Hi All,
I'm not usually the type to post anything on forums, but I will have to get used to this with the car that we are building. I am part of BMI Racing, and we are in the process of putting together an RX8 4 Rotor, it is something that we have been working on for quite some time. I would like to take this opportunity to thank SVEN at NRS SEALS for providing the 2mm 2 piece apex seals for the engine, Sven did a wonderful job at ensuring that these seals we top notch. You may have seen his link from a few days ago of the engine running. I would like to let you all know that I will start a new thread soon giving you some information on the setup and a few pictures also - in saying this can someone please let me know where a suitable place would be to post this.
Thanks
Sarah

 

Thanks for chiming in Sarah! It has been a pleasure working with you and the BMI team. You can post all the info here but I think if you want to start a separate thread the "Rotary Car Performance" section would get the most views. Alternatly the "Race Car Tech" section would do as well but I think you would get more exposure here.

 

Yup, that is his comment above.

 

This just in from Pete:
Hello Sven,

Here are the compression results, along with applicable notes.

Engine: RR street port (new), 2 piece NRS Apex seal, Ceramic NRS corner seal. 9.0:1 engine compression ratio

Condition, Ambient temperature 22 deg C, 101.5kpa pressure

*0km on engine, tested from engine stand*

Rear Rotor average (picture include) 128psi

Front Rotor (picture included) 132psi

Comments: This is a noticeable increase in cranking compression over other same engines (new, same port timing but with one piece NRS seals and OEM corner seals)… On average the one piece RR engine develops about 95psi compression, this engine you can see is at the 130psi range (OEM sealed engines on same specification develop about 105~110psi).

This compression figure will go up once the seals are bedded in and when the engine is tested at operating temperature. It was tested without manifolds hooked up, but the influence give the very low air flow rate will be negligible. Further tests will be conducted after the engine has be initially fired up and then again after the run in period.

 

I almost forgot, a set of 2mm ceramic corner seals and hard faced c.s. springs are on their way to Pineapple Racing for the static drag testing. Rob will make a fixture to test the drag created by the steel corner seals and we will compare this to the drag created by the ceramic corner seals. He figures he will need a couple of weeks to get the fixture done. This should give us a baseline to quantify and compare to the real world results. The data will also help us to quantify any changes made in spring pressure as we will be trying a couple of different spring thicknesses for better sealing and rotor stability. Then they will be installed into an engine and all the data collected will be put to the test. There is a real possibility these corner seals could find their way into the SpeedSource RX8. We will present this opportunity to them when the time comes. Their engines consistantly produce power within 1 or 2 hp from one to the next so this would be an ideal situation to prove the benifit of ceramic corner seals.

I will post pics and results from Rob when they become available.

 

Looks like good numbers, congrats. Hope all goes well with the running engine.

 

on the rotor he had less compression, he cut the side seals with a larger gap in regards to the other rotor. he needs to learn the trick to extract equal compression... no reason to get a difference in compression with the engine being new and all.. he should've had equal compression..

 

Cut? You need to hand file each one for precise fitment and the best compression. Takes forever but when done right you will have a good motor. And I know that because of you.

 

Hi Sven,
Im impressed with the gain in compression, but why is the comp so low on the other same spec engines with mazda seals(95psi)?? they still should be around the 120-125psi mark, I see it all the time even on heavily ported engines, dont get me wrong as im not stiring,just not sure that the specs are exactly the same like condition of parts, preperation of parts and same clearances on rest of seals etc?? I mean theres no reason why there should be any difference in psi from front to rear.
I see 132psi with steels on both rotors all the time on big ported turbo motors which arent fill of oil and gas,If I got the gain that Rice has then **** Im probably going to see 140-150 :shock: this would be a big gain in power especialy when on meth.
Again, Im not just trying to blow my own whistle, just I would hate to spend alot of money and not see much gain, I would seriously think of trying some 2mm 2pc with the corner seals but I think Ill wait a while to see how much more Rice's comp comes up after run in. And also see how the methanol RX3(Judge Ito's friend) goes,have they tested them yet Judge ito??
I also would be using them in a high power methanol setup.

Regards
Brent

 

hi Brent, leduc is waiting to get his car back. his car was at Puerto Rico for the recent import revolution event. in about a month he will be out testing the 2 piece NRS seals

 

Thanks Judge,I look forward to hearing how it goes

 

From Pete regarding the variation between rotors:

Hi Brent,

100% brand new engine blocks, porting specifications as per here (you can list yours if you have them?) I would be very surprised if you replicate the EXACT timing specifications of mine that you get *any* difference in compression... I have had people copy it in various places and replicate exact same figures.

