Abarth X1/9 Engine Swap
- Thread starter TonyK
- Start date
CnC79X19
True Classic
Hi sir,
I’m renovating my x1/9 and want to upgrade the power plant to an abarth..did you complete such a swap?
Bjorn Nilson
True Classic
I like the Abarth swaps why but why do they all keep the Abarth ECU? Doesn't make sense to me.
ng_randolph
Bjorn H
There isn't a lot of choice; I have never seen an after-market solution for multi-air engines. The electro-hydraulic valve system has to be operated by the ECU, and it is unlike any other variable valve timing / lift system on the market.
Bjorn Nilson
True Classic
Yeah, you're right. I was thinking about FIRE.
Jonohhh
True Classic
Thankfully, swapping to the TJet upper head is not at all complicated and allows the use of any old standalone- though you have to consider the TJet VVT in the ecu setup.
The multiairs Marelli ECU is immensely complex, and even some of the oldest and most thoroughly revised tunes for the 1.4T are temperamental to say the least. Many limiters get upset, power gets pulled for what seems like no reason, and so on- mainly once you push above about 200 wheel.
Also, I believe the TJet head is ever so slightly more compact. Not by a lot, but the edges specifically are much more sloped off if I remember correctly.
The multiairs Marelli ECU is immensely complex, and even some of the oldest and most thoroughly revised tunes for the 1.4T are temperamental to say the least. Many limiters get upset, power gets pulled for what seems like no reason, and so on- mainly once you push above about 200 wheel.
Also, I believe the TJet head is ever so slightly more compact. Not by a lot, but the edges specifically are much more sloped off if I remember correctly.
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kmead
Old enough to know better
Yes Tony has completed two. There is a thread where he goes into painful detail on both. By painful I mean there were times where it was really painful for him, for us it was immensely interesting and frankly amazing.
This is not a mod for the faint of heart and you had better have a great relationship with a Fiat dealer to have them fiddle with the software.
A T-jet headed Fiat engine would be the better candidate but was not available on any car in north America.
Jonohhh
True Classic
Some people have been able to get the TJet heads shipped over from Europe for decent cost, and as the lower head is the same, it's really just the upper cam box section that has to be swapped. I'm not sure what source people are using though- whether it's eBay or a personal connection. The ports, valves, and such are identical between the two. Pretty neat how modular fiat made the FIRE engine.
Bjorn Nilson
True Classic
But older 500 has FIRE engines? Is it hard to get those engines over there? 250-260hp is not very complex to gain from a FIRE 1.4, and it fits well in a X at least in comparison with a K20. And it has the strong C510 trans as well.
Maybe this is an option also for you @Andy X ?
Jonohhh
True Classic
I do apologize if I am telling you something you already know- I'm fairly new around here, but have been in the Abarth 500 (2012+) since 2014.
The FIRE has been around for a very long time- apparently its production started in the 80s.
The Abarth 500 engine (both in Europe and USA as the blocks are identical) is still a FIRE engine- though I'm not sure how much can be interchanged between the old and the new.
The only difference between the actual euro Abarth engine and USA Abarth engine (not including the turbo option differences, as well as motor electronics such as the Bosch Motronic vs Marelli ECUs, and vacuum pump) is the upper part of the cylinder head, the USA one with Multiair SOHC (shared with the european Punto Abarth) , and the european one with TJet DOHC, (which also has a single cog for the timing belt) of course both are 16v because well, they share the same lower part of the cylinder head. Swapping a USA Abarth engine to be a TJet instead of a Multiair (and thus allowing the use of a standalone ecu on what is 90% a USA Abarth engine, only requires removing the upper cylinder head and replacing it. As far as I am aware, the actual head can stay on the engine during this process, so you don't even need to break the engine down to the head gasket to do this conversion. I believe this, to some, may represent an easier option than running the Multiairs temperamental Marelli ECU, though you would of course have to tune it yourself, find one already made, or get someone to tune it for you.
This is the "cam box" or "cam carrier" as some call it. This is the only difference between a Multiair and Tjet Abarth engine. The single cam has lobes for each exhaust lifter (8) , as well as one lobe per cylinder to drive the Multiair hydraulic buckets which ultimately drive the two intake valves per cylinder. Everything below the cam carrier is indistinguishable from a TJet engine...because well, a that point it's not really a TJet or a Multiair.
The multiair unit (below) attaches to this cam carrier, on the section near the back of the photo, and pushes down on the actual valves. You can see the roller followers- one per cylinder. You can also see, on the bottom face of the unit, the contact points for the top of the valves.
The cam carrier (which the MA unit is on) mounts to the lower head as seen below. This part is shared between the two engines. It doesn't care if there's Multiair cam carrier or a TJet cam carrier on top of it- both bolt up and actuate the valves in the same manner, bar VVT and VVL capabilities. If you are swapping a Multiair to be a TJet, this is as far as is necessary to go into the engine.
