Discussion
First off I'd like to say this isn't strictly a reader's car as this is little more than a pipe dream at the moment, however...
My plan of action is to take a mega-miles but solid Audi Coupe of mid 90's fame, tear out its heart and electronics and replace it with a period Audi 4.2 V8 (BCS engine code I believe from an S8). 'It's been done before!', I hear you shout, but I'm interested in carbing this one.
So far as I can tell, it's 'simply' a matter of rigging up a new inlet manifold onto which the carburettor can be attached, linking the HT leads to a distributor which is in turn linked to a coil pack and doing away with all the nasty electronics. A new loom would be made up encompassing all things electrical (starter, lights, new low pressure fuel pump etc.) all activated with various switches and buttons on the dash. The injectors would be left in place unconnected to plug the holes they sit in.
Now I know the engine can be fitted, but I'm unsure as to whether this is feasible, what with the new fueling and ignition system, along with (possibly) electronic bits and pieces I can't do much about (oil pressure, engine temperature and VVT). I say possibly as I am unfamiliar with these engines and don't know what parts beyond the obvious are controlled by the ECU.
If anyone can give advice as to the feasibility/idiocy of this dream, it would be much appreciated, as would any information regarding the engine.
Many thanks in advance!
(If this is in the wrong forum, apologies.)
My plan of action is to take a mega-miles but solid Audi Coupe of mid 90's fame, tear out its heart and electronics and replace it with a period Audi 4.2 V8 (BCS engine code I believe from an S8). 'It's been done before!', I hear you shout, but I'm interested in carbing this one.
So far as I can tell, it's 'simply' a matter of rigging up a new inlet manifold onto which the carburettor can be attached, linking the HT leads to a distributor which is in turn linked to a coil pack and doing away with all the nasty electronics. A new loom would be made up encompassing all things electrical (starter, lights, new low pressure fuel pump etc.) all activated with various switches and buttons on the dash. The injectors would be left in place unconnected to plug the holes they sit in.
Now I know the engine can be fitted, but I'm unsure as to whether this is feasible, what with the new fueling and ignition system, along with (possibly) electronic bits and pieces I can't do much about (oil pressure, engine temperature and VVT). I say possibly as I am unfamiliar with these engines and don't know what parts beyond the obvious are controlled by the ECU.
If anyone can give advice as to the feasibility/idiocy of this dream, it would be much appreciated, as would any information regarding the engine.
Many thanks in advance!
(If this is in the wrong forum, apologies.)
Why do you want to fit a carb?
If its for ease of installation and simplicity, then in my opinion its the wrong way to go about it. Converting an engine to carb that was originally designed for injection is quite a bit more difficult than it seems! You'll NEVER get it running as smoothly, efficiently or as powerfully/torquey as it would be on the standard injection.
You mention a distributor - do you know if the engine has the ability to drive a dizzy? It's not just a case of bolting it on, there may not be a suitable place and if there is somewhere you'll need to find an 8-cylinder dizzy with the correct drive to fit the camshaft (which is the most likely suspect), or make a suitable adaptor plate. Then you'll need to rig up a trigger wheel on the crank pulley in order to drive the coil pack - quite a lot of work and figuring out of things to get it to work with an 8-cylinder engine.
If its for reasons of 'doing something different' then I can sort of understand, but it seems to be to be slightly backwards to take a reasonably modern mid-90's car that at the very least would have had mechanical fuel injection (9A 2.0 16V) and fitting a carb. You'll likely need to find a V6 or possibly 5-cylinder base vehicle for ease of engine mount installation, and the V6 comes fully equipped with quite advanced EFI already.
The V8 conversion itself sounds great, but if you're using the engine from a S8 of a similar vintage you may well find that the wiring transplant is easier than you think. There might be quite a lot of similarities in the looms and its actually quite satisfying spending time figuring out wiring looms using wiring diagrams, and even more satisfying when it all works
Not trying to poo-poo your idea, but I just think there's a lot more thought to go into it to make sure you're not going to get halfway through the project and decide its a waste of time.
If its for ease of installation and simplicity, then in my opinion its the wrong way to go about it. Converting an engine to carb that was originally designed for injection is quite a bit more difficult than it seems! You'll NEVER get it running as smoothly, efficiently or as powerfully/torquey as it would be on the standard injection.
You mention a distributor - do you know if the engine has the ability to drive a dizzy? It's not just a case of bolting it on, there may not be a suitable place and if there is somewhere you'll need to find an 8-cylinder dizzy with the correct drive to fit the camshaft (which is the most likely suspect), or make a suitable adaptor plate. Then you'll need to rig up a trigger wheel on the crank pulley in order to drive the coil pack - quite a lot of work and figuring out of things to get it to work with an 8-cylinder engine.
