Ignition advice re: my Scout II

P

Patrick Morris

Member
I'm thinking, in addition to a carb rebuild (per a different thread), it's time for cap-n-rotor and new wires. Possibly a new coil as well, if there's a benefit to doing that. This is my current (ha!) system:

  • engine's overall condition: stock 345. Lots of miles but good oil pressure and it still passes its smog test every two years.
  • carburetor: Holley 2300/7448 most of the time. I swap back to the factor 2210 for inspections (shhh!)
  • distributer: stock, original prestolite w/ pertronix ignitor trigger. Ignitor was installed in 2003. Can't remember off-hand if it's a "II" or what. I can check.
  • ign. Timing: factory setting, 5* btdc.
  • cap & rotor: napa? Been on there 8 - 10 years.
  • coil: jacobs. About 15 years old now.
  • wires: bw "coolwires", 7mm, if that matters. About 15 years old and in need of replacement.
  • plugs: autolight. New as of 7/2008.
  • other: msd6a, installed about 15 years ago.

I definitely want new wires, but they don't need to be fancy. I'll probably get the wiring from napa. I've read that people have good luck with their premium sets.

New cap & rotor too. Is there any particular brand to either look for or stay away from?

For the coil, do they degrade over time? I assume they either work or they don't? Is there anything to be gained by "upgrading" from this coil? I heard jacobs coils have always been pretty good. Or is the jacobs just the same as some others (blaster, flame-thrower, etc.) but with a jacobs sticker?

Also... I'm thinking about adding an msd timing control at some point, but not immediately. I always liked that idea---being tweak the advance w/o ever having to touch the distributor again. Btw, I always run regular (87) gasoline. My engine never pings. I'm grateful for that.
 
I don't know if anyone cares, but I found the instructions to the pertronix dealie I swapped to. It's just the standard ignitor, either p/n 1441a, 1483a, or 1484a. I'm not sure which, since the instructions cover all these models.

I remember it said here or on the binderbulletin that the standard ignitor has some deficiencies compared to the "II". Maybe it was with coil compatibility (current limitations?) and/or the non-II model can be wrecked if the ign. Is left on? Without ithe engine actually running is what I mean. 'zat sound familiar?
 
Ignition coils don't "wear out"...they do fail just like any other component. Most especially oem-type coils which are oil-filled. The oil leaks out over time.

The jacobs coil was "hi-tek" way back when but is nothing special in today's world. In actuality, jacobs was absorbed and then dismantled and only now exists as a "brand" for a few components. An early version of an "e" core coil, those coil designs came from the industrial engine and motorcycle/marine world originally.

Today's e core coils from pertronix, msd, mallory, and crane (the crane stuff will be around on the shelves for years!) are all good pieces. Chose your poison, disregard the marketing hype, pick the coil ya like the color of and the type electrical connections.

The only thing that matters in choosing a replacement "performance" coil is the primary resistance value. It must be compatible with the type distributor trigger and ignition box being used.

The pertronix unit you describe is the oldskool version, not a p-II. Again, nothing wrong with that trigger, it is still state of the art. The "advantage" of the p-II...if ya leave the ignition switch in the "on" position, it will sense that and turn itself off. A p-II also claims to incorporate an "adaptive dwell" feature which is useless on any IH engine app due to the fact they can't turn enough rpm to have the "dwell" become an issue. P-II also has a rev limiter of sorts...again, with an IH motor that is a useless feature!

If ya leave the key switch "on" with a breaker point system, the points "burn up", if ya do the same with either a Holley gold box or the prestolite electronic, the modules will overheat and self-destruct.

The number one issue with any distributor is wear! Shaft-to-bushing wear, mechanical advance wear, and end play wear. All of those factors demand attention if stable timing is expected throughout the entire engine rpm operating range. Same for a correctly functioning vacuum advance unit if one is being used.

Back to the coil....since you are running a 6 series msd box, you can run any "low resistance" ignition coil ya chose, do not go below 0.4 ohms however for a street-driven rig. A coil of that value cannot be used with a pertronix module alone however, it must be operated by the msd/mallory/crane "6 series" box, the p-tron only "triggers" the box, therefore it can be used with a low resistance coil.

Once all this juju is installed, the engine must be power timed...scruu any "factory" specs. This is not emissions stuff, it is performance stuff. There is no reason to add all this guapo unless you wanna tune the motor to take advantage of any possible benefit provided.

There is no way to avoid "never touching a distributor again"! Distributors require periodic maintenance! Only way to avoid that is fab up a "crank trigger" system. I'll soon start doing one of those for myself and will document the process fully. When a p-tron is installed, it must initially have a recommended "air gap" adjusted. That air gap is what determines the "dwell" regarding the ignition system. As the distributor wears over time, the dwell will degrade accordingly, along with timing.

As for the adjustable timing control...with that system you advance the base timing way beyond what would be used without a controller, then dial the timing "back" (retard) based upon audible detonation and engine performance. Problem is, ya better have good ears when pulling a pass with a load, otherwise you will learn what internal engine destruction is all about before ya know it.

With a crank trigger system, cd box, and a programmable timing controller, you can dial in any advance curve ya want for your engine. You'd have a real hard time convincing the kalifornikate smognazis that is a good thang though!

Watch this thread, some more changes are in the works now...

http://www.forums.IHPartsAmerica.com/ignition-tech/644-ignition-system-performance-upgrades.html
 
Thank you. That's exactly the kind of answer I was hoping to see.

It's been a while since I played around with the timing---maybe 10-12 years ago or so. A friend of mine showed me how to adjust the timing in conjunction with the idle-mix screws on my 2210. If memory servers, the object is to achieve the highest vacuum at idle, balancing the mix with timing advance. I guess we'd advance the timing a little, then open the air idle-mix screws gradually while watching the vacuum gauge. The vac rises up to some point, then begins to fall off again. So you roll back the adjustment to where the highest vacuum was. Then test drive the vehicle and see how it runs under a heavy load. If everything's okay, you advance the timing a tad more and do the idle-mix adjustment again.

I recall getting noticeable improvement in, especially, low-end power with the ignition at 11* btdc, though it was happiest running mid-grade gas with that advance. I plan to do this again with my 2300 once I've sorting out any kinks it's having. Only thing for me to consider is whether I want to limit myself to more expensive gasoline or not.

For the timing control (or "ping control" as msd used to label it) I like the idea from the point of view being able to adjust for bad gas, etc. ... and to quickly adjust it for better power if I felt like splurging and getting the expensive stuff . I guess you wouldn't want to put the adjustment knob in a place where you might bump it and rack the advance way up without noticing it right away though!
 
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