Thinking out loud: Fiat 128 with k swap?

So I'm on the internet like usual. A 77 Fiat 128 rally coupe pops up. I want it.

K swap? B swap? Any of the Honda high revving VTECs? Is that bonkers?

I see some k20s have been put in an x1/9 but obviously that's on the other side of the car and I'm currently not up to snuff on any Fiat stuff. Like at all.

Are there better swaps out there? Looking for something that isn't fragile and Challenge budget friendly. End goal would be a 202*Challenge car with potential to be a Crap Can racer afterward. Needs to be cheap, so no crazy ECU stuff since I imagine that won't be budget friendly. I know the stuff won't just bolt together, but I have metal glue gun loaded with some flux core. I'd be happy with 125-150 horsies but more is always better right?

I've also got a smaller turbo sitting on a shelf waiting for a home, but that adds complexity to things.

72780332_2635590576501140_4547550577466277888_n by hatchethairy, on Flickr

I mean, there's one really obvious answer.

you could miata swap it.. but the Honda motors are much more fun.. 

Measure carefully to see how much you need to cut.  I did a K24 swap in my 89 Civic last year, and the engine is enormous compared to the d16 we had before.   If you are racing it then you'll find it is demanding on the cooling system, the only way to keep my water temp under 210 on track was with a big aluminum circle track radiator with good ducting and big ass oil cooler with 8 quarts in the system.   
 

Once you get past all that it is an excellent driveline, I'm really pleased. 

A K swap involves too many high dollar bits to be considered for  $2k challenge build under normal conditions IMHO. 

I won't say it's impossible. But lets say you got a K20Z3. Couple hundred bucks is the general going rate and it's the cheapest 200hp capable K motor. 

If you have the facilities and patience you might be able to build a drivetrain behind it and make the motor work.. But the simple options for the base bare bones swap kits far exceed the challenge budget. 

Could be a neat toy if you put the challenge idea out of your mind, but of course very involved.

Fueled by Caffeine said:

you could miata swap it.. but the Honda motors are much more fun.. 

Depends on how much time you want to spend on the swap. The Miata setup is compact and already attached to a really good RWD transmission. No adapter plates or messing around, and no need to install the gauges from the donor car or have some sort of custom ECU reflash or replacement. If you find driving is more fun than building (this is not universally true), then the Miata motor may indeed be more fun.

It also looks right underhood whereas a K looks like you left your toolbox under there :)

I am of two minds on this. First one is "AWESOME!" Do it!

But then 

captainawesome said:

potential to be a Crap Can racer afterward. Needs to be cheap. I know the stuff won't just bolt together, but I have metal glue gun loaded with some flux core.

 

I know I am in the minority here but that car is rare as a rare thing and is very cool to boot. It will go up in value someday and I feel like it would be a shame to sacrifice it in the name of crapcan racing. 

I say do it, but do it well.

There's a certain synergy in aftermarket development going on right now between S2000, Miata, and BMW tuners.

S2000 people have been doing K swaps for years, and have a slew of parts that are useful for turning the engine 90 degrees. 

KMiata has a slew of parts for mating K engines to Miata and BMW ZF (E36) transmissions.

Because of that last point, Ks have started showing up in E30s.

The K can be run with relatively cheap electronics from certain mid-2000s K powered Hondas.  The ECU needs to be chipped to remove the immobilizer but otherwise, based on my experience with the KMiata harness in my NB, it's all very much self contained and just needs constant and switched 12V.

All that said, I have no idea how you could use any of those off the shelf components and do it for challenge money.  The trans adapters and flywheels alone are more than that.

Keith Tanner said:

Fueled by Caffeine said:

you could miata swap it.. but the Honda motors are much more fun.. 

Depends on how much time you want to spend on the swap. The Miata setup is compact and already attached to a really good RWD transmission. No adapter plates or messing around, and no need to install the gauges from the donor car or have some sort of custom ECU reflash or replacement. If you find driving is more fun than building (this is not universally true), then the Miata motor may indeed be more fun.

It also looks right underhood whereas a K looks like you left your toolbox under there :)

Wouldn't a FWD to RWD conversion be really difficult?  

Keith- it seems you are thinking of a 124, which is a RWD coupe (and there is one on Copart right now).  Whereas the 128, like the 131, are transverse FWD.

(or is it me that has them mixed up...)

In reply to alfadriver :

You are correct the 128 is transverse FWD

I am not a Fiat nerd and know little about them, other than the fact that they turned into Ladas :) Also that my parents bought one new and had to do valve jobs about as often as they had to do apex seals on the RX-4.

I thought the car in question was RWD. If it's FWD, that changes the math considerably. There's certainly a FWD version of the Miata engine out there but a Honda option makes a lot more sense in this case.

General information follows.

It IS really easy to convert a Miata engine to FWD, if anyone cares to do so. All you need is a matching transmission/clutch/flywheel out of an Escort GT, a bunch of Mazdas or a specific Kia. Bolts on. If the packaging of the intake or exhaust manifold is problematic, then you get the manifold(s) off the car that donated the trans. 

