6tfo said

Something is seriously wrong. Here's the valve specs, just as an 'xample, on a 72 340, right out of the shop manual: (318 is left column of numbers, 340 middle, 360 far right.) Notice that exhaust opens WAY BEFORE Bottom Dead Center (BDC) or 180*

You should be able to get (or have!!) the exact timing specs for whatever cam is in the engine. MOST especially, if the crank is degreed or "timing taped" you should be able to walk it through a whole cycle of the no1 cylinder (Don't confuse yourself with others) and see where you stand.

6tfo said

We turned the engine back to TDC compression stroke and added 12 degrees (12 BTDC). .

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You sure you are at 12 BTC, or 12 AFTER TDC?

6tfo said

...... we decided to try total timing. So we went back to 18 BTDC initial, increased RPM and at over 4K RPM set timing at 38 BTDC. This brought initial timing down to 12. We test drove and to my surprise it ran pretty good. There was still some miss firing and power loss upon acceleration but it wasn't terrible. We agreed that with a little tweaking it may run decent and if nothing else the timing setting as is shouldn't hurt anything. ...................Honestly, I'm still puzzled.

This thread has probably gone on for too long to be productive to others anymore.

Thanks again.

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I've been trying to get you to use total timing, until you get it sorted. ANY engine should run "fair" negating dist. advance curve, at around 35-40 in the context of this type engine.

ARE YOU sure you don't have a crappy wire or two, or bad plug?

I disagree the thread is "getting too long."

PLEASE keep us updated

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