2L 20v running on race fuel

A&Q about 350Z
Q:

Hello, right then heres a little problem for ya! We've currently got an AGU 2l 20v which i am putting into a 2000 polo for VWracing, but as we got it from south africa and it used to race in a series over there, it has been built to run on race fuel, roughly 110 octane i think. But we're wanting to run it on standard pump fuel so we can possibly enter it into the VW cup. Is it the conpression that needs lowering to do this? and if so how would i go about it? can you get spacer plates made or would that be a bit sketchy?
Anyone had any experience with this before?
A:

how did you/ they achieve 2ltr's from the engine new crank ? bore? stroke? all of the above ???
A:

not sure mate, it's an AGU code and as standard is a 1.8. We've got another engine in bits which they sent us. what do ya want me to measure? i havn't got a vernier to hand though i'm affraid.
A:

But we're wanting to run it on standard pump fuel so we can possibly enter it into the VW cup. Double check VW Cup regulation before proceding, to make sure it meets the *engine swap* rules.
A:

not sure mate, it's an AGU code and as standard is a 1.8. We've got another engine in bits which they sent us. what do ya want me to measure? i havn't got a vernier to hand though i'm affraid.
i have been told they use a diesel crank to achieve 2ltr but dont tell me from what , any sizes would help ie bore , piston and rod length will help other than that i am not really sure
A:

Double check VW Cup regulation before proceding, to make sure it meets the rules.
I'm working for VWracing at the mo, apparently it goes, but if not then it will be sold on as a race/track day car...
A:

Sure - the reg says the engine needs to be older than the car & not vice versa. Suppose AGUs were around, I think, pre 2000, so I guess it qualifies.
I presume it's a normally aspirated 20V? On standard plenum or TBs?
A:

Right then, the bore is 82.511mm, and the rods are roughly 144mm centre to centre. I've tried to find a part number on the crankshaft but can't at all! this any help? If ya need anything else let me know.
A:

Chris, yeah it's NA on standard inlet but with a different throttle body. The saffers have made up an adaptor plate so this one fits. If anyone can make ETKA tell you what things are from then i can give you a part number. Any idea on making it run with pump fuel?
A:

Right then, the bore is 82.511mm, and the rods are roughly 144mm centre to centre. I've tried to find a part number on the crankshaft but can't at all! this any help? If ya need anything else let me know.
cheers i thought as much with the crank tho
A:

Right then, if this helps the throw on the crank is approx 50mm from centre of crank to centre of one of the big ends. The pistons are 82.45mm diameter, 49mm deep, and approx 30mm from the top of the piston to the centre of the gudgeon pin. I think the part number on the crank might be behind the timing chain gear which ain't comin of for nothin!
A:

yet again cheers for that info will be looking for various cranks now
A:

Thats alright mate, so, does anyone know anything about using race fuel and lowering compression ratio?
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What does the dialynx cars run on Chris?
A:

What does the dialynx cars run on Chris?
they have race fuel additives in 97 ron fuel
76 cool blue if i remember correctly
A:

Hello, right then heres a little problem for ya! We've currently got an AGU 2l 20v which i am putting into a 2000 polo for VWracing, but as we got it from south africa and it used to race in a series over there, it has been built to run on race fuel, roughly 110 octane i think. But we're wanting to run it on standard pump fuel so we can possibly enter it into the VW cup. Is it the conpression that needs lowering to do this? and if so how would i go about it? can you get spacer plates made or would that be a bit sketchy?
Anyone had any experience with this before?
Yr going to have to measure the cc of the combustion chamber in the head, head gasket thickness (cc again) and cc in the bowl and/or valve cut outs of the piston (if any), and work out yr current compression ratio. Dont the people you bought it off know ? if it really does need to run on race fuel they should know what they set the current compression ratio to surely.
If you do need to run a race fuel there are "pump fuel" based race fuels available, though obviously check yr regs.
I'd also imagine the crank is a 92.8, standard 2ltr VW, a diesel crank at 95.5 would take it over 2ltr.
A:

I'm pretty sure they know what the compression ratio is, 11:1 rings a bell but not 100%, i'll check tomorrow. Is it simply (lol) a case of lowering the compression ratio then? and if so by how much and what is the best way to do this?
Is the 92.8 and 95.5 the totall throw of the crank?
A:

You don't need to lower the compression ratio to use lower octane fuel, you need to alter the ignition timing. Race fuel generally goes up to about 106RON, although there is some other pretty potent stuff out there. If you have to use pump fuel BP do a 102RON fuel (although its about £2.50 a litre) or tesco 99RON which is a bit cheaper. The easiest way to lower the CR is to skim the pistons if they are thick enough or fit a couple of head gaskets - with a bigger risk of failure.
A:

i guess you already know this but AGU is early 1.8T motor.... turbo'd, and the non turbo same sized port head was ADR
Cyl heads are pretty similar if not identical. (big port)
A:

I'm pretty sure they know what the compression ratio is, 11:1 rings a bell but not 100%, i'll check tomorrow. Is it simply (lol) a case of lowering the compression ratio then? and if so by how much and what is the best way to do this?
Is the 92.8 and 95.5 the totall throw of the crank?
11:1 will be fine on pump fuel providing the Ignition timing is correctly mapped.
My new engine is 11.8:1 and will be run on V power worth some octabe boosert possibly thrown in for saftey on track.
A:

My new engine is 11.8:1 and will be run on V power worth some octabe boosert possibly thrown in for saftey on track.
mine runs 11.5:1 (stock vw compression) and runs fine on 95...
would of thought 11.8:1 isnt much different...?
A:

Thats interesting! The engine that was in it previously had was a 2L 8v which blew up. It was run on standard pump fuel, it was only after that we found out that it was meant to run on race fuel. I wasn't about when it was running but i presume that it wasn't mapped properly. Superchips is our ECU sponsor so hopefully they will be able to remap the ecu to use standard fuel. Is it just a case of retarding the ignition timing then?
A:

Basically yes. To get the most out of it you could get it on the dyno and redo fuel and spark maps.
A:

you would only need to alter compression if it was forced induction.
11.5 isn't that high though for a N/A car
A:

My new engine is 11.8:1 and will be run on V power worth some octabe boosert possibly thrown in for saftey on track.
mine runs 11.5:1 (stock vw compression) and runs fine on 95...
would of thought 11.8:1 isnt much different...?
What stock engines run 11.5:1?
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