[Home | Mail Archive | Join the mail archive | Photo Gallery ]

Mazda Rotary Pickup Forum
you are logged in as
profile | register | faq | search (active threads) | memberlist
Sponsored by:
Index > Engine/Drivetrain > Thread: What sparkplugs to use?
Thread: What sparkplugs to use? [' This thread is 2 pages long: (1) 2 ']
bliffle


Revvin Up
Posts: 95
posted March 02, 2004 10:55 AM

What sparkplugs to use?

Might as well change the plugs, etc., on my new REPU. What's right? I have Denso W25EDR14 and NGK BR8EQ14 plugs here already.

B

       
View IP (Administrators only)
Klaus43


Rotorhead
Posts: 1259
posted March 02, 2004 05:10 PM

Personally...

I prefer the NGK's. Whether or not you need the # 7, 8, or 9 heat range... I've had great results with their 'BUR' series plug as well...

       
View IP (Administrators only)
Jeff20B


Moderator
Posts: 661
posted March 02, 2004 10:07 PM

Honestly, it depends on your ignition system.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
View IP (Administrators only)
Elysian


Revvin Up
Posts: 60
posted March 10, 2004 09:19 PM

quote:
Honestly, it depends on your ignition system.



i always tend to use the plugs intended for 3rd gens, they give solid performance in all my rotary vehicles

        Click here to send Elysian an AIM message. 
View IP (Administrators only)
Jeff20B


Moderator
Posts: 661
posted March 11, 2004 12:13 AM
Edited By: Jeff20B on 11 Mar 2004 00:20

I have BR8EQ-14s in all four holes on all my engines so far. Next time I buy plugs, I'll get some BUR7 or 9EQ for leading (DLIDFIS) and will assess the need for new trailing plugs on a per-engine basis. I sorta doubt I'll ever need to buy another cap and rotor as well simply because engine performance is no longer linked to their condition.

Ported engines generally do better with a cooler plug. Some have said the BUR9EQs in leading are better for streetports. I'd say that's probably a little cold for streetports. Maybe bridgeports would be better with 9s. Instead, I might be able to get my hands on some BUR8EQs. They are the stock trailing plugs for JC Cosmos (well, for the 20B at least). Leading is BUR6EQ (very hot!) which is good for the luxury car style of driving they recieve.

I installed some BUR7EQs in a rotary B2000 with GM HEI ignitors set up for DLIDFIS. The trailing also has a GM HEI ignitor run through the leading part of the cap into BR8EQ-14 plugs. The plugs sort of match the ignition system (BUR7EQ in leading for direct fire and BR8EQ-14 in trailing for cap-n-rotor ignition). The drivability of the engine seems much improved.

I got three BUR7EQs for my 20B. I needed a cooler plug because I won't be lazing it around. :) Oh, and it'll also have two leading sparks per rotor face, which is probably a good idea. I just sorta wish somebody else out there had already done this so I could hear it. The engine's sound is very important to me, and I'm afraid the ignition system may change the way it sounds like it did on my two rotor engines (they sound like 2nd gen RX-7s now, which I think sound better, personally). I'm kinda pioneering it for a 20B, I guess. I'll record an audio clip or two when I get it running.

That went a little off topic at the end. :)
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
View IP (Administrators only)
kansei


Redlining
Wankelized
Posts: 423
posted March 16, 2004 05:36 AM
Edited By: kansei on 16 Mar 2004 05:38

Believe it or not....

I'm certain all or some of you have already discovered this, but I have found (very reluctantly at first, I'll admit) but in any of my 7s, an Autolite 2626 will fire a flooded engine right up, every time. I have gone through two or three sets of NGKs (various part nos.) in a poorly tuned engine in the past, maybe just trying to get some poor soul's car running for them so they can get to work the next morning (gotta love those 9-10pm calls..."hey, I heard you might be able to help me...."). I install the 2626's and they never fail me. I honestly have not researched the heat characteristics yet, but I have a feeling the real reason they work so well is just that they are the SSD style, not necessarily their heat range. For what it's worth....


Neal.

____________
Neal A.E. Swigert
Greenville, Michigan
1974 REPU Resto Project
1976 808 Wagon
1977 Cosmo
1978 Savanna RX-7 GT
1980 Leather Sport RX-7
1980 Petty Targa RX-7 #11
1985 GSL-SE RX-7
1988 RX-7 10th Ann
1993 RX-7 VR Touring




        Click here to visit kansei's homepage. Click here to send kansei an AIM message. 
View IP (Administrators only)
Klaus43


Rotorhead
Posts: 1259
posted March 16, 2004 10:13 AM

And Bosch Platinums...

...will even fire in oil...

