Another boring one.... 360 Timing?

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polosteve
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Another boring one.... 360 Timing?

Post by polosteve »

Hi all,

Stock 360 with aftermarket four barrel and manifold, its a 72 with a Mopar factory style electronic ignition.

What initial timing would you go for?

What was the original factory initial timing recommendation out of curiosity?

Its at 8 bttc, with the dizzy vac advance plugged.


When the car is up to temp it runs good/smooth, no worries. But smells a little rich/'fuely' all the time and there is a little black smoke.
Also when cold and on the choke its very black smokey, chucks black cr*p on the wall.


So before I play with the carb more I though I would ask about timing?

Also is it worth getting a Vac gauge to tune the carb with?

Cheers,

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Pete
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Re: Another boring one.... 360 Timing?

Post by Pete »

Get it running - around 12 degrees initial - and warm it up and strobe it to 34 degrees Total advance maximum.

Then see what you have got initial timing, hopefully around 14 - 18 degrees, if not you may have to get the welder / file out.....
Pete Wiseman; Cambridge.

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Dave999
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Re: Another boring one.... 360 Timing?

Post by Dave999 »

Yeah get the initial timing right first before you look to set idle mixture...... it will make that job so much easier and the motor will respond quickly to your mixture changes

what it was back in the day for 4 star style leaded petrol means nuffin with the current fuel
but its likely to have been a few degrees before TDC

if you time it to total advance of 34*
there is a good chance that your initial timing will still be ball park 5- 8* as the standard curve in an original dizzy will pull in 24* or more
...hence the hints from pete
you will probably need to take about half of the movement out of the armature that the rotor arm sits on, by limiting how far the weights swing out

but you won't know how much till you try.

to get mine right

it wanted 14 BTDC initial advance
and 28 total advance any more made no difference

so i had to mess with my dizzy to limit the advance so that it only pulled in 14* at the crank

i did this by clamping the drive in a vice
putting my timing disk so it fitted over the rotor arm mounting, on the top of the dizzy casing
put a pointer (lolly stick with welding wire taped on) into the cut out section of the rotor arm mount, aligned it with 0* and twisted it

initially i could twist it 14 degrees against the springs which equates to 28 degrees of advance for the motor. (so no way could i set initial at 14)

I wanted 7 degrees twist against my timing disk
to get 14 degrees mechanical advance in my dizzy

so i could have 28 total at 3000 rpm with 14 initial at 800 rpm. 14 initial + 14 in the dizzy = 28 at 3000+

my dizzy uses 2 round posts to act as the stop for the weights its a bosch below the plate with chrysler stuff above, an aussie one basically.

i just sleeved them in brass model makers pipe and filed a bit off until i got my advance
your dizzy, if its an original mopar one, will potentially have slots which you can solder/braze or weld up or you can use a disk from FBO to act as a limiter.

its a bit of a fiddle but worthwhile

to get this done by a shop is £100+
an hours work + a load of pennies for their expertise.

this gets you 95% there. the last step is to choose the right springs... i never bothered i was quite happy
try to limit it so there is still tension on the springs so they don't fire off

it dumps in what advance it has by about 2500 rpm
and 14 * initial for my motor means no stinky tail pipe at idle.

i just need to sort the rest out now :)


other methods exist. you could plumb in the vacuum advance to manifold vacuum to put in advance at idle only....but i didn't want to..... the method has been explained to me by blue and the proof is sitting in morgan's engine bay (and many others) but as an awkward begger i didn't want to do it that way :) mainly becasue i didn't have a problem with advance anywhere else i just needed more initial

in fact my car runs ok locked at 15..not as good as it can but you know.... feels OK


Dave
David Gray. This year i am mainly In Twickenham, sometimes in Watford, often between the two but only between the hours of 07:00 -09:00 and 17:30-19:00

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Blue
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Re: Another boring one.... 360 Timing?