Converting the 128 to RWD would be a matter of a hat car. You can make that difficult (hello NOHOME) or you can make it relatively easy if the cars are pretty close in size. Drop the Fiat on to a Miata rollerskate. This is more common in some circles than you might think - for some reason, the Morris Minor guys love it.

alfadriver said:

Keith- it seems you are thinking of a 124, which is a RWD coupe (and there is one on Copart right now).  Whereas the 128, like the 131, are transverse FWD.

 

The 131 is RWD  

Keith Tanner said:

Fueled by Caffeine said:

you could miata swap it.. but the Honda motors are much more fun.. 

If you find driving is more fun than building (this is not universally true), then the Miata motor may indeed be more fun.

It also looks right underhood whereas a K looks like you left your toolbox under there :)

Naturally aspirated and stock for stock a Honda will produce more power per liter..  insert prove me wrong meme here..  :-)   a K20 is pushing 100hp per liter like the B16 before it.  The 1.8 miata engines.. 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In reply to Keith Tanner :

To put a Miata engine in a FWD application, the easy button would be to start with a Protoge or Escort 1.8l.  And I bet they would be cheaper to start with, too.

But, IIRC, the 1.6 Honda motor is smaller, and would fit with less cutting and welding.

And it sounds like easy is better than hard- so keep it FWD.

Jumper K Balls (Trent) said:

alfadriver said:

Keith- it seems you are thinking of a 124, which is a RWD coupe (and there is one on Copart right now).  Whereas the 128, like the 131, are transverse FWD.

 

The 131 is RWD  

Thanks- I don't know all my Fiats, either.

Fueled by Caffeine said:

Keith Tanner said:

Fueled by Caffeine said:

you could miata swap it.. but the Honda motors are much more fun.. 

If you find driving is more fun than building (this is not universally true), then the Miata motor may indeed be more fun.

It also looks right underhood whereas a K looks like you left your toolbox under there :)

Naturally aspirated and stock for stock a Honda will produce more power per liter..  insert prove me wrong meme here..  :-)   a K20 is pushing 100hp per liter like the B16 before it.  The 1.8 miata engines.. nope....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................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Sure. Once it's running. But IF WE ARE TALKING ABOUT A RWD APPLICATION then my statement remains accurate. Installing a Honda engine is a far greater pain in the ass than installing a Miata engine. Is the engine worth that pain? Is it more fun to have an actual car that is driving or a project that cannot be driven? This is a question that must be answered by the builder who is standing in front of the car.

Also, power per liter is not a measure of fun. It's a measure of specific output. The engine in my classic Mini is huge fun to drive but it's not scoring high on the power per liter gauge.

alfadriver said:

In reply to Keith Tanner :

To put a Miata engine in a FWD application, the easy button would be to start with a Protoge or Escort 1.8l.  And I bet they would be cheaper to start with, too.

But, IIRC, the 1.6 Honda motor is smaller, and would fit with less cutting and welding.

And it sounds like easy is better than hard- so keep it FWD.

Keith Tanner said:

I thought the car in question was RWD. If it's FWD, that changes the math considerably. There's certainly a FWD version of the Miata engine out there but a Honda option makes a lot more sense in this case.

Bolded for those who missed it because of other words.

Answering again now that I understand which wheels are driven :)

On a challenge budget, 90s Honda engines will be much easier due to the simpler electronics.  140hp LS Integra B18B would be your absolutely best bang for the buck.  I haven't priced out B18Cs in a while but VTEC might put you out of challenge territory.

Keith Tanner said:

 

Sure. Once it's running.

 why must you focus on the details... :-)

I think packaging will be my biggest hurdle, so for that reason alone I'm leaning more towards the smaller B series. Also looks like there are inexpensive aftermarket go fast parts unlike the k20-24 variant.

Is there a specific Honda motor I should be looking for? VTEC isn't 100% necessary I don't think. Also, if I wanted to throw 10 psi at it, is the stock internals going to hold up?

Bah, put the entire K-series FWD lump behind the seats.

I think the obvious answer is a second gen cr-v with a k24, awd, and a five speed as drivetrain donor, then start cutting stuff and welding stuff together until you have a car. 

[DISCLAIMER] The build suggestions I make on the internet are based purely things I think would be awesome, and have no basis in reality. I've never even seen a fiat 128 in person. I have no idea if a cr-v engine and trans will fit between the front tires. I don't know if it will fit under the hood. I know cr-v were available with manual trans, and awd, but I don't know if they came with both. Gearheadmb and any of its subsidiaries are not responsible for any physical, emotional, or economic hardships caused by following my ill conceived and poorly thought out advice. 

In reply to captainawesome :

94-95 OBD-1 Integra LS is a non-VTEC 140hp 1.8L, the gearing leaves something to be desired but the much better GS-R gearbox bolts right up if you can find one for cheap.  The same engine was available through 2001 and will run on OBD-1 electronics with a few minor sensor changes.  They take boost well.

In reply to steronz :

Is there a trans/gearing swap that could be done or is it something I'd have to live with?

B-series transmissions don't use cables so your shifter location is limited to where it sits stock or where you're willing to cut and weld the shift rods too.

On the plus side, the shifter feel is great and they all come with intermediate shafts to help combat torque steer.