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Grrr. Just as soon as I get the top end of the PV's motor all squared away with the new cam, the modified head, the Weber DCOE's, the Mallory distributor (just recurved and working perfectly), etc and knock knock knock - a rod knock appears! I've been fooled by bad timing gears and various valve train maladies before, so this evening I took off the roller rockers, put on the solid rockers to see if it made a difference, but no - still a hammering knock at about 3000 - 4000 0with slight throttle applied. Then I recalled the trick about pulling the plug wires at idle. With all 4 on there isn't much of an audible knock at idle - at least the usual clatter drowns it out. And nothing changes hen #1,3, and 4 wires are pulled. But pull #2 and yuo get a nice clear knocking sound.
Sigh... I was going to rebuild the bottom end sooner or later - just to finally get rid of the oil leaks and to get it balanced. But, like the cam gear, I guess it wanted to happen on its time schedule, not mine. It was rather casually balanced way back when when it got the big bore rebuild, and was a bit buzzy at high rpms. And I probably hastened the demise of the rod bearing by occasionally tapping into the new high end power by revving it up to 7000. Felt and sounded so good I did it probably a bit more than I should have. :D
Anyhow, to finally get to some sort of point - any suggestions on how to rebuild the bottom end to make something that will withstand some high revs? It's currently a 6 bolt cranks, rods from (I think) a 1973 B20E, and an old set of 92 mm IPD big bore pistons. Would an 8-bolt crank and some particular year's B21 rods work better (with some B21 pistons of course). Some non-Volvo rods of some sort? Some high dollar lightened 6-bolt cranks from KgTrimning? It will be a while before I pull it apart, so some scrounging for obscure parts isn't out of the question.
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