NOOB with a TIMING light gun

Thank you Rusty. I have learned that from previous threads I have read from you and others. Now he has learned that. Hopefully he will heed the good advice. I did and now my Dart runs like a champ. I took it out last night for a spin and it was great.
I know some of us can get bogged down with all the advice we get but we (the rookie, noob, input adjective here) do want the information or we wouldn't be on here looking for it. But because we don't know, it may take us a bit to wade through the flood of info that comes our way.
Thanks for staying with us Rookies
We actually do appreciate it.

facite, quod vultis

Heywodja said:

That is a great light, you should be good to go by just hooking the timing light up properly with the pickup on the #1 plug wire,

slightly loosen the bolt on the distributor hold down.
disconnect and plug the vacuum advance line at the distributor,
start the engine and let it warm up,
then bring the rpm's up to 3000 or so,

Point the timing light at the timing mark, and turn the dial clockwise until the timing mark on the harmonic balancer is aligned with TDC on the waterpump housing.

If you are between 32 and 34 you are done.

reduce the rpm's to their normal speed for idle, make any necessary SMALL adjustments to the idle speed and mixture screws.

Check the timing again at idle by using the dial to once again align the timing marks to determine the initial setting.

hook the vacuum advance back up, if the idle changes you may have a vacuum leak at the diaphragm in the advance canister.

Subtract the initial timing setting from the number you set the engine at at the 3000 rpm, this was you will be able to determine the total mechanical advance of your distributor.

shut down the engine and let the engine cool if necessary and tighten the distributor hold down.

restart the engine, double check that you did not move it off the initial timing setting and you should be good to go.

Test drive it, if there is any changes to be made from there they should be 1 or 2 degrees either way, which really should not be that significant.

Good Luck

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PERFECT.. thats all i needed. -
thanks all is good now. timing expert. :cheers:

RustyRatRod said:

Everybody seems to be caught up telling him to set total timing. That's not the correct way. Set initial timing FIRST, then look at total. If total needs adjusting, then do it. Usually on stock distributors, you set initial around 18-20 or so and limit total to 34-36. Nobody's said any of that here.

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perfect. thanks. :cheers:

yeah thanks RRR like the header states (NOOB) im like a newborn handling this timing light but now that the wisdom has been brought down onto me i can pass it down and use it for my self.

I am grateful for all of you guys ( FABO. )

BIG-B-Barracuda said:

PERFECT.. thats all i needed. -
thanks all is good now. timing expert. :cheers:

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If the distributor has a lot of mechanical advance, that method is horrible. Sometimes you get lucky. I've fixed a lot of cars that used the total method.

Using the total timing method to set up a street car is a ROTTEN way to go. It's not even good on a race set up unless the distributor is locked out.

Find the total number your engine wants and run it there. I've had BB's that liked 40+ and others that were 30-32. Big swing in performance running them short of best timing profile.

Simple test. At idle, twist the distributor a little clockwise, if the engine picked up RPM, it wants the timing at idle. Initial timing is finding the point where the engine is running most efficiently where it will still start when hot.

RustyRatRod said:

Everybody seems to be caught up telling him to set total timing. That's not the correct way. Set initial timing FIRST, then look at total. If total needs adjusting, then do it. Usually on stock distributors, you set initial around 18-20 or so and limit total to 34-36. Nobody's said any of that here.

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Really? 18-20 initial on a stock 440? And it starts hot without hitting against the starter? Several people did mention a range of 34-36. I don't see where anyone said to "set" timing with the vacuum hooked up but to "check" it or see what it is just to make sure you don't melt it down at cruise. If with the vacuum connected and at 3000 RPM you get more than say 45 degrees there is potential for overheating or detonation when accelerating from cruise. Depending on which vacuum can your distributor is equipped with there can be easy or not so easy ways to limit the vacuum advance. Depending on how weak the springs are that hold the advance weights initial can be all over the place.

mguner said:

Really? 18-20 initial on a stock 440? And it starts hot without hitting against the starter? Several people did mention a range of 34-36. I don't see where anyone said to "set" timing with the vacuum hooked up but to "check" it or see what it is just to make sure you don't melt it down at cruise. If with the vacuum connected and at 3000 RPM you get more than say 45 degrees there is potential for overheating or detonation when accelerating from cruise. Depending on which vacuum can your distributor is equipped with there can be easy or not so easy ways to limit the vacuum advance. Depending on how weak the springs are that hold the advance weights initial can be all over the place.

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Yes. Really. Stock engines can deal with high initial timing because they have low cylinder pressure. That's why engines with high static compression need less initial timing.

It's perfectly normal to have total timing including vacuum in the 60* range at part throttle. Vacuum cans typically pull in around 20* or so.

Perfect example. My stone stock 351M Ford has 21* initial timing at idle. Starts just fine when hot. Has total initial + mechanical of 34*, PLUS whatever the vacuum can pulls in. Runs like a top. Lower compression engines NEED more timing.

Everyone seems to think high initial timing is a "hot rod motor" thing. It's not. A real hot rod motor with higher static compression needs less initial timing since it has higher static compression and higher cylinder pressure.

This seems way too complicated, there is certainly more than one way to do everything. I am by no means an expert, so I am always on the lookout for opportunities to enhance my knowledge.

RRR you could be on to something here, the factory recommended initial setting for a stock 1973 (Electronic Ignition) 440 of 7.5 +/- 2.5 degrees BTDC, should / could have been actually 18.

If his ignition is in good operating condition, I'd wager that after he sets the total advance, that his initial would probably wind up at or near the 8 degree mark. Most stock Chrysler ignitions of that era probably have an advance of approximately 24 +/- a degree or two anyway. Of course there is no way to tell unless you have a baseline and you know the total mechanical advance, or you have a sun or similar distributor machine that can verify the advance and curve outside of the vehicle.

