plz can i rebore the block of my 1116 cc motor to fit the pistons of the 1372cc and turn it to 1372cc?
if it can be done what parts do i must modify and replace and what crank and connecting rods?
and what stock cam and carb i must fit to this motor?

no one to reply thx

Aren't the 1116 and 1372 from a seperate engine family, the 1116C dating back to the 60's while the 1372 being from the more modern FIRE range? Or am I talking crap? If you are taking about rebores etc you might be better off looking for a low mileage replacement of the capacity you are after.

no both from the 128 based engines non fire engines

still no reply

i dont know the answers sorry pm a user called oldschool he may be able to help but not seen this post

Brief rundown on the sohc Fiat engine

available in the following sizes,

1116cc, 1290cc, 1299cc, 1301cc, 1372cc, 1495cc, 1581cc.

These are acheived with a combination of bores and strokes.

Bores sizes (std) 80.0mm, 80.5mm, 86.0mm, 86.4mm.

Stroke lengths, 55.5mm, 63.9mm, 67.4mm.

What Ahmed wants to do (I think) is take a 128 series engine (80.0 x 55.5 1116 cc combination) and install a 67.4mm crankshaft and rebore to 80.5mm (1372cc capacity) ... which will work, but unfotunately not with a combination of standard Fiat parts.

The 67.4mm crank from a Tipo/brava/bravo/uno etc etc will fit into the 1116,1290,1299,1301,1495 crankcase, with a slight bit of file work to the sides near the gasket face to allow a little clearance.

But the standard 1372cc combination from Fiat doesn't use the shorter of the two block heights used in the sohc engine series...

so if you install the long stroke 67.4mm crank into the short block you need to use either

A) very short conrods, and I know of none from the Fiat parts bin that will do the job. , so they would be custom items.

B) have different pistons made with a shorter compression height (distance from the gudgeon pin centre line to the top of the piston) again I know of no "off the shelf' Fiat items with the correct bore size and Comp. height, so they would be custom items

Another thing you need to know is the two block heights have differnt conrod lengths also, the shorter stroke 1116 and 1290, 1299 and 1301 cc combinations use a shorter cast con rod, whereas the taller block engines use a longer conrod which (most of the time) is a forged item.

SteveC

thank u steve for your reply.

you can put the 1400cc ( fiat uno engine) crankshaft, and buy special pistons for that modification. Here in Argentina is a very common modification. You do not have to modify the bore!!!
The pistons are easy to buy here I dont know if are common in other countries.
You can use the UNO carb and intrke manifold with no modifications.
See my car in Members motors!!! I have installed that carb.

The standard compression height of the sohc 1116cc engine is 34.7mm, the standard stroke is 55.5mm.

If we were to modify the stroke to 67.4mm and keep the same conrod length and block height, we would need to shorten the piston compression height by (67.4 - 55.5) /2) 5.95mm to make it all fit , meaning we want a piston with a similar head design, but a compression height of 27.75mm (34.7 - 5.95)

Looking thru lists of pistons in my Mahle catalogue, there is one that "could" perhaps do the job from the Fiat parts bin.

M645 and 182.B6 (Euro 3) variants of the bravo/brava/marea/stilo 1596cc engine ... they are 16valve engines so the flycuts won't be correct, but they are 80.5mm and have a CH of 28.65 but have a dished head... so they could be "made" to fit and are certainly close enough to investigate further...

The other option at 81mm is from an Audi A6...81mm bore , 28.8 CH and a 5.2mm dome ...

SteveC

here are the special pistons


thy are fabricated specially for the modification, they don´t modify the compression height.

powermeter said:

here are the special pistons

thy are fabricated specially for the modification, they don´t modify the compression height.

Click to expand...

how much did it cost for these pistons

about 300 U$ plus shipping