risingsunroof82

iTrader: (3)

So I've been talking with a few other guys about this in another thread but I think I might have better luck with another person thats had this prob before but has never seen my other thread.......

Heres the problem..... I have a street port 12a that was once turbo'd but began to knock. So I took the setup off thinking it was the turbo's fault and went back to N/A. I now have a 465 holley and it runs GREAT when first started and ran. It pulls really hard and takes off. But as soon as everything starts to warm up it starts making this "chattering" niose from under the hood. It only does it if I step on the gas or if I hit a hill....... pretty much only under load. It starts to do it if I'm taking off from a stop too, it kicks in at about 3k. I've changed the coils, wires, whole dist and have messed with the carb. And thoughts at all on what could be happening here?????

JoeyMazda

This happened to a friend of mine before. When it was cold, it was ok but when it warmed up it started sputtering and acting up. He troubleshooted for 3 days until I asked him if he did a compression test on it. It turned out that the apex seals were real worn out. I'm not saying this is what's wrong with yours but you should do a compression test and see if that's the problem. Or check the carb.

risingsunroof82

iTrader: (3)

I'll compression test it. I know it's not the carb. It's only got one summer on it and it ran awesome on a running engine not more than 6 months ago and it's doing great right now. Thanks for the response Joey.

raerae

any overheating issues?
missfiring?
firing order correct?

bad 83

iTrader: (3)

More than likely a rotor bearing.............

g14novak

iTrader: (1)

What is your exhaust setup?

risingsunroof82

iTrader: (3)

MY exhuast has changed a couple times since I've had it and it's done it every time. Right now it's got 2.5 all the way with a high flow cad and a flowmaster on the end..... but it was too loud so we added a turbo muffler between the cad and flowmaster to get it more quiet. And it never overheats, and the firing is all set up right from what i can tell.... someones put different markings on the pulley and all kinds of different little things so it's hard to tell if it's timed right. It doesn't change at all if you advance or retard the dist. Nothing changes in the idle.....

Super82

iTrader: (1)

High flow cat? Dude, there is no good reason to have a cat on streetported motor. You're just holding that thing back. Not that the cat is your problem but it certainly must be removed if you plan on making that thing run the way it should.

g14novak

iTrader: (1)

No need to give the OP bad information. Their isn't anything wrong with running a high flow cat unless its like a full built turbo car. I find it hard to believe that changing the timing doesn't affect it knocking at all.

Try and find the original two timing marks on the main pulley and put the timing mark in the middle of the two. Restab the CAS with it zero'd and see if this helps. Turning the distributor if its off by a tooth or 3 can seem like its doing nothing. The difference in timing will actually get smaller as you get further away from having it timed correctly. I had a friend that was driving a turbo car for almost a month with it knocking before he realized he was almost 4 teeth off on his timing.

Kentetsu

I would say to start by confirming the timing. Verify where TDC is (writeup in archive, looking for thin area on flywheel), then compare to the front pulley.

Second, verify the ignition wiring. Unplug the trailing ignitor and make sure you still have spark on the leading (ignitors not reversed). It happens sometimes...


However,,,

This sounds familiar to me. I went out of town for a race, and when I pulled off the freeway I heard a knocking sound whenever the secondaries would open up (mech secondaries). Several rotary owners listed to it at the race, but we were all left scratching our heads. About 1K miles later, she coughed up an apex seal. Apparently, the apex seal had cracked, chipped, or was just too far out of spec (213,000 miles) and would only "pass gas" when the secondaries opened. You could rev the car as high as you liked on primaries alone and it wouldn't make a peep. But as soon as the secondaries opened you could hear it very clearly. If this is your situation, then you're going to want to rebuild before you actually toss a seal and ruin the rotor and housing. Good luck...




.

Jeezus

iTrader: (4)

Or all bearings



Sorry OP, had a friend with a knocking sound from his engine as well, 6port bridge. Ran good and everything. Tore it down, EVERY bearing was bronzed or beyond.

risingsunroof82

iTrader: (3)

Well the high flow cad is necessary to be legal, can't get it inspected without it. Well.... I could but if i get pulled over the cops not gonna like that much.
And i wasn't saying it doesn't change just the knock by turning the dist....... it doesn't hardly change the way it runs all together by turning it.
Kentetsu...... I did the whole flywheel thing and when the flat spot of the flywheel is facing up the marks should be towards the spark plugs correct? Well I put it there cause it wasn't set right and it didn't have the markings show up at all. The marks show up with the timing light only when the flat spot and the pulley marks are facing opposite directions. Whats that mean?
And I've never even cracked a rotary open...... I have a couple spare motors I could salvage a seal from.... lol I know...... probably not the ideal solution. But i don't have the money for a rebuild kit and such. I really wish I had another rotor head locally so they could help me on my first rebuild.

risingsunroof82

iTrader: (3)

And Novak.... Whats the CAS? And whats OP stand for? I'm still getting abreviations.... lol!