IO = Intake opens
IC = Intake closes
EO = Exhaust opens
EC = Exhaust closes

Primary and secondary Ports same on std Rotor
IO 15° ATDC
IC 67.5° ABDC
EO 78° BBDC
EC 60° ATDC

Rice Racing street porting.













I have seen the difference between rotors every now and then on a brand new engine, its normally to do with *one apex seal (affecting two chambers)l*, can be various reasons but that distribution generally disappears after a some load is applied over a certain time period. Being two piece it can even be something as silly as too much super glue on one changing a clearance to the main bar. I did have one of the rear apex seals corner pop off during assembly and I had to re-glue it quickly b4 sealant went off (never a fun job with slippery fingers!).

Remember it has not even had been started and no combustion gas pressure has been applied to fully seat everything. As you well know no matter how well you clearance everything you will always end up with variations when you use good equipment to measure this stuff.

I will update once she is through the run in stage.

p.s. Yes the porting is what I do on all my engines, and the result I put up is the indicative gain I saw. I have no doubt on stuff with different timing specs you will see much higher gains, would not be surprised if people got 140~150psi on 9.0:1 CR set I tested one FD3S car that had ~140psi with 30,000km on clock so I def think it is possible for sure.... biggest variable is the port timing when trying to compare engines that are otherwise the same mechanical specification.

 

Sven, sorry to add my two cents on rice's psi difference in rotors. this thread is about your awesome seals. on a tech note. equal compression will always be achieved regardless of ports. Sven, Jose came by to show me the new 2 piece seals. can't wait to see some results..

 

its normally to do with *one apex seal (affecting two chambers)l*, can be various reasons but that distribution generally disappears after a some load is applied over a certain time period. Being two piece it can even be something as silly as too much super glue on one changing a clearance to the main bar. I did have one of the rear apex seals corner pop off during assembly and I had to re-glue it quickly b4 sealant went off (never a fun job with slippery fingers!).


I think what Pete is getting at is that the piece he had to re-glue may not have broken free if it was not glued longer than the housing width. I glue them to 3.153" so they break free as the tension bolts are sequenced.

 

Hmmm I guess everyone has a different approach. I've never had to glue a 2 or 3 piece apex seal corner piece to keep it from popping out during assembly. Some petrolium jelly holds them in without any problems. When the plates are torqued down, they slide into place.

 

I've never heard of this glue approach.. very interesting. I've just used petroleum as well. then again I don't build engines on a regular basis.

 

glue is the way to go..

 

I just talked to Ernie and Ray should have his car on the dyno hopefully by this Friday. We'll have some results very soon

 

results yet?

 

Nothing yet, I left Ernie a message so hopefully he will chime in soon. Perhaps there was a slight delay and we'll have something this week?

 

As you know we are always striving to improve the quality of the final product. I am happy to report that we have refined our annealing process to offer the highest increase in fracture toughness possible. This takes our material to even greater heights as we redefine once again the record books on what is acheivable with this material. Our results have yeilded an increase in toughness of 1.5 MPa over and above the earlier reported figures. This sets NRS ceramics miles above the rest.

Our testing is done with the most accurate methods accepted. 4 point bend, notched with a very sharp crack induced at the bottom of the notches. It is important to have the sharp crack on the bottom of the notch for the most accurate measurement, otherwise a higher value would be noticed.

This testing yeilded a fracture toughness of 11 MPa +. With proper annealing this value could exceed 12 MPa to possibly 12.5 MPa

We noticed from a sample with slightly different processing an increase from approx 10 MPa up to 11.5 MPa with the refined annealing process. The latest material starts at 11 + MPa so we would expect to see a similar increase and should yeild upwards of 12 MPa + as noted above.

Where does this put NRS material in relation to others? Most other like materials fall into the 4 - 6 MPa with 8 MPa being about the top.

 

My parts took longer than expected gettting balanced. Car should be done this weekend.

 

My engine is delayed as well. Some intake parts where delayed for almost 2 weeks. They arrived yesterday. And the intake is now done. So the engine has been taken apart again. And will be put together again tomorrow. So expect startup and pre start comp readings monday or tuesday next week. Im going back to england on thursday to pick the car up, and be there for the last dynoing.

JT

 

It sucks that sometimes race cars take longer then expected.. My car is been a slow process but at least it's getting there.

My setup is a semi peri, turbo, alcohol.

I have to finish up the wiring, fuel system, and brakes and i'm ready to go.
I'm hoping to make it out for the pan ams..

We bench tested the engine's compression and we made 15lbs more compression over what we normally would make with other 3mm seals..

I'm using 3mm 2 piece NRS seals..

Let's just say i have a very good feeling about these seals

 

So what is the highest level of boost that you guys have ran on these NRS apex seals has anybody tried 50 - 60 lbs yet .