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-   -   Ticking noise under hood on 12a turbo... (https://www.rx7club.com/1st-generation-specific-1979-1985-18/ticking-noise-under-hood-12a-turbo-823140/)

risingsunroof82 02-28-09 04:01 PM

Ticking noise under hood on 12a turbo...
 
Well I got the car running better with a new intake gasket and water rings but now when I get to about 6K-7k it starts making a ticking noise from under the hood. Now that means it's loud enough for me to hear even when the cars running almost redline. I have no idea what this is but could it have something to do with me not locking the dizzy yet? I know people just say to set leading at 10 degrees leading and trailing at 0 and take the springs out BUT HOW?!?!?! WHERE ARE THE SRINGS AND DO I SET THE TIMING AT THE BASE OF THE DIZZY? I've never really had to mess with a rotarys dizzy so I have no idea! I REALLY need help here. One more thing, I have never driven a turbo'd car so is it normal for it to stutter a little bit when you step on the throttle? Thanks guys!

bad 83 02-28-09 06:33 PM

If you are having rotor knock (detonation), lay off it before you blow it up. To lock the dizzy, you need to remove it from the engine. At the base of the dizzy is a gear. Push the roll pin out and remove the gear. Then you can slide the shaft out through the top. This will allow you to get to the springs. You can just remove them. When you reinstall your dizzy set your leading to 10 advance, and set the traling to 0. Then your golden. Not that hard. If you search for "locked dizzy", there is a nice write up with pics.

If your running a blowthrough, this shutter is coming from going pig rich when you stab the gas. This is something you will have to learn to drive into. Please do not run anything but premium fuel. Low octane will blow it up.

risingsunroof82 02-28-09 06:38 PM

Thanks man, GREAT INFO! So a simple water/alcohol injection system would fix the rotor knock right?

risingsunroof82 02-28-09 06:39 PM

Oh, and it's not a blowthru, it's a drawthru.

bad 83 02-28-09 06:42 PM


Originally Posted by risingsunroof82 (Post 9007028)
Thanks man, GREAT INFO! So a simple water/alcohol injection system would fix the rotor knock right?


It will help, but a proper tune will do you and your engine alot better.

risingsunroof82 02-28-09 06:59 PM

Proper tune?

bad 83 03-01-09 03:14 PM

Making sure air fuel mixture, timing, plug gap, proper coils, octane, etc. It's always more than you realize to get it "just right".

risingsunroof82 03-01-09 04:26 PM

Another question.... I'm supposed to run a methanol and water mixture in my coolmist system but what if I run out of methanol? Can i just run plain water in the summer until i get more methanol or could I even run alcohol?

racerlinkfc 03-01-09 05:39 PM


Originally Posted by risingsunroof82 (Post 9008908)
Another question.... I'm supposed to run a methanol and water mixture in my coolmist system but what if I run out of methanol? Can i just run plain water in the summer until i get more methanol or could I even run alcohol?

run alcohol, its better to run that than mix .. and bad83 is on point! well done bad83, you have learned alot!

risingsunroof82 03-01-09 11:24 PM

So running straight alcohol is ok in my methanol/water injection kit? And just straight 100% alcohol? What about rubbing alcohol?!?! lol :)

Jeezus 03-02-09 12:02 AM

Just get a water/meth mix. Snow preformance sells their mix, or you can just run to walmart for some Windshield Washer fluid, provided the ingredients are correct.

It would be best to tune with just straight water from the bottle. Water is always free, and it will help with detonation.

risingsunroof82 03-02-09 12:49 AM

So you can just run washer fluid too!!! Thats pretty cool! What kind of mixture do you wanna look for?

yetterben 03-02-09 10:48 AM

Winter blend for washer fluid buy it now while you can. Like sam said pay attention to the small stuff. But i have a feeling if you have heard true rotor ping your seals are already damaged.

risingsunroof82 03-02-09 12:49 PM

See I don't know if it was that or if it was something else... But no one has given any other possibilities. The owner before me drove it A little bit here and there with the same setup but no major driving. And the motor was newly rebuilt not long ago at all. So with such little driving after the rebuild I am really hoping thats not the case.

risingsunroof82 03-02-09 12:52 PM

And another question, in a normal (piston) motor detonation knock doesn't really hurt anything, so what would make a rotary any different if you hear detonation knock?!?! That usually means that your surpassing the compression limits of the motor or using too cheap of gas in a higher compression motor. Even if that is in piston motors whats the difference?

yetterben 03-02-09 01:52 PM

um detonation does major damage in piston motors breaks ring lands skirts etc. In a rotary pieces of the apex will chip off.

risingsunroof82 03-03-09 01:35 AM

So if i did a compression test and everything checks out fine i should be ok... for now at least?

bad 83 03-03-09 10:54 AM

The sad part is, by the time you hear knock in a rotary it's usually too late. The damage is already done. With a drawthrough setup, it's not a good idea to run more than 6psi of boost because it gets real hard to get enough fuel in it.

risingsunroof82 03-03-09 12:27 PM

I've never heard that? Every time I've ever heard ANYONE talk about drawthru's they always say 10 pounds.

84stock 03-03-09 12:51 PM

I heard my buddy's s/c 12a knock like marbles in a can and it didn't blow, it depends on the seals. My factory mazda seals fell apart from detonation. Use blue winter washer fluid, I have the snow kit. But heed my and others advice, tune first without it, then you can add a little timing using jsut water and have the methanol as insurance. If you rely on the wather/meth and the pump fails or you run out of fluid, then pop.....

84stock 03-03-09 12:52 PM

Unless it's just a lifter ticking, lol

risingsunroof82 03-03-09 01:18 PM

Well i was thinking of getting rid of the dellorto carb since it's so finiky and making my own holly intake to go onto the end of the turbo. It shouldn't be too hard, just bend 2.5 inch pipe at a 90 degree bend measure, cut to the right length and weld a holly adapter plate onto the end of it with a couple brackets.

yetterben 03-04-09 11:37 AM

:icon_no2:

cmanns 03-04-09 11:55 AM

OP sounds like he needs to experience his motor popping before he'll care lol

Turbos arnt magic OP, from being on this board over the years the #1 thing I've learned with rotarys and turbos is they need to be tuned, should probably have a shop tune it just to be safe.

Also "Every time I've ever heard ANYONE talk about drawthru's they always say 10 pounds" yeah cool maybe they do, with a tuned setup. When your motor goes pop! will you hear them say "we'll rebuild it for ya"

doubt it, awesome that you got a 12a turbo, treat it good, learn, once it does blow figure out what went wrong and learn :D

risingsunroof82 03-04-09 01:29 PM

Well the whole "tune' thing is the reason i wanna put a holly on it. I can tune a holly carb, but not some italian carb....... whys it so hard to understand my reasoning to put a holly on?!?! Besides, I was told by the previous owner and many others THIS exact setup is set for 10 pounds! Now why are you guys lashing out towards ME?!?! I'll admit I've never run a turbo car before and this is my learning experiance.... so I"M LEARNING!!!!


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