Re: Oil pan
The pan is a super poor casting, (you can't use a socket on half the bolts because there isn't enough clearance with the side of the pan) the oil baffling is laughable, this coupled with your comments that it is a 600 pan got us thinking about other options. The 903 pan is a much better quality and performance piece.
I agree. I found that using one of the newer-style ratcheting box-end wrenches makes this job a lot easier with oil pans like the one on your OTAS. A shallow-profile (half as tall as normal) socket with a swivel on it also works well for areas with less side clearance, like the exhaust side on a 600.
I also agree with your comparison of the 2 oil pans; the boxed trap-door baffling of the 903 pan is far superior to the single divider wall of the OTAS pan, the 903 pan is more ruggedly built & the 903 pan floor also sits level as it should.
This same "tilt phenomenon" also happened with the early Abarth OT 850/1000 Sedans, where factory photos show the early cars using a 600-based Abarth 850TC alloy pan (sitting at the "wrong" angle) & later photos show the "proper" 850-based OT1000 alloy oil pan installed, instead. This shows that Abarth realized the error of using a 600-based pan on the 850, & corrected it by designing a new pan to suit the need. Giannini did the very same thing with their 850S vs. 1000 oil pans, where the 850S model used a pan like the Abarth 850TC, & the 1000 used a pan similar to the Abarth OT1000.
Abarth OT850:
Giannini 850S:
Abarth OT1000:
Giannini 1000:
That said, I have been doing some sleuthing and the pan is another unique piece for the otas. Specifically made by Giannini for the 843 / 820 Otas motor. You can find it on page G of the 1994 Schmidt catalog.
While this pan may have been fitted to the OTAS engines, Giannini did not make them
specifically for the OTAS - they were also fitted (or offered as optional) on the Moretti Sportiva 850 (since Giannini built a 1000 engine variant). I imagine that John Edgar (an importer of both cars back in the day) still has a few of these pans hanging on the wall of his barn/shop. The fact that the tilt angle is 600-style shows that the pan was originally made for the 600-based cars, & I've both seen & owned a few 600-based cars with this very same alloy pan. I also bought/sold a lot of these back in the mid-1990's when they seemed to come out of the woodwork with the advent of the internet.
Is this pan "correct" for an OTAS? Technically, yes, since it was what was originally period-fitted by the maker &/or importer. From a mechanical point of view, I'd say "no" because they suffer from the fitment issues as you've experienced & are inferior in quality & function to the Fiat 903 alloy pan. I've always wondered why they didn't simply use the 903 pan (since it was available in 1968 in Italy/Europe), I imagine it was probably due to costs management or something similar (since Giannini already had a bunch of their own alloy pans on hand vs. buying new 903 pans from Fiat).
This pan coupled with the Nardi 817 exhaust are what I would call period Otas parts that I doubt anyone else has. It would be nice to keep the package on the car. My dad is pushing for the 903 pan due to it's better quality. It will require a monza or Abarth type exhaust.
I'd say that if the car is not going to be driven hard, then the original pan will work fine - keep it. It's not often you'll need to pull the pan with the engine still installed, but if you do, just use tools like I mentioned above to make the job easier.
The Nardi exhaust is also a nice "period-correct" item that I'd keep on the car if at all possible.
If you do end up going with the 903 pan, the Monza exhaust will work fine & give the engine a little more top-end performance, & you can fine-tune the system using your choice of muffler/glasspack & end pipes/resonators. If going with an Abarth-type repro unit, you will more than likely need to tweak it (bend/rotate the lower half horizontally counter-clockwise) a bit with a hot torch & a mallet to get things lined up correctly. This has been a known issue with all of the repro's from 3B, OMP, Ansa & other makers, some needing more work than others. :2c:
Abarth parts technically don't have a place on the Giannini built Otas mechanical. Probably over thinking it but those are the gory details.
I agree, apples vs. oranges. I had the same dilemma when hunting for "correct" items for my Giannini 850S replica. Do I buy the Abarth intake manifold with "ABARTH" clearly visible cast into the sides (available now)? Or do I keep looking for the "correct" Giannini manifold? Luckily this car is not on a strict timeline, so I can afford to wait it out. Or maybe just buy the Abarth manifold, grind off the ABARTH cast letters & install it on the engine? :grin:
