Alright, to get things clear from the bat, i've already had a different topic on this build with my previous account. Just in case you will recognise some of these pics haha [emoji1]

As long as I've been able to hold a wrench and was able to work on cars, I've always dreamed to get into engine building, so here it is. I could have done this MUCH cheaper probably, bit since I want this to be my daily engine, I didn't wanna cut any corners.

Current setup:

Moving stuff
Mk2 1.2 16v bottom end (strongest out of all 1.2 engines, including better rods)
Mk1 1.2 8v MPI head (portmatched, exhaust ports + chambers polished)
Saab 9000 2.0 water cooled turbo
Protoxide 1.2 8v forged pistons
1.4 mls gasket to compensate for the loss of CR deu to the 8v pistons being slightly shorter then the original 16v pistons.

Misc
EMU classic ecu (to implement TC and BBG in my seicento)
Water injection for lower EGT on high rev runs (ive already melted away 3 coolant hoses with my current setup [emoji23] )

Some more pics will come tonight when I have access to my laptop. But for now...

View attachment 189547

Today i've decided to shove the MPI head aside for now. It turned out that polising the exhausts ports was a bigger pain in the ass then I thought, but since I am already 30% in, I cant simply slap this one on the rest. Instead I will be using a regular 1.1 head since they have the same valve sizes, with the 866 shaft, and a custom plenum (which was already part of the plan)...

Alright, picture time :slayer:

Why not 16v? it should flow better and still have a nice idle.
And, i imagine, for the 16v... you could get parts from the t-jet to fit

aurick86 said:

Why not 16v? it should flow better and still have a nice idle.
And, i imagine, for the 16v... you could get parts from the t-jet to fit

Click to expand...

I've been asked that many times before, and the answer is simple. Because I want to

Yes, the 16v has a better flow in the high rev range, but this is not going to be a high revving monster, so I prefer the less mechanical inertia of the 8v for faster response. And last but not least, this is my first engine I am building from the ground up, and I want to keep it as simple as a home brewed turbo engine can be.

Today I picked up the freshly machined parts, and boy do they look sweet...

So I am currently having 2 issues. The first one being that I am still trying to figure out any safe numbers to run on stock mk2 1.2 16v conrods. Ive read this topic over and over again, but can't find any specific numbers other then the 170 BHP he made before he broke his gearbox

https://www.fiatforum.com/cinquecento-seicento/233699-turbo-rolling-roaded-mpi-gt17-big-turbo.html

Now, knowing that my rods are stronger then his mk1 1.2 8v rods, I am still going to replace the conrod bolts with ARP bolts (getting back at this later), but even then I would like to figure out what a safe Torque/BHP number would be to run in my NON-stripped seicento (full weight). It's gonna be daily driven, hence I want to go for a bit more safety over power...

As far as specific info regarding conrods, I was looking into maybe getting a set of forged rods from a different vehicle al togther since there is pretty much nothing to find for fiat other then the classic 500, punto GT and the 5 cillinder one... The problem is that I can't seem to find the dimensions for any conrods, and I dont really feel like asking my former boss to just rip apart every block and compare conrods to mine

Now, about the ARP bolts. Getting the same issue here... I know the threads are m8x1 (and some length), but no matter what webshp I look at, they simply don't provide any details about the bolts themselves, only on what engine they fit. And again, in this case I cant find any set of ARP bolts, other then for the Punto GT, which I still don't know the details of the threads about

So long story short... Where would I be able to find a database to find specific part info like this?

Thanks!

Also blu73, On one of your replies I noticed a dual radiator setup. Would you mind me asking why and how you did this?

Well:
That is why i said some t-jet parts might fit... and better yet, they are off the shelf parts , easily available... and so much more performance parts out there on the market.
Unfortunately not that much info out there for the t-jets.. but certenelly much more.

Here, have a look here at rods dimensions for the t-jet, compare with what you have:
https://www.aliexpress.com/item/T-jet-engine-TurboJet-T-Jet-1-4L-connecting-rod-for-New-Fiat-500-turbo-kit/32547520214.html

Also if suitable... consider getting a t-jet crankshaft.. the're supposed to be forged steel (and maybe even hollow-if i remember correctly, i read that somewhere)


I'm sure you don't want to hear this: You can easily get a complete t-jet car that has everything on it, manifolds, crank, rods and pistons (that are ok for 250 hp stock), ECU sensors, gearbox...etc .. for ~1000? even less if it's crashed.. would be great for parts at least.



