, so even on identical new engines 5 or 6 bhp difference was common. I know this as my dad was involved in 4 pot VW engine development at GTI Engineering in the 80's, in many cases engines were stripped out of cars and run in controlled conditions on a testbed. The thing about VW engine numbers is a little more complex too, as specific engine production number ranges determine the components used and not the main engine code e.g. 9A