There is no doubt that some fine tuning or other adjustment adjustments can yield some better results after the baseline has been established and it may run best at 10, 12, 13 or even 18.

When we were really into this stuff we we bought our motors from Rod Hall in Reno and took our distributors over to the little Mallory shop in Carson City NV.
Guess what they did? Spun them up and checked the total advance, then adjusted the curve, and based on what our engine combo/application was, limited the total mechanical advance if necessary. Some of our distributors were pegged at 34, 38 or whatever worked best, that's right timed at 34 degrees all the time.

A street motor will benefit from a vacuum advance. This will add some additional advance during part throttle cruise and light acceleration but:
No vacuum advance at idle, if you are using the correct port on the carburetor.
No vacuum advance at wide open throttle.

The vacuum advance system is really intended for emissions control, drive-ability, and fuel economy.So during part throttle, you may see initial plus additional advance. The result may even be 48, 52 or even 56 degrees. But it does not add any additional advance during low vacuum (full throttle) or high rpm.

I should have known better than to offer advice...

RustyRatRod said:

Yes. Really. Stock engines can deal with high initial timing because they have low cylinder pressure. That's why engines with high static compression need less initial timing.

It's perfectly normal to have total timing including vacuum in the 60* range at part throttle. Vacuum cans typically pull in around 20* or so.

Perfect example. My stone stock 351M Ford has 21* initial timing at idle. Starts just fine when hot. Has total initial + mechanical of 34*, PLUS whatever the vacuum can pulls in. Runs like a top. Lower compression engines NEED more timing.

Everyone seems to think high initial timing is a "hot rod motor" thing. It's not. A real hot rod motor with higher static compression needs less initial timing since it has higher static compression and higher cylinder pressure.

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I'm sure we all speak from experience. "Stock" engines can actually have higher static compression since the "stock" cams are typically of less overlap etc... My 70 Cuda with the 440 +6 engine had an old school Crane 520 with split duration in the 292/282 area and pistons down in the hole about 0.050 with thick head gaskets. It liked 19 degrees initial but it was hard to start hot without the retard solenoid. It seems quite logical to me that the OP's stock 440 might have the same issue. This was also before the new starters were so plentiful but I did have the longest of the old school starters. You can easily have 19 degrees initial at Idle RPM with weak springs and still be less than that with the distributor at rest or a lower RPM than your normal idle. Many of the "ALL in at 2500-3000" crowd went overboard on the soft spring trend and had erratic timing at idle which was not really an issue on a drag car but can have drivability issues on a street car.

mguner said:

I'm sure we all speak from experience. "Stock" engines can actually have higher static compression since the "stock" cams are typically of less overlap etc...

No, this is incorrect thinking. Camshafts have zero to do with static compression ratio. Cylinder pressure, yes.


My 70 Cuda with the 440 +6 engine had an old school Crane 520 with split duration in the 292/282 area and pistons down in the hole about 0.050 with thick head gaskets. It liked 19 degrees initial but it was hard to start hot without the retard solenoid. It seems quite logical to me that the OP's stock 440 might have the same issue. This was also before the new starters were so plentiful but I did have the longest of the old school starters. You can easily have 19 degrees initial at Idle RPM with weak springs and still be less than that with the distributor at rest or a lower RPM than your normal idle. Many of the "ALL in at 2500-3000" crowd went overboard on the soft spring trend and had erratic timing at idle which was not really an issue on a drag car but can have drivability issues on a street car.

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This is why I have said over and over timing is not specific. In other words optimal timing is something you have to experiment around with to get best results. There is no "one size fits all" so expect to spend some time getting timing just right. Pun intended.

Ok so.... CYLINDER PRESSURE. His stock engine can easily have more cylinder pressure than a high compression engine during start up because of the effect of camshaft profiles. My engine had relatively low "static compression" and cylinder pressure but was still not happy starting with 19 degrees initial but I had no sloppy springs in the distributor and was at 3600 Ft ASL which should have actually helped one would think.

I

crackedback said:

If the distributor has a lot of mechanical advance, that method is horrible. Sometimes you get lucky. I've fixed a lot of cars that used the total method.

Using the total timing method to set up a street car is a ROTTEN way to go. It's not even good on a race set up unless the distributor is locked out.

Find the total number your engine wants and run it there. I've had BB's that liked 40+ and others that were 30-32. Big swing in performance running them short of best timing profile.

Simple test. At idle, twist the distributor a little clockwise, if the engine picked up RPM, it wants the timing at idle. Initial timing is finding the point where the engine is running most efficiently where it will still start when hot.

Click to expand...

This method works good. I like to limit total to 34 for a BB/RB for reasons. Find what it likes at idle, keeping in mind the more initial timing you add you need to keep closing the throttle and adjusting mixture. Once you find the spot that timing does not increase the idle rpm and it does not buck the starter you have a base. Take that # and add or limit mechanical to get to 34. Much more and you may or may not have cruise temp issues. That all depends on your cooling system design and street/strip use. My 383 509mp cam wants about 18 initial for good response and no hot start issues. The 15.5 plate (half crank degrees) in the distributor put me at almost 52 total. The motor ran fine with no ping but cruise temps where high! A little welding and filing to limit the mechanical to 7.5 (15 crank degrees) stopped my cruise temp issues with no performance loss. Every engine, car, use combo will differ and using the basic principle to find it is what matters.

I do not use the vacuum advance and block the line with a bb or something ( visual only). IMO it is not required unless you are trying to get all the fuel mileage you can get out of your combo! How many of us use our BB/RB cars for daily drivers and are concerned with fuel mileage?

Now after all that you fine tune the carb!