Do your research on tiger before you order from them.

 

Its super mixed as is every JDM importer. Sunrise is one of the more recommended

 

agreed. i have heard more negative than positive about tiger. Shop around do your home work.

 

i thought a bad apex seal went 1-pff-pff-1-pff-pff

 

Ray, did you get a rough compression number for your rotor faces? If you get hi-hi-hi and hi-hi-lo, then it's likely a side seal. Blown apex seals are similar to a head gasket, in that two faces will exchange gasses under compression, so you'll get low compression on two faces rather than 1. Just a thought.

 

turbo or not, definately go 20b.

 

Yes. Side seals will still show 2 puffs instead of 3, where as an apex will show 1 puff.

 

OK then, it sounds like it is a side seal, not an apex seal. It is definitely a hi-hi-low cadence. I was wondering about that too. But does it matter? Is there a better chance I haven't totally destroyed the chamber?

The used turbo is a thought Joe, I'd have to think about the gas mileage though. After all, the main purpose of my 7's is commuting, not racing (which also rules out Stu's street/bridge/peripheral and Michael's 20B). Also I'd kind of like to take this chance to build an engine (with some help!).

 

we need to know two things:

what will the car be used for after its done?

whats your budget?

 

Use Mazda seals, solid corner seals (the rubber plug in the OEM one deteriorates, and might as well not be there after a few thousand miles), Clean and inspect rotor housings by wiping the sealing surface with an MEK (or gasoline) soaked rag to remove deposits, and Clean rotors in a bucket of 50:50 water/Zep industrial purple cleaner for a few hours and brush off carbon deposits. While you're in there, put in a turbo oil pump, port the oil pump passage, and shim the pressure regulators.

Oh, and PAINT EVERYTHING! I used a secret ghetto powder coat on my engine...

 

It may be a good rebuild candidate since it did not toast an apex seal (which usually kills a housing). Take it out, take it apart, get the rebuild video and you're in school.

 

Ray, we should have a Bridgeport install party for me and that may open up a stock 12A that needs a good home.

Although everyone who heard it this past weekend would swear it was a Bridgeport

-billy

 

OK I'm convinced, this is what my 12A will look like in a few months:



In the mean time I'll be driving the Silver One.

Donny that's a good question, I'm still not sure exactly how it would be used but doing the 110 mile a day commute at least once in awhile would be nice. I'm going to use this opportunity to learn about rebuild options and how to do it, the project will probably evolve as I go, especially when we crack it open. What it gets used for will probably depend on what we do to it.

I was imagining that broken apex seal wrecking havoc inside the chamber but maybe it won't be so bad if it's just the side seal (whatever that is).

I'll try to post a short movie of the compression test this evening for the record.

Thanks for the help guys!

 

Ray, I've got 1.5 engines taken apart in my shop, and the half is on my engine stand. You're welcome to come by after work and I'll walk you through what's what. I can even show you what I've collected so far for my first engine assembly.

 

Ray, with your longevity concerns, I'll suggest a mild street port. You can retain all your nice emmisions, and have a little more kick. As you well know, the more power you make, the more abuse you'll give it . Just check our last meet video.

 

Just when I thought I had it figured out, it starts to get interesting. I went out tonight to take a vid of the front rotor compression to show you guys, the one that was missing every third compression spike yesterday. So here it is tonight:

http://s259.photobucket.com/albums/h...t=DSCF1052.flv

Looks just like the rear one, nice steady even spikes.

I tend to be an optimist, but this stretches the imagination - has my 12A repaired itself?

It's been sitting for several days with the chambers soaking in Sea Foam. Do you suppose that side seal resealed?

I can't wait to clear the Sea Foam and see if it runs, but if it really is healing itself I figure I'd better do what I can to help with the recovery. So I squirted in another half can of Sea Foam according to Kent's directions, put the plugs in and gave it a few spins. I'll soak and spin and start it up tomorrow.

Anybody placing bets? What will we see tomorrow?

This:

http://youtube.com/watch?v=N7lGhIMeS0A

Or this:

http://s259.photobucket.com/albums/h...=engmov004.flv


Crit, I do need to take a closer look at one of your engines from the inside, I'm getting kind of curious about what's going on in there.

But now I've got the bug and I want to build a mild street port, like Sam says, maybe with or without the rat's?

We'll see what happens with the White One, I think she is trying to tell me something.

Billy, what's this about a bridgeport install party?

Here's Kent's suggestions, form another thread:

"Ray,

Yes, hi-hi-low = side seal. However, this may mean that you are in luck. Typically the side seals receive little wear (much less than the apex seals). They dont typically break either except in the case where people have done a bad port job and the edge of the side seal catches on the closing part of the port. It may be that your side seal is just gummed up with carbon and is not sealing properly. It might be worth another soak in seafoam and maybe running the engine with some seaform or mmo in the tank. Put seafoam down the carb, rotate the engine, add more.. squirt some in the spark plug holes with a turkey baster. Let soak for a few days. See if that will help.

