Should I do a partial BP on my new engine?
 

Every time I crack open one of my engines, I threaten to bridgeport it. Well, I have tried to be low key and not mention names and such, but I have been waiting 2 MONTHS for a used rear housing from Hayes -- all in an effort to save some money over a new one. Bad idea. I cracked the rear housing on the original engine when my EVC stepper motor failed, causing mad boost followed by popped vacuum lines off of many devices including the BD-FPR. Ugh. I was on the dyno, so I did not feel the engine stop pulling, and the broadband was too slow to react. No internal damage whatsoever, but the housing cracked in the typical location: right at the tension bolt below the oil filter. Thus, I had to tear it down and do a complete rebuild. I am using '89 housings which are much stronger in this area of the housing than my old ones. Well, the rest of the engine is ready, and I am getting BORED as, umm, the UPS driver waiting to deliver my housing -- the ONLY part I need to put it back together. So, I will make this a true interactive experience for all of you. I will collect votes here, and will do what you guys think is the best /most fun/whatever... heck, I'll even ramble on about the whole thing, and post dyno results if you want. Deal? I would only BP the end housings, and very small at that. My goal would be to keep a small lip to retain the o-ring without RTV. I am using Hayes O-rings, so I am not sure how they will work with this setup, as they are bit fatter than the factory o-rings. Crispeed? Want to share some secrets? Ok, and here is the special bonus! I ordered a new rear housing from Mazda today, just in case the other does not come in time. Yep. Immediate, vicarious gratification for all - that is, if you are into this kind of stuff. So, fire away -- let me know what you think! This car is track only for the most part; it only sees the street to get to the track, and to occasionaly remind the locals why rotaries rule the planet. Cast your vote.

Do you plan on using your car as a daily driver with all the comforts such as AC and power steering etc.?

crispeed
87TII
9.20@150mph
13B-REW Bridge
T-72@35psi
2600lbs

chris:
I purchased the car 9 years ago. Approximately 8 years, 11 3/4 months ago, I removed the AC and power steering. Hope that answers your question? :) The car is driven, perhaps, 500 miles a year on public roads. All steetablity was thrown out years ago. I do not plan on taking the thing out in stop-and-go rush hour traffic, just an occasional late night adventure, and mostly to the track.
Hmm.. the votes seem to be going for the BP. Anyone have any specific comments on this? Chris? How small can I make the BP and still have significant gains? I really want to keep the O-Ring intact and, ideally, a small lip to help retain it. Secrets! Secrets! Please?

There is no turning back now! I just finished porting the front housing. I will post pictures tomorrow as soon as I am at my regular computer. Basically, I used Dykem on the rotor housing around the port. Then, I took an old rotor with a corner seal in place and rotated the rotor several times to mark the edge of the corner seal. I used the outer mark as the inner limit for my port. I realize it is possible to go further, but I felt this would be adequete while keeping the bridge stronger, and less prone to failure. Then, I placed the rotor housing and marked the inside -- purely for reference. I pulled everything back apart, and used a 1/4" bit on a drill press to create several starter holes. I will space these much closer when I port the front housing to speed the process. Next I attacked the housing with an arsenal of 'weapons' attached to my dremel flex shaft. Much, much, later I had a finished housing. It took lots of very careful griding with a wide selection of implements. I left about 1mm of lip beyond the o-ring to completely retain its integrity.
Next, I cut the rotor housing to match my port. I did not get as agressive in this area as other pictures I have seen. My notching in the rotor housing is only as deep as the port -- again, I was trying to keep clear of the O-ring. Any of the BP gurus have any thoughts on this?
My exhaust port has been enlarged (only slightly larger than streetport specs). Nothing like RiceRacing's massive ports!! Any comments here? Do I need to get medievil on these things? REAL big, or just big?
One other question. Chris? On the rear rotor, do I need to install the apex seals upside down so the small apex piece is not consumed by the port? I have 2-piece 3mm seals (stock, steel).
Well, I now feel that I have tried to destroy just about every material Mazda has used to produce our cars. Let me tell you, it is amazing how tough some of these components are. Of note, the chromium plating on the rotor housings is a TOUGH material! Well, hopefully a rear housing will arrive tomorrow so I can drive this thing by the weekend.

This is starting to look bad; 3 posts in a row from the thread creator! Anyways, here is a picture of the ported housing. Yummy!

that's all huh. Seemed to me with your other posts you were a serious cat. ahh well. may be next time.
(dripping with sarcasim)

I got a PM from someone complaining about aspect ratio, etc, blah blah because of the orientation of the image. IS THIS BETTER? I guess it would be like looking at a picture of your girlfriend laying on its side (the picture!).

The porting looks beautiful at least to my "swineful" eyes! :)

Rick
https://www.rx7club.com/vforums/atta...=&postid=98665

(heavily Beavis-ing) hehheh hehheh hehheh brap brap BRAP BRAP BRAP AHHHHHHH!!!!!!!!!!!


