i dont blame steve he is great and the motors all last a few thousand miles so they arent bad from the start there is something going wrong. i do have good fuel pressure and alwys let the car warm up and cool down.

 

Hm. Have you checked your engine wiring harness to make sure it hasnt been compromised? also, are you running a power fc with resistors wired into your secondary injector wiring harness? this could cause problems if the resistors arent to spec.

 

only 3 engines? I wish I were in your shoes.... I'm on number 11 now.

Damn hurley seals....

 

Well if youre going to get another motor, I would change the fuel filter, get your injectors cleaned up and make sure your pump is good. Buy a walbro from the group buy 80bux and wire it straight to your battery. Get yourself a wideband and an electric fuel pressure guage for inside the cabin so you can monitor your pressure under boost.

 

Just wondering, have you checked your wastegate, I see that you are running a single turbo...maybe your wastegate is malfunctioning every now and then or the vaccum line might have a slit or something...just a thought

 

You're kidding right?

 

There's your problem right there. The old original engines have the crappy 3 piece apex seals. These seals get very brittle over time and break easier compared to the more structurally sound older 2 piece design. Some seals break from just being stuck from carbon with no detonation. Ask me how I know. My S5 NA engine has been rebuilt twice within 140k miles all because of carbon related issues. J-Spec engines (especially the auto Cosmo engines) tend to have heavy carbon deposits because those engines operate with the automatic transmission. People just don't run those engines hard enough with the automatic. Just because you think the engine is clean and pulling good vacuum, doesn't mean that it's in good enough condition to be run and modified. The carbon still needs to be cleaned out. When you install an un-opened engine like this in your car, the carbon deposits will eventually break away from the rotor faces and sometimes can cause apex seal breakage because of the carbon chunks being thrown around the rotor chamber. A good tune from Steven isn't going to prevent this. Your best bet with the J-spec engine is to go ahead and open it up to clean and spec everything. While your in there, go ahead and replace the apex seals with the new 2 piece ones. Then get the injectors cleaned and flow tested to make sure that they are flowing as they should. Clogged injectors can and will cause a boosted rotary to blow. Again a perfect tune can't prevent that from happening.

 

I'd lean towards injectors.

Were they the same/similar in all 3 motors?

Dave

 

I have popped 6 motors with hurley seals. If you fart too hard while WOT, they will break. seriously.

 

I've got bad gas too, literally.......... if you want to run hurley seals you'll need a good colin cleansing every week or so.

 

I think its time for some pistons

 

I went through 7 motors when I had my rx-7. The first was coolant seal failure. The 2nd was an improperly set intake temperature correction setting and heat soak, then running the 1/4 mile. The next five I could not find the source of. I think you have some sort of intermittant electrical problem in your car. Aside from the things everyone else said I would look at these: It could be in the engine harness or body harness. I would replace both. I would also replace all your fuel injectors or at least send them out to be serviced. I'd also switch the fuel pump and wire it to constant 12v via some relays. Maybe even swap ecus. I'm pretty sure thats what my car had. It would run great for a few thousand miles. Then all of the sudden detonate and blow. I got tired of looking for the problem so I sold the car. Good luck. This might be a tough one to find. If I had to do it again I'd do an LS1 swap.

 

yep, 3 mm in my new motor

 

where is a good link on how to do this??

 

3 motors in one year suggests something other then the obvious is wrong. I had blown 2 motors in one year and they were both fresh rebuilds. After switching from my old power fc to a full microtech setup, i found that one of my injector clips were shot. The wire was barely connected and the clip was broken. This could be the case for you. So assuming that you are running a power fc, i would suggest either buying a new wiring harness for the car (since the old one is probably shot, anyways) or going to a new ecu that comes with its own wiring harness (which actually can be cheaper after selling your power fc)

 

Unless Colin objects, obviously...

 

Man you guys make me nervous.. I have hurley 2 piece 2mm seals in my current engine. Got 6000 miles on it.

 

Its DSM specific instructions but the basics are the same... www.vfaq.com go to fuel then fuel pump rewire.

 

Great contribution to the thread. Maybe one of these weekends he can just 'swap out the motor.'

 

There is a good link over on Nopistons. I have it saved in my favorites on another computer.

 

Ack, and at that power level??

You are on borrowed time my friend, I am afraid to say. I would invest in some water injection to stave off any hint of detonation and to give your motor a fighting chance. Seriously.

 

well i think i will sell the car if i cant find the solution before i put a new motor in. i guess the first thing to do is pull it and see if its the rear rotor again. i will also send the primaries off to see if they are flowing properly if they are then i think i'm screwed.

 

I dont see how you are 'screwed.' stop getting jspec motors, have a motor properly built or just get a mazda reman, and run water injection as added protection. I have spoken to a well-known member who got a bad tank of gas and the water inj saved him from detonating. additionally, a friend is an instructor and has road raced his FD for 12 years now.....first 9 years, one motor popped per year, with aquamist, 3 years on the same motor. works for me .

Rich

 

Secondaries clog worse than the primaries since they aren't on all the time. Save yourself more headaches and send in both sets. I had mine in my S5 vert recently cleaned and the numbers were no where near even across the board. After was a different story. Also after you get them cleaned and flow tested, place the highest flowing primary and secondary injectors in the rear rotor since that rotor naturally runs the leanest.

 

the secondaries are new. i bought tehm wheni got the last motor but the primaries have been there the whole time.