Almost forgot..... I tried turning the dist one tooth ahead and one back and both tries I couldn't even get the thing to run........ Maybe it's off a couple teeth, like on the opposite side it's supposed to be. Would it even run if it was 180 off? So how do i find out whats the exact tooth i gotta be on?

diabolical1

iTrader: (3)

for the record, i'm going with the understanding that when you say "knocking", you're describing an actual "clack-clack-clack"-like sound as opposed to detonation events. verify the timing, but if all was truly well before you removed the turbo, then i think it's just an exercise is denial. as was said, i think the bearings are toast - at least! perhaps something went wrong in assembly and/or break-in.

in the one experience i have with this, the rotor bearings were damaged to the point where one of them actually came out of the rotor. the mains were damaged, too, just not as severely as the rotor bearings. the eccentric shaft did not appear to be scored, which i thought was weird, but i opted never to use it again. the thrust bearings were both done. one of the scary things is i never even found the needles. if i remember all the apex seals were fine, but a couple of the corner seals had cracked.


CAS = crank angle sensor
OP = original poster (you)

Kentetsu

Verifying TDC:

The purpose of this is to confirm that the front pulley has not been installed in the incorrect position, which would throw off the timing marks. You set the motor according to the flat spot on the flywheel, then put the pulley back on the car in the correct position. Then you install the distributor in the correct position. Then you start the car and set the timing with a light.

If your pulley is mounted in the wrong position, your timing may be 90/180/270 degrees out of whack.

It sounds like you only performed a portion of the procedure, and your TDC is still not set correctly. I really think this is the place you should start. Also, did you verify that the trailing ignitor is running the trailing system, and not reversed (running leading)?

risingsunroof82

iTrader: (3)

Double post.....

risingsunroof82

iTrader: (3)

Well since last post I went to bed and i just now got up so I didn't have a chance to do anything yet.
So heres what I have discovered......... if the marks only show up with the timing light hwen the flywheel and pulley are facing oposites that mean it's off by 180 degree's right? Cause when I set it correctly it doesn't show at all..... cuase the dist is off by 180. And i didn't have to take the pulley off to change the angle, I just took the bolts out and turned it. That aint gonna do anything bad right??? lol I just find it hard to believe that it would run with it 180 off.

Kentetsu

Yes, they will run when ignition is out 180 degrees. It's kind of amazing what conditions these motors will run under...

trochoid

iTrader: (6)

Do a compression test, that may tell more than anything else. Then we can talk about how the engine was broken in and what kind of rpms it has seen.

diabolical1

iTrader: (3)

well, i know Kentetsu already said it, but i'm here to confirm that they WILL run with the distributor 180º off. and they run fairly well actually - at least, well enough to fool some people.

g14novak

iTrader: (1)

The CAS (Crank Angle Sensor) is the EFI (Electronic Fuel Injection) version of a dizzy (distributor). It has electrical timing advances/retards on top of the standard weights. And OP is original poster (being you since you started the thread).

Yes, the car will start and run with it 180º off. Like I said, I had a friend with a turbo car that was 4 teeth off which is almost 60º! A very reputable mechanic told me that a rotary will start on almost every tooth of the dizzy except for 3. Try resetting your timing and let us know what happens.

80's old school

iTrader: (7)

When checking for TDC, pull the cover off where the carb/exhaust are. When the flat of the flywheel is visable here, the pully marks should line up with the pointer.

Then pull the distributor out, align the dimple on the dist. gear up with the mark on the body of the dist. (you will see it), drop the dist back in and point the arrow of the rotor towards the drivers seat. Then make sure the arrow points to L1 port. This will put you in "starting" range.

If you have a bunch of CRAP by the carb/exhaust and cannot remove the plate, remove the top plate and run the flatspot of the flywheel to the top. When it is to the top, rotate the crank approx 90 degrees toward the exhaust ports, this is also a way to do it.

3rd and final 7

iTrader: (9)

the CAS was starting to be used in 2nd not first gens even in the GSL-SE's which are FI did not have CAS

Kentetsu

You know what? I was just thinking (happens every once in a great while).
Have you tried running the motor with the belts off? You would only want to do it for, I don't know, maybe a minute or so tops (what do you guys think?). Anyway, you'd have to warm it up first, then pull the belts off. Only run it long enough to determine if the sound is still there. This would eliminate the possibility that the bearings are going out on your alternator or water pump.

If the sound persists, then its got to be internal. And sometimes those items mentioned can be very convincing when it comes to impersonating a bad motor.

risingsunroof82

iTrader: (3)

Well the sound isn't constant... only under load. I can actually rev it to redline just sitting there and it won't do it but as soon as you try it while driving it knocks. But now that I think about it..... the water pump is farly new cause it's a blue color and looks newer and i was told it was new. So maybe it was installed wrong or is defective.... I'll check into it.
So I checked the timing and I used my mazda book to help....... it was off 180 degrees i think. lol But it still KNOCKS!!!!! AAAHHHH!!!!! I lined the leading mark on the pulley up with the crank needle and then lined up the dimple and mark on the dist. But I wasn't sure how to put the dist in after lining it up.... you could tech put it in a couple different teeth. So old school, what do you mean line the arrow up with the drivers seat? And if the flat spot of the flywheel is straight up you would want the pulley marks pointing somewhere towards the drivers motor mount wouldn't you? Its the same as the side cover being removed just rotated a bit. And whats the L1 port? I'm getting close! And just an FYI I'm gonna try the compression test over the weekend.