My 13B engine configuration (tentative)

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

dwalker

Well-Known Member
Joined
Mar 6, 2021
Messages
370
Location
Tennessee
Yes I found the same AD when I googled. It was the only one I found.

The 13BREW is not twin-scroll, it is sequential and there is no divider. I stand corrected on the 13B-T, I think the last time I bothered to look at a stock 13B-T manifold was 2008-ish, so obviously my memory failed me, likely thinking of the "more common for me to see" HKS cast manifold.

Regardless of all of this, it remains that I will be using 321SS on my turbo manifold and most likely a turbocharger in the GT3582/82R range with an 82 or 1.01 V-band in/V-band out turbine housing, externally gated. Because it will work and live a long time. If I have to build a new exhaust manifold every couple of years it will not hurt my feelings. I might even build two just to "have one on the shelf", because I believe in having spares of everything practical.
 

Lendo

Well-Known Member
Joined
Feb 6, 2013
Messages
801
Location
Brisbane
Dwalker, we all appreciate your posts, comments and information. Aircraft application is different to motor racing developments, some opinions overlap and it seems some don't. For myself personally I'm happy to hear all opinions and develop my own approach to what I consider the best package for Aviation use.

The bottom line is we are all interested in a good lightweight Rotary engine, Powersport went a long way in Achieving that, Mistral as well but they dodged the Peripheral Port issues - experienced at the time.
All I can say is keep-up the good work.
George
 

PMD

Well-Known Member
Joined
Apr 11, 2015
Messages
508
Location
Martensville SK
You had me genuinely curious. I know when I asked Jim Medere of Racing Beat about using inconel to build the turbo manifold in the PPIHC turbo 13B, running E85 making roughly 490whp, he basically laughed at me. I expressed concerns about the amount of heat in the manifold and the lack of air to cool it between race start at 8000ft and the finish line at 14,000feet.
Just a HUGE caution about comparing E85 anything builds with things that burn plain old gasoline. My experience was with ESO speedway engines. For club races, we limited them to M100 and at the end of a heat (4 laps at 100% power) you could pull into the pits and put your bare hands on the exhaust pipe right up close to the head. It would get warmer when we raced away from home (had to tip the nitro jug to be competitive), but now I am extremely interested in what EGTs the NA and turbo rotaries are seeing with gasoline, avagas and E85????

Now: to those of you who DO burn E85 - do you now or have you experimented with water injection? I have a good friend who has built all kinds of things that run on aqueous fuels, the most radical being E50/H2O50. Not only is EGT super low, power can be super high!!!! Not really a practical aircraft topic (or at 50/50 at low to mid altitudes is it????)
 
Last edited:

dwalker

Well-Known Member
Joined
Mar 6, 2021
Messages
370
Location
Tennessee
Just a HUGE caution about comparing E85 anything builds with things that burn plain old gasoline. My experience was with ESO speedway engines. For club races, we limited them to M100 and at the end of a heat (4 laps at 100% power) you could pull into the pits and put your bare hands on the exhaust pipe right up close to the head. It would get warmer when we raced away from home (had to tip the nitro jug to be competitive), but now I am extremely interested in what EGTs the NA and turbo rotaries are seeing with gasoline, avagas and E85????

Now: to those of you who DO burn E85 - do you now or have you experimented with water injection? I have a good friend who has built all kinds of things that run on aqueous fuels, the most radical being E50/H2O50. Not only is EGT super low, power can be super high!!!! Not really a practical aircraft topic (or at 50/50 at low to mid altitudes is it????)
So a couple of things-

I mentioned e85 in that example because accuracy matters, and it was an important piece of that equation.

I have used water/alcohol injection on many, many things. It was used in WWII and some Reno Racers use it.

In general, my turbo egts were lower than my NA egts. I can go into detail when I get to my laptop.
 

rv7charlie

Well-Known Member
Joined
Nov 17, 2014
Messages
1,895
Location
Pocahontas MS
13-B at 4500rpm puts out 120hp all-day easy without a turbo.
SkyTrax gearbox can handle 300hp.
Anyone combined the two yet?
The RWS RD1-C gearbox for the rotary handles 300 HP, and actually fits the rotary.
The SkyTrax that I'm familiar with is integrated into the Yamaha engine itself, replacing part of the structure of the engine, with 'damper' assemblies/clutches (depending on model) tuned to the specific engine.
 

dwalker

Well-Known Member
Joined
Mar 6, 2021
Messages
370
Location
Tennessee
Now: to those of you who DO burn E85 - do you now or have you experimented with water injection? I have a good friend who has built all kinds of things that run on aqueous fuels, the most radical being E50/H2O50. Not only is EGT super low, power can be super high!!!! Not really a practical aircraft topic (or at 50/50 at low to mid altitudes is it????)
E85 is probably more practical for sport planes than anything other potential application in GA, because the fuel cannot be left in the tanks for extended periods of time without risking phase separation and that would be a serious issue in an aircraft.
On the "plus" side the engine will run cooler, there is more power potential, and the motor will run cleaner.
On the not as plus side the fuel really should be mixed with a two-stroke oil to help prevent cylinder washdown, there is a risk of oil dilution, and you tend to use more of it.
There seems to be some belief that E85 is harder to start, which I have not found to be the case. I have also found that most tooners (intended spelling) tend to run e85 way richer than needed and create other issues for themselves doing so.

