i've probably posted this before, but i'll do it again just to liven up the conversation if for nothing else. I wish I could post a few pics of what follows but......
anyway, my mentor tuned and raced Heralds & Fiats, and later, Fiat-engined Formula Indians for over 30 years at Sholavaram (not rallying). He has some of these cars at his place in mysore, and having seen (breathed even) and experienced them ever since I was a kid, I can say that this variety of 1100 is probably the most exotic found among any modded fiat in india, bar none.
probably no engine in the world has been used in mainstream racing for over 30 years, a reflection of the pathetic Indian automotive industry....the 1100 has seen it all. The Group A2 (unlimited) & A1A (indian parts only) saw the most action.
My mentor's A2 class engine is a piece-de-resistance (as far as Fiat engines go) It is bored out to the max. possible (1194cc, I think, not sure) using domed Arias pistons. Both the head and the block are milled, this combo gives 12.5 compression and will not run on anything less than 110 octane because of the cam combination. The cam is a special grind from Iskenderian . The rockers are offset bored and the entire rotating assembly is statically balanced (meaning each cylinder has parts of equal weight to a 1 gram tolerance). The head has a lot of development work on it; all I can say about it is that the valves are bigger and have a multi-angle cut (not just 3 angles). some places in the head are extremely close to zero wall thickness (near the water jacket).
the intake and exhaust really depends on what car its being used in; if its a saloon then the header is different, if its the Formula (which weighs about 400 kg) the header is different. Same with the carburetion; for the Formula Indian, only Indian carbs could be used so it was either twin Solexes or 4 mikunis (from the RD350). For the A2 it was either a single or twin 40DCOE Webers. The exhaust is the normal cannister type with side exit.
An electric fan is used, and even the water pump is cut down to reduce hp loss.
For some applications a close-ratio gearbox from the Triumph Herald was used. We dont know the bhp figures, but what we do know is that with the Formula Headers and twin DCOE combination, the car will pull (notice I said pull, not merely rev) to 8000 rpm with ease.
I cannot describe the sound that this engine produces with words. It is both defeaning and orgasmic at the same time. This is because of the unique port configuration of the Fiat (its called a siamese exhaust port, where the center cylinders fire into the same exhaust port). If you hear it rev, you wont even guess its a Fiat 1100 engine, cause you are used to seeing and hearing anemic response from stock 1100s. When the engine fires up, it sounds like the timing's out. The idle and off-idle are extremely poor. This effect continues upto 3000 rpm at which point it "comes on the cam". After that its just one mad rush to 7500 which, I am told, is the ideal shift point.
The formula's another piece of brilliant engineering, but thats another story.
This engine now resides in a Dolphin (after I "re-kindled" the racing spirit in my mentor; how ironical) which was supposed to have raced in Speedrun '06 but we couldnt finish the car in time. Its a sleeper in the true sense, we found the car buried halfway in a field in Maddur and planned to race it as is, without any exterior mods. Even the wheels had rust on them and that would have been something to watch, even though it might not have won against the present open class cars.
Ananth |