Hey guys,

It has been a while since I posted something. I'm curently building a 1.2 8v spi seicento. The engineblock is almost done, waiting for my 25% lighter flywheel and balanced crank to be sent back to me.

Now i have a full 1108 spi from a seicento, that is still in my car and I have a 176.B4.000 1.2 8v spi complete engine.

After searching a bit I'm confused what head to use with the block. Do I use the 1108 or the 1242 head?

Some people say it's the same others say the 176.B4.000 head has smaller ports thats why the compensated them with 866 camshafts.

Can anyone help me with this?

I found:

1108 cinq engine (176.B2): Inlet 31.5mm
1108 punto engine (176.A6): Inlet 30.5mm
1242 punto engine (176.A7): Inet 30.5mm
1242 punto engine (176.B4): Inlet 31.5mm

all use 27.5mm exhaust valves.

Can anyone confirm pls?

As far as i know 1.1 and 1.2 spi are the same head, same valves and stuff.
P75 head has the same valves as spi.

Done quite a few Fire heads and all had the same valves.

On the mpi head you can open up the inlet valves a bit more.
Don't know if you're gonna run spi/mpi or itb/turbo?

I'm going to run spi 38mm TB.

Read on this forum that by switching from p60 to p75 headgasket that compression raises a bit more? Is this true?

Jajr2009 said:

I'm going to run spi 38mm TB.

Read on this forum that by switching from p60 to p75 headgasket that compression raises a bit more? Is this true?

Click to expand...

The headgaskets are the same. There is a 0.5mm steel one from a 1.4 8v
With a 38m spi take the spi head, the manifold wil bolt straight to it

They are both spi heads, never sayd I had the p75. I have a p60 176.B4.000 complete engine with intake manifold. I'm using my car everyday, so if you say both heads are the same, then I prefer working on the one from the p60. That way I can still drive my car while working on the head.

Hey Jajr
Where did that info on the inlet valve sizes come from?

I got it from searching here on the forum:
https://www.fiatforum.com/cinquecento-seicento/58287-1242-engine-head-1108-block.html?p=677265

As i'm busy with the 1.2 8v swap in a spi seicento i'm trying to get as much info to not use the wrong parts or buy the wrong parts. Till now i've been busy on the block.

25% lighter flywheel. Balanced pistons and rods and balanced crankshaft.

The crankshaft will be balanced with clutch-flywheel-crank-crankgear-pulley

HI Jajr2009.


Great to see someone building a 1.2 8V SPi engine, as me and my colleague are doing (mostly) the same thing.


We have 1.1 8V SPI (sei) engine with colombo bariani camshaft, and P75 1.2 8V MPI engine (688/889 cam).
We've already dissasembled the head and engine block, so I can measure intake valves. Just give me a few days to jump to the garage.


Where are you sourcing 38mm TB from?
Which intake manifold are you planing on using?


Are you doing a stroker/bore diameter modifications ? Are you installing new/lightened pistons ? Lowering the engine? Raising/lowering compression?
Did you do the flywheel/mainshaft enlightment ?
What is the aproximate port size on intake/exhaust side on the 1.1 8V SPI head? I can measure the 1.2 8V P75 head...




We'll we all have a lot of questions I presume Let's help eachothers, as I can see that all the threads have only part of the information needed to do serious mods...


Greets from Slovenia.

The 38mm tb is from the p75, u use the bottom of the p75 and match it to the top of the 1108 spi. I have done i before check one of my old post when i had the yellow cinq. Back them i did it with a dremmel. It worked out well.

You are indeed correct, missing details on the 1.2 8v spi swaps, most people start a project and then dont finish or start with tons of questions en end up selling their car.

I do think the 1.2 8v swap is nice to do. Wanted to try it out myself, 1st swap so it will be for experience and dont need to hassle with stabdalone atm as the 1.1 spi ecu learns a bit. Not optimal but just enougj so it cam run faily well.

The car is goin to be used as daily driven, so i didnt go nuts on the tuning. The flywheel has been lightened 25 % lighter so from 6.5 kg to bout 4.7. The pistons are not being lightened, just balanced along with the connecting rods. The pressure plate flywheel crank crankgear and pulley will be balanced together. The blok will be skimmed a bit, need to calculate how much still. Thats for the block.

The head will be matchported & polished, intake matchported to fit the 38mm tb, the 38mm tb will be gasflowed. As cold air intake a dexcraft with bmc filter..Exhaust ports polished with a 4-2-1 manifold, 38 mm decat exhaust and ulter backbox. As cam i got the catcams 271°/271° with adjustable cam gear. When this is all done a Roling Road remap and hope for the best.

I'm having a blast doing this, even if i prob wont break the 75 hp.. atleast i had fun cleaning up and building the engine in my kitchen.

a 1.2 spi swap is very easy. it just plug and play.
I know you have a 1.2 bottom end zo you've got the most importend part.
Just stick the 1.1 head on it with manifold and 38mm th and 866 cam or catcams one.

And if you not getting over 75hp you're doing something wrong. I got 80hp with the same setup but with a stock 1.1 block. Only thing different was a supersprint manifold with 2 inch straight exhaust/ remus back box

You'll never know i found someone on this forum who did same swap and says:

Hi, got my car dyno'd the other day and its running 73.22hp. Im running a 1242 8v, 75 bottom end with a 60 head, 75 cam, Tricker 40mm TB, Mckcrich chip, is that about average power for this set up, im fairly chuffed.

You saying he did something wrong? I do notice alot of different results with this swap from diff people. Some 72 most of them 80 and tricker got 95...

I think the torque curve is different from a 1.1 compared to the 1.2 block, but we end up with almost same hp becuase of the spi injector, guess we missing fuel. Only 1 way to figure out. Finish the build and see what dyno, fuel pressure guage and wideband tell us.

I think it is dangerous to go without ECU tune with that much engine tuning.
Cams and TB change A/F ratio a lot, and if SPI injector won't catch up with the fuel demand, you are going LEAN, which ain't all too good for your engine...
Dyno curve should show if you run out of fuel at high RPM, which is probably why someone got stuck at only 70ish HP.

I know that most of the people stick bigger TB on the Sei's 1.1 and it works like a charm. But going bigger cam, TB and changed compression + bigger displacement...I don't know man, I'd at least go for W-O2 and maybe played with fuel pressure if needed...

In the meantime, nothing changed at our project. Engine & head are still waiting for someone to come to garage, put on overalls and do some work on them...

We're looking to get a bigger TB. Someone made a 41.5mm TB out of P75 TB (originally 38mm). But the walls on the TB are thin as paper, which is dangerous. If that breaks and falls into engine, no good will come out of that...
Left 1.1 SPI 30mm TB , Middle P75 38mm, right P75 TB enlarged to 42mm
http://imgur.com/UdoHRF9

And the same guy made this out of P60 Punto TB. Originally 36mm, bored out to 41.5mm
You can see that there's stil some space for further enlargement...

http://www.igreklik.com/slike/viewer.php?file=71897105578819643091.jpg&file_imgur=scXeHuW.jpg
http://www.igreklik.com/slike/viewer.php?file=44681042774456548314.jpg&file_imgur=ZUSqJpR.jpg
http://www.igreklik.com/slike/viewer.php?file=59577632532008416077.jpg&file_imgur=iZuWMJ6.jpg