Daisy chaining 2cv engines together
Discussion
How daft an idea is this.
2CV engines are lightweight and given high compression pistons turn out in the region of 35-40hp. What if you were to join two engines together along the crankshaft?
Essentially a 4 cylinder, air cooled, lightweight 80hp engine. Now drop that in a mk2 polo and you have a very simple, 160 bhp per ton track car.
Now, as I know nothing tell me what I’ve missed. The obvious ones being
• How do you do the actual joint (UV joint?)
• Gearbox and clutch?
• Would the bearings hold out?
• Could you run them as separate engines or would you have to convert them to injection and run a single ecu?
2CV engines are lightweight and given high compression pistons turn out in the region of 35-40hp. What if you were to join two engines together along the crankshaft?
Essentially a 4 cylinder, air cooled, lightweight 80hp engine. Now drop that in a mk2 polo and you have a very simple, 160 bhp per ton track car.
Now, as I know nothing tell me what I’ve missed. The obvious ones being
• How do you do the actual joint (UV joint?)
• Gearbox and clutch?
• Would the bearings hold out?
• Could you run them as separate engines or would you have to convert them to injection and run a single ecu?
[quote=(steven)]How daft an idea is this.
2CV engines are lightweight and given high compression pistons turn out in the region of 35-40hp. What if you were to join two engines together along the crankshaft?
Essentially a 4 cylinder, air cooled, lightweight 80hp engine. Now drop that in a mk2 polo and you have a very simple, 160 bhp per ton track car.
Now, as I know nothing tell me what I’ve missed. The obvious ones being
• How do you do the actual joint (UV joint?)
• Gearbox and clutch?
• Would the bearings hold out?
• Could you run them as separate engines or would you have to convert them to injection and run a single ecu?
[/quote]
sounds like an interesting idea!
i guess if you where doing it in your shed then you would just join the two engines together, crank to crank. you would problably have to make some kind of frame to stop the engines from snapping the join. you could use a shaft but thats going to make the engine long.
alternatively you could look for a diffrent engine.
i hear the scooby lump fits into a madded front end of a polo. fab a RWD box, or convert the $wd into a FWD and you have more power than you could ever want for the polo. 
thanks Chris.
PS. have you thought about a snowmobile engine??? these little 2stoke make MASIVE power for there size and weight. think the race stuff is getting over 300bhp form 900cc triples!! now that could be a very nice engine!
2CV engines are lightweight and given high compression pistons turn out in the region of 35-40hp. What if you were to join two engines together along the crankshaft?
Essentially a 4 cylinder, air cooled, lightweight 80hp engine. Now drop that in a mk2 polo and you have a very simple, 160 bhp per ton track car.
Now, as I know nothing tell me what I’ve missed. The obvious ones being
• How do you do the actual joint (UV joint?)
• Gearbox and clutch?
• Would the bearings hold out?
• Could you run them as separate engines or would you have to convert them to injection and run a single ecu?
[/quote]
sounds like an interesting idea!
i guess if you where doing it in your shed then you would just join the two engines together, crank to crank. you would problably have to make some kind of frame to stop the engines from snapping the join. you could use a shaft but thats going to make the engine long.
alternatively you could look for a diffrent engine.
i hear the scooby lump fits into a madded front end of a polo. fab a RWD box, or convert the $wd into a FWD and you have more power than you could ever want for the polo. thanks Chris.
PS. have you thought about a snowmobile engine??? these little 2stoke make MASIVE power for there size and weight. think the race stuff is getting over 300bhp form 900cc triples!! now that could be a very nice engine!
Depends on the "kind" of power you need. IIRC Snowmobile engines are very much like bike motors - very revvy. Be easier to just use an established bike engine.
Orrrr - a mercury V6 outboard - 2.5 litre V6 producing anything from 200 to 400 horsepower in the lightest possible package and still with a decent amount of torque. Not great mpg or emissions though, but has been done in the states for various offroad vehicles, including 1 variant that used a gimler belt for drive.
Orrrr - a mercury V6 outboard - 2.5 litre V6 producing anything from 200 to 400 horsepower in the lightest possible package and still with a decent amount of torque. Not great mpg or emissions though, but has been done in the states for various offroad vehicles, including 1 variant that used a gimler belt for drive.
MattYorke said:
Depends on the "kind" of power you need. IIRC Snowmobile engines are very much like bike motors - very revvy. Be easier to just use an established bike engine.
Orrrr - a mercury V6 outboard - 2.5 litre V6 producing anything from 200 to 400 horsepower in the lightest possible package and still with a decent amount of torque. Not great mpg or emissions though, but has been done in the states for various offroad vehicles, including 1 variant that used a gimler belt for drive.
intresting! didn't really think about the boat stuff! what sort of gearboxes do the off road guys use?? got any more info on the engines?? getting 400bhp from 2.5 ltr is no mean feat! Orrrr - a mercury V6 outboard - 2.5 litre V6 producing anything from 200 to 400 horsepower in the lightest possible package and still with a decent amount of torque. Not great mpg or emissions though, but has been done in the states for various offroad vehicles, including 1 variant that used a gimler belt for drive.
