[tc]

Racing yesterday, 2nd time trial, tires hooked and slipped a few times at the launch. After shifting into 2nd gear the engine quit running. No spark.

Took cap off and saw this ( photo ). Took dist out and can't find anything wrong with it. Put an old rotor on and engine runs.

I wouldn't think the rotor would come apart just from spinning, without hitting something.

I thought the Standard Blue Streak DR-318 were the rotors to buy. Anyone else have problems with these and what do I purchase now for a new one.

[Schurkey]

Standard/Blue Streak used to be top-quality. Last Blue Streak parts I bought were Made In China, and I sent them back.

I am not totally sure that Blue Streak is part of the Standard product line--it may be that they've been sold-off to another company. No promises.

What are the chances that the cap wasn't held on with all four holddown screws; or that the engine lifted under heavy throttle and the cap got bumped? If not that, I'd be looking real close at the distributor bushings.

...and if the cap, motor mounts, and distributor bushings were good, I'd be trying to find the box that rotor came in, to see where it was made.

[steve25]

Had this rotor and cap combo previously ran fine?

Did you have it apart to check how things looked before this day's racing, sometimes something as mondane as putting the cap back on can cause us to not think twice in terms of if we did such right!

I have run the blue streak stuff forever and never had a issue with there construction.

My best guess as to what took place is that the last time you had the cap off and one of the hold down arms was facing inward and that the rotor tip just happened to be in the right spot to get cought by that arm and you bent up the rotor tip just enough for things to rip apart.

In my opinion depending on if and when this start of the mishap took place you where lucky to even get the car into the staging lanes, or maybe even on the trailer to get to the track!

Where you able to srouge up a rotor and race the rest of the day Tom?

[67Fbird]

what did the cap look like? I have seen a post inside the cap actually rotate...when you wiggle the plug wires to make sure they are seated...but obviously, that didn't run it only turned over as it broke stuff immediately. I'm with ^^^^^ something had to have MOVED in order for there to be contact.

[steve25]

You have a great point there as a possibility 67Fbird!

[mgarblik]

I have seen a few HEI rotor rivets come loose then contact the cap terminals, then it's game over. All the aftermarket parts are crap now days in materials, tolerances, and manufacturer. Standard ignition, Blue Streak, Sorenson, Neihoff all USED to be quality tune up parts. Now days, only Echlin HEAVY DUTY tune up parts are decent among them and you have to be careful buying them. NAPA has three lines of tune-up parts. NAPA Mileage Plus is absolutely 100% crap from China. I won't use it period. Echlin Brand is Hit or miss and some made in China. Echlin Heavy Duty is still pretty good in my experience. Good luck getting it all fixed up with good parts.

[Formulabruce]

Rotors for MARINE applications are better built. A mid 90's HEI rotor from a mecruiser chevy 350 will work, and be more reliable. The cap may be copper tabs as well, vs Aluminum.

[Schurkey]

Originally Posted by Formulabruce

The cap may be copper tabs as well, vs Aluminum.

Brass, I'd believe. Not copper.

Copper is a wonderful conductor. Mix molten copper with some zinc, you get brass which is not a great conductor, but it's reasonably stable so it doesn't corrode. Aluminum actually conducts better than brass, but aluminum corrodes.

(Mix molten copper with tin, you get bronze, which is also a crappy conductor--but well-made bronze is stronger and better than poorly-made iron. For awhile, Roman officers got bronze shields and swords, while the "grunts" got iron.).

[tc]

A few years ago I set up this dist. The bushings are fine, no slop in the shaft. I need to take the dist apart and check the bushing in the advance plate ( piece the rotor bolts to ) since that took some abuse.

I did check the dist before I started racing in August. I know those hold down clamps can be tricky, so I try to make sure they are in their proper place. I have 23 1/4 passes and street miles before Saturdays racing. Saturday I did 4 open time runs before the time trials started.

Not sure about the engine mounts, but the chain/turnbuckle from the front of the head to the frame is intact. There is plenty of room around the cap, so I don't believe the outside of the cap touched anything.

All the plates inside the cap are still located properly, unable to twist. You can see where the ( plastic portion of the ) rotor hit the ribs ( between the plates ) on the inside wall of the cap. Most ribs are broken off at the plate height.

