im gonna try to make sure no one ever uses them again

 

i couldnt find a phone number

any help?

 

wwilliam54, following is some questions/info that may be of value during your problem solving with respect to the potential of the plug sticking inside the chamber.

Your plug # 2526 has a .75 inch reach (reference to posted page) which is from the washer to the end of the threads.

How long is your plug from the washer to the very tip of the plug ?

The APPROX distance from the motor plug mounting surface to the inside of the chamber is .924 inches.

If the plug is longer that APPROX .924 inches it could/would protrude into the chamber for the LEADING plug.

The TRAILING plug hole has a APPROX .187 inch diameter hole through to the chamber. With a OEM rotor housing the Autolight # 2526 plug tip would not fit through the .187 inch hole. If the plugs are to long from washer mounting surface to the overall tip of the plug when you look down the trailing plug hole with mirror & light you would see the alum housing material goudged/torn up.

If the plugs are not all that damaged (your words) then why didn't ALL the apex seals get damaged ?

David

 

i initially thought they protruded
but after talking to a mechanic, im getting more convined that they cuased detonation

ill look in the holes tho

btw all the apex seals are damaged, i rechecked
just that the others are much more minor

 

Did the motor actually run with the Autolite spark plugs? And for how long? Did she ping or sound like a coffee can full of rocks rattling (bad pinging)?

Or was it install, crank.... snap x 6 ? Never fired up?

 

its ran about 2 days
i didnt really hear any pinging, but it seemed to miss more

 

Ya. Kick them in the nuts for killing your FB. Stupid people **** me off.

 

I've known for years not to put autolites in any rotary. Sorry you had to find out the hard way.

NGK, all the way.

Lol I also don't care what others who've had good results with them say, either. No autolites for me, ever.

 

what's lame is that if you go to schucks or whatever, there's a reasonably good chance they'll stick autolites in your face if you ask for plugs for a 1st gen.

it's a good thing i'm picky about what goes into my car or i would've bought a set for my '84 last weekend.

 

I contacted autolite and told them that they can have my engine and the plugs to try to find out why they're plugs killed my motor.

I also asked them for a motor, it had 90k on it, so maybe they will help

 

Only substitution I make for the ngk's are denso plugs. I really don't like using denso plugs but if I have to use something else thats what I'm using.

 

I don't see how anything other than the plugs protruding into the housing could have caused that sort of damage.

I've never seen or heard of detonation causing the seals to break like that. Usually they'll crack or shatter. And it will never be every damn apex-seal in the engine. To get an n/a engine to detonate in the first place would be a miracle in itself.

It makes sense that one seal in each housing would have taken the most damage as the initial contact would have knocked a bit off the plugs as well causing them to stick out less.

Try taking some measurements of the plugs. Some pics would be good too.

 

the plugs look just fine, but for just a little tiny tiny rub spot

im not sure whether they are from casting or what, ill find out from autolite

 

i would imagine ANY contact at all on the plugs would weaken the seals enough to cause that sort of damage.

 

Would they hit if the gap is set to high?

 

they are factory gapped, so it shouldnt be an issue other than bad QC

 

That sucks man.


I'd find someone with some degree of importance and give them the evidence and ask them what they're going to do to make things right.....
As for proving the cause.... Do the plugs line up exactly with the chips?
Also, if you're engine's dead anyway, take it apart and manually turn the rotor in just one housing with the plugs in it?


Hope things work out

 

ill talk to whoever i have to at there place to get it fixed,
and you can see in the pics that the chips line up

and im not taking the engine apart, ill let them do that

 

wwilliam54 & others, I provided some dimensional info up the thread a bit. Some times when your going to approach a company & claim their stuff is $hit it's good to have a gun at the fight rather than a knife. Ya know it's good to have solid footing to stand on so that you don't sink in your own $hit. I went to the friken parts house & measured a Autolight # 2526 plug. The thing measure approx (6 inch scale & eyeball) .875 inches from the mounting side of a uncrushed washer to the very tip of the ground. As I stated in the earlier post the distance from the motor mounting surface to the inside of the chamber is .924 inches. That leaves approx .049 inches with an uncrushed washer. It should not hit the apex seal in the LEADING plug hole. If the mounting surface to the inside of the chamber is the same distance for the TRAILING plug that is another story. If the AUTOLIGHT PLUG CHART specs the same plug in the LEADING & TRAILING plug hole that could be an issue because the TRAILING plug hole has a bottom with an approx .187 hole into the chamber.

Three questions:

A. Did you look with light & mirror at the bottom of the hole for the trailing plug ? Was it screwed up from the plug bottoming out ?

B. Did the Autolight plug chart spec the # 2526 for both the leading & trailing plug ?

C. To support you effort would you like me to buy a autolight plug # 2526 & screw it into a non assembled rotor housing that I have & provide you the results ?

David

 

a. im going back home this weekend and will look at the trailing holes
b. it is the only speced plug for 12's
c. i have an extra engine that i can get a housing apart on. but if you want, go ahead, i would appreciate it.

i think it was a lack of QC more than anything

 

wwilliam54, I just finished pulling up the Autolite (Autolight, my spelling sucks) chart & you are correct the # 2526 is the only plug on the chart for the 12A. I will buy a plug Thursday, install it & post the results from my rotor.

David

 

this is why the rx-7 community is awesome!

 

I was gonna ask that, but someone beat me to it... That sounds like the plug is too long...

I always order my plugs by part number...

Me: Good afternoon! I'd like a box of NGK BR8EQ-14's please.

Clerk: What car is this for?

Me: 1985 Mazda RX-7, 1.1 or 1.2 liter, whichever is smaller by your listing... Carbed.

Clerk: We have those for $4.50 a plug, so it'll be about $20 for a box after tax... We also have autolites for $2 a plug if you'd like those.

Me: (Walks away)

Clerk: Sir! Sir! Where are you going! (Comes from behind counter to catch me)

Me: I'll forget you said that if you give me a bottle of Marvel's mystery oil for free...

 

I'm not sure this will prove anything one way or the other. Others have used these plugs without a problem so if they did cause the damage (which I'm sure they did) it was possibly a quality control issue. Maybe they stamped the wrong part number on the plug or whatever.

And to answer your question, all Mazda rotary's use the same plug leading and trailing. The only difference being the heat range for turbo engines.

 

Why does NGK mark their plugs as L and T then?