I started to take stuff of my engine so I could take it out to replace it with a 350 and when I removed the rotor I discovered that the guy had put a cheap plastic one on and the key had sheard off, now lets say this advanced or retarted the timing, could this cause major overheating, enough to cause a seized engine? Also this just goes to show you thatsome people just don't get why to spend just a little more money to get better parts.



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1987 Black 305 TPI 5spd IROC, seems to be fully loaded, but can't find RPO codes.
AIM: SzkiRM125
---Give up the defending ***** stuff camaro_hunter_d, there is plenty to do to out cars, if not more----

 

If it advanced WAY too much, it could cause over heating. Too much timing will cause detonation which raises engine temperatures. Also, if it retarted too much, it would cause your exhaust temperatures to get way too hot and could plug the catalyst which could lead to overheating. So to answer your question, yeah, it could be the problem, but I don't know for sure.

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End with 2.77:1 Gears.

Current Mods: LT4 HOT Cam, Comp Cams 1.52:1 Roller Rocker Arms, Edelbrock TES 1 5/8" Headers, Catco 3" High-Flow Catalytic Converter, Hooker 3" Aerochamber Cat-Back System, Transgo Shift Kit, Performance Resource Chip, Accel Ignition, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET: 14.32 @ 97.7mph
(corrected for elevation)

 

The rotor will not affect timing. That's a function of the triggering mechanism, which is built on to the shaft and interacts with the sensing pickup on the distributor body. All the rotor does is point in the general direction of the spark plug wire terminal in the cap for the cylinder that is supposed to be getting the spark at that time. Old mechanical/vacuum advance distributors would vary the point the rotor was at relative to the cap terminal at the time of spark by as much as 20 degrees.

Retarded timing will raise overall engine temp faster than advanced. Advanced can cause piston damage, though.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam and intake, World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

 

But he said that the key that slides into the groove on the shaft sheared off. That would cause the rotor to not follow the shaft like it should. It would definetly cause a retard in timing. No matter how much the ECM tried to overcome it, it couldn't. For example, if it was about 4-5deg retarded (before it bound up on the shaft) then the ECM would not know that and wouldn't be able to advance to 22 deg. max like it's programmed. The timing would only reach 17-18 deg advance. But the ECM would never know it. It would still think that it's advancing 22deg. It wouldn't sense any knock through the Knock Sensor, so it would just keep it fully advanced most of the time, except at idle. Therefore, even at idle, the ECM would think that the timing is set at the 0 deg. BTDC like GM intended it (w/ the plug disconnected), but in reality, the timing would be 4-5 deg ATDC after that rotor moved.

I know what you were trying to say, but if the rotor is not connected to the dist. shaft correctly, then the position of the rotor will affect the timing. That's what timing is right? The relative position of the cap and rotor using TDC as a reference, right? Moving the rotor counter clockwise would be the same as moving the cap clockwise, which would retard the timing.

But I fail to see how this could cause excessive heat. Advancing the timing too much will cause a lot of heat (engine ping burning holes in pistons), but not retarding the timing. All that would cause is a real lack of efficiency and power. Don't confuse ignition timing with compression ratio or A/F ratio. I've never retarded the timing in a car and had it run hotter. Have you?

BTW, one more question. Do they make rotors out of anything other than plastic? I've never seen them. Just curious. It'd be interesting to see how they would do that.

[This message has been edited by AJ_92RS (edited July 07, 2001).]

 

I was just about to ask the same thing. If they do, I havn't seen 'em.

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1985 Camaro SC - 2.8L, auto.

http://www.xenodrgn.f2s.com/Frontright.jpg

 

The rotor does not affect timing. All it does is to direct the spark to the appropriate cylinder whenever it occurs, as controlled by the parts that do affect timing. Those parts are the pickup coil and its little starwheel thing, and then the ECM after it receives the "information" from those parts about the engine's mechanical position. The rotor is not part of the mechanism that determines when the spark occurs, though, so it can't affect timing, only which cylinder it gets sent to.

They don't make rotors out of anything other than plastic, because the material has to be an insulator. The coil is producing a shot of electricity that is several tens of thousands of volts from ground; the rotor has to be a good enough insulator to make the spark stay in the ignition system and not jump directly to ground inside the distributor, which would prevent it from ever reaching the plugs.

So... to answer your original question, no, a damaged rotor cannot cause anything like you described; all it can do is feed the spark to the wrong cylinder, which will make the car run so bad (if at all) that no one in his right mind would even attempt to drive it or give it back to a customer as supposedly "fixed".

There are some really cheap rotors out ther though, just like everything else. There's a famous quote that says something like "The bitterness of poor quality lingers on long after the sweetness of low price is forgotten"... That quote is hundreds of years old but is just as true now as it was then.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Since all the rotor experts are here right now... I'd like to ask a question. I work at Discount Auto Parts and we sell three types of rotor. A Wells basic, a Wells Gold, and an Accel... The wells gold and accel use Brass ends while the wells basic uses something else. Does it really matter which one you get. This is for both rotor and cap.