Below is an unfortunately grainy photo showing the top and bottom of the heads separated.
And one final photo, showing a complete TJet lower head and cam carrier. Notice that the TJet head does not have a valve cover, the only gasket present is the one where the lower head and upper head "cam carrier" mate. The orange gasket and everything below is identical to the 500crew photo shown above. Though the TJet is a true DOHC, it has a single timing belt cog as mentioned above, likely to enhance compatibility with other FIRE engines, among other reasons. Inside the TJet cam carrier is a no service needed chain which drives both cams together. There is a VVT phaser inside the head as well, which is completely passively controlled via oil pressure (I believe).
I hope this helps! I hope this isn't threadjacking- just elaborating on a point made about these engines and the ability to run them on a standalone. Do not take my word as the blind truth- I could most definitely be wrong about anything said above, however this is what I've grown to know by hanging around the Abarth community for quite a few years (my 500c Abarth was my first car...fiat fanatic from the very beginning).
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kmead
Old enough to know better
Yes we never got the FIRE based engine on anything in the US until the 500 Multiair family. In the US the normally aspirated Multiair only puts out 102hp with the turbo version having 160. So there is no previous stock of FIRE type engines to scavenge.
If this is the case (and not doubting it is), it would certainly offer many more options for upgrades that keep it in the family. There are Abarth and NA versions of the current 500 engines and transmissions basically being given away by junk yards as there is almost no market for them in the US as the engines are not the weak point in these cars. Added to that, and this parallels the past, the low resale value of the cars and you end up with cars being junked rather than repaired due to high labor costs.
I would be very happy indeed with a normally aspirated current Fiat engine and over the moon with a turbo version despite having to figure out how to all the plumbing. The normally aspirated engine with mods would be my preference just because I prefer them.
Have a look on LKQ and you can see lots of these engines going for low dollars relatively speaking.
Good post and this is an appropriate bunny trail given the open ended initial question.
If this is true and can be done there is money to be made scavenging EU cams and upper head cam carriers for us unfortunate Americans and Canadians…
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kmead
Old enough to know better
Above and beyond the fact this guy is crazy, this show the the cam portion of the head can be moved to the Multiair engine complete.
kmead
Old enough to know better
Maybe an option for more than just AndyX…
Bjorn Nilson
True Classic
He is crying for missing a deal for an UT engine. -Just wanted to cheer him up
. But of course this is an option for all X-heads that would like to keep the car plain FIAT.
Jonohhh
True Classic
As much as I hate all of the drama and headache Eddie and John stir up in the community, I have to give them credit for doing good work in some areas. I believe it may have been them that really pioneered the MA > TJet swap. Other tuners acknowledged the ability years before... because well, it's not too hard to figure out given the plentiful information out there, but they were some of the only to actually go through with it, document it all, and tell others.
The swap for him was really straightforward- all of the issues he seemingly had were with getting the Marelli ECU to run it. It seemingly had a lot of issues getting cycle lock/ref sync done during startup....at least that's what it looked like in the video.
But anyway, I'll get off my soap box
Jonohhh
True Classic
Haha I'm actually looking for an engine for my Abarth at this very moment. A couple of months ago it got hydrolocked ( long story, my mom got caught in a flash flood). Sparkly oil and a bit of a knock. Somehow it's still driving, but I don't trust it to drive the 4h up to school.
New engine is getting some goodies before going on
As a side note. At some point, around about 300lfbt for 2015+ and 280ish? for 2012-2014, the c510 blows apart. I guess strong is relative... but it's a bit of a limitation to the top 10% of modded Abarth owners. But I imagine that In an X1/9 ya don't need any more than 300lbft. The FIRE is a loooong stroke small bore engine that loves to make torque. It unfortunately doesn't have that Lampredi SOHC eagerness to rev...at all...but then again, what else does?
kmead
Old enough to know better
I think that is a limitation most of us except @Dr.Jeff could live with…Haha I'm actually looking for an engine for my Abarth at this very moment. A couple of months ago it got hydrolocked ( long story, my mom got caught in a flash flood). Sparkly oil and a bit of a knock. Somehow it's still driving, but I don't trust it to drive the 4h up to school.
New engine is getting some goodies before going on
As a side note. At some point, around about 300lfbt for 2015+ and 280ish? for 2012-2014, the c510 blows apart. I guess strong is relative... but it's a bit of a limitation to the top 10% of modded Abarth owners. But I imagine that In an X1/9 ya don't need any more than 300lbft. The FIRE is a loooong stroke small bore engine that loves to make torque. It unfortunately doesn't have that Lampredi SOHC eagerness to rev...at all...but then again, what else does?
Very good point about the stroke ratio and rev-ability.
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Bjorn Nilson
True Classic
Also the UT doesn't rev that much. My UT engine is completely dead above 7k but lots of torque and power over the whole powerband.
The Norwegian X1/9 in this video has a FIRE. Compare revs with the other cars and you'll see it revs about the same (except for some screaming V6).