Finding port timing with CAD
04-27-11, 09:05 PM
#1
Finding port timing with CAD
So, I've spent some time in SolidWorks modeling a rotor housing, rotor and e-shaft as accurately as I can (I only have a 0-1" mic and a pair of cheap digi calipers). I have a working model that has a 'similar' geometry to what it should look like. The rotor housing was tough. I was having the trouble getting the trochoid shape, but ended up using two cemicircles and replicating the curve in between.
Here is my question:
I am using the MFR peripheral port timing for intake as an example.
IO 86° BTDC
IC 75° ABDC
What I'm confused about is the fact that I cant make out how the intake is open. Maybe my model is off enough that I can't see the subtleties of how it opens. It's pretty obvious to see how the intake closes, as the apex seal passes over where the port would be.
Ive attached pictures to help clarify.
The first is Intake opening, second is closing.
Note: the random rectangles in the part are there to give reference to TDC/BDC
Here is my question:
I am using the MFR peripheral port timing for intake as an example.
IO 86° BTDC
IC 75° ABDC
What I'm confused about is the fact that I cant make out how the intake is open. Maybe my model is off enough that I can't see the subtleties of how it opens. It's pretty obvious to see how the intake closes, as the apex seal passes over where the port would be.
Ive attached pictures to help clarify.
The first is Intake opening, second is closing.
Note: the random rectangles in the part are there to give reference to TDC/BDC
04-27-11, 11:53 PM
#2
Cool! The port timing thing always confuses me because you have TDC, BDC ATDC, ect. You may have to program all these parameters in. Funny I see things better in my head than trying to work with the numbers side of things. LOL!
http://www.rotaryengineillustrated.c...-ports101.html
Ok your 1st pic is way off if that's suppose to be open. When a PP begins to open, it's more at BDC (see #4 in this link http://www.turborx7.com/images/repics/rotcyc.gif). In your 1st pic, the PP is closed there as the apex seal is well past a NORMAL closing position for a PP but full open for the next cycle. The 2nd pic is more in line with a closed PP.
http://www.rotaryengineillustrated.c...-ports101.html
Ok your 1st pic is way off if that's suppose to be open. When a PP begins to open, it's more at BDC (see #4 in this link http://www.turborx7.com/images/repics/rotcyc.gif). In your 1st pic, the PP is closed there as the apex seal is well past a NORMAL closing position for a PP but full open for the next cycle. The 2nd pic is more in line with a closed PP.
04-28-11, 10:43 PM
#5
So, I think I wrapped my head around some of this.I'll try to explain and attach pictures to go with my reasoning.
If the e-shaft lobe is at 9 o'clock, The intake is at TDC. Minimum volume.
If the e-shaft lobe is at 6 o'clock, The intake is at BDC, Maximum volume.
If the e-shaft lobe is at 3 o'clock, The exhaust is at TDC, Minimum volume.
If the e-shaft lobe is at 12 o'clock, The exhaust is at BDC, Maximum volume.
Each cycle takes 270* of crank rotation.
1080* of crank rotation for 360* of rotor rotation.
1080/270=4, 4 stroke. Make since?
Here are picutes of TDC and BDC of both the intake and exhaust cycles.
Also attached, opening and closing pictures for the MFR Peripheral Port, IO 86° BTDC IC 75° ABDC
I measured the distance between the opening and closing points of the PP. 43mm. Sounds reasonable.
If anyone's interested, I can try modeling side ports.
-Alex
If the e-shaft lobe is at 9 o'clock, The intake is at TDC. Minimum volume.
If the e-shaft lobe is at 6 o'clock, The intake is at BDC, Maximum volume.
If the e-shaft lobe is at 3 o'clock, The exhaust is at TDC, Minimum volume.
If the e-shaft lobe is at 12 o'clock, The exhaust is at BDC, Maximum volume.
Each cycle takes 270* of crank rotation.
1080* of crank rotation for 360* of rotor rotation.
1080/270=4, 4 stroke. Make since?
Here are picutes of TDC and BDC of both the intake and exhaust cycles.
Also attached, opening and closing pictures for the MFR Peripheral Port, IO 86° BTDC IC 75° ABDC
I measured the distance between the opening and closing points of the PP. 43mm. Sounds reasonable.
If anyone's interested, I can try modeling side ports.
