Previous Thread
Next Thread
Print Thread
Page 1 of 2 1 2
440 Timing Issue #2417220
12/12/17 08:55 AM
12/12/17 08:55 AM
Joined: Feb 2005
Posts: 3,957
SW Fla.
CYACOP Offline OP
master
CYACOP  Offline OP
master

Joined: Feb 2005
Posts: 3,957
SW Fla.
I think its a 1973 440. If I set the initial timing at 10 degrees with the distributor advance vacuum hose disconnected and plugged it often back fires through the carb when I road test it. Seems worse when cold. It runs better at about 20 degrees BTDC but still isn't right. Any ideas what to do to to set it at 10 degrees and tune from there. Its always been like this with different carbs. I have check firing order countless times. Any ideas how to approach this? I dont have any history on the car but the motor still seems to be in decent condition.

Re: 440 Timing Issue [Re: CYACOP] #2417254
12/12/17 11:45 AM
12/12/17 11:45 AM
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
R
RapidRobert Offline
Circle Track
RapidRobert  Offline
Circle Track
R

Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
Road test it with the vac can hose unhooked/plugged. Confirm the reluctor gap is at .008" with a brass feeler gauge (or eyeball it & want it fairly close but not touching) & confirm the springs are retracted which they should be (not stuck) & when you twist the rotor CCW that it springs back smoothly. With a 1&1/4" socket/breaker bar hand bump the dampener CW till the magnet is dead even with the tooth that places the rotor under or near under the #1 cap terminal (don't go backwards & if you go past then back up & creep up on "dead even" again, & at that point see where the timing marks are on the dampener and how far away the rotor is from being straight under the #1 dist cap terminal outside "bulge". this'll get us started. On the fuel side it may have a vac leak (valley pan). EDIT ported or manifold? MORE EDIT way way lesser potentials are timing chain sprocket dot error/slipped dampener but we'll start with the easy potentials first. the more I think about it the more I potentially think vac leak/lean. clamp the PB hose for a quick test just to get that out of the way.

Last edited by RapidRobert; 12/12/17 12:14 PM. Reason: bored

live every 24 hour block of time like it's your last day on earth
Re: 440 Timing Issue [Re: CYACOP] #2417263
12/12/17 12:18 PM
12/12/17 12:18 PM
Joined: Feb 2005
Posts: 3,957
SW Fla.
CYACOP Offline OP
master
CYACOP  Offline OP
master

Joined: Feb 2005
Posts: 3,957
SW Fla.
Thanks RR, Ill have a look at it. It has the stock cast iron manifold on it. I did replace the manifold gaskets on it a few years ago, When I bought it someone had disassembled it to the timing chain cover, so I also know the timing chain is not worn out. I'm thinking not a vacuum leak because when I run it advanced it idles pretty good and you can hit the throttle and it will come right back down to the same smooth idle and the RPM's don't wander around.

Re: 440 Timing Issue [Re: CYACOP] #2417269
12/12/17 12:30 PM
12/12/17 12:30 PM
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
R
RapidRobert Offline
Circle Track
RapidRobert  Offline
Circle Track
R

Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
Quote:
when I run it advanced it idles pretty good and you can hit the throttle and it will come right back down to the same smooth idle and the RPM's don't wander around.
at that point if it is all good can you leave it there? but it still backfires?


live every 24 hour block of time like it's your last day on earth
Re: 440 Timing Issue [Re: CYACOP] #2417297
12/12/17 01:04 PM
12/12/17 01:04 PM
Joined: Jun 2008
Posts: 3,913
usa
L
lewtot184 Offline
master
lewtot184  Offline
master
L

Joined: Jun 2008
Posts: 3,913
usa
maybe it's not a timing issue but a fuel problem,....?

