RocketNerd

I think my dizzy has some issues. I've been trying to get rid of the bog I feel when I hit the gas to accelerate hard. Going smoothly, i can baby it into the higher RPM's, but any more than that and it bogs significantly, hesitating until a second or so later and it accelerates. I had the carb cleaned, rebuilt, and tuned by Lars and its been worlds better. So i am thinking its my timing. taking a light to the engine, plugged the vac. advance, I noticed my initial is set somewhere around 22, when i give it some RPM's the advance only moves about 8 degrees in total, and is all in around 2800. I then moved the dizzy to be all-in to be at the 36 degrees and my initial goes way up, outside of the timing tab. when its at 36 all in, i decided to take it for a quick spin to see how it did, felt smooth and no more hesitation on the pedal, however when i got home, i realized i hadn't connected the vac. advance, so I let it cool and did so. Driving this morning after a nice warmup, it had the same issues with the hesitation when i give her more than 1/4 throttle, now that the vac. adv has been put back on.

I'm still very new to this game, and I am looking for home help from this well of knowledge. Do i need to adjust my springs, do i need a new vacuum advance, is there something i'm missing that will help me dial it in and get it within the specs? Is it time to buy a new drop-in MSD dizzy altogether?

Its a 1976, AT, and the block is not the original, is a Goodwrench 350 from Mexico the previous owner replaced years ago. I have no intent to keep this original. Thanks in advance (no pun intended).

Rescue Rogers

Some people do run without the vacuum advance but you loose some low end mileage and around town drivability. Each motor will vary a bit on that. Contact Lars again and get his timing and distributor papers. He updates them so the ones you'll find in a search are sometimes out of date. You are a bit high on your initial and you need to reset your idle once the vacuum advance it attached but you can get too much vacuum advance too. Look and see what the total is with vacuum advance, Lars recommends staying below 50* with todays gas.

For comparison my initial is 14, 36 total and 48 with vacuum advance. Stock didtributor vac advance cans have a plastic round shim on the end of the arm to limit how much advance you get. When it falls apart the bare arm can give you way too much advance. Rebuild spring and weight kits can come with a brass shim that is pressed onto the arm to restore and limit the travel. You may wan tot take the cap and rotor off and see whats going on in there. The PO may have monkeyed with it to give him what he wanted for travel and advance. You can ask Lars about rebuilding it too. He may still do distributors.

As for the bog, once you get the distributor sorted, i would recheck the carb. If your secondary air flap is opening to fast you will get the bog. ITs adjusted on the passenger side near the choke limit

RocketNerd

@Rescue Rogers Thank you for the help. I contacted Lars a few months ago when to get his papers when I started my front end rebuild, and he also included the Timing papers. They were a great help, but you are right, I think i need to get into the cap/rotor and see whats going on in there.

pltmgr

No expert here but if it advance only 8 degrees Id check the weights and the the slot that limits total mechanical advance.