jjacob
Member
I did some research online about the need for reinforcement plates when doing bore increases on 110F engines. The need for these was not apparent to me, although I am sure some here knew why they are required. Thought I would share my information.
The plates are more accurately described as spacer plates. The reason is the 110F block is 10mm shorter in height than the 126 600cc or 650cc blocks (126600, 126a000, and 126a1000). So the 110F factory barrels sealing surfaces from crankcase to head are 10mm longer than the 600/650 blocks. 110F barrels are 90mm, 126 barrels are 80mm.
When you buy barrels that increase the standard 110F bore, these bigger barrels are built to the 126 block dimensions. So when installing one of these kits on a 110F block you need a 10mm spacer under the barrel to raise the barrel to the correct height for the block. Otherwise the piston would rise 10mm too high at TDC.
I am sure that there is also some reinforcement that occurs also.
I found most of this information on the fiat500club.org.uk site. Here is a link to the thread: http://www.fiat500club.org.uk/clubchat/viewtopic.php?f=1&t=6070&hilit=big+bore
Pictures show the difference in barrel and block height. You can see the block differences if you look at the pushrod holes and the inside of the bores for the cylinders. The barrel differences are obvious from the length of the fins, the 110 has more.
One of the interesting things is that you could adjust your compression ratio by varying the thickness of the spacer plate.
John
The plates are more accurately described as spacer plates. The reason is the 110F block is 10mm shorter in height than the 126 600cc or 650cc blocks (126600, 126a000, and 126a1000). So the 110F factory barrels sealing surfaces from crankcase to head are 10mm longer than the 600/650 blocks. 110F barrels are 90mm, 126 barrels are 80mm.
When you buy barrels that increase the standard 110F bore, these bigger barrels are built to the 126 block dimensions. So when installing one of these kits on a 110F block you need a 10mm spacer under the barrel to raise the barrel to the correct height for the block. Otherwise the piston would rise 10mm too high at TDC.
I am sure that there is also some reinforcement that occurs also.
I found most of this information on the fiat500club.org.uk site. Here is a link to the thread: http://www.fiat500club.org.uk/clubchat/viewtopic.php?f=1&t=6070&hilit=big+bore
Pictures show the difference in barrel and block height. You can see the block differences if you look at the pushrod holes and the inside of the bores for the cylinders. The barrel differences are obvious from the length of the fins, the 110 has more.
One of the interesting things is that you could adjust your compression ratio by varying the thickness of the spacer plate.
John
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