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the one Ryan is alluding to, is that the seals seal to the housing, but also they seal to the side of the apex seal groove. just like a piston ring seals to the cylinder wall AND the top (or bottom) of the piston ring groove
j9fd, I did have a look through my pictures of the EandJ and RA seals. The wear mark is pretty consistent across the seal except for where the Atkins corners sat. Very loose there. The wear mark does look like it is wider compared to the picture of the POWER seal...That would indicate a tighter slot to seal tolerance? Maybe too tight? As the seal heats up it makes the tolerance too small but I'm not sure what the effect would be.
After doing a quick internet search cast iron does not grow as much as steel...interesting
Last edited by Michael Mansour; 07-03-23 at 09:47 AM.
The combustion gasses push the seal against the side of the groove, if the clearance is too tight then the gasses can't get in there (or the seal binds). if you go a little looser, it seals better, but too loose and its worn out.
Mazda has a clearance in the FSM for the NA and the T2, and then in Japan they offered a Mazdaspeed 10% higher power engine with yet again different clearances, so its a thing.
the Turbo seal to groove clearance is 0.051-0.101mm and the Mazdaspeed engine is 0.65.075. tolerance gets tighter
Cylinder Honing happens for every rebuild... What backyard junk engine building are you doing?! Of course the housings are wear items!
It's not about happening frequently, it's about for when it DOES happen that the person driving isn't endangered more than they have to be.
By all means, you advise people how you wish to. I'm telling you what makes sense for engineering factors of safety on engine design. We aren't dealing with opinions; these are metallurgic facts.
I'm not building junk backyard engines, I've heard that is your niche market, and you can keep it.
Yes, they wear over time, but you talk about it like you have to build it with bendy seals because you won't be able to drive home from a track event or land your airplane if you don't. Engines should not be losing compression so quickly, and you shouldn't have to use seals that tear up housings and therefore treat housings like you throw them out after every few thousand miles. They should last for 100k miles.
The frequency absolutely matters. But go on, keep stating your facts, hopefully that doesn't include bending seals in a couple thousand miles and/or replacing housings as common wear items to replace.
The factory seals have been researched by Mazda for many decades. They are built for reliability and longevity at lower power than we all want. The choice of apex seal will still be hotly debated for years to come.
There must be a mechanical or a tuning related issue that is causing the seals to fail .
Mechanical possibilities are that the apex seal slot is not properly clearanced (rx72c) which can cause the seal to pinch in the groove, or not move as freely. This lack of movement may put more pressure on the housing surface and more friction heat into the seal itself (My reasoning). This though would show as a score in the housing I would think. Other mechanical possibilities would be a weak ignition but I have 4 brand new IGN1A coils and very good wiring to them. Still scratching my head on the mechanical possibilites...
Tuning issue possibilities are endless technically. The first one that comes to mind though is that my trigger is somehow offset incorrectly. I did use the FFE wheel which only bolts on one way, but it does not line up with the factory marks on my pulley. The only idea i have at the moment would be to set the timing based on the pulley marks and not the actual trigger wheel tdc mark. That though is scary and could lead to more damage. Mabye ill check TDC with the flywheel flat side just to make sure, but it is hard to be confident.
Your tuner should know how to set timing properly on any current market trigger wheel.
FFE is very simple.
The FFE Logo matches to the Sensor itself with ignition locked at -5° on Leading 1 Coil on the most recent iteration.
Previous iterations will have -20, -15, -10, -5, 0, 5, 10 and the needle on the front cover will align to 0° when Leading 1 is locked at 0° and the proper offset is selected.
These trigger wheels are 87-93° on FD or 57-63° on FC, so you'll never really have a larger offset than +/-3°.
This is the older design. The newer one has a small arrow that points directly to the sensor.
Again... Tuning issues can be endless, exactly how you've just said. It's not for everyone...
Thank you Jeff for helping clarify for Michael, that's an excellent way of saying that.
Your tuner should know how to set timing properly on any current market trigger wheel.
FFE is very simple.
The FFE Logo matches to the Sensor itself with ignition locked at -5° on Leading 1 Coil on the most recent iteration.
Previous iterations will have -20, -15, -10, -5, 0, 5, 10 andthe needle on the front cover will align to 0° when Leading 1 is locked at 0° and the proper offset is selected.
These trigger wheels are 87-93° on FD or 57-63° on FC, so you'll never really have a larger offset than +/-3°.
I have confirmed with FFE that the needle on the front cover is no longer used.
"..when the (new) supplied pointer is at the 0 (zero) on the wheel, the engine is at TDC." - Jason Kennedy @ FFE.
Are you suggesting there are two versions with different indicators?
For those questioning the trigger wheel please re-read post #56 in this same thread. It has the detail from FFE in an email screenshot. I'm not worried about the timing. I already checked it lol. My offset is set to 61°.
I am using an FC wheel not an FD one that was pictured above.
Last edited by Michael Mansour; 07-04-23 at 11:49 AM.
Here's the Arrow. Here's the arrow aligning to the sensor.
This is what my wheel looks like. I have made a TDC mark using the arrow as reference when the engine was apart. It is in-between the factory marks on my wheel which is why i believe it was marked incorrectly.
This is what my wheel looks like. I have made a TDC mark using the arrow as reference when the engine was apart. It is in-between the factory marks on my wheel which is why i believe it was marked incorrectly.
For the FC Trigger Wheel, your sensor, either Hall Effect or V Reference/Mag will align centerlined with the arrow on the trigger wheel.
The ONLY reason for bringing this up is because on your original dyno run video the timing is significantly off and I'm trying to make a forum a lasting, valuable platform for others.