Re: 440 Timing Issue [Re: RapidRobert] #2417509
12/12/17 06:54 PM
12/12/17 06:54 PM
Joined: Feb 2005
Posts: 3,957
SW Fla.
CYACOP Offline OP
master
CYACOP  Offline OP
master

Joined: Feb 2005
Posts: 3,957
SW Fla.
Originally Posted By RapidRobert
Quote:
when I run it advanced it idles pretty good and you can hit the throttle and it will come right back down to the same smooth idle and the RPM's don't wander around.
at that point if it is all good can you leave it there? but it still backfires?


It doesnt backfrire but will ping when you load it with some throttle on the street. I have to back it off on timing advance to stop it from pinging but Im still way advanced.

Re: 440 Timing Issue [Re: lewtot184] #2417511
12/12/17 06:58 PM
12/12/17 06:58 PM
Joined: Feb 2005
Posts: 3,957
SW Fla.
CYACOP Offline OP
master
CYACOP  Offline OP
master

Joined: Feb 2005
Posts: 3,957
SW Fla.
Originally Posted By lewtot184
maybe it's not a timing issue but a fuel problem,....?


Possibly I think it has a 650 Edelbrock carb that I put on there new a few years ago. Just bolted on a new one not knowing much about the details on the carb. It ran the same with the old holley I took off.

Re: 440 Timing Issue [Re: CYACOP] #2417512
12/12/17 06:59 PM
12/12/17 06:59 PM
Joined: Feb 2005
Posts: 3,957
SW Fla.
CYACOP Offline OP
master
CYACOP  Offline OP
master

Joined: Feb 2005
Posts: 3,957
SW Fla.
I'm going to try to go out there tonight and fool around with it some.

Re: 440 Timing Issue [Re: CYACOP] #2417610
12/12/17 09:52 PM
12/12/17 09:52 PM
Joined: Feb 2005
Posts: 3,957
SW Fla.
CYACOP Offline OP
master
CYACOP  Offline OP
master

Joined: Feb 2005
Posts: 3,957
SW Fla.
Ok I reverse engineered RR's procedure and lined up the timing mark at 10 BTDC, opened up distributor, loosened the distributor and rotated the distributor until the pick up coil center lined up with the rotor star to line up with the pickup coil. Gap was close to .008 as it was. The big rotor on the end of the distributor shaft also lined up center of contact in distributor for number 1 plug wire.
Cranked it up and checked timing with the light and it was dead on 10 BTDC. Adjusted carb a bit to raise idle and set both idle jets. Pinched booster hose and no change there. Put vacuum guage on carb port to distributor and vacuum increases with throttle but not sure if it is the correct amount of vacuum.

Still not right but will test drive tomorrow.
Thanks, Ill let you know how it goes tomorrow.

Re: 440 Timing Issue [Re: CYACOP] #2417652
12/12/17 11:02 PM
12/12/17 11:02 PM
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
R
RapidRobert Offline
Circle Track
RapidRobert  Offline
Circle Track
R

Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
Alright we're getting closer. what does not seem right? I would bump it to 15 (which likely will require shortening the slots to get it back to 36-38) & the FBO $22 plate is by far the easiest/cheapest way to do this. My bone stock 85 318 does great on 19 initial. are you on ported or manifold?


live every 24 hour block of time like it's your last day on earth
Re: 440 Timing Issue [Re: CYACOP] #2417701
12/13/17 12:32 AM
12/13/17 12:32 AM
Joined: Feb 2005
Posts: 3,957
SW Fla.
CYACOP Offline OP
master
CYACOP  Offline OP
master

Joined: Feb 2005
Posts: 3,957
SW Fla.
Ported off the carb. I have zero vacuum at idle and it progresses vacuum as RPM increases. Just running it in the garage its just not responsive as it should be and runs rough with no load. I think Ill bump it up to 15 as you suggest and run it down the road tomorrow. Maybe you are into something suggesting initial 15 and limiting the max advance to stop the pinging.

I'm not really looking for a lot of performance, I just want a good running engine. It is crusty looking though. I have had the car (1972 Roadrunner) for over 10 years. Its always been able to move on its own power and is close to being able to drive on the street so that's all I'm really trying to do.

