Stilo1.8 16v swap

My1stCar

My1stCar

Daily Driver
Hi all,

I'm new to the forum, but have researched the wealth of information available with great attention because I recently pulled my first car out of its 20 odd years of storage.
My project is to swap a 1.8 16v engine and c510 gearbox from a 2002 Fiat Stilo into my X1/9. As far as I've seen this swap has not been documented, so I thought I'll give it a try.
The engine is the final evolution of Fiat's 4 cylinder naturally aspirated 1.8l Pratola Serra engine that was previous versions in the Barchetta, the Punto HGT and the entry level version of the Coupé. In the Stilo it delivers 133hp and 162Nm of torque, not the 160+ of the Abarth 1.4 (or more for the K swaps), but plenty of power to make the X even more fun to drive.

Marc,
Normandie France
 
After some relatively mild modifications to the engine bay, the engine hangs in the right spot
IMG_20220926_202739.jpg


But it is a bit tight
IMG_20220926_203417.jpg


Obviously the engine bay will get cleaned, welded and painted when the engine mounts etc. have been sorted
 
Welcome to the forum, glad you are sharing this cool build. Please tell us more about it.

That is tight, but it appears to require less cutting than the K20 swaps. ;)
 
Longitudinal said:
Is the Stilo's transmission shifted by cable or by rod linkage?
Click to expand...
Hi,

The Stilo's gearbox shifts with cables. I dissassembled the Stilo's shifter ball mechanism, turned it and the gear selection pivot upside down (to get 1-2 to the left and 5-R to the right). Then welded the gear selection stalk that I cut from the Stilo lever to the X lever and reassembled it again. Next I inversed the direction of the push/pull to get 1-3-5 forward and 2-4-R rearward. For that I made a 13mm ball pivot point bolt that is bolted instead of the rear most inertia weight bolt on the gearbox, wich reverses the action of gear engagement. I use the factory cables mounted on a modified tunnel end plate with adjustable extension rods from the shifter to the cable mounts.
I'll post some pictures later.

Best regards, Marc
 
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The distance between the longitudinals is 6cm wider in the Stilo and they are also wider themselves. This would result in engine mounts beyond the X's frame rails, in the wheelarch. So the mounts have to be modified. Below the before/after of the right side engine mount, the aluminium cast is replaced by a welded steel bracket (actually 2 grams lighter), that moves the engine pick-up point 2cm closer to the frame.
IMG_20220928_142707.jpg
 
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Bjorn Nilson said:
If the 1.8l fits there is a chance that the 2l 5cyl 20V fits?
Click to expand...
I doubt the 5 cylinder would fit. I assume the 5 cylinder block is about a cylinder bore wider, and I foresee that I already have to make some creative adaptations to the left lower suspension arm to clear the transmission that protrudes about a cm into the wheel arch.
But basically the same 4 cylinder block was also used as Twinspark in various Alfa Romeo vehicles, in 1.8 and 2.0 liter up to 165 hp (a slightly different aluminium 1.8 block version lives with a turbo in the 4C at 240 hp)
However these are rare (and expensive) in France, while I got my Stilo real cheap. I think I should be happy enough with 80% more power and torque so it stays a bit more drivable for normal road use.
 
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I believe member @rachaeljf has done some Alfa engine swaps before. She seems to have great knowledge about the engines you've mentioned and might be able to offer some insight. Hopefully she'll visit the forum sometime soon and see her name referenced here.
 
