Hello all,
New member from Greece here...
Own an ~88 750 Fire, Ecobox, 4spd, which I swapped an 999 uno Fire a while back..Bothe motors ~250,000 kms...

Wife cooked the head gasket last week. I replace the head/carb/manifold from the 750 complete onto the 999 block. Did not notice any "lip" in the cylinders while the head was off...

Car is running seemingly fine, except...

1. car pinged under load, traced it to a dead distributor diaphragm..
2. Oil light takes ~5-6 seconds to go out when starting (hear rattles during this time) Then everything is smooth...

Questions:
1. Are the Fire cranks forged/durable/nitrided? I would replace crank/main bearings, but cannot spring for a regrind. Meaning do these engines wear out their bearings, cranks, or both?

2. Are the carb/inlet/head/valves the same between the 750/999 Fire? They looked the same to me, but did not have time/thought to measure. The only diff I saw on the carb was a "180" vs. "170" jet which I swapped.

3. The 750 head was previously rebuilt/shaved. I now have a static compression ratio os 230 psi. COuld this be a potential problem? Are thicker head gaskets available for these Fires?

4. Do the the non-Fire, Uno 1 Liter motor, 5 speed transmissions fit on the Fire motor directly? I can get a freebie, but would have to pull it out first..

Would appreciate feedback based on your experiences...

regards,

nikos

A lot of questions - I can't answer them all, but here goes:

I haven't known one wear out the bottom end of the engine - provided it has regular oil changes.
They should do about 300K kilometers.

If the oil drains out of the main bearings while standing, either the oil is too thin (15W40 is the intended grade), or the filter has no "non-return" valve, (or the engine is rather worn).

There are differences between the 750 and the 999.
The 750 is 5 mm smaller bore (the 999 and 1108 are the same at 70 mm)

IMHO, the compression is way too high - but how much of that is down to the head being on the wrong block, and how much the skim is unknown.
I don't know if you can get "oversize" headgaskets for this engine.

Don't know about the gearbox swap.

Re: FIRE q's : Uno Technical

Hi Nikos,

Welcome to the forum! Sorry I'm late - just stumbled on your thread.

zucherro said:

Hello all,
New member from Greece here...
Own an ~88 750 Fire, Ecobox, 4spd, which I swapped an 999 uno Fire a while back...
...Do the the non-Fire, Uno 1 Liter motor, 5 speed transmissions fit on the Fire motor directly? ...nikos

Click to expand...

I'm not sure TBH Perhaps if you post this one in our Uno Technical you'll get a better response .

Kind Regards,

I can remember when Charlie Browns broke the exhaust manifold on a freinds 999 Panda many years ago, we went to a scrappy and took one off a 750. When compared to the 999 manifold, the ports were much smaller on the 750 so you'll be strangling the engine with the 750 top end.

Can you not get the original head skimmed?

the tranny should fit but i'm not sure, i know the one from the uno 999cc fire(45) fits on the panda but thats a fire engine

as for the head they are quite different all the ports are different sizes and the combustion chambers are also different sizes(750 has a smaller bore)
the best combo i've found so far is to swap in a 1108 or 1242 head/intake/manifold onto a 999cc fire it will bolt right in and give 10hp+ with no other mods (they are hard to find and expensive though)

Thanx for the feedback guys,

I am not at all pleased w/ the current setup above. Car still rattles on start then kinda quiets down....
Severe pinking though :-(...

Got another Uno FIRE engine that came out of a wreck (999cc).
Took out the pistons and crank and was amazed to minimal wear on the con-rod and main bearings and the cross-hatch pattern from the factory hone was clearly visible...
I've rebuilt more than a few engines, and the FIRE engine is really a very well balanced and durable design...

Anyway, dropped 100 euro and got rings, gaskets, bearings, bolts etc...
Steam cleaned the the block and will hone and assemble the thing tonight/tommorow.

Will report back...
I'll post afew other q's on separate threads...

regards,

nikos