Making a modern engine work in a classic

[grumpybadger]

As I plan to upgrade the mechanicals on my fiat 850 my thoughts are turning towards the engine and how best to find reliability.
I'm not concerned about the power except that I don't want too much of it.

I'm currently looking at a 1.1 or 1.2 fire from a panda mounted to a vw box.
If I transplant the whole engine including sensors and ecu from a donor car are there any reasons it won't work?

Is a bespoke ecu the only way to go?

[bmw2101]

is the engine and box in the car good and healthy? you could just modern electronics on it, ecu, cranks sensor, map sensor, tps, and maybe even a simple spi injection system.

This is what i plan for my mini, much easier to do than changing engines.

[grumpybadger]

It runs fine but is a counter clockwise rotation so upgrade parts are rare and expensive.
For example a full 123 ignition is £700

They're pretty gutless and are notorious for over heating and electrical issues.

Plan was to bin the original for a modern motor. Low mileage pandas can be had for under a grand.
That would also provide me with a brake upgrade and various other useful spares.

But if the ecu won't work then it's a non starter.

[Rich]

You can transplant anything into anywhere. You have a few choices, choose a donor car with no immobiliser system, and that will make life immediately easy. Secondly if you do end up with IMMO you can utilise the system into the car as anti theft or you can have the ecu IMMO feature bypassed, I have used and found a company called ECU Decode very helpful but there are hundreds of people who can do this for you.

[mr2fc]

There's a 126 on here somewhere with a Peugeot/Citroën/Toyota 3cylinder in it

[mr2fc]

forum.retro-rides.org/thread/143497/1976-fiat-126-aygo-power?page=1

[mk2cossie]

Surely if the normal engine runs counter clockwise, fitti g an engine that also runs counter clockwise would be the easier option and retain the gearbox fitted

Any of the Honda B series engines should fit possibly, unless they are huge compared to a FIRE engine

[grumpybadger]

Sept 7, 2022 17:18:41 GMT mk2cossie said:

Surely if the normal engine runs counter clockwise, fitti g an engine that also runs counter clockwise would be the easier option and retain the gearbox fitted

Any of the Honda B series engines should fit possibly, unless they are huge compared to a FIRE engine

The 850 box isn't known for its strength also, I suspect most counter clockwise hondas are getting on a bit now and I'd hate to brake something that might give others joy to get one.
Whereas 2010 pandas are two a penny.

[mk2cossie]

Sept 7, 2022 17:50:27 GMT grumpybadger said:

Sept 7, 2022 17:18:41 GMT mk2cossie said:

Surely if the normal engine runs counter clockwise, fitti g an engine that also runs counter clockwise would be the easier option and retain the gearbox fitted

Any of the Honda B series engines should fit possibly, unless they are huge compared to a FIRE engine

The 850 box isn't known for its strength also, I suspect most counter clockwise hondas are getting on a bit now and I'd hate to brake something that might give others joy to get one.
Whereas 2010 pandas are two a penny.

The single cam Honda engines aren't renowned for all the power in the world tho
May be worth a look at dimensions of the engine from the older carb fed Hondas with rotten bodies

[metalshapes]

Sept 7, 2022 17:50:27 GMT grumpybadger said:

Sept 7, 2022 17:18:41 GMT mk2cossie said:

Surely if the normal engine runs counter clockwise, fitti g an engine that also runs counter clockwise would be the easier option and retain the gearbox fitted

Any of the Honda B series engines should fit possibly, unless they are huge compared to a FIRE engine

The 850 box isn't known for its strength also, I suspect most counter clockwise hondas are getting on a bit now and I'd hate to brake something that might give others joy to get one.
Whereas 2010 pandas are two a penny.

No, that is the Fiat 600 box.

But I'd still get about a season of racing out of a good one ( but I've also broke 6 of them in one month, in one particularly bad month, once...)

The 850 box was used , with a special Abarth bell and input shaft, for the larger 124 engines ( modified for reverse rotation )
Which of course meant that people bolted the later twin cam versions to them when they became available.

A very well known Abarth specialist in Germany told me the 850 boxes are good for 180Hp.

I'd recommend you get in touch with scmick .
He has built a Honda powered Simca before ( similar reverse rotation gearbox as a 850), and a Simca powered 133 ( which is a 850 with a facelifted body)

He probably has more first hand experience with what you want to do, than anybody on this forum...

[scmick]

I fitted a 1590cc twin cam D series engine from an '89 Honda CRX to a SIMCA 1000. The SIMCA 1000 was developed from the FIAT 850 and shares its anti clockwise rotation. I used it for trackdays where it got serious 'hammer' and managed to wreck two SIMCA 1000 gearboxes. Road use might not bring up these issues. The weak link on the SIMCA boxes was the final drive, stripping the teeth off one pinion. I'm currently restoring one of my former SIMCA racecars that's returned to me and hope to fit the Honda twin cam in that but I plan to use a Renault UN1 box from an early (inline) Renault Espace which would need driveshafts adapting. The SIMCA and FIAT 850/133 shafts are interchangeable. The Honda engine was run on carbs (twin Dellortos from an ALFA) on an adapted ford CVH manifold running a '2 wire'. distributor from an earlier Civic.

[grumpybadger]

That sounds like a lot of garage time over the years.

The renault boxes seem to be quite rare and expensive these days.

The thinking is to create a reliable tourer with improved driveability, also for better parts supply.
It's not going to get a hammering, i doubt I'll ever take it over 65mph and If it reaches that within half an hour it's good enough.

Any reason to not use a vw transaxle with a clockwise motor?

[scmick]

I'm lucky with the Renault box, it came from the Espace I scrapped after 18 years of mostly reliable service. Despite the high mileage the box is still in good condition... the Un1 was obviously one of Renault's better efforts..!! As for the VW transaxles, they seem to take anything. The VW karmann ghia I grasstrack raced way back (before they were worth £££s) had an early Beetle box which handled a Lotus twin cam engine without problems for several seasons.

[grumpybadger]

My biggest concern is getting the ecu to work.

[kevins]

Best option is to get a running donor car and disconnect everything you don't want one connection at a time making sure it runs in between, mark all the redundant connectors and then once you have taken the loom out you can then strip all the wires which were not connected out.

[2p2g1m]

I did it exactly as above. Really happy with the results.

[giuliettaevo]

You could also use an audi a4 gearbox upside down with a normal clockwise engine. Quite common on for instance tdi conversions in the vw t3.

[grumpybadger]

Sept 8, 2022 20:27:11 GMT kevins said:

Best option is to get a running donor car and disconnect everything you don't want one connection at a time making sure it runs in between, mark all the redundant connectors and then once you have taken the loom out you can then strip all the wires which were not connected out.

That makes a lot of sense.
Looking through the wiring diagrams the ecu appears to take a feed from almost everything!

[grumpybadger]

Sept 8, 2022 21:33:43 GMT giuliettaevo said:

You could also use an audi a4 gearbox upside down with a normal clockwise engine. Quite common on for instance tdi conversions in the vw t3.

I did look at flipping a couple of different boxes but this can bring its own issues, space being the no 1.
It's pretty tight in there.

[slater]

Always seems a waste of time using original ecus. If it's an ecu engine as standard then all you usually need a is a aftermarket ecu wired up to it and a day on the dyno. Original ecu limits you to standard engine. Even putting different exhaust on will throw it out.