Post by Blue »

If anyone has saved Dave Robson's excellent Timing guide we could do with making that a sticky, It disapeered ages ago.
"Jesus died for somebody's sins but not mine"

polosteve
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Re: Another boring one.... 360 Timing?

Post by polosteve »

Thanks Gents,

This one?


http://www.moparuk.com/forums/viewtopic.php?f=6&t=35679


by Dave-R » Sun May 22, 11 2:21 pm

They will all smell rich until you have a lot more initial ignition timing than stock. You need to sort that out before adjusting the carb.

Even with a completely stock engine you will need at least 12 degrees initial and maybe as much as 20 degrees. If you advance the timing as the car idles, find the spot where the engine revs start to level off. That will be about the spot you want for initial.

There is only two ways to get that kind of initial without also giving the engine too much total advance at higher revs.

The first and most simple way is to use manifold vacuum for the vacuum timing on the dizzy instead of ported vacuum as stock.

The second way (which I prefer) is to limit the amount of timing in the distributor either by welding the weights in the dizzy or by fitting a plate made by FBO.

Only when you have the timing right can you start adjusting the carb. Set the idle speed to 800rpm and adjust the manifold vacuum to JUST to the lean side of max vacuum.

After that look up the tuning tips somewhere on here for tuning the jets.

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Blue
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Re: Another boring one.... 360 Timing?

Post by Blue »

That's probably it, thought it was longer than that. Only thing I would add is when you are finding what initial advance your engine wants, when you think you have enough turn the engine off for 10 mins then restart it, if it starts easily you've got it right, if it labours back it off 2 degrees and repeat until it turns easily and then you can limit the total to 34 degrees. Lots of initial folks, take the time to sort the timing and you'll be amazed how much better your car runs
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Re: Another boring one.... 360 Timing?

Post by Dave-R »

The easiest way to get enough initial is to set the total mechanical advance (vacuum disconnected) to 34 degrees at 3500 rpm and then just hook the vacuum advance up to manifold vacuum off the carb instead of ported vacuum.

Most will run fine like that but at worst you might need to limit the vacuum advance which can be done by just twisting wire around the lever from the vacuum can.

Pointless trying to adjust a carb without doing the timing first.

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deppmobile
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Re: Another boring one.... 360 Timing?

Post by deppmobile »

Fab info, here. Thanks!

I'll be starting up my 360 for the first time soon enough to break in the cam - as you can't mess around in that first start, how do you get an initial setting?

Thanks!

polosteve
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Re: Another boring one.... 360 Timing?

Post by polosteve »

Ok, next question... which will show my experience in this.

1. How do I measure total advance? (Marks on the timing cover go to ten only... :lol: )

Currently I have very cheap draper timing light, I assume I need a decent timing light instead?
Or
Using timing tape? - Is that a good idea?

2. What 'proper' timing light that does not break the bank would you recommend? If its a £300+ snap on one than I need an alternative at the minute...

(This work, dug up old thread from Guy: https://www.ebay.co.uk/itm/Adjustable-a ... 53f04188e0)


3. Is this the plate? https://www.manciniracing.com/fbomodilipl.html


Thanks again gents,

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Blue
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Re: Another boring one.... 360 Timing?

Post by Blue »

You need a timing light with an advance facility. Personally I've always preffered Snap On lights there are plenty for sale used on ebay. Digital are the easiet to use and are a good investment as they hold thier value. Someone will be able to suggest a cheaper alternative, Timing tape isn't very accurate and tends to come off in my experience. Yes thats the FBO limit plate, also available on ebay.
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Dave999
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Re: Another boring one.... 360 Timing?

