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Discussion Starter #1
It came out pretty sweet thanks to PBMF's $8 million dollar bore gauge.

 

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Using it on a BS3 setup? How much cam and valve spring are in it? We haven't had good luck with that style sensor in applications with large load on the camshaft. Depending on the application, they can work great though.
 

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Using it on a BS3 setup? How much cam and valve spring are in it? We haven't had good luck with that style sensor in applications with large load on the camshaft. Depending on the application, they can work great though.
Yeah. We've run this thing in quite a few combos. I'm not sure why cam/spring loads would impact a part that doesn't see any of those loads. Can you elaborate?

~300 on the seat, 750 open, 270's duration, .440 lobe lift.
 

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Yeah. We've run this thing in quite a few combos. I'm not sure why cam/spring loads would impact a part that doesn't see any of those loads. Can you elaborate?

~300 on the seat, 750 open, 270's duration, .440 lobe lift.
You probably won't have any issues with those numbers. The further from the crank that sensor is mounted, the larger the chance to fall out of the 15 degree window for cam/crank advance. There is the slack of the belt/chain/gear drive, the twist of the cam when there are large spring loads, lash between the cam and drive gear, and last on the list is sometimes a poor fit between the shaft and reluctor that add up really quick. Going to a sensor mounted in the cam gear removes three of the four potential problem points for less than $75 and cleans up the back of the manifold in the process. I have seen swings of 12 degrees with the GM drive be reduced to a 3 degree swing the entire run when using a different pickup.

If you are going to use the drive, I would at least recommend to weld the reluctor to the shaft, and machine the drive housing to allow for unlimited positioning of the pickup. Watch that cam/crank advance closely, if it dances around while revving or while holding the engine at a steady high rpm I would get rid of it first thing.
 

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You probably won't have any issues with those numbers. The further from the crank that sensor is mounted, the larger the chance to fall out of the 15 degree window for cam/crank advance. There is the slack of the belt/chain/gear drive, the twist of the cam when there are large spring loads, lash between the cam and drive gear, and last on the list is sometimes a poor fit between the shaft and reluctor that add up really quick. Going to a sensor mounted in the cam gear removes three of the four potential problem points for less than $75 and cleans up the back of the manifold in the process. I have seen swings of 12 degrees with the GM drive be reduced to a 3 degree swing the entire run when using a different pickup.

If you are going to use the drive, I would at least recommend to weld the reluctor to the shaft, and machine the drive housing to allow for unlimited positioning of the pickup. Watch that cam/crank advance closely, if it dances around while revving or while holding the engine at a steady high rpm I would get rid of it first thing.
Yeah we modify them to use a standard dist hold-down with additional adjustment.

Front mount hall effect we used on previous motor was nice but we cam drove the fuel pump on this motor. It swung 3-4 deg max like you've seen. I'll post up results. Thanks for the history so we can watch for any potential problems.
 
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