Chris.
Sam_68 said:
thong said:
citroen's already done it for you
So has Volkswagen, for that matter... Only reason I am looking at air cooled engines is it brings down weight and complexity a lot. Potentially I am barking up a strange and potentially expensive tree here. Even if I find a engine to fit which has a decent power output (Need 80hp minimum really) I fear the cost of getting it mounted and joined to the drive wheels is going to be rather offputting.
I'd have thought that installation in a FWD Polo would be more hassle than it's worth, given the marginal weight advantage that you'd achieve, to be honest.
The more pragmatic approach, if you want a small hatchback track car would be to find yourself a stolen /recovered Seat Ibiza Cupra... basically the Polo floorpan with a 160bhp engine and a decent handling/suspension package already developed for you by those nice people at VAG.
If you really are determined to go the aircooled flat-4 route, the Beetle engine is still the better option. There are loads of tuning parts available. The engine is aslo sued in Formula Vee single seaters, so there's tuning knowledge available from that source, too.
80bhp wouldn't be a problem for the Beetle unit. IIRC 130bhp is considered quite achievable from the larger capacity variants of this engine.
The more pragmatic approach, if you want a small hatchback track car would be to find yourself a stolen /recovered Seat Ibiza Cupra... basically the Polo floorpan with a 160bhp engine and a decent handling/suspension package already developed for you by those nice people at VAG.
If you really are determined to go the aircooled flat-4 route, the Beetle engine is still the better option. There are loads of tuning parts available. The engine is aslo sued in Formula Vee single seaters, so there's tuning knowledge available from that source, too.
80bhp wouldn't be a problem for the Beetle unit. IIRC 130bhp is considered quite achievable from the larger capacity variants of this engine.
450hp is often seen from turbocharged beetle engines- still as crap as a 2CV engine though. The reason they are easy to increase the power on is because they were crap in the first place!
Get a 13c turbo from a Volvo 940 (too small for the Volvo, perfect for the Polo), slap it on the Polo engine, Megasquirt it and you have a fast engine with much less effort
Get a 13c turbo from a Volvo 940 (too small for the Volvo, perfect for the Polo), slap it on the Polo engine, Megasquirt it and you have a fast engine with much less effort
BB-Q said:
Get a 13c turbo from a Volvo 940 (too small for the Volvo, perfect for the Polo), slap it on the Polo engine, Megasquirt it and you have a fast engine with much less effort
Had considered something similar (supercharging as that doesn't need an oil tap), just I can't find anything on the polo engines on the net. Obvious question being can the engine internals take turbo charging? I would have thought I would need to fit low compression pistons etc etc. Are the stock internals okay for a little bit of power tuning? Does anybody know if they changed anything in the engine for the G40?
thong said:
citroen's already done it for you
http://www.citroen.mb.ca/cItROeNet/passenger-cars/...
I had one of those. You could (if you wanted to) start it with a crank handle! And I think the brake system worked on a on/off valve as it was all or nothing.http://www.citroen.mb.ca/cItROeNet/passenger-cars/...
Having no water jacket it did not like the cold for starting but the heating was instant as it used some heat exchanger system.
Morningside said:
thong said:
citroen's already done it for you
http://www.citroen.mb.ca/cItROeNet/passenger-cars/...
I had one of those. You could (if you wanted to) start it with a crank handle! And I think the brake system worked on a on/off valve as it was all or nothing.http://www.citroen.mb.ca/cItROeNet/passenger-cars/...
Having no water jacket it did not like the cold for starting but the heating was instant as it used some heat exchanger system.
Edited by dern on Thursday 27th September 22:00
thong said:
citroen's already done it for you
http://www.citroen.mb.ca/cItROeNet/passenger-cars/...
That is just crying out for a pair of twin choke downdraught carbs...http://www.citroen.mb.ca/cItROeNet/passenger-cars/...
Morningside said:
I had one of those. You could (if you wanted to) start it with a crank handle!
All cars ought to have a starting handle, it ought to be a legal requirement. Especially for automatics.Check out the compression ratio as standard. With careful tuning you should be able to run up to 5lb of boost at ratios of upto 10:1, using Super Unleaded. Rods have a bit of an easier time under boost as they constantly subjuected to the same compressive force rather than being forced from compression to extention on the intake stroke. For 5lb of boost you should get away with stock internals just fine. Use a cheap generic Ebay intercooler (far, far better than anything that came on a production car, with the exception of the Cosworths)and you'll be fine.
But a word of warning- boost is very addictive!
But a word of warning- boost is very addictive!
Not sure about mating 2 X 2CV engines together really... However, I've got a tiny turbocharger sitting in my garage which was removed from a 700cc 3 pot Smart car engine.. I wondered for a while what uses it could be put to. It was only yesterday, or the day before that I thought it could be quite fun on a 2CV engine. Preferably still attached to the rest of the 2CV mind.
P,
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