i had my rebuild dowelled. pettit suggested it. however, is it contradictory that they recommend dowelling a motor, but say run low boost (10ps1). is the pinning of the block necessary if the load on the engine is going to be that low? i was just wondering, because i am proud of the motor, and the fact that it is SUPPOSED to be stronger. can someone add?

btw....they suggest 3mm seals. but in my case, had a choice, because i needed new rotors. i chose the 3mm hurley....

louis

 

Wow, guess all my **** is a waste of time just because a few guys can argue otherwise...I did say it was a waste of time, right?

Wow, now I gotta waste my vacation by logging in here just to take care of your queries?&nbsp Didn't I say it was a waste of time?&nbsp You think I'm going to worry about your **** while I'm enjoying my summer in Hawaii?&nbsp Come on...get real...gimme some of that good **** you're smoking...


-Ted

 

i dont smoke anything, never have and i doubt i ever will. so i dunno WTF you are on about but you are off the landing mark by a good couple of kilometres. maybe there was high wind in hawaii..............

 

Aren't the recent housings a bit stronger (series V rotor housings)? Would a FD engine block need doweling if you plan to run 9krpm or 10krpm?

J

 

I am using 3mm Hurley racing seals. The feel very light. I haven't compared the weight of them with stock 2mm seals, but by hand I could feel a big difference opposed to my stock mazda 3mm seals. The springs are also very sturdy and thick opposed to the stock springs. With these seals I pull around 16 vacuum with a ported motor. opposed to 12-14 before with mazda steel seals.

It seems the Hurley seals are lighter, softer, and the springs are stiffer.. How about we add them into the mix of 2mm vs 3mm debate.

Could they possibly out weigh the normal disadvantages of steel mazda 3mm seals?

 

what do you think about those hurley engineering seals? just asking since they are 2 pice and the stock mazda is a 3 piece design..

/jönsson

 

My head is spinning!?!?!?!?

 

At least IMHO this thread should be relegated to the archives by now and closed.

 

why close it? all you have to do is not read it.

 

Whats funny is no one had posted for 4 days which around here means its pretty much dead and you are the one bringing it back....lol that doesnt make much sence does it

STEPHEN

 

true...got an email from late I guess. But then why did you post *7* days after the last one

 

2mm apex seal are just as good as 3mm, 3mm will make less hp,

 

Guys, I am new to this forum but i believe from my experience with FD's that 2mm are the best.

At this moment i am having a new engine builted from a Japanese tuner of FD's. His opinion on apex seals is that 3mm are out of discussion. For lightly modified engines that are street used he recomented 2mm Mazda originals whereas on heavily modified race engines the recomented 2mm racing apex seal.

I have been talking to many Japanese Tuners lately and the most of them proposed to me the above as well.

I have no reason not to believe Japanese record setter tuners for their knowledge on Rotary engines.

Without aiming in offending American tuners, on my opinion the philosophy of the American tuners/racers is to built an engine that will race today and rebuilt it tomorrow at low costs whereas Japanese tuners/racers built engines with reliability and longliveness in mind. There is no doubt that Japanese tuners bulit the best rotary engines in the whole world. After all the RX7 was borned in Japan.

 

jeff48, the Seals are forced out by centrifugal force, but this is not as important as the mass of the seal, when something is more massive, it is harder to accelerate, 3mm seals are more massive, and thus tend to skip at high rpm. This is why very high rpm engines use carbon seals, their small amount of mass means that the force (gas, spring and centrifugal) can more eaisily change there direction from twards the rotor to away from the rotor, apex seals are effectivly reciprocating mass at high rpm, its exactly like unsprung weight on your suspension if you have alot of it, even if you apply more spring force to the wheel, it still wont stay in contact with the road aswell as a lighter set up. this leads to seal float at a lower rpm than with stock 2mm seals, as to how much it reduces it, im unsure, but it is significant. 3mm seals are also more prone to chatter marks due to their harmonics, mazda had to deal with this extensivly when they first aquired their rotary engine project, the thick iron seals they were using were hitting harmonics and leaving nasty chatter marks that would make the engine die at about 10k, one solution was drilling holes in the seals along their length, this changed the harmonics and helped, but ultimatly they went with 6mm carbon seals because their lightness and self lubricating properties eliminated the chatter marks. awhile latter they came up with the pourous chrome coating we now have, that retained a small amount of oil, thus becoming self lubricating and elimintating the need for the carbon seals which have a higher wear rate than the iron ones we now have, they solved the harmonics problem by going to thinner 3mm iron seals, the thinner the seal, the higher rpm it will hit harmonics and chatter/ possibly crack the seal. Ever wondered why the 3mm 12A's had a 6500 rpm redline and the s5 2mm 13b's is 8000? and dont say rotor weight because one model 13 be had rotors nearly as light as s5's. answer: floating and harmonics

 

o also the 3 piece 2mm seal better at low rpm, and cause less friction which requires less oil

 

Please, moderators, close this mislabeled thread so it will die and never return.

-Max

 

Agreed! At least close the friggin' poll! Those things should have a 30 day life!

 

why do people care if they close a thread. as said before, just dont point your little arrow on it and click, then you can imagine it is gone...

just thougth i would throw this is, centrifugal force is not a physical force, it implies a force pulling directly away from the central point of an axis in a spinning object. this "force" is jsut an imaginary product of centripetal force which is a force at a tangent to the circumference fo the given object. it feels like it is pulling directly out but it isnt.

Justin

 

OT but ....Centripetal force is a force directed toward the center, not at a tangent to the circumferece. Granted, if the force was removed from an object 'orbiting', it would spin off in a tangent but the force is towards the center. Centrifugal force is a fictitious force as you stated.

 

It's not the thread, it's the poll.

Everytime someone votes, it bumps the thread up...one might think there is a useful post, but it is just a vote. If a thread is going to be revived, let it be for useful content.

 

poor guy, are the threads tricking you???? wasting your time??? i dont care if the poll is closed, my comment was directed towards maxcooper, not you. dont mean to sound like an ***, im just picking...


daviddeco,

you may be right, its been a while since physics... i thought that was the tension, and the centripetal force was the tangent force, but now that i think of it, it sounds right..

Justin

 

Hell, I had to put my Physics degree to some use

Tension could be responsible for Centripetal force as in a string with an object at the end being whirled around. But it doesn't have to be Tension ....gravity does the same, so does electrical charge in an atom.

Way way off topic, but this thread has been dead for some time so why not post *****

 

who

 

me???

 

Yeah