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what sort of revs have you been pulling? you can see the start of chatter marks forming in the top of one of the housings.little ripples. may want to try lap that out so new seals don't keep skipping.i have been following thread but can't remember are you running water inj?
What apex seals were you using?
Is the exhaust ported?
ALS seals
and no, it's stock intake and exhaust port, I did this to try to maintain the torque of the engine. there is a big discussion about it earlier in this thread.
Originally Posted by IAN
Very clean rotors. How many KM's? Here is mine after 1000km. No idea what happened. After which I more or less rebuilt it and then just let the car sit for lack of time and tired of using vacation and my free time on her
I rebuild this engine 2 years ago? so probably not more than 10,000 miles
Originally Posted by moneymaker42141983
Nice to see your still at it with the car man. If you need anything you know where I am. How did the FD upper work for you?
it worked out nice, I put it on with the v-mount with a custom elbow going into it.
Originally Posted by BLUE TII
Very nice!
Glad everything looks in good shape besides the apex seals.
Never had that weird apex seal wear (different height across the length of seal). Could it be the apex seal springs got seated weird on the rear rotor with the short spring pushed out of its land and up onto the long spring's outer land? Maybe this caused that side of the apex seal to resist being pushed into the rotor slot and so excessive wear.
You might see something on the backside of the apex seals where the springs rub.
White chalky sounds like burned coolant or water wetter to me.
The only thing I can think of is that maybe the springs did something funny when I replaced just the rear plate a while back? I'll check to see if there are any witness marks on the back side.
Originally Posted by Rotate86
what sort of revs have you been pulling? you can see the start of chatter marks forming in the top of one of the housings.little ripples. may want to try lap that out so new seals don't keep skipping.i have been following thread but can't remember are you running water inj?
I have my rev limited set @ 9000 and I've hit it occasionally. I assume you're talking about the second picture? that housing is much older, and probably has close to 50k on it (the other one got replaced during the last rebuild)
I'm not running water injection, I was planning on it, but then just decided to go right to E85 instead.
I understand the desire to move away from the unbreakable seals, and back to the OEM seals. Given how pristine the engine looks, I would run those seals again. Pulling the engine out to replace apex seals sounds better than pulling it out to replace rotors/irons/housings/turbo.
I guess what I am trying to say is that we don't want to you going to the dark side at some point!!!
I'd be to scared of stock seals while running the efr. damge that turbine and yea you know the rest. in saying that I know your going e85 so maybe it's a non issue.
I'd be to scared of stock seals while running the efr. damge that turbine and yea you know the rest. in saying that I know your going e85 so maybe it's a non issue.
modern stock seals (2 piece) are a lot stronger than most people give them credit. I put my original ones through hell and back and they didn't care until I went super lean several times in a row.
with the ability to run low boost (8psi) if the ecu detects a problem, a fuel pressure sensor and a flex fuel sensor along with a fuel surge tank I think my setup will be pretty rock solid.
fair call on the fail safes but I have had a trigger issue before and taken a turbine out luckily was a masterpower so cheap to replace.. no fail safes activated in that scenario
Very nice!
Glad everything looks in good shape besides the apex seals.
Never had that weird apex seal wear (different height across the length of seal). Could it be the apex seal springs got seated weird on the rear rotor with the short spring pushed out of its land and up onto the long spring's outer land? Maybe this caused that side of the apex seal to resist being pushed into the rotor slot and so excessive wear.
You might see something on the backside of the apex seals where the springs rub.
White chalky sounds like burned coolant or water wetter to me.
Just to follow up, looking at one of the apex seals, it seems to have witness marks on it exactly where I would expect, so still a mystery...
I've been in the "since the engine is apart" mode and things have gotten a little out of hand.