- The Wuss with Little Bitty Street Ports

Well, the housing I was waiting for never came, but a new one overnighted from Mazda did. I finished porting last night, and assembled the block. Today I have been installing manifolds, acessories and such. The replacement for my cracked flywheel should arrive tomorrow, so I might get to hear it run this weekend! Should I continue to document my process? Does anyone REALLY care? Be honest! Or it just fun for me to hear myself talk?

I do, and take alot of pics.

Yes you should install the rear rotor apex seals upside down!

crispeed
87TII
9.20@150mph

I care TOO!:):):)
What turbo are you using?

crispeed
87TII
9.20@150mph

I also care. I don't know enough to be able to offer advice on most threads but I am on hear reading posts from people like you and crispeed and learning more all the time.

Chris: Luckily, I did install the seals upside down. This was an uneasy feeling. I had already loose assembled the engine, and was waiting for my rear housing when I started considering the BP. So, I had to pull it all apart. Of course I broke the factory glue on one of the seals, and had to re-glue it. I hate that. I used some very good epoxy this time, after dealing with less-than-stellar glue (ie, super-glue) on other re-builds. Anyways, the epoxy did not let loose until about the 10th revolution of the engine, and made a very distinct sound when it went loose. I was almost tempted to unbolt the engine again and check things out, but assured myself that everything was OK in there -- but spent an hour with a bright light and a small mirror just to be sure!
My turbo is too small. It is a Turbonetics T04 with a Q trim turbine, and an H trim compressor. I would prefer a 60-1 on the compressor if I stayed in the T04 family. I think the A/R is a .96, but I will have to double check -- too many turbos around here, all of which are too small! What do you recommend for this beast, Chris? Want to fab me up one of your super-manifolds I have been hearing about, and pick a nice, big, juicy turbo for me? How about that Kai 51-R? Did you ever compare the inducer measurements to yours?
Ok, here is my big question, and I would really appreciate some input from the other BP guys on the list. Tuning!! I don't have an intuitive idea of where to set some base numbers -- especially timing. I use an Electromotive, but some general info would do -- or even a map for another ECU in excel format, text, whatever. I am usually very conservative on timing, and tend to run slightly rich. I just installed the 1600s to complement to the 720s, all fed by a big Weldon pump. More that enough for the hungry bridge I hope? Well, being my impatient self, you will probably read my results here before I have a chance to entertain some answers!
The engine is completely assembled now, just waiting for a flywheel to arrive tomorrow and I will drop it in. It only takes an hour or so to install when all the accessories are installed prior to installation. The engine compartment is VERY bare. I also have to build a custom driver for the secondary injectors. Laugh away haltec owners, BUT I have a very old TEC II (testiment to how long I have playing with my rotaries) that only has 2 injector drivers. I ran all 6 injectors in my old setup in alternate arrangement (3 at a time!). I am now switching to 2 injectors, and staging the secondaries off a general purpose table, as a percentage of the primary pulsewidth. I am using a pair of beefy SSR's to drive them, so I will need an additional few hours to build this and test it on a scope.
Well, that's the state of things at the moment. I will take some pictures tomorrow morning and throw them up as soon as I can. Until then, some timing maps and such would really help, unless my original maps are still ok? I just want to hear it idle!!

I'm listening, but as I'm 1 step behind you, I can't add anything. Keep us 100% informed.
Don.

Chris do you run the stock rear end in that monster? Or is there some sort of american made thing under it?

Just a quick update. UPS shafted me for the 7th time this month. They lost the flywheel in the local distribution center, and can't predict a delivery date. Arghh. They have lost 3 other packages for me this month alone, and destroyed 3 others! Anyways, I will try to stick some pictures up of the current, halted, state!
I probably should not answer for Chris, but I am hightly envious of his setup! He has a ladder bar kit (straight axle) with a mopar rear end. Really cool. Darn, now I will have to go watch the video of him launching again. and again, and again, and again. Ok, I am back. Can't watch that video too many times. Chris, do you have a new one for us? I still have '9_7_pass.mpg' -- my favorite video in the collection!

http://www.cr-racing.com/video's.htm check out the wheelie one!

when its done, make mp3 file of it I could listen to that all day.

Turbo Porting
 

This is a great thread guys!!!
I have been trying to find out info on how far you can port a turbo motor... and going to a brdigeport is insane!!
I would really like to know the in's and out's of how far you can port a turbo motor and what kinda things you need to be careful off (ie: overlap, intake port size, exhaust port size blah blah blah)

Some of you appear to have gone down this alley and i would love to know what your impressions of it all are.

Thanks heapz

Big fat booty Peripheral Port is as far as you can go with a turbo engine, and yes that is the same as you can go with a normally aspirated engine.

It's ALIVE!!
 

