engine? need help

[speego]

My sons 76 fiat quit on him driving down the freeway. Thought it was timing belt, but in turning engine over, the crank turns over but the timing belt doesn't move??? any ideas. I don't think this is good.

[pope]

Better check the backside of the timing belt. He has most likely stripped the teeth off the back of the belt near the crank gear.

[speego]

do you think it's done major damage?

[maytag]

do you think it's done major damage?

too early to tell. we need more information. But the good news is that the motor is NOT an "interference" motor. Meaning that it's very unlikely he's been banging holes in pistons or other such.

[speego]

really? I thought they were all "interference" until 1980?

[maytag]

well, I don;t consider myself a Fiat-specific expert, so I guess that could be. But that would be news to me. So far, everything I've read would indicate to me that none of the 124's various engines was 'interference'.

[fiasco]

I'm pretty sure the '76 motor is an interference motor. Mine was.

-- se

[pope]

All spiders up until sometime in 77 were interference engines. But its going to take some investigation before you know whats wrong for sure. When did he last replace the belt?

Good Luck, and keep us apprised of the results.

[So Cal Mark]

76 was an interference motor, unfortunately. Losing the belt at high rpm will most likely result in a minimum of 4 bent valves. I wouldn't turn it over any more until you slip a new belt on and set the cam timing

[speego]

So even though the timing belt is intact, it still could be the timing belt?

[So Cal Mark]

that style of belt with square teeth will shear teeth off rather than break.

[majicwrench]

Like was already said, if you check belt you will probably find that the teeth are gone in a section. So while the belt may appear intact, the damage has been done. Put a new belt on it, roll it over by hand, then check compression, go from there.
Keith

[roanokeSpider]

Best bet is that you have 4 bent valves and valve guides it happened to my 76. It cost me just over 400 including parts to fix that mistake.

[speego]

So should I pull the head first or replace the timing belt first?
thanks for all the info so far

[So Cal Mark]

just slip a t belt on it and evaluate the motor. Don't put any of the covers or anything back on until you check out the motor. Who knows, maybe the engine was rebuilt at some point with late pistons with the larger valve reliefs