2.X L conversion of 2.0 L engine

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dino176
Posts: 62
Joined: Wed Nov 27, 2013 6:29 pm
Dino: Fiat Dino 2.0 Spider

2.X L conversion of 2.0 L engine

Post by dino176 »

Dear All
I have now started my motor upgrade project – let me name it 2.X L conversion (I will explain in the following).

In Mike Morrison´s book the 2.3 L conversion is mentioned (page 101). Among the modifications are new wet liners to take the standard 2.4 L pistons – and it is here the confusion starts.
The 2.0 Pistons have a compression height of 32 mm and the 2.4 L have only 30 mm. Meaning using the 2.4 L pistons in a 2.0 L engine will end 2mm below the upper egede of the liner (at TDC).
This agign will result in really bad compression, unless I machine 2 mm of the block (or use custom pistons or conrods). I am affreight that machining 2 mm will result in other problems, like weakning of the block and problems with components relative to the heads, thermostat housing, intake manifold etc. And I am not funned about the idea to use custom pistons or conrods either.

So I was thinking why not use the 2.4 L crankshaft, with 60 mm stroke compared to the 57 mm of the 2.0L engine, the 2.4 L will compensate for 3mm/2=1,5 mm in top position. With this setup I will max need to remove 0.5mm of the block. I will also be able to take usage of the additional 3 mm stroke, resulting in a 2.4 L conversion.
The advantages are obvious – not only will I get 2.4 L but I will also spare my engine for a lot of custome parts/modifications.
Now the qustion, Has someone in the group experice with the 2.3 L conversion and have you faced the same dificultys ? Have some one tried to fit a 2.4 L crankshaft in a 2.0 L engine ? Does someone have a spare or defective 2.4 L crankshaft I could buy/borrow.

Regards Jesper
GaryS
Posts: 47
Joined: Fri Dec 27, 2013 5:56 pm
Dino: Fiat Dino 2.0 Coupe

Re: 2.X L conversion of 2.0 L engine

Post by GaryS »

Perhaps differences in combustion chambers between the 2.0 and 2.4l heads would compensate for the different piston height spec? FWIW years ago i spoke to Mike Elliot about his 2.3 kit, and he candidly said it just works .. better than it has any right to. Mike refused to credit himself, saying it was just plain good fortune that the mix worked so well. Big torque gains and Rev happy. Unquestionably an improvement over the factory 2.4. My takeaway all these years later would be to stick to the original Elliot blueprint - I would think Superformance can answer any build questions you may have.
Gary
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