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91 Z28
Best Time Slip:
60' - 2.098
1/8 - 9.137 , MPH - 76.21
1/4 - 14.213, MPH - 97.55

Mods: SLP Exhaust, umm...nothing else..sorry

Stereo: Alpine 855, Infinity Kappas all around, Infinity 150x2 amp (POS), Infinity Perfect 10 in hatch.

Webpage coming soon.

 

I'm no expert, but I know for a fact that brass conducts electricity much better than metal or aluminum. It also is less suseptible to buildup inside the cap/rotor.

Just DON'T BUY THE ACCEL

Mine had the terminal come loose in the tower that goes to the coil, causing a code 42 every time I hit a bump.

ACCEL is JUNK IMHO.




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Mike L.
It ain't pretty.......

1987 IROC Z TPI 350 A4 3.27 Borg-Warner.

Mods: 2300-2500 Stall Converter, Shift Kit(GM parts), TPI Specialties Stage 3 PROM, Modified Airbox w/ K&N's, homemade cold air, Relocated MAT sensor, Gutted MAF, 160* thermostat, Accel 8mm Wires, bypassed TB coolant, Flowmaster 3 chamber single 3" in/out muffler, 3" MAC mandrel intermediate, custom dual !cat Y-pipe. airfoil, ported plenum. !smog

http://www.MichaelLasiuta.home.att.net

**BOYCOTT LAPEER DRAGWAY**

 

Cheap or expensive doesnt seem to matter, all of them can fail just the same. Sometimes that stuff is dropped before it makes it into a box too, and that can damage any part no matter how expensive it is.

As for those who say a rotor cant affect the timing, I had one that the end hit the cap terminal and twisted it 90 to its original position (non-GM product) and the car ran like crap, like the timing was off. Ill be exact and PC and say that a damaged rotor can easily affect the ignition system and cause the car to misfire at random.

As for the brass/non brass, the brass stuff lasts longer before it corrodes and gets zapped away by electricity and other stuff thats in there. Usually a cheaper rotor is ok and a more expensive cap is a good idea.

 

But if the rotor was put on, then the timing was set, & later the key on it broke or craked or whatever, then that could've (and probably did) move the position of the rotor/ terminal. That would have the same effect as rotating the distributor cap position. Your saying it doesn't? That key is the only thing holding the rotor in place on the shaft. If that rotor moved at all after the timing was set, then the timing will change. It's the same as if a wheel weight moved on the rim after it was balanced. If the weight moved on the wheel, but the tire didn't, then the tire/wheel combo would no longer be balanced properly.

Just like you should always check the timing after you change the cap & rotor. You should always check the timing after changing those parts due to slight differences in the manufacturing of those parts. The position of that key, the contact terminal on the rotor, the location of the wire terminals on the cap, and the screw hole locations will always vary. Even .1" of an inch can change the timing by 1/2-1 degree.

 

I'll vouch for the poor quality of Accel products. Just today (5 months after its installation) I found my Accel cap&rotor kit all nice and green and moldy...what a joke.

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1991 Firebird Formula
305 TPI,Auto,Custom 3" Mandrel bent I-pipe, Flowmaster 80 series muffler, 3" hi-flo cat, Accel Cap & Rotor,Taylor Spiro Wires,Bosch Platinum Plugs, K&N Filter, Grant GT Steering Wheel, 5% Rear tint, Pontiac Windshield Decal, Fresh paint

Former owner of an 88 2.8 Firebird....RIP

 

Thanks madmax. Maybe I'm not explaining it the correct way. But at least someone on here understands what I'm trying to point out.
Don't get me wrong. I myself am too often guilty of over looking the obvious. But after it's pointed out and explained to me, I'm like "Duh!"

Maybe you can also explain that if the rotor moved, that it would retard the timing, due to the rotor moving clockwise. But that it would not cause the engine to overheat or seize up.

 

That's a characteristic of brass, not Accel. It turns green just like copper if it's exposed to moister and not kept sealed from the elements.

 

"Affect the timing" and "affect the ignition system" are specific and general terms, respectively. Like RB & I tried to explain, the rotor will not "affect the timing", as in change by a few degrees when the spark occurs. But, sending it to the wrong cylinder or being too far away from the terminal when the spark occurs will "affect the ignition system", and either of those will cause the car to run poorly or not run at all.

As for the brass vs. aluminum debate, as conductors they are about equal. The difference comes in longevity due to non-conductive surface build-up, and the brass wins that contest. If you have a choice, spend the extra few $'s for the "Select" or "Gold" versions which use brass.

I've not had problems with Accel products, other than the cost for what appears to be no better quality than others using the same materials.

 

Sorry guys, guess I should mention that there was more wrong then just the green....the green was just so obvious