Re: 440 Timing Issue [Re: CYACOP] #2417704
12/13/17 12:35 AM
12/13/17 12:35 AM
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
R
RapidRobert Offline
Circle Track
RapidRobert  Offline
Circle Track
R

Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
Understood, we are getting closer. EDIT I forgot about the pinging, we cannot allow it to ping. what is the total (with the can capped) and what springs are in there. we might need stiffer springs to stop the pinging (& limit the total to 36).

Last edited by RapidRobert; 12/13/17 12:50 AM.

live every 24 hour block of time like it's your last day on earth
Re: 440 Timing Issue [Re: CYACOP] #2418196
12/13/17 10:55 PM
12/13/17 10:55 PM
Joined: Jan 2006
Posts: 91
Pacific NW
cuda66318 Offline
member
cuda66318  Offline
member

Joined: Jan 2006
Posts: 91
Pacific NW
Ported vacuum source? .... as air speed increases through the Primary venturi it creates high pressure in the center to fracture the fuel into small particles, the opposite and equal reaction is Negative wall pressure. If you look at the primary venturi you'll see a small hole in the venturi wall...That is the vacuum source for Ported Vacuum. So as you accelerate the vacuum increases with air velocity and draws more timing into the distributor via the vacuum can. It will pull the amount of timing into the motor based on the numbers stamped on the vacuum arm x 2 ie: 6.5 Arm X2 will give you 13* at the crankshaft.

So if you have the initial timing set at say 6* and the distributor has 28* of mechanical timing in it then as you build rpm you will hit the 34* based on the spring tension (6* initial + Mechanical of 28* = 34*)and THEN it will advance another 13* of ported vacuum timing for a total under load of 47* PING PING BOOM!

Ported Vacuum is for emissions controlled engines with a OBD1 computer that will retard the timing based on the data it receives from multiple sensors such as TPS, O2, knock sensor, engine temp sender, MAP and others as they became more sophisticated.

Think about the fuel formulation your trying to burn in these cars, it's designed for extremely lean burn, sophisticated combustion chamber, high combustion chamber temperature engines, this new fuel is formulated to run in a Injected aluminum V-Tech designed for MILEAGE not your old cold iron push rod motor.

Yes some of the old factory stuff was hooked to ported but look at the timing numbers some as low as 5* BTDC with total at maybe 25* and then the ported vacuum would pull it up another 10-12* to make it run.... very inefficient and always a 5-10MPG gas hog but gas was 28 cents a gallon who cared?

GM perfected the Vacuum advance distributor hooked to Constant Manifold Vacuum and all GM cars were always connected to constant, they also made over 300 different combinations of distributors by using different vacuum cans, vac arms, pin positions on the advance plate and limits on mechanical advance cans to accommodate everything from their 6 cylinder trucks to a 427 corvette.

In today's real world we need to have all the initial timing the motor will take without kicking back or dragging the starter down, that number depends on the compression ratio and the cam duration or valve overlap, the bigger the cam the more initial timing you can run. The Vacuum canister needs to be adjusted to read the manifold vacuum level at idle and then it needs to be set to the correct amount of timing (usually in the 28-32* range)at idle and at part throttle cruise (42-46* range). Where the mechanical curve is set is whole set of different perimeters but it needs to work together with the vacuum timing to maximize engine performance at all loads and RPM levels.


If you have a performance engine the distributor needs to be curved to be compatible with modern fuel and still achieve reasonable fuel economy and still squeeze all the power you can get out of it. Although our 6 position disc really helps in tuning your distributor it's not a $25.00 tune up in a plastic bag. Even after you get the distributor all dialed in you still need a good ECU that won't drop output when hot, retard the timing under load or skip cylinders because of an inadequate coil. Just because someone says this is a "The Best Coil" you have no way to test it to see if it's marketing or engineering data? We do, we tested over 30 coils and then programmed our Microprocessor to optimize it's efficiency even further without compromising longevity or reliability.

ANY ECU utilizing slow old 1960's transistors will NOT do the job in today's world I don't care what color it is or what ridiculous claims they're making there is NO Substitution for Modern Level 5 Electronics using Intel Technology microprocessors and Good Ole American Manufacturing Skills and Quality Controls.