       
View IP (Administrators only)
Jeff20B


Moderator
Posts: 661
posted March 19, 2004 10:39 AM

NGK BR8EQ-14 don't fire in oil, but I'd never put a Bosch plug in any of my engines. If you have too much oil getting to your plugs, don't blame the spark plug!
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
View IP (Administrators only)
bliffle


Revvin Up
Posts: 95
posted March 19, 2004 01:06 PM

I took NGK "B7EM" plugs out of my 74 (which started hard when hot), which has std points ignition, and put in B8EQ14s , which miss a lot and start hard when hot. So I ordered some of those Autolite 2626s to try out. At $1.29 each they're cheap to try. I've never had a hard time starting with my 3 FBs (12A engines), but I understand the 13Bs are prone to flooding.

Maybe I should convert to electronic ignition.

B

       
View IP (Administrators only)
Klaus43


Rotorhead
Posts: 1259
posted March 20, 2004 09:33 AM

Definitely!

You'll wonder why you didn't convert sooner. Now, I wouldn't *run* Bosch plugs in any rotary, either... except, perhaps, when the only handy option on hand for resurrecting an ancient, not-run-in-years oldschool car... (precisely this was the case, at one point.) They do work for that!
The only 13B's 'prone' to flooding, to the best of my knowledge, are the 2nd-gen's... of course, any rotary can get 'loaded up' from too much fuel/ too many attempts at firing up, with no real run time in between... just like any 2-stroke.

       
View IP (Administrators only)
Jeff20B


Moderator
Posts: 661
posted March 20, 2004 10:04 AM

A carbed 13B is like a 12A.

Of course it'll be hard to start a points engine with the wide gap of electronic ignition plugs. The gap of B7EM plugs is pathetically small.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
View IP (Administrators only)
bliffle


Revvin Up
Posts: 95
posted March 20, 2004 10:38 AM

OK, I've got std points ignition (all new parts coming from mazdatrix, but meantime I'm experimenting). Usually, points only handle an .025 gap, and I think std for Rotary electronic is .050, which I believe is what the BR8EQ14s are. That would explain why the BR8EQ14s are NG on my REPU.

I'll convert to electronic as soon as possible. M'trix sells a used elect dist for $250 (!?) but maybe I can get one from the boneyard (tho the've always been gone, before) and the coils are req'd, too, per M'trix. I suppose I need the J109 ignitors too, but I've got a box of those for my 7s.

In the meantime, I'll try those Autolite 2626s, but now I worry that they're gapped .050 and won't fire well. I haven't found B7EMs locally, yet. Heck, I can't even find my plug gauge and points gauge (must've thrown them out a few years ago when I discovered even my 20 yr old cars had electronic!), and I'm not even sure the parts store still carries them. Oh well, I can get gauge stock at "Toolland" right here in Redwood City.

Maybe what I gotta do is get some single electrode plugs and gap them to .025, whatever plug that is. As long as the tip doesn't extend into the combustion chamber and clip the passing apex seal!

Those 2626s are supposed to be in the store this afternoon, I'll check 'em out before installing (heck, I REMEMEBER what an .025 gap looks like from years ago! Who needed a gauge then?)

B

       
View IP (Administrators only)
bliffle


Revvin Up
Posts: 95
posted March 20, 2004 10:42 AM

quote:
I'm certain all or some of you have already discovered this, but I have found (very reluctantly at first, I'll admit) but in any of my 7s, an Autolite 2626 will fire a flooded engine right up, every time. I have gone through two or three sets of NGKs (various part nos.) in a poorly tuned engine in the past, maybe just trying to get some poor soul's car running for them so they can get to work the next morning (gotta love those 9-10pm calls..."hey, I heard you might be able to help me...."). I install the 2626's and they never fail me. I honestly have not researched the heat characteristics yet, but I have a feeling the real reason they work so well is just that they are the SSD style, not necessarily their heat range. For what it's worth....


Neal.



Are any of those 7s running the old points ignition? And what is the ""SSD style"?

B

       
View IP (Administrators only)
kansei


Redlining
Wankelized
Posts: 423
posted March 20, 2004 04:55 PM
Edited By: kansei on 20 Mar 2004 16:56

Yeah, my '79 is still points ignition, too lazy to swap it over, and besides, I haven't decided what to do with her. SSD stands for Semi-Surface Discharge. It's basically a permanently gapped solid plate around the electrode, basically what the FD RXs called for when first released. I can't remember what the gap is, sorry. The neat thing about SSD plugs is that they tend to be a default plug in essence as far as heat ranges go- they (in my opinion) don't seem to be as finicky as twin, triple or quad pronged plugs.
____________
Neal A.E. Swigert
Greenville, Michigan
1974 REPU Resto Project
1976 808 Wagon
1977 Cosmo
1978 Savanna RX-7 GT
1980 Leather Sport RX-7
1980 Petty Targa RX-7 #11
1985 GSL-SE RX-7
1988 RX-7 10th Ann
1993 RX-7 VR Touring




        Click here to visit kansei's homepage. Click here to send kansei an AIM message. 
View IP (Administrators only)
bliffle


Revvin Up
Posts: 95
posted March 20, 2004 06:35 PM

Thanks for the info. I picked up the 2626s, and I see they are basically without a ground electrode: the center electrode discharges to the surrounding surface at points of opportunity. Nice, but totally un-gappable. And the hard gap is at least .050, maybe more. So I doubt it'll work with the points ignition.