If your car glows a manifold like that with that exhaust note, it's either not firing on leading plugs or timing is WAY retarded/unsynced.
For the FC Trigger Wheel, your sensor, either Hall Effect or V Reference/Mag will align centerlined with the arrow on the trigger wheel.
The ONLY reason for bringing this up is because on your original dyno run video the timing is significantly off and I'm trying to make a forum a lasting, valuable platform for others.
If your car glows a manifold like that with that exhaust note, it's either not firing on leading plugs or timing is WAY retarded/unsynced.
Gucci,
Thank you for the information and concern. In the original video I was running 9 heat range plugs and 22° of advance at 14 psi. The tune I believe was too aggressive and in combination with the poorly designed manifold the heat built in the manifold quickly.
Thank you for the information and concern. In the original video I was running 9 heat range plugs and 22° of advance at 14 psi. The tune I believe was too aggressive and in combination with the poorly designed manifold the heat built in the manifold quickly.
I truly believe it was the opposite of that and your exhaust temps and engine note say otherwise.
There's nothing wrong with BUR9EQS up to about 450whp or any other Heat Range 9 Plug. BR9EGs would be totally fine at a similar power level.
22* Advance at 14psi is a bit aggressive, but I'd think an average calibrator would walk it up to that and do so with a reason (it made more power consistently up to that point?). This would have likely been because the base timing was retarded and 22* on something that's way off is irrelevant.
Looking forward to hearing how the car sounds now.
For those questioning the trigger wheel please re-read post #56 in this same thread. It has the detail from FFE in an email screenshot. I'm not worried about the timing. I already checked it lol. My offset is set to 61°.
I am using an FC wheel not an FD one that was pictured above.
Sorry to have cluttered, I just wanted to point out that the original pin is ignored for anyone using the FD wheel (USE THE NEW POINTER ONLY).
The FC trigger kit does not add a new pointer so no worries there.
Are some of you guys not using a timing light to check timing for all four coils? This is one of those places where I think the phrase "If you're not testing, you're guessing" is appropriate.
Whether you built the harness or someone else did, getting a couple of coil signals switched can cause a lot of harm especially on a rotary.
Switching the CAS wires on a two-wire VR sensor can also cause the ignition timing to be wrong, especially at high RPM.
If you're unlucky, your ECU config might have some ignition trims active that you aren't aware of.
Spark plug wires or ignition coil connectors could be swapped.
Even if your timing mark isn't perfect, you can still check that the trailing coils are firing after the leading coils and that the front and rear rotor leading coils are firing at the proper angle (on a setup without the OEM wasted spark).
Use a paint pen to add a second mark on the pulley so you can check the rear rotor's coils are correct. Most times I've seen harness problems the Coil1 output is OK and the problem is usually one of the others, so it's very important to check them all.
"Use a paint pen to add a second mark on the pulley so you can check the rear rotor's coils are correct"
i was going to post that earlier today. mark your timing wheel 180 degrees out and check the timing on the rear rotor...as well as the trail plugs. don't forget to rev the motor a bit to check for drift.
Howard and Scotty thank you for the recommendation. I do have an extremely basic timing light that I have always used. It just has a power button that you press and hold and it flashes. I will do the paint pen and check the rear coils. What is the best way to measure the 180 mark?
Howard and Scotty thank you for the recommendation. I do have an extremely basic timing light that I have always used. It just has a power button that you press and hold and it flashes. I will do the paint pen and check the rear coils. What is the best way to measure the 180 mark?
Ruler across the pulley face is close enough for a sanity check. 1mm is close enough to 1 degree on the factory crank pulleys for sanity checking offsets too.
If your leading and trailing ignition were both firing and at reasonable timing or over advanced exhaust temps would be low, not high, especially if starting to run into knock. For some reason people think over advance or knock drives up EGT, it's exactly the opposite, it's burning faster, earlier, dumping more of the energy into the internal components.
Ruler across the pulley face is close enough for a sanity check. 1mm is close enough to 1 degree on the factory crank pulleys for sanity checking offsets too.
If your leading and trailing ignition were both firing and at reasonable timing or over advanced exhaust temps would be low, not high, especially if starting to run into knock. For some reason people think over advance or knock drives up EGT, it's exactly the opposite, it's burning faster, earlier, dumping more of the energy into the internal components.
Thank you for the input. I do understand that advance keeps the heat in the internal components. What is odd though is I do not see excessive EGTs with my very "conservative" timing. One would expect high EGTs from such retarted timing in boost, or mabye the fuel just managing it as expected.
Thank you for the input. I do understand that advance keeps the heat in the internal components. What is odd though is I do not see excessive EGTs with my very "conservative" timing. One would expect high EGTs from such retarted timing in boost, or mabye the fuel just managing it as expected.
I think rotaries have a broader effective crank angle range than piston engines which helps there. Definitely worth double checking it all with a light though.
I will get a picture of my timing light, marks, and will take a video after work today of the flashing/marks so that it can be clear for anyone else reading at a later date.
Alrighty folks. so I managed to sneak a few pictures during lunch.
Here is my timing light:
Here are my current markings on the pulley, note the location of my TDC. Inbetween the two factory marks. Thats what makes me so un-sure. But then look at the pointer on the FFE wheel itself.
Kinda hard without proper documentation, but it looks like the pulley is on the leading 5ATDC mark. The one to the left is probably the 20ATDC for the trailing plug and I would bet the right mark is TDC. So if it's locked at -5° it looks spot on if that's leading plug on the front rotor.
07-03-23, 09:42 AM
