CosmoTT's full bridge port 13BT build thread
12-11-11, 04:18 PM
#27
BRAAAAAP pssh BRAAAAAP
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hey MaczPayne, it was from CoolTurbo, you can get them from ebay i believe, it was one of the best ones on there, 2" thick and held up to temp higher than all the others.
i think it was called CoolTurbo or something like that
i think it was called CoolTurbo or something like that
12-11-11, 04:22 PM
#28
http://stores.ebay.com/Cool-Turbo-Blankets
probably them.
and yes it's thick as hell, was difficult squeezing it in there.
unfortunately looks like they don't have anything for sale now and no site popped up with a search.
probably them.
and yes it's thick as hell, was difficult squeezing it in there.
unfortunately looks like they don't have anything for sale now and no site popped up with a search.
Last edited by RotaryEvolution; 12-11-11 at 04:25 PM.
12-11-11, 04:43 PM
#29
pinning requires milling the stock tension bolt holes through the whole engine so the whole block has to be done at the same time. there is also oversize tension bolts and studs which do similar but mostly pinning is deemed to be superior but a little bit more expensive to perform and not something for everyone as shipping a motor shell adds to the cost. some oversize bolts and studs also require milling the block, there is no easy way around it.
for durability, i can guarantee this engine won't come apart. most of the engines pushing up to and beyond 1k horsepower are pinned.
but also remember that even though the engine can no longer twist doesn't mean seals can't still blow out. but a good combination of seals like ALS/Goopy in combination with pinning is about as bulletproof of a rotary engine as we will likely ever see.
for durability, i can guarantee this engine won't come apart. most of the engines pushing up to and beyond 1k horsepower are pinned.
but also remember that even though the engine can no longer twist doesn't mean seals can't still blow out. but a good combination of seals like ALS/Goopy in combination with pinning is about as bulletproof of a rotary engine as we will likely ever see.
to elaborate on this i did speak to Goopy racing a while back about their motors and what they had seen with their highest horsepower builds. with an engine over 1000 horsepower they did find that upon reassembly the dowels did not fit exactly right meaning the pins or the block had started to deform. he did not elaborate on which it was or possibly didn't know for sure.
at any rate the engine was still ok and put back together, they later switched to milling the whole length of the engine to use thick studs to act as dowels. i doubt either method is really superior and each requires about the same amount of effort to accomplish.
the twisting forces on the engine at that power level is just going to twist the motor regardless of any safety measures but in the end they still do their job. i mean how long would anyone expect a 1.3liter engine to push out over 1000 wheel horsepower? it won't last indefinitely as nothing does but it's the best we can hope to expect without using some space age materials that NASA uses.
going beyond 1000 horsepower will likely need even more ideas to improve up on the design. but how far can we really go? that is the million dollar question. is there a turbo efficient enough to realistically go beyond that? add nitrous to spool a turbo larger than the engine? 1500 horsepower from a 2 rotor? will even the toughest apex seals survive the environment? will the rotor faces cave in due to the extreme pressures? time will tell.
Last edited by RotaryEvolution; 12-11-11 at 04:49 PM.
12-12-11, 05:51 PM
#30
made a separate thread regarding timing the engine and how i came up with a solution to check every engine moving forward.
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/how-properly-time-your-engine-while-disassembled-980099/
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/how-properly-time-your-engine-while-disassembled-980099/
12-12-11, 06:22 PM
#31
part of the issue was the lack of original pulley and how each set is a "matched pair". i translated the marks from the pulley on my own personal vehicle to the gilmer drive pulley on this engine as there realistically is no other way to properly find TDC without the engine torn apart. even the keyway method is a rough ballpark at best and can go either way.
the timing mark i used was on the peak of the gear drive where the paint was rubbed off in the middle. timing was advanced about 10 degrees. not good for a high boost high compression 9.4:1 engine. this is with the engine timed to 5*ATDC which is even further advanced than most stock pulleys are stamped to read.
the timing mark i used was on the peak of the gear drive where the paint was rubbed off in the middle. timing was advanced about 10 degrees. not good for a high boost high compression 9.4:1 engine. this is with the engine timed to 5*ATDC which is even further advanced than most stock pulleys are stamped to read.
