1585cc vs 1796 cc ?

[geert]

1796 cc original calif spider 1977/78 100.000 miles = +-80 hp-ish original
but with 32 ADF carb, antipollution stuff removed, 4-2-1manifold = ?? hp
( what caused the low compression ratio on those cars ? )

or should I swap with a
1585 cc Fiat 132 +- 1984 60.000 miles = 98 hp ?
( same carb, same manifold ) ?

is a 34 ADF carb an option on both ?

[vandor]

I'd stay with the 1800.
The compression was from flat-top pistons, no dome. The 34ADF works very well on the 1800.

[djape1977]

it would be well worth while if you could get the 1756 up to euro spec.
it was originally 107 and 111hp with plenty more torque than 1585cc

[So Cal Mark]

bigger is better, size does matter

[geert]

it would be well worth while if you could get the 1756 up to euro spec.
it was originally 107 and 111hp with plenty more torque than 1585cc

thanks for the replys.

What does it take to get the 1796 to euro spec ?
other pistons ?, ... ?
differences in head/camshafts ?
( inlet/exhaust/carb not in question)
with higher compression, does the engine still works on 95-ron lead free fuel ?

geert.

[djape1977]

you'd need euro spec pistons with 4mm dome, weber 34adf-250 carb, 42mm intake manifold, 4-2-1 exaust to get it to 107bhp. in order to get 111hp, you'd need head with slightly bigger intake valves (42.5 vs 41.8mm) and longer duration cams. dunno what fiat used these heads and cams on US market but 124 spider 1592cc engine does have long duration cams, in europe at least, as well as fiat 132 1800 special (1756ccm) which had both big valves head and long duration cams.

by carefully choosing parts from a fiat parts bin you can assemble pretty frisky motor and 1756 was always a starting point of my choice for that, even rather than 1995cc unit. by the way, you do know that fiat 131, sold in US as Brava and SuperBrava also had same twincam engines as 124? perhaps those weren't so crippled by anty pollution stuff as in 124?

and yes, in europe we drive our fiats on "95 octane" unleaded and they run just fine. and i beleive it aint even close to 95...

[geert]

thanks everybody, answers are very usefull.

groeten, Geert.

[Daniel]

in order to get 111hp, you'd need head with slightly bigger intake valves (42.5 vs 41.8mm) and longer duration cams. dunno what fiat used these heads and cams on US market but 124 spider 1592cc engine does have long duration cams, in europe at least, as well as fiat 132 1800 special (1756ccm) which had both big valves head and long duration cams.

there's no such think as a Factory longer duration cam by Fiat for these engines ! all the cams were the same expect
for the early 1438s some were fit with a bit more lift and duration . Another myth about the 1608 cams being
more wild as well but if anyone compared them would see the are just as mild as the 1800 or 2000 engines cams .
It's so interesting how these false facts keep getting spread out there I wonder who comes up with this stuff it
must be people hearing from one source then passing it on to another and so on .

[djape1977]

nope, you're not right and i'll proove it to you as soon as i manage to find 'em in my pile of parts.
so far, i've found longer duration cams in fiat 132 1592ccm engine and in fiat 132special 1756ccm engine.
cams from 1608 are exactly the same as in 2 litre and 1585ccm strada, 131, 132 etc

[Daniel]

what countries had the 132 ? we never had those over here in the US, I heard of them and read some info about the car .

[djape1977]

all of europe, south america, africa, middle and far east... pretty much anywhere except USA. maybe 1592ccm spiders had the same cams as early 132 1592ccm? dunno, never had a chance to see one in person.

as far as i know, and i've worked on A LOT of old fiats, all cams on twincam enines are interchangable but there are different ones. diferent opening timing, diferent duration and diferent lift. for example strada 130tc had 11,9mm lift short duration cams.

there's a lot that can be done to improove fiat twincam if you have a big parts bin from diferent models.
example:
strada 105tc head
1592ccm cams
strada 130tc intake and dual carbs
regata 100s/strada 105tc 9mm dome pistons
lancia beta exaust manifold
electronic ignition from any post 1977 124, 131 or 132
on a 1756ccm block and crank
croma turbo head gasket

will give around 135bhp on a dyno. and that's all bog standard stock parts just from diferent models

[Daniel]

all of the twin cams fiats over here had the same cam profiles no variables in timing, lift or duration . If there were any
changes it might have been on the cam pulleys since i haven't checked those enough to know for sure . The exhaust
and intake cams are identical even down to the pin location, I'm surprised at the lift of the 130tc strada with 11'9 mm
of lift that is a lot for a stock engine for its size and era what was the duration on those cams ?

[djape1977]

dunno exact duration but it's shorter than standard 2 litre cams. i'll take some pics tommorow if i manage to spare some time for it.
as far as i can tell, and i really have no experience with US spec fiats, seems that you guys were robbed of good stuff because of polution controls. i mean charchoal canister???

[Abarthnorway]

I'm surprised at the lift of the 130tc strada with 11'9 mm
of lift that is a lot for a stock engine for its size and era what was the duration on those cams ?

The 130 TC cams lift are 10.03 mm and 240 duration @ 0,4 mm (16"thou) - exactly same profile as later 8v Croma, Thema etc. Fiat CC 124 coupe has 9,9 mm and 280' - the beefiest cams I have measured from the Fiat twin cam family. 1608 is a lazy profile and 9,5 lift.

Best regards

Remi

[djape1977]

unfortunately, strada 130tc cams don't fit the cam housing from croma, so lift is definately bigger.