Im working on a client's GTC car for restoration. I noticed that the Elect Fuel Pump for the car at the rear wheel has actually 2 electric fuel pumps. Car is a mid to late car 10061. I have not seen this before and was wondering - has anyone else with a GTC have 2 fuel pumps and if so are there another changes down the line of the fuel system that goes with this? I did notice as well there was a block off plate on the mechanical pump and no fuel bowl. My initial reaction is that someone has modified the orig system and flow - but before i attempt to reverse all this i wanted to check to see what other experience out here has seen. Appreciate the advise. The fuel system also has the canister for the filter at the rear wheel as well. I see nothing in the parts books that would tell me anything different than to assume this was modified. Appreciate the feedback..
Have you ever seen the supplemental Technical Information Letters pertaining to the production changes on late 330GTC/S models and onward to the 365GTC/S models? These were published in March of 1969.
Here is the page pertaining to the fuel system for the late 330GTC and 365GTC. I don't know exactly when/what serial number they implemented these bulletins into production, but the bulletins are dated March of 1969.
Ed: To actually answer your question, to my knowledge, no 330 GTC/GTS cars were built with twin electric pumps. The changeover occurred with the 365 GTC/GTS cars. Obviously the factory approved of converting the single mechanical/single electric pump setup to the later twin electrics. The reason for this change was the mechanical/electric pump cars had a tendency to have the electric pump cavitate if it was turned on "after" the engine began to get hot during heavy, slow traffic. If you saw the traffic slow down ahead and turned the electric pump on early, it would pickup the fuel and everything would be fine as the engine got hotter, but if you tried to get the electric pump to function with the fuel system hot, it would cavitate and just "click" like crazy and move no fuel. The twin electrics solved this problem.
Thank you for the reply.....i will do some research and reach out to others with higher serial numbers to evaluate if this has happened. Funny though, on our car 10061 those pumps in the picture of the 365 diagram is exactly what i took off the car! The typical copper fuel line was replaced with a rubber line on the car. Quite possible someone has been making changes before the current owner took possession of the car - which was 25+ yrs ago and parked it until now. As a side question on the original pump - was the pump the black fispa pump that mounts on the flat bracket at the rear wheel?
Ed: 10061 was right in the period where the 330 GTC/GTS switched over to the single Bendix electric pump. Only the Build Sheets will tell you for sure. However, the frame mounts are different so that could give you some guidance. My best guess is that the car was converted to the twin pumps and your inspection of the frame will tell you if it originally had a Fispa or single Bendix.
Good point, Dyke. My GTC, 10795, came with a single Fispa pump and continuous headaches, especially in traffic/hot weather when it would vapor lock and pump only fumes. The mechanical pump worked intermittently. Finally, I installed and aircraft electric pump under the spare tire and never had a problem. Since I drive my car quite regularly, both in-town and on long trips, I can't afford the nonsense with the original pumps. This is the pump I use: https://www.aircraftspruce.com/catalog/eppages/solidstatepump.php Part number 60301. I figure that if it's good enough for aircraft, it's good enough for my GTC. Bob Z.
at that time it was not other possible or available but I wonder about the cheap prices for the aircraft fuel pumps
In June of 1967 Ferrari sent a Technical Info Letter to the dealers about the vapor lock problem on the 330GTC models. I have attached it here for your review.