12-12-11, 06:27 PM
#32
Red Pill Dealer
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Karack, if you would like a nice, machined mark, exactly 90* from the keyway and on center, send me your pulley.
I'll do it for free if you pay the shipping.
Make sure the keyway side play is not excessive or you're still just guessing. I suppose, if the rotor is not at BDC when the pulley is installed, one is still guessing because the accuracy of the pointer is not verified either but hey, I could help you with an accurately marked pulley.
I'll do it for free if you pay the shipping.
Make sure the keyway side play is not excessive or you're still just guessing. I suppose, if the rotor is not at BDC when the pulley is installed, one is still guessing because the accuracy of the pointer is not verified either but hey, I could help you with an accurately marked pulley.
Last edited by TonyD89; 12-12-11 at 06:30 PM.
12-12-11, 06:39 PM
#33
Karack, if you would like a nice, machined mark, exactly 90* from the keyway and on center, send me your pulley.
I'll do it for free if you pay the shipping.
Make sure the keyway side play is not excessive or you're still just guessing. I suppose, if the rotor is not at BDC when the pulley is installed, one is still guessing because the accuracy of the pointer is not verified either but hey, I could help you with an accurately marked pulley.
I'll do it for free if you pay the shipping.
Make sure the keyway side play is not excessive or you're still just guessing. I suppose, if the rotor is not at BDC when the pulley is installed, one is still guessing because the accuracy of the pointer is not verified either but hey, I could help you with an accurately marked pulley.
in the linked thread the method was used to find true TDC to mark the bare gilmer drive pulley as well as stamp it for the reference marks as it can bolt on 2 ways.
if anything on these engines i would say the front cover pointer is probably the most accurate part of the ignition system... lol.
what i do plan on doing for the future though is use the engine oil pan deck to make a pointer base from for the huge degree wheel. then there will be 2 pointers to verify even if the front cover somehow was cast improperly.
Last edited by RotaryEvolution; 12-12-11 at 06:42 PM.
12-16-11, 07:39 PM
#37
Bridgeporting explained
disclaimer: keep in mind even if you think you are an expert at porting this will put your skills to the test, be warned before attempting this
seeing as how there isn't many writeups on bridging irons i will give a slightly rough writeup on the subject.
first start with a stock port iron, get a bridgeport template and mark your porting. most "real" bridges involve cutting an opening into the rotor housing for the bridge to actually breathe well enough to give a decent port diameter to the bridge, this will go into that process.
after you have the iron marked with paint or ink, go to the bridge with a center punch and stamp about 7-8 markings equally space along the center of your bridge template marking. next get a rather small drill and put the iron on your drill press and begin your "cheese port"(will look like swiss cheese once done with this step). be careful once near the bottom of the port not to go too fast or the bit will break in the cast iron, don't worry you will see how to take care of that soon.
drill all the stamped marks through into the port area, be careful at the marking at the very top of your port as it may NOT go into the port, if you drill it all the way through it will go into the water jacket resulting in a junk iron so do not cry to me about it. look at the angles while drilling to be sure this doesn't happen.
once you have all the holes drilled with the smaller drill, move to your dremel and pick up some small cut off wheels, preferrably the mesh carbon discs as the stone type will blow up left and right during this process. now with the small cutoff wheel, eye protection and preferably a dust mask(unless you like the taste of iron for a few days) cut between each of your drilled holes until all the way through to the port area. switch side and do this process a few more times to cut out the "cheesed" area to open up the port.
note the broken bit at the bottom of this picture?
it will fall out during the cutting process or you can at least remove any pieces if you do break a bit during the previous step. now it's gone, fell out.
keep opening the port until you can fit a small "chain saw sharpening bit" into the port, about 4mm wide.
now with your bit open the port up a bit, do not port too far towards the coolant seal but your aim will be to have a wall thickness there of about 1.5mm once done.
next you need some special bits to "undercut" the opening of the port. some people do not do this, but this is where your flow really begins to shine with a bridge. if the port was straight down the air would have to do a 90* and up a narrow path to enter the engine, doing literally nothing for performance aside from idle "brap" and wasted gas mileage.