Even though this might fix it, it might be a good time to pull the engine anyway. Once an apex seal gives, it takes out a bunch of parts with it. Better to rebuild before this happens. She has had a good life..time for a new heart perhaps. "

 

?????????????????

The compression seems to be fine, a steady three beat peaking around 90 lbs. on Crit's meter. So did the Sea Foam soak recondition the side seal to restore compression in that front rotor? Who knows.

It's getting spark to all four plugs. The carb visually pumps gas into the primaries when you press the accelerator and the engine will race right up to 7000 rpms. So it doesn't seem to be ignition or fuel.

I've checked and rechecked and rechecked for vacuum leaks - none, although as several have noted in this post it does sound like a bad vacuum leak:

http://s259.photobucket.com/albums/h...=engmov004.flv

Won't idle, no power, sounds like one of the rotors is on vacation. Back to square one.

Maybe I'll rebuild it just because I can't figure out what is wrong with it. But in the mean time if anyone has any ideas I'd sure be glad to give them a try.

I think I'll go work on the Silver One for awhile.

Thanks
Ray

 

i think youre trying to fore it to limp until it crashes. just go ahead and plan on pulling and rebuilding it. you can make it better and stronger.

 

Ray, is this your very clean looking engine with complete rat's nest and everything? The oproblem could be originating in one of the single-rotor specific emissions lines lioke the automatic trans modulator nipple, or the 2nd slow air uh... um I don't know what it's called but it's the biggish tube on/under the rear secondary runner that most people don't diagnose very easily because it is hard to see. Or is the shutter valve always closed or very nearly always closed?

It sounds like you've done all the usual things and they didn't work. Maybe it's time to remove the rat's nest and give yourself a more reliable, easier to work on and diagnose setup.

 

That's the one Jeff and it was running great until this problem showed up last week. It does have the rats nest and you may be right, there could be a problem in there somewhere. I'll take another look at the shutter valve. I've sprayed for vacuum leaks and all the tubes are in good shape, so I don't think there is a vacuum leak but there could be a problem with a solenoid or something. Tomorrow I should have more patience. Removing the rats nest is a possibility if I can be sure it's the cause of this mess.

Your point is well taken Donny, a rebuild is advised after 150,000 miles anyway. But still I'd like to know what's wrong first - imagine rebuilding the engine, putting everything back together and still having the same problem?

 

I just remembered something that my motor did a long time ago. I had a jet unscrew and fall out in the float bowl. It was a jet for the secondaries, so it only acted up when they opened up. I ended up pulling the top off of my carb and discovering the jet sitting in the bottom of the front float bowl.

 

Yeah I'm thinking those jets too, clogged, not loose. Something Ken mentioned back on page 1 and Crit reminded me about this evening.

RX-7 colleague Mike is coming over tomorrow, we'll pop those puppies out and take a look. Mike has 250,000 miles on his 12A and he doesn't even use MMO.

 

DAMN>>>>I hate "1-2-phufff...."

...almost as bad as my recently installed tranny going clunky-clank under load!

 

Ray, while I do believe that MMO is a great cleaner and additive, I think it makes a pretty lousy lubricant for the apex seals. I don't know if you were running 4 stroke or 2 stroke oil in addition to the MMO, but I sure hope that you were. I did some research a couple years ago on the lubricating ability of MMO, and I was disappointed to say the least. I don't think that using MMO is going to be a determining factor in the life expectancy of anyone's engine. Does it clean up the insides? Sure, I bet it does. But is it decreasing the amount of wear on engine components? Probably not.

Here is a link to the thread in the archives.

https://www.rx7club.com/showthread.php?p=3627781

Not trying to bash anything you've stated here. Just wanted to throw out some extra info for you to chew on if you're interested.

Keep up posted on what happens with the white car. Because of its condition, it's a great candidate for ANYTHING that you want to do to it.

Jamie

 

Thanks for the info Jamie, that's good to know - Don't count on MMO alone! To be honest, I think putting the 8 oz of MMO in every fill up probably doesn't do anything at all. But it feels good and now that this has happened I'll probably get superstitious about it and start doing it again.

In any event I still have my oil metering pump functioning so that should take care of the lubrication. But I think this would be a good time to either rebuild the OMP or at least check it for output - we have a lot riding on that thing working right. Anybody know how to check the OMP output?

Because the compression is now looking pretty good, I'm back to thinking it's a fuel delivery problem, probably to the front rotor. That may be why it was showing poor compression a few days ago (1-2-phuff), I'm thinking without fuel getting into the rotor it also wasn't getting lubricated, causing the side seals to stop working right. Then, when I soaked it in Sea Foam for a few days, they recovered.

It just gets weirder and weirder. When Mike gets here today I think we will take the carb out of my silver one and put it in the white one, maybe that will do the trick and identify the problem. For sure, the White One will ride again, one way or another.