So very stuck...

Gearhed73

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This is a hard one to follow. I would suggest the OP take a step back and spend some time learning and understand the basics of timing. This bling shotgun approach (while fun to watch) will not get you very far. Everything starts with the basics.
 

Killer6

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By the time this video was posted I had already rolled back the gear. It's working well though, set it at 16* and getting 36* all in. No more tail pipe popping. I'm going to test drive it here in a bit. 1 thing I would like to ask about, the position of the AV is pointed directly at the intake leaving almost no room to plug in the VA. Is the VA neccessary? And if so would dropping the timing to 14 and giving the vaccum hose clearance be a bad thing? Does the VA make up the lost degrees?
You're doing OK, fix the issue w/o worrying about vacuum advance first, then You can address adding it later. There are different "cans" that add different maximum amounts of timing, and then there is the spring tension adjustments, but none of that matters with Your right foot planted in the floorboards.
One thing that is lost is the that the fast-burn heads require less timing, & most J-X-U headed SBs end up with 33-34° total as best. Don't get obsessed trying to achieve a fictitious "ideal" total, & "best power" isn't always safe either, unless You've cc'd & matched all the chambers within 1-2cc's. I've seen 1 chamber cast shallow on a run of heads, in the case I often cite, 906's were run with the cyl.#3/#6 position chambers a good 5-6 cc shallow of the rest. Power timing will put six cylinders at their best, and two into detonation, because the 6 will mask the 2. Pulled heads on these & found the telltale pitting on the pistons 3&6, "running fine", so it's not worth pushing the max limit of timing....especially on a heavy ride.
P.S. I skipped a page, but be sure engine temp is normal & fuel isn't going a little lean on You.
 

R3N0

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Okay, so after some research and a bit of reducating myself on timing, I believe i have found my truck happy spot. Currently it seems to run best at 22* initial and 36* all in. Did some research on my distributor to find out I can adjust it without a recurve kit. Lossen a couple of screws and I can adjust how much all in I'm getting. Right now its 14* mechanical. Completely disconnected the vacuum advance as it's not really needed. At 22* initial im idling at 750 rpm and am pulling a steady 15hg of vacuum. Any higher on the initial and my vacuum starts getting erratic. Did a couple of pulls on our local hill and he gets right up and stays on it all the way up with no ping, or detonation detected. Now that my timing is set, I'm going to start fine tuning the carb. I may even turn up my line pressure 1 more turn to see if I get better response from the transmission... not that its bad... just feel like it can handle a bit more.
 

R3N0

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No the rattling went away, I believe it was caused by the advance. Too much on the all in, if I remember correctly it was somewhere around 42*. Once I realized that my distributor had a recurve plate installed, I simply limited my mechanical advance to 14* and moved my initial to 22*. That gave the motor the what it wanted and my distributor what it needed.
 

TT5.9mag

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@R3N0 it sounds like you have a much better understanding of what’s going on now. And I’m glad you’re on the way to figuring it out. Once you get the basic tune in the distributor and the carb happy, because it’s a street car, you’ll want to add the vacuum advance back in. There is a drivability and mileage gain when you add the cruise timing back in.
 
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