reducing capacity of 1.8T

RobT

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Nov 30, 2001
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Thread rejuvenation - from 4 yrs ago.

Right then - might now have the time to think about this project a bit more.

Just bought myself a donor engine and have started talking to the right people. It'll probably take a couple of years but will be a very interesting experiment.
 
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RobT

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Ok - it has begun. I intend to detail quite a lot of the build of this engine on here so that when it is used to break class records, anyone doubting the legality of the build can see for themselves. This is the aim of this project, nothing else will do!

I have already heard from significant people in the know that the idea is totally above board before we even start.

1400-2000cc modprod engine rules are very free - although the block must remain externally identifiable as that originally fitted to the make of car, and the car must not jump into a different capacity class to that it would have been originally. Mk2 ibiza was an 1800 or 2000cc car, so using one of these engines to reduce the capacity, and then turbo is ok. Turbo multiplier is 1.4x, so 1428cc max.

As the stroke is to be reduced dramatically, a 'short block' engine would be the order of the day. There are several to choose from but why not start with that used in the Ibiza Kit Cars - the 'ADL' - the 16V head can be used also then. Could have chosen other short blocks such as ADZ, which is almost identical, but this one came with a 16V head and was the right price.

Just so happens I picked one up today - 126K miles from a running car. :funk:

Started stripping it down to make sure all bolt holes were ok - everything actually came off quite nicely. Once stripped of everything not to be used - which is pretty much everything - the block and head will go off for proper clean and inspection before anything else happens.

block1.jpg


block2.jpg
 

RobT

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Yep. Can use anything inside the engine so it will be a billet steel crank of the appropriate stroke.

My engine man already has one 'in stock'. Like you do....

1.8s use a 86.4mm crank, 2.0s a 92.8mm crank. Max you can physically get in a 1.8 block is a 94mm. Bigger will go in 2l blocks. Going shorter is easy.....got to figure out how much can ge sliced off the top of the block to save weight, then compression ratio, then pistons and rods the right length.

Big valve head for flow. Turbo cams.

No rush. Long term project.
 
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RobT

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More stripdown info

Head is the turbo-friendly 051 casting (051 103 373D), and from engine number, block is one of last ADLs produced. 126K miles but next to no bore wear - original honing visible. Damn these are good engines!
 

RobT

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Looks like someone else had the same idea....Keith Murray of Dialynx fame has built a 3c ModProd Audi 80 with a 1415 turbo

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http://www.youtube.com/watch?v=nqzsre2U7yM&feature=related

Will be out at Loton park next weekend so might pop down and have a gander.

http://www.hdlcc.com/Events/

By all accounts this is a fwd car rather than quattro, has a 16V head, and what engine it is based on is anyones guess. But you can bet it will be quick and have some mega trick electronics - Keith is no mug.
 

RobT

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These 2 door Audi 80 'sedans' are rather rare beasts, compared with the more common 2-door coupes that were popular in the Uk.

Looks like they were available with 4 and 5 cylinder motors, quat and fwd. Followng are intetesting reads

http://forums.vwvortex.com/showthread.php?1584391

http://preview.classicdriver.com/de...asp?print=true&lPageID=3100&id=3881&section=2

Not sure if i have ever seen one in the flesh.....seen loads of short wheel base sport quats......guess that makes them a super rare beast. V.Cool.

Edit. 1020kg for 4 cyl quat with 90ps 1800 8 valve......inpressive weight for 4wd
 
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RobT

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Picked up an excellent book called International Race Engine Directory, written by the excellent Ian Bamsey. Some very interesting info inside.....

1987, audi built a turbocharged gti engine for group c racing. It had an oettinger 16v head, 82mm bore, 94mm stroke, 39mm inlet valves, 36mm exhausts, 8.5:1 cr, 8500rpm. 136kg engine package. The block was apparently ideal for turbocharging as the block skirts extended below the crank centerline giving lots of strength. Porshe supplier did the crank. 2.4 bar, 560hp at 7800rpm.

BMW megatron m12/13. Based on road car block designed inthe 1950s and used in 2002, 3 series etc. 89.2mm bore, 60mm stroke, big valves, 11400 rpm, 160kg engine package. 16v head from f2 pragramme. 3.9 bar, 7.5:1 cr, 850hp in 1986. Powerband 8.5-10.5k. Quallyboost 5 bar, 1984, >1000hp. Water spray on intercooled used 3 litres per lap in qually. Monza 1986, Berger had a 5.5 barboost qually engine which made 1300hp.

Fantastic book.
 

RobT

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Nov 30, 2001
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Update on Murray Audi 80, I am hearing its 4wd (making it perhaps one of the rarest production Audis in existence) and get this....420hp. Yeh.
 

RobT

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1415T, yep. Based on roughly speaking 1.8 GTI block but using a 16v head (which is fine as head is free in modprod). Whether the block is original 2-door Audi 80 Quat is anyones guess.

Max T reckoned 400hp would be doable, clearly it is. Nice job. Going down to see it in action this weekend. Will see if Ican get a chat to Keith also.
 

RobT

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No question this is a quattro, sub 2 sec to 64 ft at loton today in practice (not many of any class of car can do this so clearly some trick traction control system at work) and only a sniff away from class record. What a motor :-o :clap:
 
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RobT

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Great day today at Loton Park for round of British Hillclimb Champs. Murray Audi 80 Quat was going very well indeed and smashed the class record for the hill which had stood since 2008. The car just looks SO planted and I have no doubt there is much more to come from this remarkable car. Had a good nose around it and there are some very very lovely touches.

murray1.jpg


murray2.jpg
 

RobT

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Article about Keith Murray's Series 2 Audi 80 Quat in this month's Audi Driver. Interesting read.

820kg - which is well light for a 4wd car

Engine is 'based on' a 1.8 JV-series block (1.8 carb engine which will be very similar to golf GTI engine) but reduced capacity has been achieved by sleeving the block to 77mm bore, and using a custom Farndon crank for 76.5mm stroke. Apparently renault 5 GTT pistons are used but they must be massively reworked as the R5 is an 8V and Keith runs a 16V head. Capacity=1415cc. Turbo is a massive (for a 1.4) GT30. Power=450hp at 2.2bar/10,000rpm.

What a car.

Love to know what Bill thinks of this article as the inlet manifold looks nothing special to me, but probably enough for 450hp?
 
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RobT

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Interesting alternative to reducing the capacity of a 'big block' 1.8 or 2.0, is to use a 1.4. The Mk2 ibiza came fitted from the factory with the highly regarded 'AFH' 1.4 16V (100hp) which in the hands of deceased tuner Sorg made 370hp....not at all to be sniffed at, you could see a 400hp motor from this system

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Nicely boosted through individual TBs a-la top end RallyCross motors

Stock engine: 76mm bore, 75.6mm stroke, 1390cc, 144mm rods, 10.5:1 CR

Not dissimilar dimensions to what Keith is running in his Quattro (76.5mm stroke)

Downside is that this block will not mate to the 020-type gearbox pattern and uses the smaller 085 pattern, and these are not strong enough. But Sorg made an adapter plate to fit the larger box and indeed the photo shows an 02A fitted I believe.

Food for thought - in 1400 capacity, these can make 185-200hp atmo so clearly have a lot of breathing potential so could be very good to boost.

Another pic of a home built eg:

gallery_78_66_109393.jpg
 
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