Say a prayer......

I was headed to the airport today and when I got to the curves that I enjoy so much I got on it a little bit, ran it up to 7 grand in second, shifted to third, everything normal, got back up to about 4 or 5 thousand and the power went away. The engine never quit, nor did it make any catastrophic crunching noises or give any unussual smoke, just a very mushy gas peddle, will not idle but will crank. all the gauges looked good so no temp or pressure problems....... I am hoping for somekind of ignition failure ( would a leading ignition failure fit?) .

Anyway I am stuck at work right now so diagnostics (ignition and compression) will have to wait until tommorrow......

Maybe its time for that new engine...?????

 

Does it still fire up if you give it gas?

 

Yes, symptoms match leading ignition failure.

 

Yes it still cranks up, it just will not idle and makes no power.
Thanks, That was my first thought..... I will cross my fingers!

 

can you take the plugs out? that will give you a good idea. also just make sure all the wires are nice and snug.

 

I checked all the wiring on the side of the road, ( just before I called the wrecker)!!

I have a compression gaugeI will put on it in the morning right after I check to see if I am getting fire to the leading plugs.

 

ive noticed if you have a pretty loud exhaust you can hear the compression if its cranking with the throttle open. kind of makes a BUH BUH BUH BUH noise.

 

Well I can speak from experience after diagnosing my problem this morning that only my rear rotor makes a BUH BUH BUH noise, My front rotor makes a much more timid BUH BUH BUH noise.

That is to say my worse fears are realized, I have no compression on the front rotor, must have lost an apex seal. I don't guess I can complain, that motor has been in the car for fifteen years and has given me about 60,000 miles.

I need recommendations.

If you wanted a top notch 13 B 4 port street port,who would you get it from??

I do plan on rebuilding this motor, but just as a backup, I want to replace it with one built with new pieces, with clearenced and hardened stationary gears, three window mains and with high compression late model rotors. I dont trust myself to build one as nice as I want since Ive never done one before....

 

Sounds like the seal is just stuck down. Take off the ex mani and manually rotate the engine and check all three seals. It may not be a catastrophic failure, but just a stuck seal.

That's some pretty low miles, actually...

You must be planning on some serious racing with all that!

 

I do plan on checking the seals. I had thought I would soak it with MMO i hopes that the seal may just be stuck, I had not thought of visually checking through the exhausts port, good idea.

If I do have to replace it I want as bullet proof of a engine as I can get, and one that I will not have to worry about if it sees 9 grand or so.

60,000 is low ( or would be if it were a new motor but this was a rebuild that had a lot of used stuff) and I lean on my engine alot, I expected something to turn loose before now. It has spent alot of time in the 8 grand range, and..
The motor came from a place that turned out not to be famous for good work ( they went under just after I got this engine) It never felt as smooth as the original motor either.

any way I will soak it down in an attempt to unstick, if that does not work I will pull the mani and look and the apex seals.

Thanks, good idea

 

Pineapple Racing

 

Do not bother with MMO, just pull the header and see feel all the apex's using your fingers in the exhaust port

When my motor let go it was a similar story. Bought it in a barely running car not expecting much and it let go a bit over a year later. I got about 16 months driving out of it, and I flogged it plenty. My home job rebuild is still going since June 2006, and it has been turbocharged DIY style since January last year.

Fix it yourself. By your 2nd build you will be very confident to do your fancy motor with all the trick bits

 

the DIY engine building route is pretty easy. i literally have just been following the FSM for the engine i'm building.

so basically, you measure everything, and then that tells you what needs replacing...

or if you are feeling spendy, just buy everything new. ive done a couple of those engines, and they ALWAYS run really well

 

I figured the MMO might help If I had a stuck side seal. Is the "stuck seal" Keth13B refers to the apex seal or could it be a side seal.

and if it is a stuck apex, whats the best approach?

You guys are making me start to consider just building it myself.

I do not doubt that I can do it, I have a shop and the tools I need (micrometers, calipers and such), I just want to have one helluva bulletproof engine. I also was planning to have the rotating assembly balanced so it would be as smooth as possible.

My thought is that if I had bought the engine I described above instead of the cheaper alternative, then I would be driving right now with no worries, rather than diagnosing problems.

What do you think?

 

Stuck apex seal. Take the header off get a flashlight and push on each apex seal with your finger thru the exhaust port. It should push in and be bouncey. You can clean it off with WD40 and a toothbrush too. Or brake cleaner.

MMO is a good ideaer.

 

good info...

Thanks

 

Well it's going downhill........

I was a little confused from the compression test - I had no compression at all (on the front rotor) and I though it unlikely that two seals had failed, so I was scratching my head.

I removed the header and examined the apex seals and found a major failure on one and apparently it has gouged the housing to the point that there is no compression.

Rebuild time!!!!!!!!

It is an old school 13B 4 port and I'm not exactly sure whats in it.

I will be pulling the engine this weekend, I have ordered rebuild tapes from RA and Mazdatrix and a adapter for the rotary for my engine stand.


Should I use GSL-SE housings? Then I will have to get porting templates for the porting.........so much to figure out , for an engine building newbie anyway.

If my rotor is shot and I have to go to newer rotors, will I have to change my counterbalance?
Im interested in the lightweight higher compression rotors (89?)

I am running a lightened steel flywheel.

Any suggestions on locating housings/rotors?

Thoughts??

I am off to research counterbalance compatability and look for housings!

 

yes u can use gslse housings. depending on the condition of the intermediate housings weather or not u have to replace them, or they can just be resurfaced. u can get those from a 12a if u have to replace them. if the damage extends to the rotors, gslse rotors can be used. whatever rotating assembly u end up with i suggest having it balanced.

 

GSL-SE rotor housings are still available new. You can buy them from Mazdatrix and they can port them for you ala carte. They did a set for me and turned out excellent.

Front and rear counterbalance must match the rotors. So if you use 89-91 9.7 compression rotors you must use counterweights that are for those rotors. Your flywheel will bolt to the S5 rear counterweight fine. This has been done many times before.

Atkins and Mazdatrix have good prices, you may try the junkyard of for sale section here or e bay. Rx8 eccentric shaft is compatible and lowest price new. Has some nice upgrades to the oil ports and clearanced for higher rpms. And .5lb lighter.

 

thanks for the info!! I really do appreciate the help.

Well, Im crunching some numbers and just the main components I will have to buy will not be alot cheaper than just letting mazdatrix build it. Maybe not any cheaper if I get all the goodies that their motor would have in it. Why didnt I stockpile some of this stuff before it became so rare??

I was getting psyched about building it myself, but now I am wondering about the wisdom of that if I can get them to build it for the same $.