But the good news is I picked up a distributor (with J109s) and coils from an 84 RX-7 at the Pick 'n Pull today for (you're gonna hate me for this!) $20! I assume that the 12A stuff can be used in conversion to electonic ignition: they wouldn't have done something dumb like change the distributor drive on the 13B, would they?

I really killed at the PnP: found a pretty good 84 GSL with an almost perfect leather drivers seat ($20) to put in my 85GSL while I get it's driver seat repaired and lowered, very good door moldings (I think that car was always garaged) for $1.50, a perfect glass sunroof (now I have 4 for 3 cars) for $8, and a good FB wheel for $10, etc., etc. Hauled it all home in the REPU. I'm in rotary heaven.

The REPU was missing a lot all day, even after I put the original B7EMs back in, so I think I goofed when I re-timed the ignition: maybe the mark is in the wrong place, or maybe the REAL mark is buried under grease. I'll put it back later tonight and see how it runs.

Some young rotary fans in the PnP parking lot loved the REPU, asked me if I wanted to sell it, but cooled off when I said $3500. But by summer I'll have the body crease out and polish it up and have the exhaust quieted and have the electronic ignition working so it'll be a primo REPU.

B

       
View IP (Administrators only)
Klaus43


Rotorhead
Posts: 1259
posted March 21, 2004 10:59 AM
Edited By: klaus42 on 21 Mar 2004 11:01

Right On!

Sounds like a day well spent. Just so lond as the '84's E-ignition isn't the one (I forget which year) they tried the 'remote mount' igniters; that one was prone to cross-triggering and is to be avoided...
I know they routinely sell for far more, and a really nice dizzy would be worth it, but I've generally paid $40 to $50 for a used 1st-gen el. ignition dizzy... mostly, even with ignitors! Always helps not to be in a hurry/needy for a part...
You'll probably find that the 4-sidewire plugs'll be your best all-around points ignition bet... and the 'no- sidewire' designs best when you've converted over.

       
View IP (Administrators only)
Jeff20B


Moderator
Posts: 661
posted March 21, 2004 10:00 PM

Klaus, '80 only. No need for worries. :)
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
View IP (Administrators only)
bliffle


Revvin Up
Posts: 95
posted March 22, 2004 08:10 AM

Kansei,

Are you telling me that the 2626s work good in your 79 with points?

I'm still puzzled that there's only one timing mark on my pulley. And, apparently it ought be off the timing pin. I'll look for a second mark with my fingernail.

When I pulled the BR8EQ14s the leading plugs had a nice tan, but both trailing plugs had significant black.

B

       
View IP (Administrators only)
bliffle


Revvin Up
Posts: 95
posted March 22, 2004 09:00 AM

I just reviewed the dist timing instructions for the RX7, and there are separate timing marks for leading and trailing. I'm concluding that there is an obscured mark on my pulley, and that somehow the leading and trailing timing have been made coincident (by the previous owner) by mis-adjusting the vacuum mount for trailing. I'll go out and check around and see if that cures it. Assuming that points system times up like electronic, which it probably ought to do.

Now all I need are those re-wiring instructions from Mazdatrix and I'll convert to electronic.

B

       
View IP (Administrators only)
Jeff20B


Moderator
Posts: 661
posted March 22, 2004 09:52 AM
Edited By: Jeff20B on 22 Mar 2004 09:56

There's really nothing to them. Each ignitor has a grand total of five conductors on it.

1)ground is easy (grounded through screws that hold it to the distributor housing)
2) and 3) back of the ignitor S and G pins that go to the pickups (no need to worry about them unless going with DLIDFIS)
4) top of ignitor with a T shaped plug. C goes to coil negative (-) only (C is for coil)
5) B goes to coil positive (+) and also key ON switch (B is for battery)

So, in reality, you only have TWO wires at the top of each ignitor. No wait, the B of each ignitor can be hooked together. Yes! You only need THREE wires coming from the dizzy. Don't forget to hook up the condensor to the B wire (it's down between the the two vacuum canister things with a bullet connector).

If you wanted to go to DLIDFIS, you could make your wiring harness a little differently. Just have FOUR wires coming from your distributor (B and C from each ignitor remain seperate so it's easier to hook up two ignitors to the leading pickup signal). Click my WWW button for more info about DLIDFIS, as I'm sure I just confused you with talk of two, three, and now four wires etc.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
View IP (Administrators only)
All times are PST (US) [' This thread is 2 pages long: (1) 2 ']
Post New Topic    Post New Reply
Rate Topic:
Powerd By: BlazeBoard

[Home | Mail Archive | Join the mail archive | Photo Gallery ]
0.027742862701416 seconds processing time