bones

I have an 89 gxl N/A. It runs really bad when accerlating but it will idle alright when i get it running. I did a compression check and the front rotor was good all bounces were even. The rear rotor had nothing. I put my finger by the plug hole and there was very little air being pushed out. Just wondering if all the apex seals could go out at once. or if there is something else the matter. Haven't tried the atf test yet. Just want to get some pointers

Thanks

Project84

If you have one bad apex seal you will get two side of the rotor that don't have good compression, because one apex seal seperates two chambers. If you get one bad reading when you do a compression test, then the side seal is bad. The side seals form the side walls of each pocket and the apex seals form the front and back. The back of one is the front of the next. Its possible you have one bad apex seal an a bad side seal. Or you can have two bad apex seals which is giving you low compression on all 3 pockets.

Black13B

iTrader: (1)

all 3 to go out at once, under the right circumstance.

although on one rotor i really dont think youd be able to get it to idle no matter how hard you tried.. but im not sure..

if it coughs up part of a seal, and the seal (on an n/a) cant quite make it past that pesky exhaust port baffle and it just bangs around, the other good seals will sweep by and definately leave an ugly mess.

i got proof sitting on my desk.

Mr. Gadget

project: I was looking at your pic's, where did you get that killer breaker bar next to your engine stand

ga88rx7

My 88 SE has one good rotor and nothing on the other, it idles fine a 1000, gets 14 mpg, and been driving it for 3 months daily to work and back, very reliable for half a motor. Pisses off everyone that gets behind me does a 0-60 in about 60 seconds and is very loud. Sounds like you got the same problem as me.

Black13B

iTrader: (1)

Really?

thats interesting..

i really would have thought one rotor with another rotor wasting the fuel and spark would have made it.. well.. not idle..

anyone ever thought of (when she drops down to 1 functional rotor) disabling the spark to that housing, and shutting off the fuel injectors?

then it would be like a 1 rotor engine with a big fat rotor-shaped counterbalance for it.

bones

thanks for the input. so i guess i need to rebuild. can i just rebuild the one rotor or do i have to do both

Mr. Gadget

Dude if your running fuel into that chamber, take a look at your cat while your running, I bet its a pretty RED color.

Black13B

iTrader: (1)

cat?

well still.. ga88rx7 just made it seem like he was running a 1 rotor powered 2 rotor engine with no mods to make it run on the single rotor.. i would imagine that you would have to modify the fuel and spark and stuff to actually get it to hold idle and stuff..

MURX

When my engine lost the rear rotor, it wonldnt idle worth crap and I had to keep it above 1700k otherwise it would die on me.

Black13B

iTrader: (1)

how high could you rev it on a single rotor like that?

bones

it goes all the way to red line just not as fast

Zach McAfee

I can second that.

To answer the rebuld Q, you'll probably need a new rear rotor & rotor housing. If you can find those used, I recommend buying a kit from rotory aviation and doing it yourself. Thats assuming you have alternate transportation and some good common sense and wrenching skills.
Don't forget to street port it.

ga88rx7

I had to adjust the idle some so it would be smoother at 1000 rpm, shakes like hell at 700. I disconnected the auxillary injector(I'm guessing) the easiest to get to on the fuel rail for that rotor, Isn't there 4 injectors? Anyway it ran a little more smoother after disconnecting. Cat didnt glow any.

Angel Guard Racing Team

I broke all three on the rear once... Engines usually break from the rear more often than the front.

Project84

That breaker bar owns. I'm a USAF mechanic and I signed it out from my shop.

mazdized

AHhhm . what do you consider SMOOTH at 1000rpm? can you put a quarter on the intake plunum and it will kinda stay ther? if not I don't think it is smooth. A well running motor with out radical port job should be able to idle so smooth you can put a coin on it and it will stay. If it starts to break dance on your motor something is not right.

Zach McAfee

We're talking about a 2 rotor engine running off of 1 rotor here. Of course somethings not right!

ga88rx7

smooth as in it doesnt feel like its going to shake it self to death, the engine is blown, yet still drivable