Just a quick update... at about 5:00 AM, I finally had first ignition of the new engine! It fired immediately, and a few quick adjustments on the TEC produced a stable, but notorious, Bridge Port idle! I was very surprised how easy the engine started for a rebuild, and how 'happy' the engine was. Many of the rebuilds we purchase and install for customers like to flood immediately, and are difficult to start until broken in. I felt the overlap would aggrevate this problem even more, combined with the fact that I was unsure of a base fuel requirements and timing. Not the case at all! For the TEC (or tech) savvy, I swapped ROM's to upgrade to WinTec. I thought my previous program would be compatible, but the translation created a TOG of 125 mS!! Believe it or not, the engine actually fired at this setting! I changed the TOG to 7.5mS, and it evened right out!
I really took my time re-installing the engine. I am usually anxious to drop a block in as quickly as possible to feel like I am accomplishing more. This time, I opted to do as much on the bench as possible to save my back from bending over an engine bay doing tedious work (I'm getting old). I decided to build a new harness for the TEC that would allow the harness to stay on the engine, and unplug from the body entirely. I used a fortune in GM weatherpak connectors to accomplish this. I also built the custom injector staging driver using a massive FET; so large in fact that it is considered a solid state relay. This was all built into a neat removable harness. I also permanently wired the AVC-R sub-harness into the main harness, along with the nitrous wiring (opps, I spilled a secret), and all the instrumentation. It was very time consuming, but the end result is very clean and simple appearing, while allowing for even faster engine swaps in the future, and peace of mind that a cheap connector is not going to pull apart.
Other adventures included cracking the TEC open to clean all of the oil that had found its way inside when the rear housing cracked. I am sure traces of oil from that incident will be found in obscure places for years to come -- much like when you break a window on your car, and find glass for the next decade. I re-worked the majority of the underhood fuel system, since I was not happy with the old routing, and was also switching from 6 injectors back to 4. I created a mega-stealth NOS micro-switch installation that I can feel confident will not ever vibrate loose, or provide an inaccurate closing. Etc, etc... after I was done with all of this, the actual engine was installed in about an hour.
Next chores involve improving the relay setup for the injectors and fuel pump,removing the stock fuse block (finally), relocating the battery, installing the NOS solenoids and lines, mounting of AVC-R, covering giant hole from transmission, installing 12-point cage, and LOTS and LOTS of programming. This should keep me busy for a while! I will try to post more pics and mp3s/mpgs after this weekend. Still hoping someone with a BP will share some timing secrets!!

It's ALIVE!!
 

Just a quick update... at about 5:00 AM, I finally had first ignition of the new engine! It fired immediately, and a few quick adjustments on the TEC produced a stable, but notorious, Bridge Port idle! I was very surprised how easy the engine started for a rebuild, and how 'happy' the engine was. Many of the rebuilds we purchase and install for customers like to flood immediately, and are difficult to start until broken in. I felt the overlap would aggrevate this problem even more, combined with the fact that I was unsure of a base fuel requirements and timing. Not the case at all! For the TEC (or tech) savvy, I swapped ROM's to upgrade to WinTec. I thought my previous program would be compatible, but the translation created a TOG of 125 mS!! Believe it or not, the engine actually fired at this setting! I changed the TOG to 7.5mS, and it evened right out!
I really took my time re-installing the engine. I am usually anxious to drop a block in as quickly as possible to feel like I am accomplishing more. This time, I opted to do as much on the bench as possible to save my back from bending over an engine bay doing tedious work (I'm getting old). I decided to build a new harness for the TEC that would allow the harness to stay on the engine, and unplug from the body entirely. I used a fortune in GM weatherpak connectors to accomplish this. I also built the custom injector staging driver using a massive FET; so large in fact that it is considered a solid state relay. This was all built into a neat removable harness. I also permanently wired the AVC-R sub-harness into the main harness, along with the nitrous wiring (opps, I spilled a secret), and all the instrumentation. It was very time consuming, but the end result is very clean and simple appearing, while allowing for even faster engine swaps in the future, and peace of mind that a cheap connector is not going to pull apart.
Other adventures included cracking the TEC open to clean all of the oil that had found its way inside when the rear housing cracked. I am sure traces of oil from that incident will be found in obscure places for years to come -- much like when you break a window on your car, and find glass for the next decade. I re-worked the majority of the underhood fuel system, since I was not happy with the old routing, and was also switching from 6 injectors back to 4. I created a mega-stealth NOS micro-switch installation that I can feel confident will not ever vibrate loose, or provide an inaccurate closing. Etc, etc... after I was done with all of this, the actual engine was installed in about an hour.
Next chores involve improving the relay setup for the injectors and fuel pump,removing the stock fuse block (finally), relocating the battery, installing the NOS solenoids and lines, mounting of AVC-R, covering giant hole from transmission, installing 12-point cage, and LOTS and LOTS of programming. This should keep me busy for a while! I will try to post more pics and mp3s/mpgs after this weekend. Still hoping someone with a BP will share some timing secrets!!

Good work. Some pictures would be nice.:D
I would try to help you with the tuning, but I'm still a little lost with the TEC II. I've gotten my car to start, but it's running very rich--the smoke makes it look like I'm setting fires in my yard. Is adjusting the TOG the primary method to lean things out?