Initial timing

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340RT

340RT

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I haven't put a timin light on the dart in 5 years.Forgot what the initial timin should be.I have a racin mopar dist. Vacuum plugged off. 360 484 purple cam Rpm intake. 650 double pumper.360heads w/some work. TTI exhaust.2800 stall.I rmember I was able to get the car to idle around 800-900 rpm.now it idles at 1100-1200.wants to stall at the stoplights.I have not wrenched on this car in years.I now have a 16 yr old son who wants to start workin' on the dart.HELP PLEASE.

dart eng..jpg
 
I'd set the initial at 10 degrees. You shouldn't get any ping with that. toolman
 
Thanks,If I remember right the motor has 9-9.5 to 1 comp.I run sunoco 93 in it.
 
That's a great lookin' motor!!!! I allways use 10 deg. as a place to start. toolman
 
Thanks.Rebuilt and detailed the driveline 10 years ago.I started on the body and lost interest.Car has been basically sitting for 5-10 years,except for bi-monthly trips around the neighborhood.

7-12-08 nikki's dart 003.jpg


7-12-08 nikki's dart 002.jpg
 
Geuss what I remembered yesterday.Back in 99' we used an early waterpump on the 360 because I had already spent mucho deneiro on recoring the radiator(the one that came with the car).The timing marks on the timing cover are covered with the outlet on the pump.I played around with the timing.Got it to run better.AWesome burnouts.
 
If you are going to do it right you need to find what the initial your particular engine wants then worry about the total.

With the 484 purple cam you are using it very likely the engine will want to see 15-20 degrees of initial advance. The typical total for a small block with open chamber heads is 34-36.

You set the initial for highest manifold vacuum while maintaining the idle rpm. If you wind up in the 15-20 range you will need to limit the timing in the distributor to stay in the 34-36 range. If the distributor was purcahsed after 2002 it should have the Mallory advance mechanism in it which will allow you to adjust the slot lengths to limit total timing.

Any other way is going to leave power or driveability on the table.
 
dgc333 said:
If you are going to do it right you need to find what the initial your particular engine wants then worry about the total.

With the 484 purple cam you are using it very likely the engine will want to see 15-20 degrees of initial advance. The typical total for a small block with open chamber heads is 34-36.

You set the initial for highest manifold vacuum while maintaining the idle rpm. If you wind up in the 15-20 range you will need to limit the timing in the distributor to stay in the 34-36 range. If the distributor was purcahsed after 2002 it should have the Mallory advance mechanism in it which will allow you to adjust the slot lengths to limit total timing.

Any other way is going to leave power or driveability on the table.
Click to expand...

Best advice in the thread. :cheers:

Set it with a vacuum gauge if you want to find what the engine wants. Max vacuum at lowest timing advance, keeping RPM constant, back out 1" and lock it down. As long as it doesn't kick back against the starter or run-on, you're good. Setting the initial with a vacuum gauge will likely get you better throttle response and carb adjustments.

Here's a good progression to follow:
Initial, total, springs/curve, vac adv (if appl)

That 484 camshaft is much bigger than the 214/224 cam in one of my 340's and my engine has 16* initial. I'd expect you to come in with at least 18* and as high as 22*.
 
I know I have a similar cam shaft In my 340, 18* Advance In my Distributor and was told to set it at 2900-3000 RPM to 35-36* which gives me a about 17-18 initial at 900-950RPM which where it seems to like it. Had a problem With preigntion was clicking a little around the 2300-2500rpm range but disconnecting the Vac advance and plugging the Vac port seems to have cured it but last tank ran some Lucas Octane booster and ESSO premium but trying to not have to Use the booster If I Can Thats what I have experienced D
 
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