I acquired some FD housings which are in really nice condition, my front housing was starting to show some chatter marks. I'm also going to send both housings off to racing beat to get the water jackets machined: Rotor Housing Water Jacket Modification for RX7 1986-1992 - Racing Beat
I'm going to try to get my RX-8 rear stationary gear (which I already had in my engine) machined for an o-ring groove (which RX-8s have in their rear irons)
I've also been doing some research on oil control o-rings. Rumor has it that RX-8 oil control o-rings are made of viton? They have a different part number than Rx-7s, but the same part number for the steel carriers. so they should work just fine. The only place I've found evedence of poeple using them is IRP's website:
Originally Posted by IRP
We also offer Viton oil control rings. These are a MUST for any motor that runs E85 as the oem rubber oil control rings tend to dry out prematurely from the ethanol. We prefer the Mazda oem Viton oil control rings out of the RX-8 over some the the aftermarket offerings that tend not to fit as well.
This also explains why i'm going through the trouble... why don't more people use the RX-8 oil o-rings?
I also placed a nice big order with mazdaspeed for all my seals and such...
I'm also going to send both housings off to racing beat to get the water jackets machined:
Rotor Housing Water Jacket Modification for RX7 1986-1992 - Racing Beat
If you have a drill press and would like to do this yourself it is really easy the way I do it.
Put a piece of plywood on the drillpress work surface to slide the rotor housing around on.
Get this Dremel bit #199.
Put a standoff on the shaft to control the cut depth and freewheel against the housing.
Lock down the drill press cut depth by moving one of the locknuts to the other end of the threaded plunger.
Set your first cut depth (I start at the bottom and work up) and cut the inside of the coolant jacket on all passages of the rotor housings you want to. Next, move the plunger depth up 1/4" and do the next cuts and so on.
Its really easy and the only thing you have to watch out for is the cutter shaft breaking or creeping down out of the chuck of the drill press if you have a really cheap drillpress as I do.
I'm still trying to process this amazing news. Moving FC TII's from SSM to SM is a huge deal. As I understood it, the reason FC's were disallowed from SM was the need for 4 doors. Yeah, You'll still be racing Evo's, but look how heavy they are. Very cool.
Originally Posted by eage8
Finally got the rule clarification back from the scca:
#18364 SM eligibility inquiry
Per the SMAC, the 1986-1991 Mazda RX7 2+2 meets the requirements for the SM class and is thus allowed to compete in Street Modified.
That in addition to this rule:
16.1.K. Rear passenger seat(s), including restraints and associated hardware may be removed.
and the fact that all the things that make my car a turboII are free to change in SM means I can run in street modified instead of super street modified. So I can avoid FDs and other crazy 2 seat cars
and I called them up and it didn't seem to be a problem.
Originally Posted by cone_crushr
I'm still trying to process this amazing news. Moving FC TII's from SSM to SM is a huge deal. As I understood it, the reason FC's were disallowed from SM was the need for 4 doors. Yeah, You'll still be racing Evo's, but look how heavy they are. Very cool.
You actually just need 4 seats. which is why the 240SXs and stuff can run in SM too... and the GTRs....
There still might be a discussion about people not reading the rules the same way I am. but I verified the other day that my TII body has all the mounting mounts for rear seats (rear striker nuts in the rear strut towers and holes for the rear seat brackets). So the bodies are exactly the same. Just to make it more convincing I'm going to take the rear bins out and the rear carpet (which was attached to the rear seats so it is fair game)
I'm actually going to have to weigh my car to make sure I make minimum weight in SM (which if I recall correctly is about 200 lbs heavier than SSM)
Originally Posted by BLUE TII
I'm also going to send both housings off to racing beat to get the water jackets machined:
Rotor Housing Water Jacket Modification for RX7 1986-1992 - Racing Beat
If you have a drill press and would like to do this yourself it is really easy the way I do it.
Put a piece of plywood on the drillpress work surface to slide the rotor housing around on.
Get this Dremel bit #199.
Put a standoff on the shaft to control the cut depth and freewheel against the housing.