-Alex
04-30-11, 05:23 AM
#7
Old [Sch|F]ool
You don't care about the "9 o'clock" position, as that is TDC for the spark plugs.
"3 o'clock" is TDC as the exhaust and intake care.
"6 o'clock" is BDC as the intake cares. "12 o'clock" is BDC as the exhaust cares.
Just like as in a piston engine, the BDC for intake timing happens AFTER the overlap event while the BDC for exhaust timing happens BEFORE the overlap event.
The fun part, for you, is that the open timing is handled by the leading apex seal and the closing timing is handled by the trailing apex seal.
What this means is, TDC as it relates to intake opening is going to be a lot higher on the housing than BDC as it relates to intake closing. (A port that opens at TDC and closes at BDC, for example, would have a significantly negative hole size, AKA it is physically impossible)
It will be fun because you will have to plot the position of both seals, which will not be a simple 1:1 transfer function, since the nature of the eccentrically geared rotor means that one degree is a different length on the circumference, EVERYWHERE. There's a definite variation between BDC and 10ABDC, versus 50BABDC and 60 ABDC.
What I simply did was put together a front housing, rotor housing, E-shaft, and one apex seal, stick the largest degree wheel I could find on the nose of the e-shaft, and manually mark it all out. It was kinda neat. I still have the rotor housing with all the degree hash marks scribed into it, but it's kind of in an engine right now and I can't show you...
"3 o'clock" is TDC as the exhaust and intake care.
"6 o'clock" is BDC as the intake cares. "12 o'clock" is BDC as the exhaust cares.
Just like as in a piston engine, the BDC for intake timing happens AFTER the overlap event while the BDC for exhaust timing happens BEFORE the overlap event.
The fun part, for you, is that the open timing is handled by the leading apex seal and the closing timing is handled by the trailing apex seal.
What this means is, TDC as it relates to intake opening is going to be a lot higher on the housing than BDC as it relates to intake closing. (A port that opens at TDC and closes at BDC, for example, would have a significantly negative hole size, AKA it is physically impossible)
It will be fun because you will have to plot the position of both seals, which will not be a simple 1:1 transfer function, since the nature of the eccentrically geared rotor means that one degree is a different length on the circumference, EVERYWHERE. There's a definite variation between BDC and 10ABDC, versus 50BABDC and 60 ABDC.
What I simply did was put together a front housing, rotor housing, E-shaft, and one apex seal, stick the largest degree wheel I could find on the nose of the e-shaft, and manually mark it all out. It was kinda neat. I still have the rotor housing with all the degree hash marks scribed into it, but it's kind of in an engine right now and I can't show you...
Trending Topics
04-30-11, 04:55 PM
#8
I drew out a few different port openings. The later the intake closes, the heighth of the port goes up almost exponentially. The adding an extra 5* of intake closing and moving the opening time 6* LATER (so effectively having only 1* LESS duration), the final port was nearly half an inch taller! This is because of the curvature of the top half of the rotor housing. Knowing this know, the actual size of the port can be a bit deceiving. A monstrously tall port can have a similar duration with fairly similar port timing to a relatively small port that is slightly lower in the housing.
Here are some screen shots.
The first port:
IO 86° BTDC
IC 75° ABDC
Port height: 1.675
Second port:
IO 80° BTDC
IC 80° ABDC
Port height: 2.031
As you can see, the second port has LESS duration, but is significantly larger in size!
Here are some screen shots.
The first port:
IO 86° BTDC
IC 75° ABDC
Port height: 1.675
Second port:
IO 80° BTDC
IC 80° ABDC
Port height: 2.031
As you can see, the second port has LESS duration, but is significantly larger in size!
04-30-11, 09:49 PM
#10
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,802
Received 2,577 Likes
on
1,831 Posts
What I simply did was put together a front housing, rotor housing, E-shaft, and one apex seal, stick the largest degree wheel I could find on the nose of the e-shaft, and manually mark it all out. It was kinda neat. I still have the rotor housing with all the degree hash marks scribed into it, but it's kind of in an engine right now and I can't show you...
04-30-11, 10:08 PM
#11
The 80 open/80 close port is one of the later ports mazda ran. Someone posted a SAE from around 1990 where mazda said that was their "optimized" port timing.
Here's the quote from NoPistons.
