Abarth Fiat 1500 engine development

Over the past weeks we’ve been developing a new Fiat race engine for the 1500. Along with steel rods and forged pistons we’ve developed a new camshaft profile and fully re-worked the cylinder head. The head features a hemi-spherical combustion chamber but the valves are angled towards each other. This means that too much overlap and the valves will collide with each other. Both the cylinder head and the camshaft have been developed side by side in order to maximize duration and lift without causing the valves to clash. Larger inlet valves have been sourced and combustion chambers and ports have been opened up and re-shaped. The result is a massive jump from 81cfm at 12mm lift to 96cfm on the inlet and a jump from 53cfm to 63cfm on the exhaust. We will find out what difference this will make when it goes on the dyno. Last time around this engine managed approximately 107bhp at the flywheel.

Fiat 1500 race engine Fiat 1500 race cylinder head Fiat 1500 race engine 2 Fiat 1500 inlet flow comparison. Old 1.375" valve versus our new 1.47" valve

3 Replies to “Abarth Fiat 1500 engine development”

  1. Hey guys, i own a 1962 Fiat 1500 Historic Touring car that has been raced in Australia since 1980. It has been off the track for a while before i bought it, but i have got it almost ready to roll. According to Dyno sheets i got with it, it has reached the sort of horsepower figures you are looking for. Anyway, thought i would share, and please email me if you are interested in pics etc?

  2. Hello,
    I read your article about Fiat Abarth 1500 engine development. I have some questions about cylinder head and pistons. It is original italian cylinder head or polish? What is your impression with exhaust ports? Did you enlarge there?
    What size (diameter) of piston did you use and how is stroke? Original were 77 mm diam. and 79.5 mm stroke.
    This engine was very popular in Poland in ’80. It was made conversion to rally and race by polish OBR SO – Research Center of Passengers Cars in Warsaw – including turbo charging.
    Sorry for my english.

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