Lock down the drill press cut depth by moving one of the locknuts to the other end of the threaded plunger.
Set your first cut depth (I start at the bottom and work up) and cut the inside of the coolant jacket on all passages of the rotor housings you want to. Next, move the plunger depth up 1/4" and do the next cuts and so on.
Its really easy and the only thing you have to watch out for is the cutter shaft breaking or creeping down out of the chuck of the drill press if you have a really cheap drillpress as I do.
you sir... are braver than I. I would definitely do it if housings weren't so expensive...
you sir... are braver than I. I would definitely do it if housings weren't so expensive...
If you mess up you are just going to have an "ugly furrow" in your field. You can't actually hurt anything. The depth of the cut is just down to the increase in thickness Mazda added to this area on the '86+ engines for faster warm-up to meet the new cold-start emissions standards.
"On the water side of cooling, the trochoid chamber;s coolant jacket and the side coolant passages have been reducced in volume: altogether, the coolant capacity is down by 0.8 liters (0.85 quart), thanks to this and the other measures, warmup is 20 percent faster."
Pg. 46 Yamaguchi RX-7 with two accompanying photos comparing '85 to '86 rotor and side housings with coolant jackets in view.
You actually just need 4 seats. which is why the 240SXs and stuff can run in SM too... and the GTRs....
There still might be a discussion about people not reading the rules the same way I am. but I verified the other day that my TII body has all the mounting mounts for rear seats (rear striker nuts in the rear strut towers and holes for the rear seat brackets). So the bodies are exactly the same. Just to make it more convincing I'm going to take the rear bins out and the rear carpet (which was attached to the rear seats so it is fair game)
I'm actually going to have to weigh my car to make sure I make minimum weight in SM (which if I recall correctly is about 200 lbs heavier than SSM)
Street modified class (SM)
Eligible Vehicles
:
All sedans/coupes (models which were originally equipped with a minimum of four seats and four factory seat belts),
all FWD (front-wheel-
drive) cars, and pickup trucks (in compliance with Section 3.1 using SM
allowances and minimum weight calculation)
.
Excluded Vehicles
:
Porsche (all)
Lotus (all)
Nissan/Datsun Z-car 2+2 (pre-1990)
MGB GT
Triumph (all)
SCCA defines original equipment as US market only.
FCs did pass US rear passenger side impact standards and were sold with rear seats in the US.
FDs did not pass US rear passenger side impact standards so were not sold with rear seats in the US. If FDs had been sold with rear seats in the US, SCCA would just add them to the exclusion list.
Yes, I get that the rules state 4 seats, but look at the list of excluded cars. They're all 2-door sports cars like the RX7. The understanding in my region is that 2-doors play in SSM and 4-doors in SSM because the rules specifying seat count don't provide a good dividing line (presumably for the sake of rule simplicity) between car "types". The "clarification" eage8 received from SCCA dissolve that ambiguity for TII's.
I'm also going to send both housings off to racing beat to get the water jackets machined:
Rotor Housing Water Jacket Modification for RX7 1986-1992 - Racing Beat
If you have a drill press and would like to do this yourself it is really easy the way I do it.
Put a piece of plywood on the drillpress work surface to slide the rotor housing around on.
Get this Dremel bit #199.
Put a standoff on the shaft to control the cut depth and freewheel against the housing.
Lock down the drill press cut depth by moving one of the locknuts to the other end of the threaded plunger.
Set your first cut depth (I start at the bottom and work up) and cut the inside of the coolant jacket on all passages of the rotor housings you want to. Next, move the plunger depth up 1/4" and do the next cuts and so on.
Its really easy and the only thing you have to watch out for is the cutter shaft breaking or creeping down out of the chuck of the drill press if you have a really cheap drillpress as I do.