[quote name='Kenku' timestamp='1079717949' post='487133']
Picked up an SAE paper the other day; by Mazda, from '90... paper #900032 if you have access to a library with the SAE transactions. It's modeling power output of peripheral port motors, followed by coming up with an "optimum" port timing. What's interesting is that the port timings they come up with are completely different than any other published ones I've yet seen. The "baseline" port shape is about the same as the published values for the MFR ports on Paul Yaw's site, but the "optimized" port is... well, I'll just come up with a little chart.
Baseline Optimized
Exhaust Open 73 BBDC 73 BBDC
Exhaust Closed 65 ATDC 55 ATDC
Exhaust Area 9.2cm^2 12.5cm^2
Intake Open 100 BTDC 80 BTDC
Intake Closed 75 ABDC 80 ABDC
Intake Area 20cm^2 25cm^2
Runner Diameter 43mm 46mm
Note that there's both less port timing and more area... and all the port timing changes made for less overlap. The ports are a lot more rectangular, extending out towards the edges of the rotor housings farther than the more square baseline ones. The model says that 30cm^2 ports will get even *MORE* flow across the 7-9k RPM band, but only by around 1% over the 25. And I have to wonder if there's room to *fit* 30 cm of port area without going the whole width of the housing.
Oh yeah, also note that the port they publish for the "baseline" one opens the intake 14 degrees earlier than the MFR one Yaw has the data for, but is otherwise identical. This might be explained by the fact that all the MFR housings I've seen for sale are supposed to be for earlier motors, so perhaps there's even development work done between the later MFR housings and the ones we're familiar with.
They don't actually publish very detailed dyno results. The "optimized" timing beats the "baseline" port by a good 2-5% volumetric efficiency from 7500 RPM on up, and trails by 1-2% below. The one dyno plot they have is of a 3-rotor motor, and seems to indicate a gain of 30hp at 8500 and 50hp at 9000, while only losing 10hp at 7k or below. Absolute power numbers... aren't on the graph, regrettably. And even the comparison numbers are estimates, as the graph is of a type used to merely show a trend. They *DO* have real test results in it to validate the model, though.
The capper to this is that the time of the paper (and some of the talk about variable length intake tracts on a 4-rotor later on in the paper) seem to indicate that this was either being developed for the R26B LeMans motor or for a follow-on effort... either way, it makes me *REALLY* curious.
Thought some of you might be interested, or maybe some experienced builders would have comments.
[/quote]
j9fd3s, do you have the 787 SAE paper or know the number? I'm a SAE member and should have access to the paper if it's not public.
Here's the quote from NoPistons.
[quote name='Kenku' timestamp='1079717949' post='487133']
Picked up an SAE paper the other day; by Mazda, from '90... paper #900032 if you have access to a library with the SAE transactions. It's modeling power output of peripheral port motors, followed by coming up with an "optimum" port timing. What's interesting is that the port timings they come up with are completely different than any other published ones I've yet seen. The "baseline" port shape is about the same as the published values for the MFR ports on Paul Yaw's site, but the "optimized" port is... well, I'll just come up with a little chart.
Baseline Optimized
Exhaust Open 73 BBDC 73 BBDC
Exhaust Closed 65 ATDC 55 ATDC
Exhaust Area 9.2cm^2 12.5cm^2
Intake Open 100 BTDC 80 BTDC
Intake Closed 75 ABDC 80 ABDC
Intake Area 20cm^2 25cm^2
Runner Diameter 43mm 46mm
Note that there's both less port timing and more area... and all the port timing changes made for less overlap. The ports are a lot more rectangular, extending out towards the edges of the rotor housings farther than the more square baseline ones. The model says that 30cm^2 ports will get even *MORE* flow across the 7-9k RPM band, but only by around 1% over the 25. And I have to wonder if there's room to *fit* 30 cm of port area without going the whole width of the housing.
Oh yeah, also note that the port they publish for the "baseline" one opens the intake 14 degrees earlier than the MFR one Yaw has the data for, but is otherwise identical. This might be explained by the fact that all the MFR housings I've seen for sale are supposed to be for earlier motors, so perhaps there's even development work done between the later MFR housings and the ones we're familiar with.
They don't actually publish very detailed dyno results. The "optimized" timing beats the "baseline" port by a good 2-5% volumetric efficiency from 7500 RPM on up, and trails by 1-2% below. The one dyno plot they have is of a 3-rotor motor, and seems to indicate a gain of 30hp at 8500 and 50hp at 9000, while only losing 10hp at 7k or below. Absolute power numbers... aren't on the graph, regrettably. And even the comparison numbers are estimates, as the graph is of a type used to merely show a trend. They *DO* have real test results in it to validate the model, though.