Now, as to EGTs on turbo rotaries, or for that matter pretty much any turbo motor, and I will limit this portion to pump gas and unleaded "race gas", my experience has been that with proper tuning and ignition control I tend to see less EGT than with an NA motor. I generally put this down to poor timing and fuel calibration running overly rich with retarded timing and the resulting dumping of raw fuel into the exhaust.

I
 

rv6ejguy

Well-Known Member
Joined
Jun 26, 2012
Messages
4,525
Location
Calgary, Alberta, Canada
There is generally no phase separation on E85 fuels. Most gasolines and alcohols will stay in solution at 15% of either constituent however this is somewhat dependent on the amount of aromatics in the the gasoline. Winter E85 may have more gasoline than 15% though to aid starting. More aromatics are usually added in this case to avoid separation.

I've never seen any problems with bore wear or oil consumption changes running alcohols with at least 15% gasoline, in piston engines at least.

The big issue with alcohols is that their stoichiometric ratio is roughly half that of gasoline so you burn a lot more fuel for the same power and therefore range is seriously reduced. It has lower energy density and also weighs more than gasoline.

The second concern is incompatibility with some elastomers, hoses, pumps, tank sealants and corrosion of bare aluminum.

If EGTs are measured after the turbo, they may be lower than an NA engine because there is a large temperature drop across the turbine (work). If measured prior to the turbo, EGTs are almost always higher at the same compression ratio on turbo engines.

Starting on alcohol is much more difficult in cold climates compared to gasoline due to the lower Reid vapor pressure.
 
Last edited:

dwalker

Well-Known Member
Joined
Mar 6, 2021
Messages
370
Location
Tennessee
There is generally no phase separation on E85 fuels. Most gasolines and alcohols will stay in solution at 15% of either constituent however this is somewhat dependent on the amount of aromatics in the the gasoline. Winter E85 may have more gasoline than 15% though to aid starting. More aromatics are usually added in this case to avoid separation.
I have seen phase separation in E85 in boats stored for periods of time- like over the winter- with e85 in the tank. I myself have not had the issue, but others have claimed to have the issue and since I have seen it in boats I ceded the point, and mention it as a possibility, not a certainty.

I've never seen any problems with bore wear or oil consumption changes running alcohols with at least 15% gasoline, in piston engines at least.
This I actually have seen, with the disclaimer that there could have been other factors involved, and again it is only mentioned as a possibility. I ran E85 daily in my Eclipse and Evo with massive amounts of boost and the bores looked great and I had no issue with any sort of undue wear. That said I DID have customers with ring galling etc. that is *usually* caused by fuel issues.

The big issue with alcohols is that their stoichiometric ratio is roughly half that of gasoline so you burn a lot more fuel for the same power and therefore range is seriously reduced. It has lower energy density and also weighs more than gasoline.
Yeap, and at some point you have to weigh the pros- cooler running, potentially higher power, etc. against the fuel consumption

The second concern is incompatibility with some elastomers, hoses, pumps, tank sealants and corrosion of bare aluminum.
Absolutely. We had all manner of interesting failures come through the shops over the years traced to incompatibility between fuel and the fuel systems. As an aside, for a while we were plagued across multiple cars from different parts of the area with clogged injectors. In a short period of time the injectors would begin to show signs of reduced flow, poor spray pattern, etc. Brand of injector, type of car or engine, etc. the symptoms were the same. This was traced to a gummy substance that would accumulate on the injector filter screen and restrict flow. Originally we (a group of several shop owners sharing information about this issue) felt that it was varnish/crud the alcohol was stripping from the fuel system and was precipitation in the injectors. This was proven not to be the case when at least two cars with brand new fuel cells/lines/pumps/rails/etc. exhibited the same issue. One of our customers was a lab scientist/chemist, and offered to analyze the sample in his lab. He came back with that it was a known fuel additive added to the "winter blend" that for whatever reason was combining with contaminants in the fuel, microscopic bits of rubber and etc., and gelling. At that point all we could do was to clean a bunch of injectors and hope they would stay clean until the "summer blend" was available. Crazy stuff.


If EGTs are measured after the turbo, they may be lower than an NA engine because there is a large temperature drop across the turbine (work). If measured prior to the turbo, EGTs are almost always higher at the same compression ratio on turbo engines.
I believe we were measuring EGT after turbo.

