Tuning help, please
Hi all, having some issues getting my 1965 with recently installed 273 tuned.
Details:
- HIPO 273. Domed pistons. Unknown if it’s ever been taken apart. Assuming 10.5:1 compression. A833 behind it.
- Original Carter AFB
- Fresh gas (pretty certain I went with 87 octane though) and new fuel filter
- Verified TDC and timing mark on balancer.
New Champion RC12YC plugs
- Using harbor freight basic timing light
Tuning story:
- Started with Mopar Electronic Ignition, but I had some bad misfiring and car quit starting. Checked through components and grounds, and although not confirmed, I’m pretty certain it was the Used - Like New cardone distributor I got from Amazon. Ultimately couldn’t get car to start at all.
Swapped in spare points distributor. Fired right up, but rattled on throttle blips. Finally got it to rarely rattle, but timing was set in the ballpark of 25 ATDC. Drove round the block, and had zero get up and go.
Coworker had an MSD ready to run unit. Dropped that in with new wires and coil. Much happier. Idled at 8btdc. Took it for a drive, and the rattle showed up again. Adjusted distributor throughout the drive and ended at about 5 atdc, and still some rattling under normal/mid to heavy acceleration. Idle mixture screws currently 2.5 turns out.
My gameplan is to:
-confirm balancer shows correct at TDC
-confirm that it has enough fuel through pump and filter
- put in higher octane gas
- keep tuning
I’m really thrown off by the timing wanting to be atdc. At 5 atdc it’s still responsive, didn’t notice any bogging.I thought the rattling was pinging, but maybe it’s something else. Oiling problem?
Here’s a clip of the sound under acceleration. Shows up at about 5 seconds in:
Apologies for the long post. Just trying to be detailed.
Hi all, having some issues getting my 1965 with recently installed 273 tuned.
Details:
- HIPO 273. Domed pistons. Unknown if it’s ever been taken apart. Assuming 10.5:1 compression. A833 behind it.
- Original Carter AFB
- Fresh gas (pretty certain I went with 87 octane though) and new fuel filter
- Verified TDC and timing mark on balancer.
New Champion RC12YC plugs
- Using harbor freight basic timing light
Tuning story:
- Started with Mopar Electronic Ignition, but I had some bad misfiring and car quit starting. Checked through components and grounds, and although not confirmed, I’m pretty certain it was the Used - Like New cardone distributor I got from Amazon. Ultimately couldn’t get car to start at all.
Swapped in spare points distributor. Fired right up, but rattled on throttle blips. Finally got it to rarely rattle, but timing was set in the ballpark of 25 ATDC. Drove round the block, and had zero get up and go.
Coworker had an MSD ready to run unit. Dropped that in with new wires and coil. Much happier. Idled at 8btdc. Took it for a drive, and the rattle showed up again. Adjusted distributor throughout the drive and ended at about 5 atdc, and still some rattling under normal/mid to heavy acceleration. Idle mixture screws currently 2.5 turns out.
My gameplan is to:
-confirm balancer shows correct at TDC
-confirm that it has enough fuel through pump and filter
- put in higher octane gas
- keep tuning
I’m really thrown off by the timing wanting to be atdc. At 5 atdc it’s still responsive, didn’t notice any bogging.I thought the rattling was pinging, but maybe it’s something else. Oiling problem?
Here’s a clip of the sound under acceleration. Shows up at about 5 seconds in:
Apologies for the long post. Just trying to be detailed.