Interference Engine?

[James H Cunningham]

I have an 86 Bertone. Is this what I think they call an interference engine? Meaning that is the timing belt breaks you wind up with bent valves? If so, how often should we change the timing belt. Is that a job which should be relegated to a mechanic or can a shade tree mechanic handle it?

 

[AKimball92]

Hi James! Welcome to the addiction! This is the best forum you will find for any vehicle model.

Your '86 came from the plant as a non interference engine. It has a 1500 cc engine which started in 79. The 1300 cc engine was interference. Between those two, the bores increase minimally (86-86.4mm) but the stroke increased the most. If original, the engine is not interference.

You should provide pictures and any and all information you want to provide for your X. A lot can be done to the engine over time, new cams, machine work, pop up pistons, etc. Odds are though yours is non interference. We just like pictures.

Also check out the wiki. There is a write up on how to change the timing belt, focusing on the 1500.
http://xwebforums.com/wiki/index.php/Main_Page

Enjoy the experience,
Andrew

 

[ng_randolph]

I have an 86 Bertone. Is this what I think they call an interference engine? Meaning that is the timing belt breaks you wind up with bent valves? If so, how often should we change the timing belt. Is that a job which should be relegated to a mechanic or can a shade tree mechanic handle it?

The US market 1500 engine is not an interference engine, but if the car is new to you it is good practice to replace the timing belt anyway. Timing belt replacement every 60k miles would be quite conservative.

Unless you know a mechanic who specializes in old Fiats, you are better off doing it yourself. There is an excellent illustrated guide in the Wiki section. The job is not difficult, but can be a bit frustrating the first time around. One thing to keep in mind is that it is next to impossible to replace the belt without the aux shaft rotating out of position. The distributor is driven from the aux shaft, so then the ignition timing will be off. Not a big deal as long as you are aware of it. Just verify ignitin timing and adjust as needed after timing belt replacement.