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| Improvised oscilloscope probe for Automotive ignition analysis. |
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| Jim0000:
I am just posting to say I have no positive news to report about this engine problem. In fact, the problems have just compounded along the way. The second camshaft is starting to fail in this engine. They are loosing lobes gradually for no apparent reason, thereby making the tappets increasingly noisy and filling the oil with fine, case hardening steel fragments.The lifters were re-faced each time. The owners (and me) are all stumped! |
| Jim-0000:
Both problems have been identified and fixed on this engine. The miss-fire was caused by an induction problem. The carb was rotated (again) this time @ 90 deg. And the engine ran smoothly. The owners brother has being saying for some time that this was the problem, and it turned out he was correct. The problem of the camshaft lobes failing (wearing away very rapidly with all sorts of problems resulting) was due to a mis-match of cam and cam followers. A ground standard Holden grey motor cam shaft was fitted, but Falcon cam followers were used. Holden and Falcon use a different method to rotate the followers: 1. Holden have the followers slightly off centre with relation to the cam lobes. 2. While, Falcon have a very slightly concave top and the cam lobes are ground with a slight taper - in the direction of the axis of the shaft. The fix was to grind the shaft again, and re-face the followers flat. At least, I think that is what they did. I will ask again next time I see one of the brothers who have been working on this. Of course, the engine had to be flushed out as good as possible and the filters changed. There would be metal fragments in the oil!............ |
| Circlotron:
Though it was first used in 1948, the Holden grey motor is basically a 1920's design. That's not to disparage this old timey donk - quite the opposite. It's surprising just how much technology and hidden engineering detail went into these old things, while being superficially dirt simple, made it something that suitably maintained would run reliably for decades. |
| Jim-0000:
Yes I agree. The only thing that I don't like about it, along with the later Red Holden motor, is the rope main bearing seal! From memory, the owners modified it to take a two part modern silicone seal. I know they did that on the turbo charged mark 3 Zephyr they are running in another car. |
| Circlotron:
Don't forget shared inlet ports, and on the grey, shared exhaust as well. Fibre cam gear. And the red motor has the fan belt in a groove around the perimeter of the harmonic balancer! For it to do it's job properly there should be nothing touching it. Sounds like a bean counter overruled an engineer on that one... :palm: |
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