Timing issues (long)

The Blue Box

Well-known member
Ok. Here we go. Same guy who posted about valves hitting the plugs. Solved that by finding some that would be positioned right when torqued. So the motor, a 66 200, has had its head cut .060 and had its block 0 decked and has its 1 barrel boss hacked off for a weber 38 2 barrel to be brazed on. I dont know what compression ratio that comes out to. Maybe someone can tell me. Anyways ive been struggling with high rpm detonation. -side note this motor is in an econoline so i can adjust the timing on the fly- So if im cruising along with the motor running at a high rpm (no overdrive) ill get the pinging detonation sound. Ok i reach down next to me and back the timing off a bit then its fine. Okay. Then i slow down still in 3rd gear (manual) and give it gas. POW! Flames through the intake. Ok then i give it advance and its fine -at lower rpms that is. Basically a never ending cycle of adjusting the timing. So i figure it needs more advance down low but less advance up high. So my first thought is to change out the mechanical advance springs for some heavier ones. I bought a kit for a gm hei dizzy and the springs seemed to be the same. Anyways the problem persisted but showed some signs of improvement. My distributor is a mallory unilite optical. Another side note. Im running this all on the highest octance available in my area. -although i did run it on 100ll aviation gas. Which it did quite a bit better on. But im trying to get this thing to like pump gas.
 
What is your cranking compression?? Hot engine, plugs removed & throttle WOT.
What is your initial advance?? Total centrifugal advance @ what rpm? How much vacuum advance in degrees???
This is the only way anyone can help without putting the distributor on a tester.
 
wsa111":3e6kq1ey said:
What is your cranking compression?? Hot engine, plugs removed & throttle WOT.
What is your initial advance?? Total centrifugal advance @ what rpm? How much vacuum advance in degrees???
This is the only way anyone can help without putting the distributor on a tester.
Im going to see if i can get a compression tester soon. And as for a timing light. I was able to get one reading before it broke. (cheap crappy light) it seemed to take a while for the advance to kick in slowly giving it more throttle from an idle. I guess i do need to get the equipment to produce data before i go asking questions.
 
'S OK, we'll get ya there, just slo'n steady...
 
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