The capper to this is that the time of the paper (and some of the talk about variable length intake tracts on a 4-rotor later on in the paper) seem to indicate that this was either being developed for the R26B LeMans motor or for a follow-on effort... either way, it makes me *REALLY* curious.
Thought some of you might be interested, or maybe some experienced builders would have comments.
[/quote]
j9fd3s, do you have the 787 SAE paper or know the number? I'm a SAE member and should have access to the paper if it's not public.
04-30-11, 10:11 PM
#12
The 80 open/80 close port is one of the later ports mazda ran. Someone posted a SAE from around 1990 where mazda said that was their "optimized" port timing.
Here's the quote from NoPistons.
j9fd3s, do you have the 787 SAE paper or know the number? I'm a SAE member and should have access to the paper if it's not public.
Here's the quote from NoPistons.
Picked up an SAE paper the other day; by Mazda, from '90... paper #900032 if you have access to a library with the SAE transactions. It's modeling power output of peripheral port motors, followed by coming up with an "optimum" port timing. What's interesting is that the port timings they come up with are completely different than any other published ones I've yet seen. The "baseline" port shape is about the same as the published values for the MFR ports on Paul Yaw's site, but the "optimized" port is... well, I'll just come up with a little chart.
Baseline Optimized
Exhaust Open 73 BBDC 73 BBDC
Exhaust Closed 65 ATDC 55 ATDC
Exhaust Area 9.2cm^2 12.5cm^2
Intake Open 100 BTDC 80 BTDC
Intake Closed 75 ABDC 80 ABDC
Intake Area 20cm^2 25cm^2
Runner Diameter 43mm 46mm
Note that there's both less port timing and more area... and all the port timing changes made for less overlap. The ports are a lot more rectangular, extending out towards the edges of the rotor housings farther than the more square baseline ones. The model says that 30cm^2 ports will get even *MORE* flow across the 7-9k RPM band, but only by around 1% over the 25. And I have to wonder if there's room to *fit* 30 cm of port area without going the whole width of the housing.
Oh yeah, also note that the port they publish for the "baseline" one opens the intake 14 degrees earlier than the MFR one Yaw has the data for, but is otherwise identical. This might be explained by the fact that all the MFR housings I've seen for sale are supposed to be for earlier motors, so perhaps there's even development work done between the later MFR housings and the ones we're familiar with.
They don't actually publish very detailed dyno results. The "optimized" timing beats the "baseline" port by a good 2-5% volumetric efficiency from 7500 RPM on up, and trails by 1-2% below. The one dyno plot they have is of a 3-rotor motor, and seems to indicate a gain of 30hp at 8500 and 50hp at 9000, while only losing 10hp at 7k or below. Absolute power numbers... aren't on the graph, regrettably. And even the comparison numbers are estimates, as the graph is of a type used to merely show a trend. They *DO* have real test results in it to validate the model, though.
The capper to this is that the time of the paper (and some of the talk about variable length intake tracts on a 4-rotor later on in the paper) seem to indicate that this was either being developed for the R26B LeMans motor or for a follow-on effort... either way, it makes me *REALLY* curious.
Thought some of you might be interested, or maybe some experienced builders would have comments.
Baseline Optimized
Exhaust Open 73 BBDC 73 BBDC
Exhaust Closed 65 ATDC 55 ATDC
Exhaust Area 9.2cm^2 12.5cm^2
Intake Open 100 BTDC 80 BTDC
Intake Closed 75 ABDC 80 ABDC
Intake Area 20cm^2 25cm^2
Runner Diameter 43mm 46mm
Note that there's both less port timing and more area... and all the port timing changes made for less overlap. The ports are a lot more rectangular, extending out towards the edges of the rotor housings farther than the more square baseline ones. The model says that 30cm^2 ports will get even *MORE* flow across the 7-9k RPM band, but only by around 1% over the 25. And I have to wonder if there's room to *fit* 30 cm of port area without going the whole width of the housing.
Oh yeah, also note that the port they publish for the "baseline" one opens the intake 14 degrees earlier than the MFR one Yaw has the data for, but is otherwise identical. This might be explained by the fact that all the MFR housings I've seen for sale are supposed to be for earlier motors, so perhaps there's even development work done between the later MFR housings and the ones we're familiar with.