Don't get me wrong, I'm sure you can build what you want.. it will cost huge amounts of money and time.... and in the end won't be that reliable as the stock 120hpTjet with minimal mods 180hp

Unfortunately Tjet parts will not fit since they have a thicker crankshaft iirc.

Maybe you can get them that cheap over in your country, but here you will not get them under ~1000 euro IF you return your broken engine. Then there is the issue with mileage and usage history. Yes, an engine with over 135k might not have been abused as much as a engine that has crashed with only 30k, but then there is the fact that out of all (super)fire engines I've taken apart with less then 150k all had rocking pistons with lots of skirt wear, which is why I wanted to build one from scratch.

So now you know why I prefer to stick with building an engine from the ground up haha. It has nothing to do with what I wanna hear or not, but I prefer spending 1500 on a basically brand new engine, then 1000 on an engine of which I know nothing about.

And in case I'm not gonna find the required parts for a decent buck, ill just have to settle with a little less torqeu.

CptFastlane said:

Also blu73, On one of your replies I noticed a dual radiator setup. Would you mind me asking why and how you did this?

Click to expand...

on that car there is the stndard engine rad, the intercooler for the turbo is front centre, oil cooler at front on right and behind that is the air-conditioning condenser.

so without reading through this whole thread one issue springs to mind... 16v block and 8v head... AFAIK there is an oil gallery or coolant, can't remember which, that is on opposite side of the engine between the 16 and 8v.. triple check your not setting up for disaster here..

Traditionally you would use a P75 bottom end as it has oil squirters unlike the others so good for piston temps.. Then whack 16v pistons in there amd that will result in CR of 7.8:1 - this is quite low but its assuming unskimmed head etc. It is as a random fact for you the same CR as a PGT.

The P75 also has the 866cam as standard and is mpi so better for fuelling.

Best of luck with it all though, keep us posted.

blu73 said:

so without reading through this whole thread one issue springs to mind... 16v block and 8v head... AFAIK there is an oil gallery or coolant, can't remember which, that is on opposite side of the engine between the 16 and 8v.. triple check your not setting up for disaster here..

Traditionally you would use a P75 bottom end as it has oil squirters unlike the others so good for piston temps.. Then whack 16v pistons in there amd that will result in CR of 7.8:1 - this is quite low but its assuming unskimmed head etc. It is as a random fact for you the same CR as a PGT.

The P75 also has the 866cam as standard and is mpi so better for fuelling.

Best of luck with it all though, keep us posted.

Click to expand...

I've heard that many times before, but no matter which 16v bottom I check, they all seem to line up with all of my 8v heads? Double checked with gaskets as well, and all seems to line up just fine. Ill post some pics here later to show some of these combos.

Idd prefer to use 8v turbo pistons since they provide a higher CR, and allows me to use a steel HG for reliability. Intake and exhaust will all be custom made by me, all tuned for low/mid range torque.

I see. I didnt know the cento came with airco, my bad haha

well i had a p60 block and p85 block and various 8v heads back when i had that car and the 8v head gaskets all had to be upside down to not cover one of the holes, like one hole on the opposite side, i'm going on what ive read and that personal experience - i can't comment for all the other fires but seems odd they'd be different... but saying that it seems odd that theyd change the block between 8v and 16v too lol.

I have also seen a 16v turbo 1108 before though which was a mk1 punto valver head and seicento 1108 bottom end, so either not all the bottom ends are the same or it can be machined to work.

Either way, just check it a thousand times before bolting it together is all im saying

Yeah I will, thanks!

Did some more checking today, and the only thing that MIGHT become an issue is that the water passages of the 8v head are narrower. To increase flow I could modify those passages, but the rest seems to be matching just fine.

Attached are some pics from a mk2 sei 8v and punto 16v block (both 1.2), and both a mk1 p75 1.2 8v head next to the original head from the mk2 punto 1.2 16v head.

Today I picked up some OEM conrod and flywheel bolts. And with all the extra drama that is starting to get involved regarding the water passages, I am starting to lean towards getting a 8v bottom end instead. Quite a shame for all the work that went into the 16v already, but it will make a nice table if I go for it