Our .0053% failure rate over nearly 6 years and well over 5000 units says that loud and clear.

Re: 440 Timing Issue [Re: cuda66318] #2418348
12/14/17 04:43 AM
12/14/17 04:43 AM
Joined: Jan 2008
Posts: 2,363
Cotati, CA
Dave Hall Offline
top fuel
Dave Hall  Offline
top fuel

Joined: Jan 2008
Posts: 2,363
Cotati, CA
This should be permanently posted to the top of the board! Who is "our" in your post? cuda66318 are you a vendor here?

Re: 440 Timing Issue [Re: RapidRobert] #2418382
12/14/17 10:47 AM
12/14/17 10:47 AM
Joined: Jan 2007
Posts: 531
Charlotte, NC
Kowal Offline
mopar
Kowal  Offline
mopar

Joined: Jan 2007
Posts: 531
Charlotte, NC
Originally Posted By RapidRobert
Alright we're getting closer. what does not seem right? I would bump it to 15 (which likely will require shortening the slots to get it back to 36-38) & the FBO $22 plate is by far the easiest/cheapest way to do this. My bone stock 85 318 does great on 19 initial. are you on ported or manifold?


A plug for the FBO plate. I have used it on two cars now, it is a really great, easy, way to alter total mechanical advance. I bought extras just to have them.


'69 Hemi Charger 500, ‘70 U code Challenger R/T
(These and a bunch others at www.dkowal426.com)

P.J. O'Rouke: "The old car ran perfectly, right up until it didn't."
Re: 440 Timing Issue [Re: cuda66318] #2418391
12/14/17 11:19 AM
12/14/17 11:19 AM
Joined: Sep 2007
Posts: 14,889
up yours
Supercuda Offline
About to go away
Supercuda  Offline
About to go away

Joined: Sep 2007
Posts: 14,889
up yours
Edited for content down

Last edited by moparts; 12/14/17 02:03 PM.

They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.
Re: 440 Timing Issue [Re: Dave Hall] #2418406
12/14/17 12:07 PM
12/14/17 12:07 PM
Joined: Jan 2006
Posts: 91
Pacific NW
cuda66318 Offline
member
cuda66318  Offline
member

Joined: Jan 2006
Posts: 91
Pacific NW
We are FBO Ignition, Oregon

Re: 440 Timing Issue [Re: Supercuda] #2418441
12/14/17 01:16 PM
12/14/17 01:16 PM
Joined: Jan 2006
Posts: 91
Pacific NW
cuda66318 Offline
member
cuda66318  Offline
member

Joined: Jan 2006
Posts: 91
Pacific NW

Thank you all for your constructive comments.


Last edited by cuda66318; 12/14/17 02:24 PM.
Re: 440 Timing Issue [Re: Dave Hall] #2418444
12/14/17 01:25 PM
12/14/17 01:25 PM
Joined: Jan 2006
Posts: 91
Pacific NW
cuda66318 Offline
member
cuda66318  Offline
member

Joined: Jan 2006
Posts: 91
Pacific NW
Thank you Dave Hall for the Kudos, glad you appreciate our factual information. Between Jim and I we've been tuning distributors for over a 100 years.

Last edited by cuda66318; 12/14/17 01:25 PM.
Re: 440 Timing Issue [Re: Kowal] #2418451
12/14/17 01:33 PM
12/14/17 01:33 PM
Joined: Jan 2006
Posts: 91
Pacific NW
cuda66318 Offline
member
cuda66318  Offline
member

Joined: Jan 2006
Posts: 91
Pacific NW
"A plug for the FBO plate. I have used it on two cars now, it is a really great, easy, way to alter total mechanical advance. I bought extras just to have them."

We appreciate you as a customer and we're very happy that you appreciate our products. Recently we went to a more polished stainless steel to make them look even better!

Page 1 of 2 1 2






Powered by UBB.threads™ PHP Forum Software 7.7.1