Starting on alcohol is much more difficult in cold climates compared to gasoline due to the lower Reid vapor pressure.
At 20deg F, 10,000ft ASL on Pikes Peak, engine stone cold out of the trailer to start the 13B Turbo on E85 all I had to do was reach into the car, turn the ECU on, and hit the start button, it would crank maybe a full revolution and light off. Hot it would maybe crank over 2-3times before lighting up. Of all the different engine applications I have done E85 work to, none were what I would consider "hard to start". Could just be my luck.
 

rv6ejguy

Well-Known Member
Joined
Jun 26, 2012
Messages
4,525
Location
Calgary, Alberta, Canada
You may not be seeing actual phase separation of gasoline and ethanol on marine stuff. More likely you're seeing that the ethanol absorbed water from the atmosphere over a period of time and the water layer is showing up. Pretty common in humid climates with vented fuel caps.
 

rv7charlie

Well-Known Member
Joined
Nov 17, 2014
Messages
1,895
Location
Pocahontas MS
That is a point I hadn't had time to bring up: what different people actually mean when they use the term. When the fuel pros talk about it, my impression is that they mean things like the ethanol falling out of suspension due to, for instance, extreme cold. I wouldn't call the binding of ethanol to water 'phase separation', but I don't know whether I'm right or wrong about that. You certainly don't need temp extremes for water binding to happen; that's how you check for E in mogas. (I did it for years while I was flying a carb'd Lyc.)
 

Cardmarc

Active Member
Joined
Jun 16, 2021
Messages
28
My 20 b has shown 1600F-1700 EGTs at the exhaust manifold, BEFORE the turbo. Using standard aviation 100LL, which is what you get at most airports (not car gas-of any kind).
 

dwalker

Well-Known Member
Joined
Mar 6, 2021
Messages
370
Location
Tennessee
I have not updated this ih awhile as I am clearing some auto projects off my plate along with the usual to-do list. However, I did pick up the first PSRU a few weeks ago. It is a Ross redrive that came attached to a S4 or 5 13B-T motor, peripherals, and engine mount for the rear of a Defiant. This particular engine/redrive has been run for engine test, warm up, and taxi testing only before it was removed along with the matching front engine- which is the same engine with a RWS PSRU, which I plan on buying as well. It is a 2.1-1 ratio and is in like new condition, which is good.

These pictures are taken at my warehouse where I am storing it until I have the time and space to disassemble and evaluate the PSRU and motor. Once I know what I have and what I am going to use, I will assemble a dummy motor to allow me to build the turbo system, intake, fuel system, wiring harness, etc. on a false firewall for the Long. When the Long is nearing completion I will assemble the actual engine.
 

Attachments

DreamersE/AB

Member
Joined
Jul 22, 2018
Messages
16
Location
Indianapolis, IN / USA
rear of a Defiant. This particular engine/redrive has been run for engine test, warm up, and taxi testing only before it was removed along with the matching front engine-
Did the seller say why they decided to remove the rotaries? Was it due to issues with their operation, or integration with the airframe?
Thanks,
John
 

rv7charlie

Well-Known Member
Joined
Nov 17, 2014
Messages
1,895
Location
Pocahontas MS
1st thing to check on the Ross is whether there's a thrust bearing on the input shaft. IIRC, lack of a thrust bearing in Tracy Crook's Ross drive (which destroyed the thrust bearing in the rotary in short order) is what caused Tracy to design his own drive.
 

dwalker

Well-Known Member
Joined
Mar 6, 2021
Messages
370
Location
Tennessee
1st thing to check on the Ross is whether there's a thrust bearing on the input shaft. IIRC, lack of a thrust bearing in Tracy Crook's Ross drive (which destroyed the thrust bearing in the rotary in short order) is what caused Tracy to design his own drive.
Yeap I am aware, although there is not thrust bearing in the rotary so Tracy's failure has somewhat confused me for a while. There are a pair of Torrington bearings that establish the thrust, but it boggles the mind that those would fail in the manner described.
I was not really paying attention back when all of this was news, but my understanding is the later Ross had thrust bearings because plain bearing engines like Subaru/GM/etc. had issues with the thrust bearing failure and Ross made a change in later production to fix that, then when Ross retired and his son took over there were many issues which Tracy did not want to deal with, and he wanted a lighter/stronger billet unit instead of the cast unit, and so created his version and put it into production. Tracy also knew that Ross JR was in trouble and the company was likely on the way out of the PSRU business, and without a steady supply of good PSRUs the rotary would fall away as a flight engine, and he was right.
 

FinnFlyer

Well-Known Member
Joined
Nov 19, 2019
Messages
60
Location
Bell, FL
With the helical V6 gear set and no input shaft thrust bearing, you'll see the input shaft splines being stamped into the 13B eccentric shaft end. The eccentric shaft "thrust" bearings are found behind the "front" cover (for oil pump, water pump housing, etc.). Those roller bearings that tend to slip out of place during horizontal assembly and get crushed when tightening the long engine assembly/tension or front cover bolts ( I forget which).
They were never designed for that kind of punishment. Apparently the Mazda transmissions do not expose the e-shaft to any longitudinal forces.

Finn
 

rv7charlie

Well-Known Member
Joined
Nov 17, 2014
Messages
1,895
Location
Pocahontas MS
My memory is of Tracy saying that those bearings only saw load in the car when the clutch pedal was depressed. Was a long time ago; could be defective memory. Certainly much less load than that imparted by the helical cut sun gear.
 
Top