cmrris

I recently built a 360, la block with magnum heads, front cover and accessories. It runs pretty good, except it likes timing to be about 34 initial and around 60 total, which has me extremely confused. It absolutely won't run if I try to lower it. I'm still in the process of tuning, and on occasion under mid-full throttle there might be a slight ping, so slight its hard tot tell. I bought a new damper for an la 360, and when I looked at the to timing covers side by side, the timing marks seemed to be in the same location. It has a mopar cam, P4349448, which i didn't degree when I install because there were no keyways in the gears, just the three: stock, advance and retard. It starts and runs great, when I'm really on it it'll even chirp the tires real good on the 1st to second shift. It idles at about 700 in gear and 1100 in park and neutral. Here's a link to a drive I took; I didn't really get on it much, but through the wind noise you can hear it run pretty good:

cmrris

Unless I didn't install the timing gears in the stock keyways....

Does anyone know how much off each keyway is?

TVLynn

ARE you including the vacuum advance in the 60 deg total. Should get 36 deg
without the vacuum advance..

cmrris

60 total with vacuum advance hooked up revving at 2500-3000 rpm. 34 with vacuum advance unplugged and blocked off at idle.

TVLynn

Your almost right on the money !!! maybe try 38 total and see how it runs.. With today's fuels it sometimes needs more timing

cmrris

It won't run 38 total. It runs 34 initial at idle vacuum advance blocked off. Only 8 degrees mechanical advance doesn't seem right especially since with 60 total like it is now it's pulling so hard a chirping tires at gear changes. It runs good, just trying to figure out why timing is so far off from normal.

cmrris

Did older la motors have timing tabs in a different location?

Iowan

I'd say you have the distributor drive gear a tooth off.

cmrris

If it was a tooth off, wouldn't it run like crap?

Coronet 500

I couldn't find that cam by your part number.

1st adjust vacuum advance down to 50-55 degrees.

2nd if your initial is 8 you have 26 in the distributor. Restrict mechanical advance so initial of 12-20 plus mechanical will = 34.

Without knowing the cam specs I would think 20 initial + 14 mechanical will work much better.

RacerHog

You might have to take the font end back apart to make sure you installed it rite. Might get a Stock True roller timing set. Some of the off shore sets had issues.

Just my thoughts

moparted

if it runs ok leave it alone

RacerHog

https://moparforums.com/forums/f81/t...problem-15278/

We looked at this a few years back...