Technical mpi engine in cinq

[jonjg]

im looking to replace my tired 110k engines in 1 of my cinquecentos. does anyone know if a seicento lump is a straight fit in? apart from modifying the inlet manifold bolt pattern and plumbing in a temp guage is it a problem?

does anyone know if i could drill and tap the head to fit the cinq temp guage?

any info would be great,the cinq engines all ready to drop out.

 

[rallycinq]

The MPi has smaller valves.

Put the bottom end in and refurb your head.

D

 

[jonjg]

thanks for the reply. how much smaller are they?

 

[rallycinq]

thanks for the reply. how much smaller are they?

To old to remember, I am afraid.

D

 

[dante giacosa]

i fitted a temp gauge to a Seicento engine, by fitting the sensor into a threaded blanking-plug space in the coolant gallery.

It was high up on the NS belts end of the block, and I used an Alfa 156 gauge mounted into the RH centre air vent

 

[David C]

The MPi has smaller valves.

That may depend on year.
To start with SPI & MPI used the same valves:
Exhaust 46514754
Intake 7770334

But there was a change to the MPI engine in 2004 with "lightened valves and new pistons", from then they used:
Exhaust 55194994
Intake 55194993

Unfortunately the heads are only listed complete with valves, so can't see if the heads changed in 2004 or not.

 

[jonjg]

thats helpful thanks. i should think they would have changed the heads in 2004 aswell if the valves were changed. sorry to sound dumb, but what does the long valve number represent? were they smaller or bigger valves after 2004? its ashame we dont know from what engine number the valves changed.

 

[Schumi2001]

i fitted a temp gauge to a Seicento engine, by fitting the sensor into a threaded blanking-plug space in the coolant gallery.

It was high up on the NS belts end of the block, and I used an Alfa 156 gauge mounted into the RH centre air vent

I use an OBDII based display - gives both oil and water temperature. Very useful when I do track days.

 

[David C]

That's helpful thanks. i should think they would have changed the heads in 2004 as well if the valves were changed. sorry to sound dumb, but what does the long valve number represent? were they smaller or bigger valves after 2004? its a shame we don't know from what engine number the valves changed.

The numbers are the Fiat part numbers.


Just Googled p/n
46514754 is 27.5mm head with a 7mm stem.
55194994 is 27.3mm head with a 5mm stem.

7770334 is 31.5mm head with a 7mm stem.
55194993 is 31.9mm head with a 5mm stem.

So for the 2004 change, the intake valve got slightly bigger and the exhaust slightly smaller, but both with narrower valve stems which will increase flow and easily counter the slightly smaller exhaust valve head.

The valve pistons & head changed at engine number 2543171

 

[dante giacosa]

that's VERY interesting to me Schumi-

about the OBDII display; does that go into the diagnostic socket and pull the data from the ECU??

Can you explain..?

I had no idea such a thing was available for these cars...

 

[Schumi2001]

If you have a Sei MPI (not sure if SPI cars have it, to be honest), then you have a OBDII socket.

This is what I have. It's a great bit of kit - when I broke down in January, I'd diagnosed a crank sensor failure within a few minutes so could report it into the AA as needing a tow.

AUTOOL X60 Car OBD2 Digital Multi-function Speedometer Over-speed Alarm Water/Oil Temperature Gauge Battery Voltage Tester Scanner Tool, Trouble Code Reader/Cleaner for 12V OBDII Auto SUV Pickup Truck: Amazon.co.uk: Car & Motorbike

 

[dante giacosa]

I'd read you said that before; about diagnosing the crank sensor within minutes, and I did wonder how

I've got to be honest; I had no idea such a tool was available for these cars.

There is a world of this stuff for VW /Audi stuff seemingly; and there's a diagnostic fed display which was made back-in-the-day for the FIAT Coupe; but I'm astonished to learn of this.
And it's SO cheap!

Thanks for going into detail...