Timing????

[A38Valiant]

Car=71 Polara 4 dr sedan
Engine= 318, .030 over, 9.5 compression, 284 duration/.484 lift, Edelbrock 1405 625? cfm carb on iron TQ intake, 95-96 360 Magnum exhaust manifolds, 2 1/4 inch duals

Trans= 727, stock converter

Rear= 8 3/4 with 3.91 gears

I don't have an advance timing light, and was just curious what my initial timing should be. Currently about 12 BTDC with a regular light and vacuum unhooked/plugged, kicks back when cranking but acts like it would like more once running.

 

[Newp]

Does the dist. have an advance curve, adjustable vacuum advance, or is it stock?i

 

[A38Valiant]

stock. adjustable vacuum advance. Going to buy an advance timing light, but was wondering what my initial or base timing should be. Never really messed with anything much with a cam that was non-stock.

 

[Husky]

It all depends on the advance curve of your distributor. Small blocks like about 35 deg total mechanical advance so that's what you should aim for. Set inital to 10-12 degrees adv and then run up to 4500 rpm to see what total advance is. Back it off if it's more than 35 or add more until you reach 35, bearing in mind that too much inital timing will cause hard start up when warm. So you might need to trade off some initial. Run ported vacuum and have it disconnected and plugged when setting mechanical advance.

 

[70bigblockdodge]

stock. adjustable vacuum advance. Going to buy an advance timing light, but was wondering what my initial or base timing should be. Never really messed with anything much with a cam that was non-stock.

If you can get a copy of mopar action Feb 2013 issue there is an excellent article about timing with non stock engine and explanation of why it works

 

[moper]

If it's kicking back at 12° you will want to look at your starting system too. Check the cables, grounds, the starter itself, and the battery. It should not have a problem turning over with that and a lot more. As far as what you need - I'd call 12° initial the lowest amount I'd want to run but with a stock distributor you will need to properly curve it to do much more.

 

[saylor]

the book says a '71 318 2bbl is TDC for both manual and auto transmission cars. hrum I didn't expect that.

 

[Husky]

the book says a '71 318 2bbl is TDC for both manual and auto transmission cars. hrum I didn't expect that.

yeah, sign of the times really. These settings were deliberately retarded for emissions purposes, and not something the engineers of the day would have endorsed. You want as much advance as the engine can bear at idle for a cool engine.

 

[70bigblockdodge]

I would say something is amiss because with that cam it really should not be kicking back. you need to check for real TDC against timing mark for accuracy make or borrow a TDC tool your ring might have slipped on vibration dampener. You can make one out of a old spark plug break out center, tap threads and insert long bolt. Screw spark plug tool in #1 hole roll engine over clockwise appox 20 degrees btdc snug bolt down onto piston top mark dampener at 0 mark rotate ccw till piston hits tool mark dampener at 0mark, split the difference and that is your true TDC if it is spot on timing mark there is definitely a weak piece in your starting system if its only off by a couple of degrees use new mark if its off a lot get a new dampener cause its probably slipped big blocks are almost always a couple degrees advanced. this is all in the article I mentioned, it really is a must read if your really serious about getting your timing spot on for your specific engine, I know it sounds tedious but you will be amazed at the difference it makes especially the further you get away from stock. I WAS and I thought I had my stuff was good it got better. Hope this helps

 

[Newp]

Great advice 70BBD. I built that tool you mentioned years ago. My 54,000 mile Newport was off 4 degrees.

 

[70bigblockdodge]

I am amazed how much some are off and seems like the ones that are close to correct are ones that year's ago I would have blamed for being a dog if you set to factory specs. I guess that's one good thing about getting older is I have slowed down on stuff like that and double check when younger in hurry up mode things get overlooked, of cores now I can't see timing mark , where are my glasses. LOL

 

[commando1]

now I can't see timing mark , where are my glasses. LOL

LMAO. I'm glad you said that. My problem is even glasses don't help.