took apart the motor the other day.... though it was blow, but its not. apex seals are perfect, and housing are in good shape too... the rear rotor bearing went https://www.nopistons.com/forums/pub...DIR#>/ohmy.png the outcome is as follows: Eccentric shaft, rear rotor, rear side housing, intermediate side housing all pretty much fucked. My question is since i have to replace all this, what should i go with... which iron should i use? my freind tells me i should go with S5 NA rotor (high comp), and S5 Na side plates.... What do you guys think, and what recommdations would you have. Im concerned with the high comp Na rotors that if i dont tunn it perfect the motor will have a greater chance of blowing then if i use my stock S4 rotors. I will also be doing a bridgeport. Has anyone used S5 NA rotors on T2, and if so what diff have you noticed, if any, from the stock ones....Ill post pics soon of the damaged goods....

I say go with the s5 n/a rotors IF you can find them. I have one, and have been trying to get a second for 4 months.. still no luck (unless i want to spend 100+ on 1 rotor)



However the S5 n/a irons have smaller ports that have a diffrent configuration. Stick with the s5 turbo irons



-Jacob

he meant if he uses s5 NA irons to port both holes into one such as this

That is *WAY* an aggressive bridgeport. I'm not sure if it's a good idea to use that as a visual example of a proper "extend port" because of it's sheer aggressiveness. https://www.nopistons.com/forums/pub...IR#>/smile.png



I'd like to know how the bearing and crank assembly failed. It's either balance (unlikely) or oil (likely) related. Can you tell us some history on the engine and everything done to it including modifications, # of miles and how hard it was driven, and then symptoms of failure?



B

sandor remember that time it was running funny and i said it sounds fucked then it ran fine for a few months........that was probably when the bearing got fucked up



this is a mazda S4 Reman with a few thousand miles on it and yeah he beats on it https://www.nopistons.com/forums/pub...IR#>/smile.png

Thats one mean ******* bridge port right there

that port is too big, too peaky. I hated the one car i drove that had a port like that.



Get big injectors, a stand-alone and nice fuel pump and use the NA rotors, with the t2 irons and housings

id trash the whole motor and start over, mine did that...how many miles were on your motor?



there is lead and bearing material EVERYWHERE in your motor, all oil passages, in your e-shaft, in your oil pump, everywhere



if you are running oil coolers, they are tarnished as well, flushing them will not do anything, not with this much damage

i kinda knew it as soon as i realized i blew the motor. I starved it of oil. I drove it pretty hard tru out the week, and at the end of that week i raced somone. car was running fine and all, then i get off the exit, and the motors shaking like crazy, vac is like 9, and i was like F$#% its blown. I pull over and inspect the motor, go to check the oil and the dipstick is almost dry. https://www.nopistons.com/forums/pub...1047683664.gif https://www.nopistons.com/forums/pub...1047683358.gif ya a REAL stupid reason to blow a motor....



93 BLACK FD- how did you motor blow like this? did you starve it oil as well or was it from somthing else.



My plans are to get a haltech( done with piggy backs) full t4, and brigdeport. As of right now im going with S5 irons, still dunno which though, NA or T2, and S5 high comp Rotors.



My mods are listed under my sig

That sucks. I did that once 5 years ago in Decembre 1998 when I left my oil filter off my car. It happens to the best of us.



Let me do your bridgeporting and your motor; I can help you with the Haltech setup as well and getting a map done for the motor. It's right up my alley.



B

my advice if it counts,stay away from the bridgeport,unless you have a major engine budget.life is generally shorter on a bridge.as far as making power a well know steet port works very well.(its the turbo that makes the power)

well with dumping all the money he already has in his car i don't think he's worried about the engine life (with the right setup bridges will be perfectly reliable)...and turbos do make power, but ports are what make them flow efficiently....

When speaking of bridgeports that leave either extremely little metal for the corner seal and apex seal edge(s) to ride on *or* bridgeport cuts that protrude into the inner water jacket o-ring land, or further, then you've got reliability issues. Otherwise, there's nothing wrong reliability wise building one that has bridgeports that are more conservatively done w/o major interruption to other components.



