High breaker arm tension ignition points 28-32 oz.

[Duke W.]

I have seen a number of Internet posts that recommend NAPA CS786 or CS7860 as the high breaker arm tension (28-32 oz.) ignition point set for all high revving applications (over 5500) particularly mechanical lifter engines.

I do not believe these sets are high breaker arm tension, nor is the NAPA online part number for "high performance" point set (CS7860C) a high breaker arm tension set. Despite being referenced as "heavy duty" or "high performance" I don't believe that any of these sets are 28-32 oz. breaker arm tension.

The trouble is that the high breaker arm tension set was never OE on any Corvette engine application, and current catalogs key off the OE specification, not a "field upgrade". The original GM high breaker arm tension set (1966294, Delco short number D112P) was not released until circa 1966, and Chevrolet never specified them for any Corvette applications. I'm not sure if Chevrolet specified them for any applications, but they were OE on some BOP muscle car engines.

Using cross reference catalogs, other brand high breaker arm tension points cross to NAPA CS89 and vice versa. The CS786, CS7860, and CS7860C cross to the 19-23 oz. set(s) in other brands, and I don't know what the real difference is between the above three NAPA part numbers.

Keep in mind that Standard Motor Products now owns all the replacement brands including Echlin, which used to be owned by Dana Corp. as is NAPA, but Dana sold its Controls Division to Standard Motor Products a couple of years ago, which included the Echlin brand name. SMP also owns the BWD brand, Niehoff, and is a supplier to Delco, but Delco no longer offers the high tension point set that I am aware of either under the old number or a new number

Based on my catalog/cross reference research I have the following part numbers for the high breaker arm tension set, and they are all very likely manufactured by SMP. Bluestreak is SMP's long time premium brand, and SMP doesn't offer a high breaker arm set under there basic "Standard" product line.

Bluestreak DR-2271XP
BWD A112HP
Niehoff DR8P
NAPA CS89

The one thing I have not done is physically confirm that CS89 is the correct 28-32 oz. set, so if anyone plans a trip to NAPA, can you inspect a CS89 set and compare them to the other NAPA part numbers? It's easy to tell if they have the high breaker arm tension by opening the points with your finger and comparing them to a OE replacement set that is 19-23 oz. The difference in breaker arm tension is unmistakeable.

Duke

[John H.]

Re: High breaker arm tension ignition points 28-32

Duke -

Jerry MacNeish owns, restored, and runs the ex-Dave Strickler "Old Reliable" '68 Camaro Z/28 (302), launches at 7500 and shifts at 8400 (runs 10.90's @ 130mph at 3400# in NHRA E/Stock), and swears by Accel high-tension points; don't know offhand what the part number is. Not too shabby for a Delco single-point distributor

[Joe L.]

Re: High breaker arm tension ignition points 28-32

John-----

Accel #110130. Accel also makes an excellent cap and rotor for Corvette distributors. Their part number is 8124 which is a rotor and cap set. This one's even black. It's superior to the "L-88 dark brown with copper terminals" cap. If one can get past the "Delco-Remy script" and "patent pending", the 8124 is the way to go.

[John H.]

Re: High breaker arm tension ignition points 28-32

Thanks, Joe!

[Duke W.]

Re: High breaker arm tension ignition points 28-32

Accel lists a "32 oz." point set - 110128 - and for all I know this is the SMP manufactured set available in all the other brand names, at least one of which can be ordered at your closest and most convenient auto parts outlet.

I think Clem once posted that a 48 oz. set exists, but I don't recall that he listed a brand and part number. In any event, a 32 oz. set is adequate for the 7200 maximum revs I recommend for a properly blueprinted 327 mechanical lifter engine restoration.

With the same prep, a 302 Z-28 engine should make useable power to over 7500 because of the shorter stroke, but the OE exhaust system is much more restrictive than on a Corvette, which will probably limit useable revs to the low 7000s unless the OE exhaust system flow is improved, but to go above 7200 you need to install the OTC 3927142 valve springs in place of the OE 3911068.

I tested my distributor (after figuring out how to make it work at high revs) on a Sun distributor machine 35 years ago, and it was dead on at 7000 revs, which was plenty good for me and will satisfy the requirements of most high revving road engines.

My ignition chronically broke up at high revs in the sixties, which is why I installed a TI from the "12-mile L-88" in 1968. In the early seventies I finally figured out how to make a single point work - shimmed up the end play, new, wobble free breaker plate, high breaker arm tension points - and when the TI went TU for the second time I put the blueprinted single point back in and never knew the difference except the nice feeling that it wouldn't take a dump with no warning.

The TI ended up back on the original L-88 from whence it had come in the late eighties.

I've never been a fan of "electronic conversions" as it puts you back in the same boat of possibly suffering a no-notice breakdown. Point type ignitions rarely fail without warning, and the nice thing about these vintage cars is that they are free of electronic black boxes that can lead to such no-notice failures. Their simplicity is elegant!