They don't actually publish very detailed dyno results. The "optimized" timing beats the "baseline" port by a good 2-5% volumetric efficiency from 7500 RPM on up, and trails by 1-2% below. The one dyno plot they have is of a 3-rotor motor, and seems to indicate a gain of 30hp at 8500 and 50hp at 9000, while only losing 10hp at 7k or below. Absolute power numbers... aren't on the graph, regrettably. And even the comparison numbers are estimates, as the graph is of a type used to merely show a trend. They *DO* have real test results in it to validate the model, though.
The capper to this is that the time of the paper (and some of the talk about variable length intake tracts on a 4-rotor later on in the paper) seem to indicate that this was either being developed for the R26B LeMans motor or for a follow-on effort... either way, it makes me *REALLY* curious.
Thought some of you might be interested, or maybe some experienced builders would have comments.
05-01-11, 11:34 AM
#13
Senior Member
Join Date: Nov 2008
Location: Czech republic
Posts: 357
Likes: 0
Received 0 Likes
on
0 Posts
They don't actually publish very detailed dyno results. The "optimized" timing beats the "baseline" port by a good 2-5% volumetric efficiency from 7500 RPM on up, and trails by 1-2% below. The one dyno plot they have is of a 3-rotor motor, and seems to indicate a gain of 30hp at 8500 and 50hp at 9000, while only losing 10hp at 7k or below. Absolute power numbers... aren't on the graph, regrettably. And even the comparison numbers are estimates, as the graph is of a type used to merely show a trend. They *DO* have real test results in it to validate the model, though...
Its just speculation, but I think its preaty spot-on.
This is certainly very interesting, whole picture of area/degree relationship of peripheral ports, not only in duration on its own, but its very timing also
05-01-11, 05:32 PM
#14
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,802
Received 2,577 Likes
on
1,831 Posts
The 80 open/80 close port is one of the later ports mazda ran. Someone posted a SAE from around 1990 where mazda said that was their "optimized" port timing.
Here's the quote from NoPistons.
j9fd3s, do you have the 787 SAE paper or know the number? I'm a SAE member and should have access to the paper if it's not public.
Here's the quote from NoPistons.
j9fd3s, do you have the 787 SAE paper or know the number? I'm a SAE member and should have access to the paper if it's not public.
the other interesting tidbit is that mazda only listed 2 part numbers for the 13B P port housings.
4801-10-100 and ZR03-10-B10.
the 4801-10-100 is the one most commonly listed, and sold in the US, part number dates from the 70's
the ZR03-10-B10 is listed in the 3 rotor section from my 97-98 mazdaspeed catalog, its not the mazda comp, but an actual japanese mazdaspeed book. this is the "over the counter" 450hp 3 rotor engine. slide throttle efi, dry sump etc etc.
the weird part is we checked availability and mazda had neither, but both numbers would have shipped the same part.
so ok, what's weird about that? what's weird about that, is i have seen a couple of variations in MFR housings, the later dry sump engines loose the little dog leg flare out part for the oil pan, and are just straight. what part number were those housings?
and of course also there are the 3 plug R26B housings. which have a different dowel pin location.
so what do we know? we know there is one style, from 1978? 1979? that services the 13B and 13J/450hp 3 rotor. which are not available anymore. we also know there is a housing that works with a dry sump engine and has a different oil pan rail foot print, but no part number. the "optimized" "500hp 3 rotor" port might be this one...
we also know there is a 3 plug housing, but again no part number.
05-01-11, 09:37 PM
#15
http://www.scribd.com/doc/7062188/Ma...-Engine-LeMans SAE#920309
the other interesting tidbit is that mazda only listed 2 part numbers for the 13B P port housings.