Very conservative

http://bdc.cyberosity.com/pictures/R...Secondary4.Jpg



Slightly more radical yet still unobtrusive and reliable

http://rx7.cyberosity.com/87GTR/pics...3/DSC01868.JPG



B

i would really want to see the dyyno chart with exact same portign minus teh bridge and all the same turbo hardware and all same boost. i just dont think its realyl worth bridgeporting unless u really do a large bridgeport. i tend to belive that when bridgeportign your main goal is to make that bridgeport the main concern of flow or atleast givign it great attention of the way teh air will flow.

i think goign all the way in up to teh water seal and nothing the rotor housing is the best for the flow without really affecting the reliability. but leaveng the bridge itself somewhat thick and not put so much overlap on the original (streetport) part of the port.

Well I guess it isn't all bad, won't cost you as much as you were expecting.

BDC,



I must say...that BP is BEAUTIFUL https://www.nopistons.com/forums/pub...IR#>/boink.gif

actually no, i didn't starve it of oil, oil cooling, or oil flow, i had the motor optimized for maximum oiling effeciency (dual coolers, -10 lines, stage 3 oil mods from pineapple, etc)



it just failed....and pineapple concluded it wasn't their fault



sucks eh? at least you know what killed your motor

Perhaps debris left in the motor from all of the machining work ,etc. that was done prior to engine assembly ....



B

I would tend to agree but I believe that this rule is susceptible to the goal and power output of the car, the purpose of it, etc. From what I've noticed, on turbocharged cars, is the smaller bridgeports as additions to the main extend port lend for higher peak horsepower and torque at high RPM as well as "stretching" the powerband out further all the while not heavily reducing low-end streetability, take-offs, etc. to still keep the car moderately comfortable to drive.



B

some pics of his engine

one more

one more 2

one more 3

last one https://www.nopistons.com/forums/pub...IR#>/smile.png

If you have ever drove or rode in a car that is BP you won't beable to say it isnt worth it.

The theory behind BP turbo is becoming more widely accepted, so it is only natural to have coots mouth off against doing that to rotary motors. I just did my BP turbo and will post up on the whole adventure, and thanks to BDC, he convinced me that reliability would not be a major issue.

I was completely against it last year and the year before and refused to do it. But, after finally being convinced, I'm totally sold on it. I think there's particular ways it has to be done but it seems to be quite effective.



B

yeah i mean if you're only going for like 300hp theres no point to a bp turbo motor...

That's an arguable point but nonetheless valid. I would argue that it somewhat depends on the user and what they're looking for. Even though the setups I generally do are geared and intented for high 300's and above, it wouldn't be unheard to have a half-BP engine w/ a T4-sized turbo making 300rwhp. The user may want the cool idle and attention-getting of the noise and lope even though he or she isn't making gobs of power.



Practically speaking, I think you're right and I think the half BP is better designed for a turbo setup that's looking to drive a slightly larger turbocharger with higher peak HP and torque figures.



B

This is off subject but I have to know after reading through this. How do you guys get so low on oil with out you oil level buzzer going off??



If I am 1/2 a quart low and take a hard left turn I know instantly I need 1/2 a quart the annoying buzzer says so.

did anybody see that he was using the stock thermal by-pass pellit or was i just seeing things.hmmm the rotor bearing was wiped out the e-shaft too.one might think some loss of oil pressure here.

i agree

I didn't notice the bypass pellet but I did see the bearing. Good eye; I bet that's the problem with it.



If it's got oil starvation and/or oil overheating, you'll see signs of varnish (dark gold/brownish coloured spots) on the front counterweight, oil pump assembly, and the bottoms of both rotor housings. Can't miss it. The e-shaft will also have scratches parallel with the rotor and gear bearing journals as well as blue-ing from heat. The thrust plate may have a groove on either side from either needle bearing.



Bunch of nasty stuff will be evident if it's been oil-starved...



B