Post by Dave999 »

i got me one of these....mainly because i saw one on the cheap....

set to timing
dial in 34
and if the TDC mark lines up with 0 on the timing cover tab at 3000 rpm you have total timing of 34*



i believe the snap on is probably more robust and easier to get but similar features

does everything apart from work with multi spark systems. (if you want one that works with an MSD you need a 7 quid analogue one from china with basic electronics that can't detect the multi part of the multi spark)

had it for 10 years

they die if you drop the metal jacketed inductive pick up (same for all of them and most are plastic) but this one unplugs, you don't need a full new unit, and spares are available.

Dave
David Gray. This year i am mainly In Twickenham, sometimes in Watford, often between the two but only between the hours of 07:00 -09:00 and 17:30-19:00

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Dave999
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Re: Another boring one.... 360 Timing?

Post by Dave999 »

deppmobile wrote:
Thu Dec 05, 19 7:35 pm
Fab info, here. Thanks!

I'll be starting up my 360 for the first time soon enough to break in the cam - as you can't mess around in that first start, how do you get an initial setting?

Thanks!
set it to 12 BTDC
if electronic make sure rotor is nominally at lead 1 and the inductor lobe is bang on the middle of the pick up
start.

this gives initial timing of somewhere between 10 and 14 BTDC

if points
gap them correctly with brass feeler
put bulb in the wire from points, or connect bulb from coil - to the engine block, switch on ignition move dizzy to have rotor pointed at lead 1 then jig it back and forth to find the switch on/off point for the bulb.
this should be bang on 12 BTDC initial

start car

bring revs to 2500+ on throttle stop check timing advance goes no more than 34* adjust if necessary
David Gray. This year i am mainly In Twickenham, sometimes in Watford, often between the two but only between the hours of 07:00 -09:00 and 17:30-19:00

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deppmobile
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Re: Another boring one.... 360 Timing?

Post by deppmobile »

Perfect!

Thanks :thumbright:

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Steve
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Re: Another boring one.... 360 Timing?

Post by Steve »

This brings it all back to me when I first got my car. I had the same great advice and Daves thread should be etched in stone, its great.

I bought a Snap On timing light from a pawn shop in Milwaukee (online and cheap) and its been a great investment. It also has a tach on it which is accurate and great for checking RPM when the timing hits total advance. Half inch spanner, light and a hill to do hill starts on was a good way for me to learn about this (you don't actually need the light to start with as a bit of experimenting on the road was surprisingly productive in my case).

I tried tape etc but you cant beat a good light that you can dial in the degrees. Once the penny dropped regarding the difference between initial and total timing, why you need more advance at higher RPM and how the transition between the two works, all the advice made perfect sense. Its very interesting stuff and its amazing how few people who own old cars actually know even the basics of timing. As soon as you mention it at car shows etc, most people either glaze over or walk away. A good indication for me is if they have a firm handshake and dirty nails, they know all about timing! :D

The FBO plates are very good quality and easy to fit.

Cheers Steve :thumbright:
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Charger
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Re: Another boring one.... 360 Timing?

Post by Charger »

fear not

it's all here

i'd saved the links a long while ago and i'm happy to regurgitate as and when necessary ...

Dave’s laws ...

ignition ...
https://web.archive.org/web/20160214201 ... f=13&t=828

carb ...
https://web.archive.org/web/20160214202 ... =11&t=5308

loads on here about timing ...

http://www.moparuk.com/forums/viewtopic.php?t=45873

http://www.moparuk.com/forums/viewtopic.php?t=35148

http://www.moparuk.com/forums/viewtopic.php?t=35679

my recent timing exploits ...

http://www.moparuk.com/forums/viewtopic.php?t=46913

and some more of the same ...

http://www.moparuk.com/forums/viewtopic.php?t=46806

:thumbright:
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1970 Charger 500 <- this is my car
383 | 4bbl | 727 on column | PAS | PAB | buckets/buddy - check out my photos HERE

If you don't want another same old brand-new car ... you could be DODGE MATERIAL

WARNING!! - my posts contain flash photography
the Charger code, the 3 P's ... 68 - Prototype; 69 - Production; 70 - Perfection

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