Fiat 2000 Head Swap to 1756 Head, Correct Part number 4372291?

[FLGordie]

Looking to do a performance upgrade cylinder head swap to increase compression and less air restriction. Is this the correct 1756 Head to use for the swap? Seems this casting number is from a late '78 engine and could have more restrictions.

Can anyone confirm that this is a good swap for performance improvement?

Part number 4372291 is marked on the casting.

[FLGordie]

i bought the head and it arrives in a day or two. i think this is the correct model to give more compression and greater air/fuel flow. I need to test for cracks, have the intake polished, and possibly new valve seats, springs, guides, and valves. Project for the heat of the summer.

[rridge]

4372291 is the head casting number, not the part number. The same casting is used to product both FI 1995 and late 1756 heads. Machining details making the differences, which are combustion camber size and the number of air injection ports. I believe the 1756 has four air injection ports, and the FI has none. I believe the carbed 1995 used a different casting with an exhaust reticulation port running across the front of the casting. The 1995 chamber size is 53ml. The 1756 is 47ml. More info here: https://www.mirafiori.com/faq/content/h ... eadid.html

[AndyVAS]

Stock for stock, it is a power gain. That said, it is so little you can't feel it. It is only good for roughly 0.2 increase in static compression.

You can upgrade the valves in all the heads. You can polish all the heads. You can port all the heads to about the same depending on how good each head's individual casting was.

[FLGordie]

Thanks for the information on the casting number. The head has four air injection ports as you stated and I am confident it is for the 1756 engine.

Finally, sent the Head over to the machine shop to get tested, bead blasted, and resurfaced.

I plan on keeping the spend under control and stay stock and enjoy the slight compression increase and better air flow head over the 1980 2000 Carb head with the pollution controls that I have today.

[FLGordie]

Machine shop cleaned the head, valves, springs. Everything checks out good, except one valve guide is broken and need new valve stem seals. Everything checks out as stock. Has USA stamped in red ink on one side. Is that typically of 1977 heads?

Valve stems polished up good and seat well in the seats.

My goal for the 1980 2.0l Carb engine is the easy performance upgrades for dependable street driving. Carb 34ADF (Done), 1800 intake manifold (Done), 4.2.1 exhaust manifold (Done), removed swapped CAT for test pipe (Done), 1800 head (in progress).

Do I change the springs? If I do, is there advantage to going to the ISKY performance springs or do I remain with the stock springs?

Since the old stock valves cleaned up well, is there a need to change the valves?

[FLGordie]