Junk Motor

[jeffko]

Well we have found it, I would even say remarkably easy to break a Ford engine under a lean condition. Let me just say I am convinced of it, but the engine has not been disassembled yet. However, I think they will find severe heat destruction due to the fuel delivery system being inadequate, very inadequate.

This engine dynoed at 670 with 42lb injectors. We still do not know what the fuel delivery was at that time, but the fuel delivery system that was sold as a kit with the car was a 110 gallon/hr pump that was delivering 40 psi. Keep in mind that this engine has a 9lb supercharger?

I never did know much about fuel injection and still don't, but I can say that based on what I have been told by people that do know fuel injection, formulas and the engine build sheet this is more like what the engine should have had for fuel delivery. The injectors should have been 65lb with a pump delivering fuel at 275 gallon/hr at 53 psi based on an 80% duty cycle and 9lbs of boost. The exact calculation is 67.4 lb/hr at 708 cc/min instead of the 42 lb/hr at 441 cc/min. Another term I learned of is BSFC which stands for brake specific fuel consumption. This is how much fuel an engine uses in terms of pounds/hr per horsepower. It should have been .60 rather than the actual .41.

I have built several engines, including the 470 rwhp 393 in my cobra, and spent a lot of time over the last year with the finer points of carburetion so I have some knowledge of car engines. Originally I had though detonation to be the more likely suspect. Even though it is unlikely that the timing slipped or the distributor advance malfunctioned I thought it more unlikely that a lean condition could kill this engine is less than 10 miles.

Guys, this is what makes this website so valuable. It's a classic case of buyer beware!!! Do your homework and stick your nose where they don't think it belongs. Because in the ends it will be you sitting in a $50k car that won't move for whatever reason and may still have at least a fight and maybe even more money to spend on your hands.

Now what is left to see is if the people responsible make good.