If its for reasons of 'doing something different' then I can sort of understand, but it seems to be to be slightly backwards to take a reasonably modern mid-90's car that at the very least would have had mechanical fuel injection (9A 2.0 16V) and fitting a carb. You'll likely need to find a V6 or possibly 5-cylinder base vehicle for ease of engine mount installation, and the V6 comes fully equipped with quite advanced EFI already.
The V8 conversion itself sounds great, but if you're using the engine from a S8 of a similar vintage you may well find that the wiring transplant is easier than you think. There might be quite a lot of similarities in the looms and its actually quite satisfying spending time figuring out wiring looms using wiring diagrams, and even more satisfying when it all works
Not trying to poo-poo your idea, but I just think there's a lot more thought to go into it to make sure you're not going to get halfway through the project and decide its a waste of time.
I agree with Tom. I reckon that you are thinking it will be easier to get it running on carbs, but this is entirely the wrong approach. If you take the engine electronics as a whole, all you need to do is get 12V power going into them in the right places, and find any sensor outputs you need to make the instruments etc work. The only sticking point might be if you change from an auto to manual box.
Doing it your way, you have a complicated chunk of electronics, and you are trying to remove half of them and replace with mechanical devices that work in the same way. Keep the EFI, and you just have to "reanimate" the engine electronics rather than modify them at all.
Doing it your way, you have a complicated chunk of electronics, and you are trying to remove half of them and replace with mechanical devices that work in the same way. Keep the EFI, and you just have to "reanimate" the engine electronics rather than modify them at all.
I don't think anyone is trying to pee on my parade as it's this kind of advice I'm looking for, constructive or otherwise. I've no intention of starting something that won't be worth it, hence my asking. Unfortuntely I work with modern vehicles and never come across anything pre-ECU and my knowledge of carb run engines is minimal.
While keeping the electronics would be the sensible thing to do, there's something about good to honesty motoring that does it for me. I was looking at sourcing a 60's-70's Chevrolet/MOPAR engine, but this would be a massive gamble owing to their age if bought privately, and to buy a professionally rebuilt engine is ££££'s. Rover V8? No thanks.
Granted the modern engine on carbs wouldn't run as nicely, or return decent economy (miles per what?), but it's the challenge of doing it that appeals to me. However having said that, if it's going to be a massive pain in the proverbial then it might be better to stick with a safe bet.
As mentioned above, an auto to manual box could present an issue (another reason for wanting to lose the computer) as I'm assuming (the mother of all f
k ups) that most S8's were sold with the 5 speed auto, and finding an engine that was mated to the 6 speed manual might be difficult. With no computer, I can mate a manual gearbox to any engine regardless of what it's original configuration was.
Anyway, this is little more than an exercise in information gathering at them moment.
Edit: Dr G, could you please post a link to said thread?
While keeping the electronics would be the sensible thing to do, there's something about good to honesty motoring that does it for me. I was looking at sourcing a 60's-70's Chevrolet/MOPAR engine, but this would be a massive gamble owing to their age if bought privately, and to buy a professionally rebuilt engine is ££££'s. Rover V8? No thanks.
Granted the modern engine on carbs wouldn't run as nicely, or return decent economy (miles per what?), but it's the challenge of doing it that appeals to me. However having said that, if it's going to be a massive pain in the proverbial then it might be better to stick with a safe bet.
As mentioned above, an auto to manual box could present an issue (another reason for wanting to lose the computer) as I'm assuming (the mother of all f
k ups) that most S8's were sold with the 5 speed auto, and finding an engine that was mated to the 6 speed manual might be difficult. With no computer, I can mate a manual gearbox to any engine regardless of what it's original configuration was. Anyway, this is little more than an exercise in information gathering at them moment.
Edit: Dr G, could you please post a link to said thread?
Edited by Alias218 on Saturday 14th January 13:10
Sounds like an awesome project, but I would look into individual throttle bodies rather than carbs. People have fitted Direct-To-Head throttle bodies to the ABZ engine before (as it's basically two 16v engines joined at the crank), I imagine something similar could be done with the S8 motor.
Have a browse on Motorgeek- quite a few V8 powered Coupé Quattros on there.
Have a browse on Motorgeek- quite a few V8 powered Coupé Quattros on there.
Hi there,
I put mine up for sale a while ago, don't want much for it considering the value of the parts, just don't have time to work on it.....have a look anyway!
http://www.s2forum.com/forum/showthread.php?t=5291...
cheers
Skinner
I put mine up for sale a while ago, don't want much for it considering the value of the parts, just don't have time to work on it.....have a look anyway!
http://www.s2forum.com/forum/showthread.php?t=5291...
cheers
Skinner
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