take your bit and port under the opening towards the intake manifold side up into the bridge to open it up and let it breathe. be careful towards the top edge of the port as you can and likely will burn through into the water passage, i have ruined numerous irons being too aggressive with the undercutting process.
now go back through with your blade sharpening bit and dremel and round off the edges leading from the inside of the engine going into the port being careful not to gouge the opposite wall of the port opening. this further opens the port entrance allowing air to flow better.
and your semi finished product, now you can clean up the rest of the port work on the port to finish it up.
overall dimensions of this port is:
bridge to coolant seal wall thickness = 1.5mm
bridge port width = 5mm
bridge to secondary port thickness = 5.65mm
bridge to intake port thickness = 5.7mm
bridge length = 51.5mm
you can undercut more than this for even better flow but it takes exponentially longer and gives you much more room for screwing up and botching an iron.
this is a rather aggressive bridge design but it is still rather reliable, about as aggressive as you can hope for with opening the secondary ports as large as you can go while retaining bridge durability.
this process requires the apex seals to be positioned directionally. the end of the long seal must line up with your secondary ports otherwise you run the risk of the apex seal boot pushing into the pocket in the rotor housing to bridge. you will see what i mean soon when i post pictures of the rotor housing modification.
don't mind the rough cut on the intake port itself, it is not done in that picture.
disclaimer: keep in mind even if you think you are an expert at porting this will put your skills to the test, be warned before attempting this
seeing as how there isn't many writeups on bridging irons i will give a slightly rough writeup on the subject.
first start with a stock port iron, get a bridgeport template and mark your porting. most "real" bridges involve cutting an opening into the rotor housing for the bridge to actually breathe well enough to give a decent port diameter to the bridge, this will go into that process.
after you have the iron marked with paint or ink, go to the bridge with a center punch and stamp about 7-8 markings equally space along the center of your bridge template marking. next get a rather small drill and put the iron on your drill press and begin your "cheese port"(will look like swiss cheese once done with this step). be careful once near the bottom of the port not to go too fast or the bit will break in the cast iron, don't worry you will see how to take care of that soon.
drill all the stamped marks through into the port area, be careful at the marking at the very top of your port as it may NOT go into the port, if you drill it all the way through it will go into the water jacket resulting in a junk iron so do not cry to me about it. look at the angles while drilling to be sure this doesn't happen.
once you have all the holes drilled with the smaller drill, move to your dremel and pick up some small cut off wheels, preferrably the mesh carbon discs as the stone type will blow up left and right during this process. now with the small cutoff wheel, eye protection and preferably a dust mask(unless you like the taste of iron for a few days) cut between each of your drilled holes until all the way through to the port area. switch side and do this process a few more times to cut out the "cheesed" area to open up the port.
note the broken bit at the bottom of this picture?
it will fall out during the cutting process or you can at least remove any pieces if you do break a bit during the previous step. now it's gone, fell out.
keep opening the port until you can fit a small "chain saw sharpening bit" into the port, about 4mm wide.
now with your bit open the port up a bit, do not port too far towards the coolant seal but your aim will be to have a wall thickness there of about 1.5mm once done.
next you need some special bits to "undercut" the opening of the port. some people do not do this, but this is where your flow really begins to shine with a bridge. if the port was straight down the air would have to do a 90* and up a narrow path to enter the engine, doing literally nothing for performance aside from idle "brap" and wasted gas mileage.
take your bit and port under the opening towards the intake manifold side up into the bridge to open it up and let it breathe. be careful towards the top edge of the port as you can and likely will burn through into the water passage, i have ruined numerous irons being too aggressive with the undercutting process.
now go back through with your blade sharpening bit and dremel and round off the edges leading from the inside of the engine going into the port being careful not to gouge the opposite wall of the port opening. this further opens the port entrance allowing air to flow better.
and your semi finished product, now you can clean up the rest of the port work on the port to finish it up.