Guess I'll have to check the cap clamp bolts every few races. I think it's hard on the car when the tires spin and hook a couple of times, at least that is what it felt like. The advance plate now is a little to loose for comfort as I can rock the rotor a little.

I have another 70's HEI that I can rebuild and take to the track with me.

I think I addressed everyone's comments. Thank you all. Steve, I did not make anymore runs. It was a fun day of non-racing. Car ran it's best, 11.85 at 113 mph.

[steve25]

Tom, when you pull it out also take out the oil pump drive shaft and confirm that all is well with that.

[67Fbird]

ah....last one...when you had your dizzy out did you check the END PLAY of the dizzy shaft? since the rotor went UP into the cap...there is a posibility there that the 2 or 3 thrust washers between your gear and housing are..dead. especially if yours uses one of the plastic thrust washers.

[Kenth]

In 40 years of wrenching Pontiac V8´s i have never noticed more than one thrust washer on an factory original Pontiac distributor.
And certainly NONE were plastic!
BTW, i have seen up to .070" up and down movement on NOS Pontiac distributors.
That´s why the rotor is spring loaded against the button in cap at upper end.
Also, shimming the gear to tight may cause glitter in oil due to oilpump gear shaving the bottom plate on oilpump and less than ideal wear pattern on cam/distributor gears.

FWIW

[Half-Inch Stud]

Check the buttom for 3 Ohm to 8 Ohm. if the Button is 3000 Ohm to 8000 Ohm then you got a toaster.

[tc]

I made a headed bronze bushing ( a few years ago ), so that checks out good. Top bushings are ok. I unhooked two adjacent clamps on the cap and it takes a fair amount of pressure to lift the cap. I can't find anything wrong that would make the rotor hit the cap, unless it spins real close to something on the inside of the cap.

Hey Mike G, is there a certain color those Echlin heavy duty rotors are?

[mgarblik]

Originally Posted by tc

I made a headed bronze bushing ( a few years ago ), so that checks out good. Top bushings are ok. I unhooked two adjacent clamps on the cap and it takes a fair amount of pressure to lift the cap. I can't find anything wrong that would make the rotor hit the cap, unless it spins real close to something on the inside of the cap.

Hey Mike G, is there a certain color those Echlin heavy duty rotors are?

The last one I bought was a tan/brown color. They are thick and heavy, not nearly see-through like the cheap ones. I will try to get a part number for you. Just looked at my pro-link site. The current Echlin rotor ECH RR173. It is lighter tan in color and doesn't look as thick in the pictures as the older ones. Still looks OK. The Mileage Plus one looks like garbage as always. Interesting NAPA sells the MSD branded HEI rotor It is part # BK7357266 It is red and looks nice and thick. It's 3 bucks less than the Echlin one at $8.99.

[soupman]

Be careful on these rotors. I had a hard time getting my mechanical timing to advance fully and finally found out the rotor was molded a little off causing the weights to not swing all the way out. I had to take a dremel and remove some plastic on the sides.

[Schurkey]

Originally Posted by soupman

Be careful on these rotors. I had a hard time getting my mechanical timing to advance fully and finally found out the rotor was molded a little off causing the weights to not swing all the way out. I had to take a dremel and remove some plastic on the sides.

What brand? What part number?

[tc]

MSD has a couple. I'd like to see how easy it is to pry off the plastic retainer holding down the copper tab. The 2nd one looks more reliable.

https://www.holley.com/products/igni...ors/parts/8410

https://www.holley.com/products/igni...rs/parts/84101

[Schurkey]

Originally Posted by tc

MSD has a couple. I'd like to see how easy it is to pry off the plastic retainer holding down the copper tab.

1. It's not copper.

2. MSD used to be a reputable company. Then they invented their "Street Fire" line, so they could sell junk imported from China without screwing-up the reputation of their main product line. Then they began selling junk from China under the MSD brand; high-failure coils, for example. I bought an MSD distributor cap for my pickup truck. Sent it back when I saw that it was a cheap import.

[soupman]

Originally Posted by Schurkey

What brand? What part number?

ACDelco professional brand D488X, I didn’t check but probably made in China or Mexico