Monday, May 30, 2011

Power problem solved

At the last autocross, I was very disappointed with the power of the car. The dyno said 290 hp and 288 ft/lbs but my butt dyno said it was a lot less than that. I even called the dyno guy and questioned the accuracy of the equipment. Well, anybody familiar with Stromberg or SU carbs will look at the pictures below and know immediately what the problem was-a torn diaphram. The diaphram raises and lowers a sleeve inside the carb, allowing more or less air in. This diaphram was ripped and so the sleeve wouldn't allow any more than a trickle of air into the 3 cylinders fed by this carb.



I also discovered a big ignition timing problem. I had purchased a new cap and rotor from a "Top Seller" on E-Bay and I should have known the quality of the parts was poor when the rotor just snapped in half when I tried to install it. Well, the cap recently failed as well so I went back to the original Lucas distributor cap. I'm guessing that the knock-off cap and factory cap didn't share the exact orientation on the distributor because the timing was suddenly 20 degrees too advanced. This now makes me question the quality of the thermostats I purchased from the same seller because even with the oil cooler hooked up, the coolant temperature is too high.

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