Engine failure 1.3S

[P. de R. Leclercq]

You should not have distortion problems using MIG to seam weld the sub frame - as I said, it is already welded.

There are various opinions about valve seats; a customer has told me that he has done over 100, 000 km in his S2 Fulvia 1300 on unleaded petrol and has had no problems. Certainly the 1600s have hard seats and I have run mine on super unleaded for years without problems and an inspection of the seats showed no significant widening of the seat or recession.

Here at Evolution Engineering we offer an "unleaded service". Fulvias usually need valve guides and we use nickel-silcon bronze ones (like those on an Integrale). We use 21/4N valves and extremely hard seats. The seats are cut to three angles, providing a useful improvement in performance. 25 Euros would be very cheap for such work. First the old seat must be removed, the new seat supplied and shrunk into place and then machined. To this must be added the cost of the guides and valves. I am not especially impressed with the original exhaust valves and after 30 years, they are usually not very good - quite understandably of course!

On this subject, the 1600s had valves made from Nimonic 80, a gas turbine type super-alloy. Nimonic is super stuff, and still used in ultra high-performance turbocharged engines. However there is some anecdotal evidence that Nimonic is attacked by lead. Certainly I have seen 1600 exhaust valves that showed some signs of erosion near the valve head, and I have also seen them in two pieces, one half usually embedded in the piston or combustion chamber....

Paul

[P. de R. Leclercq]

Regarding the specific engine problem that started the thread, I would suspect a burned exhaust valve. I have seen this on Fulvia engines - especially on No 4 cylinder when there has been a leaky servo hose.

A cylinder leak-down check would quickly indicate where the problem lies.

Causes? Old age or an over-tight tappet screw are most likely

Paul

[oliver]

Thanks everybody on the detailed advice. I will keep you posted on the results and also make some photographs - might come in handy for other novices.
Oliver

[Huib Geurink]

Good to hear we finally have a photographer in the family!