overall dimensions of this port is:
bridge to coolant seal wall thickness = 1.5mm
bridge port width = 5mm
bridge to secondary port thickness = 5.65mm
bridge to intake port thickness = 5.7mm
bridge length = 51.5mm
you can undercut more than this for even better flow but it takes exponentially longer and gives you much more room for screwing up and botching an iron.
this is a rather aggressive bridge design but it is still rather reliable, about as aggressive as you can hope for with opening the secondary ports as large as you can go while retaining bridge durability.
this process requires the apex seals to be positioned directionally. the end of the long seal must line up with your secondary ports otherwise you run the risk of the apex seal boot pushing into the pocket in the rotor housing to bridge. you will see what i mean soon when i post pictures of the rotor housing modification.
don't mind the rough cut on the intake port itself, it is not done in that picture.
Last edited by RotaryEvolution; 12-16-11 at 08:01 PM.
12-17-11, 01:54 AM
#40
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part of the issue was the lack of original pulley and how each set is a "matched pair". i translated the marks from the pulley on my own personal vehicle to the gilmer drive pulley on this engine as there realistically is no other way to properly find TDC without the engine torn apart. even the keyway method is a rough ballpark at best and can go either way.
the timing mark i used was on the peak of the gear drive where the paint was rubbed off in the middle. timing was advanced about 10 degrees. not good for a high boost high compression 9.4:1 engine. this is with the engine timed to 5*ATDC which is even further advanced than most stock pulleys are stamped to read.
the timing mark i used was on the peak of the gear drive where the paint was rubbed off in the middle. timing was advanced about 10 degrees. not good for a high boost high compression 9.4:1 engine. this is with the engine timed to 5*ATDC which is even further advanced than most stock pulleys are stamped to read.
12-17-11, 02:23 AM
#42
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Thats why you find TDC with the tool, mark your pully as such. Then scribe the DIA of the front pully you are using on to the degree wheel. From there you just pull the degrees you want back to the centre of the degree wheel. Were it crosses your pulley scribe mark, is what you mark on your pully with a pair of dividers. To easy and you can check both front and back rotors with out taking the motor apart. You dont need the key way and no need to take your front pully of.
12-18-11, 12:44 AM
#43
engine shell cleaned and repainted before reassembly, rotors cleaned, reassembled and spec'ed.
to each their own, no offense to you guys who have your own ways of measuring TDC but i'll stick to my own way which relies strictly on the keyway(which will always be 100% accurate as mazda has never varied from the e-shaft machining specs) and not the inaccurate pulleys or hubs. i work on many many engines and needed to make a tool that works for every single one of them, accurately. any other method relies that the hub bolt pattern is exact to match your pulley, so far i have found that it does not work reliably, at least here in the US where there are various hub and pulley combos over the years.
after i spent that one day working on that degree wheel i simply will not accept any other method. the degree wheel is scribed on the backside for TDC as is the pulley it's mated to marked for TDC. the thread linked explains my findings throughout the process and may shed some light to why i feel strongly against other methods.
i have also never munched a thrust bearing either.
Thats why you find TDC with the tool, mark your pully as such. Then scribe the DIA of the front pully you are using on to the degree wheel. From there you just pull the degrees you want back to the centre of the degree wheel. Were it crosses your pulley scribe mark, is what you mark on your pully with a pair of dividers. To easy and you can check both front and back rotors with out taking the motor apart. You dont need the key way and no need to take your front pully of.
to each their own, no offense to you guys who have your own ways of measuring TDC but i'll stick to my own way which relies strictly on the keyway(which will always be 100% accurate as mazda has never varied from the e-shaft machining specs) and not the inaccurate pulleys or hubs. i work on many many engines and needed to make a tool that works for every single one of them, accurately. any other method relies that the hub bolt pattern is exact to match your pulley, so far i have found that it does not work reliably, at least here in the US where there are various hub and pulley combos over the years.
after i spent that one day working on that degree wheel i simply will not accept any other method. the degree wheel is scribed on the backside for TDC as is the pulley it's mated to marked for TDC. the thread linked explains my findings throughout the process and may shed some light to why i feel strongly against other methods.
i have also never munched a thrust bearing either.
Last edited by RotaryEvolution; 12-18-11 at 12:55 AM.
