Tuning Engine swap

[Abarth 695]

Hi I know this has been mentioned before and that retro500 have the main projects here in the UK but their forum doesn't seem to work.

I want to swap the engine to something more powerful and looking at costs it is cheaper to put a none fiat 500 engine in than modify the existing one. The project will happen over this winter with a full restoration of the car including brakes and chassis upgrades. I have searched the net and have seen these conversion:

Water-cooled:
-fiat fire engine using existing gearbox
-subaru engine using existing geartbox
-motorbike engine in rear seats and chain drive to axle

Air-cooled:
-Moto-guzzi engine

I want to retain the rear compartment and integrity if the chassis so would prefer a subaru or air cooled motorbike engine conversion.

I am also looking at the BMW boxer engine. I think you can get enough ducted air cooling to them from underneath the engine.

Is the original gearbox (126) strong enough for these conversion or is there another gearbox that can do the job?

a link I have found:

 

[Abarth 695]

Ok I think I found exactly what I want. But I still don't understand how the chap managed to convert the power to the wheels so that they drive forward instead of in reverse.

Here is a clip:

http://www.youtube.com/watch?v=ZnsAPRpyd9s&feature=player_embedded#!

I am guessing he's using something like this but I still don't get how he reverse the rotation.

Any ideas?

 

[hudsonhenry]

Hi, I closed the retro500 forum a while ago as there was very little activity and it seemed like I was the only person posting.

I'm planning on updating the website later in the year if I can find time.

The car in the video has a Subaru 4wd gearbox converted to 2wd, the owner sourced this in Australia and I believe it was quite expensive. Zcars, who are building the car, had to cut the rear firewall to fit the box as its bigger than the 500 on ( no surprise there). The box can easily take 200 plus horsepower so there is plenty of scope for tuning the non turbo Subaru engine.

So far I've not come across a gearbox that will easily fit into the space that the 500 one takes up without significant modification to the body. Possible transaxles include:
VW bug
Early Audi 80 ( fwd but the gearbox was mounted in front of the engine)
Early Renault 5 (as Audi)
Renault 4, 8 etc
Skoda
Hewland
Fiat 600

Or fit some Bacci internals into a 500 box and don't go drag racing.

Nigel

 

[Abarth 695]

Great thanks Nigel,

I think I have made my mind up and having built a motorbike engined kitcar before I think I am going to do the same as these guys:





i.e. bike facing the wrong way so that it fits better in the engine bay and the bonnet can be closed.

Reasons for this option:
-Small engine and gearbox, should weigh the same as the original or less.
-Cheap (ish) power
-Sequential gearing through paddle shift, no gear lever in the middle.
- Can use donor loom and speedo
- Radiator can be smaller ( I think I'll have it at the front but "hidden" by using a mesh on the front panel which follows the traditional lines).
-Pipework for rad can run through the centre.
-Exhaust cheap and easy to build and easy to tune.

Only problem is to find a way to reverse the direction of spin. If anyone knows of a transfer box that has two cogs/gears in it that would do the job.

 

[Abarth 695]

Great thanks Nigel,

I think I have made my mind up and having built a motorbike engined kitcar before I think I am going to do the same as these guys:





i.e. bike facing the wrong way so that it fits better in the engine bay and the bonnet can be closed.

Reasons for this option:
-Small engine and gearbox, should weigh the same as the original or less.
-Cheap (ish) power
-Sequential gearing through paddle shift, no gear lever in the middle.
- Can use donor loom and speedo
- Radiator can be smaller ( I think I'll have it at the front but "hidden" by using a mesh on the front panel which follows the traditional lines).
-Pipework for rad can run through the centre.
-Exhaust cheap and easy to build and easy to tune.

Only problem is to find a way to reverse the direction of spin. If anyone knows of a transfer box that has two cogs/gears in it that would do the job.

 

[Abarth 695]

Well I found the solution but it is way too expensive. Quaiffe do a reverse gear that can have full power in both forward and reverse but at over £2000 it is way too expensive. Any one know of a good engineer with access to CAD and C&C machine?

 

[Abarth 695]

Quick update,

Honda fireblade engine now purchased. Pics to come.

Other setup options found:

 

[Bambino]

Frankenbini

Chris

 

[Abarth 695]

I was going to do a chain drive differential having the engine facing forward but I now have found what I was looking for:

Not cheap but a lot cheaper than Quaiffe's £2000+ unit.

 

[Abarth 695]

Latest updated pictures, just about to order the transfer box then off to build the cradle.

Engine will sit a bit higher (not enough wood to bring it up)

Fireblade clocks fit nicely in the original place , won't be too hard to make a housing for it.

 

[usafstud]

695, awesome post. It would be awesome to see detailed posts to gain knowledge on how to.

 

[Abarth 695]

Thanks, no worries, updates will posted when they are done. I am trying to figure out the best way to "connect" the engine/transfer box cradle to the car and at the same time strengthen the whole chassis ( It's surprisingly, nearly worryingly flexy that is for the power I am putting through it). I may add more down struts from the roll cage both front and rear. Trying not to end up making a space-frame.

Transfer box ordered.

 

[usafstud]

Wow, roll cage for a street car. I had a feeling that would have been the case due to original power load to the chassis.

 

[Abarth 695]

Some more pics with the engine up higher, I may have the air box in the compartment above the engine bay.

I am going to get rid of the chain to the diff instead have the output shaft straight into the transfer box. However I am looking how I can use a cushion drive so that it gives a bit. Maybe use a propshaft coupling or a rear hub off a motorbike.

 

[Abarth 695]

Quick question, does anyone know of a proper cv joint for the rear hubs ? None of this rubber stuff , I doubt the will take 140bhp.

 

[the hobbler]

I am begging to collect the parts required to build a replica '695' Abarth (I used to work for Radbourne Racing as a young mechanic) and have come across the Web-site for a Dutch supplier of parts for the various Fiat 500 variants. I have done business with them and they were very professional and prompt. They market a C/V drive shaft kit--look for 'Tripod cv joint' in the 'Tuning' section of their webshop--cost is about £94.00p. (plus postage). The only privisor is that I don't know its maximum BHP transmission. Hope this helps.

 

[the hobbler]

Stupid me--I forgot to mention that the Dutch supplier is:- Van Der Laan--their web-site is:- Van Der Laan Fiat 500 parts. It would seem that they are more efficient than I am!! (just put it down to anno domini)

 

[Abarth 695]

Thanks for that they do seem to have a good website.

I found what you mentioned on another one http://www.ricambio.co.uk/1706-drive-shaft-cv-tripod-joint-kit--classic-fiat-500-126

I still don't think it is strong enough.

I might be tempted to get rid of all the Fiat hubs front and back. Just need to find out what rear wheel drive vehicle to find parts from.

Any ideas?

 

[the hobbler]

Try Imp parts--people like Hartwell raced them, with a lot more than standered power using basically standered rear hubs. The Clan Clover used the Alfa-Sud boxer 4 engine, still using basically Imp rear end (the origin of the Clover was the Crusader, using Imp parts). Other people using the Imp rear end include Ginetta with their G15 and Davrian in their early models. Hope this helps