I cant quite picture your process, but the idea and info IS great Thanks for sharing!!
cone_crushr Yes, I get that the rules state 4 seats, but look at the list of excluded cars. They're all 2-door sports cars like the RX7. The understanding in my region is that 2-doors play in SSM and 4-doors in SSM because the rules specifying seat count don't provide a good dividing line (presumably for the sake of rule simplicity) between car "types". The "clarification" eage8 received from SCCA dissolve that ambiguity for TII's.
coupe1
ko͞op/
noun
noun: coupé; plural noun: coupés; noun: coupe; plural noun: coupes
1.
a car with a fixed roof and two doors.
2.
historical
a four-wheeled enclosed carriage for two passengers and a driver.
3.
historical
an end compartment in a railroad car, with seats on only one side.
Origin
se·dan
səˈdan/
noun
noun: sedan; plural noun: sedans; noun: sedan chair; plural noun: sedan chairs
1.
historical
an enclosed chair for conveying one person, carried between horizontal poles by two or more porters.
2.
North American
an enclosed automobile for four or more people, having two or four doors.
As you can see the rules specifically allow coupes (2 door cars with roofs) and sedans (2 or 4 door cars with roofs) in SM as long as they were originally equipped with at least 4 seats and 4 seat belts.
What SCCA was really trying to do with SM and SSM is separate **** boxes from performance based cars.
Now the lines are so blurred the intent doesn't really matter and we just have 2 classes with 200lbs weight difference and I believe all cars should be eligible for both classes.
What advantage would an SM FD RX-7 at 2,700lbs have over an RX-8 at 2,700lbs with the same allowed drivetrain? None, the RX-8 is the superior chassis design.
In SM at 2,500lbs the SSM FD RX-7 does have the advantage over the 2,700lb RX-8 and the RX-8 isn't likely to get to 2,500lbs with allowed mods.
You actually just need 4 seats. which is why the 240SXs and stuff can run in SM too... and the GTRs....
There still might be a discussion about people not reading the rules the same way I am. but I verified the other day that my TII body has all the mounting mounts for rear seats (rear striker nuts in the rear strut towers and holes for the rear seat brackets). So the bodies are exactly the same. Just to make it more convincing I'm going to take the rear bins out and the rear carpet (which was attached to the rear seats so it is fair game)
I'm actually going to have to weigh my car to make sure I make minimum weight in SM (which if I recall correctly is about 200 lbs heavier than SSM)
...
Where did you see the minimum weights are different for SSM and SM? The rule book is clear as mud. I swear you need to hire an attorney to build a 100% car. So calculating the minimum weight as I understand it allows us to run at 2500 lbs if you run 285's or bigger, 2300lbs if you run 275's. Am I correct?
By the way, I am excited to be here. I just picked up a 10AE that I was going to prep for SSM. The rule change is the first time the SEB has EVER made a decision that makes me happy. They have always moved classing in a way that pissed me off. Latest was a WRX that I was prepping for ESP. Two weeks after I spent $4,000 rebuilding their glass 5 speed trans for ESP rules, they started the change to move the Bugeye to ASP with it's big brother. If I would have known, I could have spent $1,000 less for the STi 6-speed and gotten all 3 lsd's with it, along with the bullet proof trans. Now I am poorer and only have one lsd and have a car that needs an entire drivetrain swap to be competitive. Anyway, rant over. I think the FC I'm building will be more fun anyway. Anyone want to buy a really clean bugeye wrx?
Where did you see the minimum weights are different for SSM and SM? The rule book is clear as mud. I swear you need to hire an attorney to build a 100% car. So calculating the minimum weight as I understand it allows us to run at 2500 lbs if you run 285's or bigger, 2300lbs if you run 275's. Am I correct?
