New Member RX-7 Technical Post your first technical questions here, in an easy flame free environment, before jumping into the main technical sections.

Rotor Shake?

Thread Tools
 
Search this Thread
 
Old 12-03-10, 11:49 AM
  #1  
Junior Member
Thread Starter
 
Dono's Avatar
 
Join Date: Dec 2010
Location: Tucson, AZ
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
WA Rotor Shake?

Okay. so i bought an 87 Turbo 2 last week, the car idled a little high and ran a little rough. The car has a stage 1 S5 turbo upgrade. I figured that the car simply hadnt been or was not tuned properly. So I went to the shop that did the swap and they said it hadnt been tuned. They also said that i had rotor shake? now i dont know a whole lot about rotary engines so i talked to a friend of mine who does and he has never heard of it. and from how the mechanic described it im not sure its possible? something about my eccentric shaft being bent. anyways. before i start putting any more money into the car i kinda wanted to know if this is something i should take care of or if they're just blowing smoke
Old 12-03-10, 06:32 PM
  #2  
Top Down, Boost Up

iTrader: (7)
 
RotaryRocket88's Avatar
 
Join Date: Mar 2008
Location: San Diego, CA
Posts: 8,718
Likes: 0
Received 6 Likes on 4 Posts
Never heard of it. A bent e-shaft would be catastrophic and instantly obvious. I would say the guy that made up this term doesn't know what he's talking about.

You should however figure out some important things like what a "stage 1 upgrade" is, what engine management system is being used, what the injectors sizes are, and what the fuel pump is. It may be a hybrid turbo (stock turbo with upgraded compressor), so fuel, fuel control and currently boost levels are going to be very important when it comes to not blowing the engine.
Old 12-03-10, 06:54 PM
  #3  
Old Fart Young at Heart

iTrader: (6)
 
trochoid's Avatar
 
Join Date: Apr 2004
Location: St Joe MO
Posts: 15,145
Likes: 0
Received 7 Likes on 7 Posts
Next time you go to that shop, make sure sure your pants are pulled up and you're wearing a belt. Somebody's blowing smoke so pucker up.

Describe the running rough in more detail and/or post a vid of it on U-Tube with a link. I've never heard of anyone being able to tell if an e-shaft is bent without measuring it, which requires a tear down. A bent e-shaft is extremely rare and I can't see it happening with Stage 1 mods. First thing I would do is a simple ghetto compression test. Pull the EGI INJ. fuse from the engine bay fuse box, remove 1 front spark plug, crank engine over. You should hear 3 even whooshes. Replace spark plug, repeat process removing a rear spark plug.

If you her 2 whooshes, gap, 2 whooshes, you have a blown side seal. 1 whoosh or none, blown apex seal.

Post back your findings and welcome to the Club.
.
.
.
Old 12-03-10, 10:54 PM
  #4  
Junior Member
Thread Starter
 
Dono's Avatar
 
Join Date: Dec 2010
Location: Tucson, AZ
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
The stage one upgrade is a s5 turbo and waste gate with a slight port on the intake side. everything else is stock. saw a wahlbro 255 go up earlier, workin on picking that up. the car idles a little rough in that itll idle at abou 900 RPMs but has a slight putter to it, i think i've narrowed that to a vacuum leak though cause i boosted today to see what my gauge was reading and it was only 3.5-4 pounds. There isn't an engine management system, never been tuned, I have tomorrow off, i'll do the compression test and get back to you. I plan on replacing all of my vacuum, coolant, intercooler and radiator hoses with silicone hoses next week, along with replacing intake seals to ensure any exhisting vacuum leaks are gone

Last edited by Dono; 12-03-10 at 11:05 PM.
Old 12-04-10, 10:33 AM
  #5  
No phonebook but OG calls

iTrader: (30)
 
BurntOrangeT2's Avatar
 
Join Date: Aug 2008
Location: Kansas City, MO
Posts: 1,018
Likes: 0
Received 3 Likes on 3 Posts
http://www.supraforums.com/forum/sho...d.php?t=559055

This will help you a ton, and soapy water is your friend btw.
Old 12-06-10, 01:29 PM
  #6  
Junior Member
Thread Starter
 
Dono's Avatar
 
Join Date: Dec 2010
Location: Tucson, AZ
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Okay, so i ended up getting called in so still no compression test, but i did fix that boost leak and its idling a million times smoother. still a little chop to it when its cold but other than that its doing much better. I tried posting a video of the idle but my camera is slightly handicapped and wouldnt save the file to the camera. For now ill just have to do the compression test and replace the rest of my lines for good measure and come back if i have anymore issues. thanks alot guys!
Old 12-22-10, 07:56 PM
  #7  
Junior Member
Thread Starter
 
Dono's Avatar
 
Join Date: Dec 2010
Location: Tucson, AZ
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Okay. after too much time at work and not enough off i've done it. compression test came back as a blown apex seal. i went and figured out what the heck that guy was talking about with his "rotor shake". I have one blown apex seal on one side of rotor 2. now im pretty sure me and my friend can do the seals. i have a copy of the FSM. is it worth it or should i try and find another motor to drop in? Oh. I also looked at my injectors. i have 4 purples, those are the 550cc ones? idk how you tell the difference between the older ones and the newer ones. stock fuel pump

Last edited by Dono; 12-22-10 at 08:15 PM.
Old 12-22-10, 10:20 PM
  #8  
Doesn't suck

iTrader: (5)
 
tasty danish's Avatar
 
Join Date: Dec 2004
Location: Pensacola FL
Posts: 701
Likes: 0
Received 0 Likes on 0 Posts
If you had a blown apex seal I HIGHLY doubt you'd run well enough to make any boost, let alone 3-4psi and an improvement when you found your intake leak... And don't even start about idling.

side seal, maybe.
Old 12-23-10, 11:58 AM
  #9  
Junior Member
Thread Starter
 
Dono's Avatar
 
Join Date: Dec 2010
Location: Tucson, AZ
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
well the thing is i absolutely cannot boost before 4000 RPMs, my turbo wants to but the motor will not. is that just a tuning issue? also, if i really push on the gas (halfway or more) the car will literally hit a wall and will just sputter and backfire. other than that the car is doing well
Old 12-23-10, 12:27 PM
  #10  
Doesn't suck

iTrader: (5)
 
tasty danish's Avatar
 
Join Date: Dec 2004
Location: Pensacola FL
Posts: 701
Likes: 0
Received 0 Likes on 0 Posts
other than that it's doing well?? what kind of cars are you used to driving?
Old 12-23-10, 12:43 PM
  #11  
Junior Member
Thread Starter
 
Dono's Avatar
 
Join Date: Dec 2010
Location: Tucson, AZ
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
haha let me put it this way. ill be 19 in three months. bought a camaro at 17, was in mint condition. i got t-boned a few weeks later. since then i've driven my brother's 1993 explorer. its by the grace of god that the thing doesnt go nuclear and explode when you try to start it. anyways. any insight on that wall i keep hitting?

oh. i failed to mention in my previous post that it only sputters and backfires undr 4000RPMs. over that it gets up and soars

so yea, kinda brings me back to my original question. should i drop in a new motor or take the two or three days to take out the rotors and replace all my seals

Last edited by gracer7-rx7; 12-24-10 at 02:29 PM.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
jase03
3rd Generation Specific (1993-2002)
26
09-29-15 10:36 AM
ZacMan
Build Threads
4
09-19-15 09:20 PM
Ian_D
New Member RX-7 Technical
6
09-06-15 10:38 PM



Quick Reply: Rotor Shake?



All times are GMT -5. The time now is 08:43 PM.