Nothwithstanding above, as you and many others know, the OE Delco single point distributors were somewhat indifferently assembled, most having way more than drawing or shop manual specified end play, which can lead to spark scatter, point bounce, and poor high rev performance. And the high breaker arm tension points are really necessary for ignition reliability above 5500-6000.

But they are quite simple and with a good inspection and proper attention to assembly detail, they perform as good as any electronic system as far as I am concerned, and once properly assembled, they are simple to maintain.

Some think that checking or replacing points and adjusting valves is some kind of onerous task, but when old timers like us have been doing it for fifty years, it's no big deal - just part of the "mystique", and a pleasant way to spend half a day in the garage - sort of a ritual.

Duke

[Duke W.]

Re: High breaker arm tension ignition points 28-32

The 110130 is a 32 oz. uniset; 110128 is the standalone 32 oz. set that requires a separate condenser.

Do you know who manufactures Accel brand products? I'm not convinced that they don't just purchase them from SMP like every other replacement brand.

Given the low volume in replacement parts for these old systems, it's tough to justify more than one manufacturing operation. It's common for various "brands" to purchase parts from competitors manufacturing operations and place them in their own box. So the competition is in the marketing channels, not in manufacturing.

It works both ways. A Dana brand may be a part manufactured by Federal Mogul and vice versa, and the independent brands source is whoever makes the particular product. I don't know if Accel is just a marketing outfit or actually owns parts manufacturing operations.

Duke

[Joe L.]

Re: High breaker arm tension ignition points 28-32

Duke----

Yes, the 110130 is the "Uniset"; that's the only type I use.

I don't know who manufactures Accel products, but I can tell you that the cap and rotor I mentioned don't look like any Standard Motor Products cap and rotor that I've ever seen.

[William C.]

Re: High breaker arm tension ignition points 28-32

An old drag car years ago (former world champ) had an inscritpion on the hood "Tricks are for kids" I think this is the same argument you are making, and I agree 100%

[John D.]

Re: High breaker arm tension ignition points 28-32

Duke, We use the C786P for the 58 to 65 FI distrs. It's not the high breaker arm strength or ounces as you call it. THe CS789P is much easier on the distr cams. Those points still give us 6800 plus with no problems. THe CS89 is the high pz wt points. But as you know Standard bought out Echlin so the parts are probably just reboxed now. I realize this info is an echo from what you said.
We don't like the DR points at all anymore. Avoid them at all cost. Blue Streaks are pretty goo.d. That Niehoff is one old name. Borg Warners are also very good.
YOu have to watch using the old NOS DR condensers as that fiber washer on the end has caused a lot of those old condensers or capicators to fail. John

[John D.]

Re: High breaker arm tension ignition points 28-32

Clem used to cheat though with the points Duke. He jammed a small piece of rubber behind them so they wouldn't bounce at high RPM.

[Duke W.]

Re: High breaker arm tension ignition points 28-32

In my experience electronic parts typically either work perfectly or not at all.

Those old mechanical systems like breaker point distributors and carburetors could be cantankerous SOBs until you learned to make them work properly. Some of this knowledge appeared to have been closely guarded secrets, so sometimes you had to figure it out yourself - like how to make a OE Delco single point work at high revs, so in that sense you were using "tricks" - but they were old.

I suppose that nowadays, replacing breaker points with an electronic switch is a "modern trick", but if you know the old tricks that made the vintage stuff work right, you just don't need a new trick - especially one that actually makes the car more complicated.

Unfortuneately as people incorporate the new tricks, the old ones will be lost.

I'm still working on old school tricks to make the old stuff work. It was only in the last couple of years that I figured out what SB mechanical lifter valve clearances should be set at after getting hold of the OE cam lobe data, and I'm mixing and matching OE lobes to come up with a better cam design for SBs with massaged OE heads.

I enjoy the challenge of making these old engines perform better using the original design components and parts that preserve original appearance and overall operating characterisitics while maintaining or improving OE reliability. They have a lot of potential without resorting to "modern" stuff.

Duke

[Duke W.]

Re: High breaker arm tension ignition points 28-32

I don't recommend modern Delco replacement parts for anything. They're just a marketing outfit now. Some of their ignition parts may come from SMP, but some may come from "less than savory" sources, and I think their online catalog/cross reference is full of errors. Most of the old part numbers have changed, and it's just impossible to make any sense out of it all.

I trust SMP, and now that I know that NAPA, Echlin, BWD, and Neihoff along with SMP's tranditional Standard and Blue Sreak brands are all from the same manufacturing source, I'm indifferent to them since the only difference is the name on the box, and the part numbers have not changed since the sixties. Buy any of those brands based on price and convenience.

Duke