By the way, I am excited to be here. I just picked up a 10AE that I was going to prep for SSM. The rule change is the first time the SEB has EVER made a decision that makes me happy. They have always moved classing in a way that pissed me off. Latest was a WRX that I was prepping for ESP. Two weeks after I spent $4,000 rebuilding their glass 5 speed trans for ESP rules, they started the change to move the Bugeye to ASP with it's big brother. If I would have known, I could have spent $1,000 less for the STi 6-speed and gotten all 3 lsd's with it, along with the bullet proof trans. Now I am poorer and only have one lsd and have a car that needs an entire drivetrain swap to be competitive. Anyway, rant over. I think the FC I'm building will be more fun anyway. Anyone want to buy a really clean bugeye wrx?
STREET MODIFIED CATEGORY
Engine Classifications
1. 4-stroke cycle and 2-stroke cycle naturally aspirated internal combustion
engines will be classified on the basis of actual piston displacement.
2. Supercharged or turbocharged SM and SSM engines will be classified
on a basis of adding 1.4L to the actual displacement. Forced induction
SMF engines will add 1.0L to the actual displacement.
3. Rotary Engines (Wankel): These units will be classified on the basis
of a piston displacement equivalent to 0.9 liters times the number of
rotors, plus the volume determined by the difference between the
maximum and minimum capacity of the working chamber times the
number of rotors.
4. Electric Motors: Cars with electric motors, in whole or part of the
drivetrain, will run at class maximum weight (2900 lbs for SSM,
3100 lbs for SM/SMF). Category weight adjustments (e.g., tire size)
are allowed.
Weight Adjustments
Cars running tires with a rated width of 275 mm or less on all four
wheels may compete at a minimum weight 200 lbs. less than their calculated
weight.
Street Modified Class (SM)
Eligible Vehicles:
All sedans/coupes (models which were originally equipped with a minimum
of four seats and four factory seat belts), all FWD (front-wheeldrive)
cars, and pickup trucks (in compliance with Section 3.1 using SM
allowances and minimum weight calculation).
Excluded Vehicles:
Porsche (all)
Lotus (all)
Nissan/Datsun Z-car 2+2 (pre-1990)
MGB GT
Triumph (all)
Minimum Weight Calculations (without driver):
FWD: 1550 lbs. + 125 lbs. per liter
RWD: 1800 lbs. + 200 lbs. per liter
AWD: 1800 lbs. + 300 lbs. per liter
Supercharged or Turbocharged SM engines: Add 1.4L to the actual displacement.
Rear wheel weight greater than 51%: +25 lbs. per liter
Solid axle RWD: -25 lbs. per liter
Tire width 275 mm or less: -200 lbs.
Regardless of the weight formulas above, no car will be required to
weigh more than 3100 lbs.
Super Street Modified Class (SSM)
Eligible Vehicles:
All two-seat cars not excluded below.
All SM eligible sedans/coupes excluded from SM.
All SM eligible vehicles.
Excluded Vehicles:
Lotus (all except Elise, Exige, & Esprit)
Vehicles not meeting minimum weights
Minimum Weight Calculations (without driver):
FWD: 1350 lbs. + 125 lbs. per liter
RWD: 1600 lbs. + 200 lbs. per liter
AWD: 1600 lbs. + 300 lbs. per liter
Supercharged or Turbocharged SSM engines: Add 1.4L to the actual
displacement.
Rear wheel weight greater than 51%: +25 lbs. per liter
Tire width 275 mm or less: -200 lbs.
Regardless of the weight formulas above, no car will be required to
weigh more than 2900 lbs.
And yes the 200lb weight break for tires 275mm rated width and under for SSM and SM, but not SMF.
So you could have a 2,300lb ND Miata on 275/35-15 competing with the 2,500lb FDs on 335mm tires in SSM with the same drivetrain (makes it interesting!).
in other news, no thermostats for electric water pumps (they don't work very well when your water pump is on the cold side of the thermostat). 1/2" NPT plug. the passage is already more or less the right size, you just have to grind down a little nubbin that's in there from where a bolt is on the other side.
I ordered an aluminum one since it'll be surrounded by coolant and it's in aluminum... but I'm not going to put any sealant on it.
01-28-16, 12:33 PM
Thanks for sharing!! 