4801-10-100 and ZR03-10-B10.
the 4801-10-100 is the one most commonly listed, and sold in the US, part number dates from the 70's
the ZR03-10-B10 is listed in the 3 rotor section from my 97-98 mazdaspeed catalog, its not the mazda comp, but an actual japanese mazdaspeed book. this is the "over the counter" 450hp 3 rotor engine. slide throttle efi, dry sump etc etc.
the weird part is we checked availability and mazda had neither, but both numbers would have shipped the same part.
so ok, what's weird about that? what's weird about that, is i have seen a couple of variations in MFR housings, the later dry sump engines loose the little dog leg flare out part for the oil pan, and are just straight. what part number were those housings?
and of course also there are the 3 plug R26B housings. which have a different dowel pin location.
so what do we know? we know there is one style, from 1978? 1979? that services the 13B and 13J/450hp 3 rotor. which are not available anymore. we also know there is a housing that works with a dry sump engine and has a different oil pan rail foot print, but no part number. the "optimized" "500hp 3 rotor" port might be this one...
we also know there is a 3 plug housing, but again no part number.
the other interesting tidbit is that mazda only listed 2 part numbers for the 13B P port housings.
4801-10-100 and ZR03-10-B10.
the 4801-10-100 is the one most commonly listed, and sold in the US, part number dates from the 70's
the ZR03-10-B10 is listed in the 3 rotor section from my 97-98 mazdaspeed catalog, its not the mazda comp, but an actual japanese mazdaspeed book. this is the "over the counter" 450hp 3 rotor engine. slide throttle efi, dry sump etc etc.
the weird part is we checked availability and mazda had neither, but both numbers would have shipped the same part.
so ok, what's weird about that? what's weird about that, is i have seen a couple of variations in MFR housings, the later dry sump engines loose the little dog leg flare out part for the oil pan, and are just straight. what part number were those housings?
and of course also there are the 3 plug R26B housings. which have a different dowel pin location.
so what do we know? we know there is one style, from 1978? 1979? that services the 13B and 13J/450hp 3 rotor. which are not available anymore. we also know there is a housing that works with a dry sump engine and has a different oil pan rail foot print, but no part number. the "optimized" "500hp 3 rotor" port might be this one...
we also know there is a 3 plug housing, but again no part number.
. wait for dgrr pics...
05-01-11, 11:46 PM
#16
http://www.scribd.com/doc/7062188/Ma...-Engine-LeMans SAE#920309
the other interesting tidbit is that mazda only listed 2 part numbers for the 13B P port housings.
4801-10-100 and ZR03-10-B10.
the 4801-10-100 is the one most commonly listed, and sold in the US, part number dates from the 70's
the ZR03-10-B10 is listed in the 3 rotor section from my 97-98 mazdaspeed catalog, its not the mazda comp, but an actual japanese mazdaspeed book. this is the "over the counter" 450hp 3 rotor engine. slide throttle efi, dry sump etc etc.
the weird part is we checked availability and mazda had neither, but both numbers would have shipped the same part.
so ok, what's weird about that? what's weird about that, is i have seen a couple of variations in MFR housings, the later dry sump engines loose the little dog leg flare out part for the oil pan, and are just straight. what part number were those housings?
and of course also there are the 3 plug R26B housings. which have a different dowel pin location.
so what do we know? we know there is one style, from 1978? 1979? that services the 13B and 13J/450hp 3 rotor. which are not available anymore. we also know there is a housing that works with a dry sump engine and has a different oil pan rail foot print, but no part number. the "optimized" "500hp 3 rotor" port might be this one...
we also know there is a 3 plug housing, but again no part number.
the other interesting tidbit is that mazda only listed 2 part numbers for the 13B P port housings.
4801-10-100 and ZR03-10-B10.
the 4801-10-100 is the one most commonly listed, and sold in the US, part number dates from the 70's
the ZR03-10-B10 is listed in the 3 rotor section from my 97-98 mazdaspeed catalog, its not the mazda comp, but an actual japanese mazdaspeed book. this is the "over the counter" 450hp 3 rotor engine. slide throttle efi, dry sump etc etc.
the weird part is we checked availability and mazda had neither, but both numbers would have shipped the same part.
so ok, what's weird about that? what's weird about that, is i have seen a couple of variations in MFR housings, the later dry sump engines loose the little dog leg flare out part for the oil pan, and are just straight. what part number were those housings?
and of course also there are the 3 plug R26B housings. which have a different dowel pin location.
so what do we know? we know there is one style, from 1978? 1979? that services the 13B and 13J/450hp 3 rotor. which are not available anymore. we also know there is a housing that works with a dry sump engine and has a different oil pan rail foot print, but no part number. the "optimized" "500hp 3 rotor" port might be this one...
we also know there is a 3 plug housing, but again no part number.
Thread
Thread Starter
Forum
Replies
Last Post
rx8volks
Canadian Forum
0
08-11-15 10:30 PM
