1100 or 1300? help me to know wich one is in my car..how it ended

ghostdancing

True Classic
my 128 coupe is a 1100 on the paper, but i suspect that the actual motor fitted in the bay can be a 1300 (the p.o. didnt say me nothing about that: just "it's all original like mother fiat built it back in '72")

on the block it's stamped 128A1, and the water jacket rear cover is a bolted metal plate (not a plug in core)..does this means it's a 1300?

i know that the complete motor code is stamped on the block near the tehrmostatic valve housing, but is so small and lightly stamped that i cannot read it

note that if yes i will have further questions: the car feels more like a stuffed 1100 than a stuffed 1300 (no more then 50hp by the seat of the pants..)
 
thank you Steve..now i didnt drove a fiat sohc 1300 back in the days, but remember that for examples lancias delta\prisma 1.3 where not boring cars (and also at least 150 - 200 kg heavier then my 128); i drove often an UNO 55 (1116) and it was really zippy (maebe lighter then the 128, but not so much)

how can be my car so lazy? note that it start promptly and does accelerate smooth, no engine noises, no problem at all..just not enough power

the carb is the DMTR32 (as far as i know same jetting from factory1100\1300), the motor is clean and tight..maebe i can check if intake\exhaust manifolds are the proper 1300 part? what do you think?
 
you just don't "feel" that much difference between an 1100 and a 1300 (if they are cammed/carbed and exhausted the same) as there's not a lot of differences between the engines...i.e. there's not a noticeable increase in torque like you get with a 1500 and it's longer stroke for example when comparing to a 1300 engine.

If the 1300 is a single barrel carb, has the crappy 1100 camshaft in it and has the single outlet exhaust, the 1300 is only a few hp more in output ... like a Ritmo 60... that's 1300 single carb and just 60hp.

So don't think a 1300 is gong to be like a "big block" in your '28...but it sure sounds like you have something holding back your existing engine.

Is it a single throat carburettor? I notice you bought a 32dmtr? so I'll guess that your car only has the 32ICEV single throat carb? and the single barrel manifold? what about the exhaust? is that single outlet too? if you add a stock 1100 12/52 9.2mm lift cam instead of the 24/68 64/28 9.75mm lift cam of the 1300 coupe / rally.... then I can understand why your 128 feels like 50hp as that 1300 when brand new in that configuration is only approx 60hp to start with.

SteveC
 
well the carb is the dual barrel DMTR32, exhaust manifold is the 4-2-1..dont know which camshaft is inside..i recently bought a 128 rally intake manifold with his carb, but i guess the carb it's just the same of the 1100 coupe (same jetting too, accordingly to the manual book)

i purchased 1300 intake and exhaust manifolds because i already sourced a 1300 motor (1981 ritmo 75S), thinking that my motor was a 1100 and the manifolds of the 1100 are slight smaller..(the ritmo motor came bare, without any fitting\ancillaries)

my guess is that probably the manifolds on the car can be the 1100 smaller diameter parts, so the motor is chocked by these..
 
my guess is that probably the manifolds on the car can be the 1100 smaller diameter parts, so the motor is choked by these..

well if you already have the 32dmtr from the coupe/rally then you must also have fitted to the car the manifold to suit and port sizes don't vary by much ... if it already has the 4/2 exhaust manifold then that's both of those are 128 coupe 75hp parts ...

Go back to basics, check the cam timing and lash clearances, ignition timing etc...

cam timing or cam issues would be my first guess for something wrong if the usual suspects check out to be OK.

SteveC
 
how it ended: yesterday i had fitted a new marelli breakerless distributor (eu 100,00): the car has litterally woke up, probably my original S135 dizzy was really bad..now i can say it's a 1.3 with 75HP (let's say 70 because it's anyway stuffed: evident blow by from the crank breather hose..)

i left the vacuum thing unconnected..mechanic says we can try to connect it to the brake booster hose with a T joint..what do you think about this?
 
Back
Top