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Which electronic ignition

Sometimes there are conditions that exist that you never know are a problem until someone points it out.
I hadn't heard of "spark scatter" before Rick E wrote about it. I have noticed that it fluctuates a bit at fast idle and up but since I'm not chasing every last inch of HP like a dedicated racing team, it is not such a big deal.
 
About the timing bouncing around - I came across this distributor shaft collar that supposedly addresses one potential cause of this issue. The purpose of adding this collar is to prevent the intermediate shaft oil pump drive gear from climbing up the vertical slop on the distributor shaft, which affects ignition timing due to the slant of the gear teeth. The lock essentially eliminates/reduces the amount of slop that the gear can climb.

Has anyone tried installing one of these shaft collars? Reviews I've ready seem positive.
I've seen some photos where the collar is installed on the end of the distributor shaft and some install it on the end of the oil pump drive shaft. I'm not sure which is better or appropriate.

I don't want to derail the thread onto a new topic, but had to ask....

Rick E-booger's ebay site sells one:
for Mopar Distributor Collar Timing Stabilizer 340 440 383 Hemi Dodge Plymouth | eBay
"If you've had trouble with unstable idle, detonation, spark scatter etc., this hardened steel collar can sometimes resolve the issue. Slips on distributor shaft to keep oil pump / distributor drive shaft / gear firmly "planted" in the block. This takes out "bounce" between the distributor shaft and drive gear (in block) , preventing gear from moving upwards as oil pump torque varies as each gerotor lobe builds pressure.
Fits all big block (383-400-440), LA and Poly small blocks, and 426 Hemis. Not needed on 318 / 360 Magnums (i.e., '92-93 up) - they are crank-triggered ignition.
Detailed instructions included."

From an E-bodies site:
"The old racers trick was to just put a length of rubber hose on the end of the distributor shaft. It does the same thing. It keeps the oil pump drive from bouncing. If the end of the distributor shaft doesn't bottom out in the oil pump drive, it could bounce. Since the teeth are cut at an angle, any up/down movement changes the timing. The problem with the hose is that it eventually breaks down from being in constant contact with the oil"

For the collar - "To set the depth correctly, install the collar on the shaft, just tight enough that it will stay where it is, but can still move. Install the distributor and make sure it is fully seated. The collar will slide up to the correct depth. Pull it out, tighten it down and you should be good to go."
Don’t worry about derailing the thread, I got the answers and help I needed, any further discussions is just helping the next guy.
:thumbsup:

Thanks, that looks like a good product. I bought a distributor from rockauto, it was one of their better brands. That was a mistake lol, the magnetic pickup was loose and I had to glue it to keep it from walking and hitting the rotor, the whole thing just seems crappy and loose. Should have known better. Bought one of Ricks distributors, haven’t installed it yet, but it already feels and looks like a better unit. I’d probably go out and say he’s got quality stuff, and a good bit of knowledge.

Mopar Electronic Ignition Distributor RB-Engine Plym Dodge 440/413/426 Black Cap | eBay
 
Hey guys, i came across this thread while looking for info if this dristributor shaft collar.
My ignition timing does move and since i am using a HV oil pump i guess the upward force of the shaft will be higher than normal.
Does anyone have/use this collar, and any idea of the distributor shaft diameter?
Since these collars are widely available i was thinking to order one to size, or drill/ream it to size instead of the need to order one overseas with all additional costs it brings.

Any info on dimensions of this collar is welcome.
I am using a RTR MSD distributor but i assume all shafts are standard diameter, it's for a 440 btw.
 
Some factory dists have a 0.491" shaft & some aftermarket ones have a 0.500" shaft. I think the MSD is 0.500".
 
Thx Geoff,
So if I get a bushing with 12mm hole I can use an adjustable reamer to get it to size, that good enough!
 
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