LarryN
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My thanks to the folks on the Forum who gave advice and checked their parts caches to help me solve the problem. A recap for those not involved: about 6 months ago, I took my Alpine Series 2 in to the shop for a routine service. The German-trained mechanic there (the shop owner) is the guy who rebuilt the engine and I take it there for most of the routine service so he can keep an eye on the car. He noticed a knock in the distributor which I hadn't noticed (I never was able to hear the noise - old ears I guess) and recommended looking into it at the next service. By the time that rolled around, the car was losing power at highway speeds and stalling around town.
I found a replacement distributor (Thanks, Rick at SS!) and it was installed. The car made it about 2 miles from the shop and died - after several dramatic backfires. The distributor drive end of the oil pump drive gear was completely destroy (as was the exhaust system). After much searching and posting on the Forum, I bought a Series 5 pump from SS and he installed it. It turned out that the oil pan on the engine was already a modified Series 5 pan (a dipstick tube had already been welded or brazed to the pan since the Series 5 dipstick was relocated to the block)so the only real chore was to rework the oil feed pipe. I had a modified pipe in my boneyard, but the braze joint was badly done and cracked (for those of you not familiar with the problem, the tubing size changed between Series 1-4 and Series 5, so the compression fitting on the Series 5 pipe won't fit the thread in the Series 2 block). The fix was interesting and I pass it along for those who may face this problem in the future: he cut the Series 2 and Series 5 pipes a bit long, and then cleaned up the OD of the Series 2 stub until it fit smoothly inside the Series 5 tube. With the 2 tubes loosely assembled, he then fitted the pump to the engine and marked the Series 2 stub at the end of the shortened Series 5 tube. Being extra cautious, he then tack welded the 2 tubes (I think this could have been done after removing the tube from the car, but I wasn't there). The joint was then brazed to complete the join and seal it.
The culprit in all of this turned out to be a bent shaft in the original oil pump. That was causing the knock and also progressed to the point of throwing the distributor out of time, which in turn caused the loss of power and the backfires, and ultimately got bad enough to break the oil pump drive. I have no idea how the shaft got bent - it is about 1/2" diameter steel and about 8 inches long, well supported by bushings, and not carrying any real load (for a shaft that size), I can't visualize anything in the engine that could generate the forces necessary (I even specualted at one point on whether the tachometer cable or drive unit could have locked up, generating sufficient separating forces in the gears to bend the shaft) (another wild theory was that one of the engines (this one is a hybrid of two units cannibalized to make one) tried to run a Series 5 cam on a Series 2 oil pump and somehow got it engage long enough to mess things up). Any ideas out there?
All of this is passed along with the caveat that I have only had a chance to drive the car about 5 miles so I may be back here in a few days to eat these words. In the mean time, I'm going for a drive...
Thanks again
Larry
I found a replacement distributor (Thanks, Rick at SS!) and it was installed. The car made it about 2 miles from the shop and died - after several dramatic backfires. The distributor drive end of the oil pump drive gear was completely destroy (as was the exhaust system). After much searching and posting on the Forum, I bought a Series 5 pump from SS and he installed it. It turned out that the oil pan on the engine was already a modified Series 5 pan (a dipstick tube had already been welded or brazed to the pan since the Series 5 dipstick was relocated to the block)so the only real chore was to rework the oil feed pipe. I had a modified pipe in my boneyard, but the braze joint was badly done and cracked (for those of you not familiar with the problem, the tubing size changed between Series 1-4 and Series 5, so the compression fitting on the Series 5 pipe won't fit the thread in the Series 2 block). The fix was interesting and I pass it along for those who may face this problem in the future: he cut the Series 2 and Series 5 pipes a bit long, and then cleaned up the OD of the Series 2 stub until it fit smoothly inside the Series 5 tube. With the 2 tubes loosely assembled, he then fitted the pump to the engine and marked the Series 2 stub at the end of the shortened Series 5 tube. Being extra cautious, he then tack welded the 2 tubes (I think this could have been done after removing the tube from the car, but I wasn't there). The joint was then brazed to complete the join and seal it.
The culprit in all of this turned out to be a bent shaft in the original oil pump. That was causing the knock and also progressed to the point of throwing the distributor out of time, which in turn caused the loss of power and the backfires, and ultimately got bad enough to break the oil pump drive. I have no idea how the shaft got bent - it is about 1/2" diameter steel and about 8 inches long, well supported by bushings, and not carrying any real load (for a shaft that size), I can't visualize anything in the engine that could generate the forces necessary (I even specualted at one point on whether the tachometer cable or drive unit could have locked up, generating sufficient separating forces in the gears to bend the shaft) (another wild theory was that one of the engines (this one is a hybrid of two units cannibalized to make one) tried to run a Series 5 cam on a Series 2 oil pump and somehow got it engage long enough to mess things up). Any ideas out there?
All of this is passed along with the caveat that I have only had a chance to drive the car about 5 miles so I may be back here in a few days to eat these words. In the mean time, I'm going for a drive...
Thanks again
Larry