I hope everyone has a safe and productive 2021! For those with major projects underway, let's try to get some of the 'hidden' deTomasos on the road later this year
I recently saw a FIM tank cap for sale (online somewhere!) and the seller claimed that it was an OEM Mangusta cap. The same cap is illustrated in the top of the first image. It's stamped with "FIM", "0,90" (bar) and "BOLOGNA". Having looked through every image I can find, I have yet to see this cap on anyone's Goose. Yet it makes sense...in that era FIM tanks were supplied with FIM caps, which came in a variety of styles. Does anyone have a period image showing this or any other FIM cap in use?
Luckily an assortment of 'real' FIM caps and various repros (like the lower image) are available. I understand quality varies but they are at least easy to find.
My car came with a round generic cap which I'm sure was a cheap aftermarket replacement installed by some well intentioned previous owner. I'm now curious about its spring pressure and think it might have been responsible for damage to my coolant tank, which is unfortunately NOT readily available. Here is the short story....
My tank always had a rough, soldered area on the bottom face where obviously something was not right (in photo 2 this solder has been removed but the area still has a solder film that marks the spot). I finally took the time to separate the tank and see how bad things were inside. I expected to find massive corrosion of some kind but found none. Instead there were several small cracks (see photo 3). Clearly these pierced through the brass and must have wept coolant. The easy fix was to to glob solder on from the outside, which did the trick but looked bad.
So it seemed like a case of repeated over-pressure in the tank. FIM caps range from 0 to 2.5 bar so clearly caps come with a wide range of spring pressures. An incorrect cap could clearly result in system over-pressure. So no guarantees that's what happened to my tank, but I'm going to stick with 0.9 bar max from here and see if things hold together better. Always something to find with these cars. I have never heard of brass embrittling over time so hopefully that is not an issue.