Today I finished welding the transmission mount. The original was a two piece cast aluminium plus stamped steel part. I cannot use the front and top exterior pick-up points because that's where the left frame rails is. Instead I pick-up the top from the inside (feels much stiffer/stronger), and found an alternate front pick-up more inboard. I'll have to check for clearance another day. The whole is 6cm more inboard, so I got about 2cm to play with.
IMG_20221001_185203.jpg


You can't see it but the two additional inner support points are used in both cases
 
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My1stCar said:
Hi all,

I'm new to the forum, but have researched the wealth of information available with great attention because I recently pulled my first car out of its 20 odd years of storage.
My project is to swap a 1.8 16v engine and c510 gearbox from a 2002 Fiat Stilo into my X1/9. As far as I've seen this swap has not been documented, so I thought I'll give it a try.
The engine is the final evolution of Fiat's 4 cylinder naturally aspirated 1.8l Pratola Serra engine that was previous versions in the Barchetta, the Punto HGT and the entry level version of the Coupé. In the Stilo it delivers 133hp and 162Nm of torque, not the 160+ of the Abarth 1.4 (or more for the K swaps), but plenty of power to make the X even more fun to drive.

Marc,
Normandie France
Click to expand...
Wow this is a cool project. No this hasn’t been done before.

Welcome to the forum, very pleased to have you bring your project here. A lot to learn about with this one.
 
Hi all,
Currently finalizing the engine mount points and consequently the height of engin w.r.t the suspension. Cordially borrowed the reference picture from @autox19 (who I think borrowed it from @fiatmonkey) and compared it to my current height.
The red lever indicates from wheel center to gearshaft center. The coilover is at shortest possible length, which is close to the future ride height.
It looks like my gearshaft axis sits ever so slightly higher/straighter. I could want a bit more engine lid clearance, but I think I shouldn't lower the engine anymore as the sump would then be the car's lowest point and that's not good. What do you think?
IMG_20221005_184650.jpg
 
The biggest structural modification turned out to be the modification of the left suspension arm to clear the transmission.
IMG_20221007_123747.jpg

I hope that boxing in plus triangulating the cut-out part provides enough reinforcement to retrieve enough strength.
Now I need to repaint the arm again.
 
my opinion in the height. I do not like my sump to be lowest. Talking to "the driveshaft shop" he said you want to have as level as possible if you are using normal CV joints, but even normal cv's allow for movement without extra wear at small angles. I sent him a pic of mine and he said it would be more than fine, but I have a little beefier CV's than stock because that is what they put on them from them making the custom shafts. When I asked him about if mine were stock would it be ok, he chuckled and said for sure. he has had dune buggy on street cv's run angles more than that for thousands upon thousand of miles with no issues and they were at a way larger angle.

Odie
 
autox19 said:
my opinion in the height. I do not like my sump to be lowest. Talking to "the driveshaft shop" he said you want to have as level as possible if you are using normal CV joints, but even normal cv's allow for movement without extra wear at small angles. I sent him a pic of mine and he said it would be more than fine, but I have a little beefier CV's than stock because that is what they put on them from them making the custom shafts. When I asked him about if mine were stock would it be ok, he chuckled and said for sure. he has had dune buggy on street cv's run angles more than that for thousands upon thousand of miles with no issues and they were at a way larger angle.

Odie
Click to expand...
Thanks, very helpful! So I'll be going 1-2 cm up to raise the sump enough so the footwells are going to be the lowest points to the ground 👍🏻
By the way, I'll be using the Stilo CV joints (will need to shorten the axles). One of the "go" moments was when I found out the Stilo CV's wheel side splines are fitting the 1500's wheelhubs. They need a 2mm spacer to get enough clearance, but that is the only modification needed. So I got a fresh pair of refurbished 1500 wheel carriers with new hubs and bearings from Midwest Bayless swiftly delivered to France.
 
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My1stCar said:
The biggest structural modification turned out to be the modification of the left suspension arm to clear the transmission.
View attachment 66772
I hope that boxing in plus triangulating the cut-out part provides enough reinforcement to retrieve enough strength.
Now I need to repaint the arm again.
Click to expand...

Bon jour Marc. I dunno....but I would be a little more comfortable also running a chunk of fairly thin steel angle welded in along the outer lower length of that arm. Would be fairly easy to do now. And would then be even stronger than stock.....

By the way...you do very nice welding and fabrication :D

Thanks for sharing your progress !!
 
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