milton

i need an engine for a formula sae car and it can't exceede 610cc so i was wondering what types of power can i get out of a single rotor engine? we have a machine shop to help us so i can bridge port as big as i can imagine. but i just wanted to see if that might be a good idea b/c our engine now is shot that we inherited for our former team? any other ideas fellows?

peejay

It soudns neat in theory, but what is wrong with a 600cc motorcycle engine? Bike engines generally already have a slick transmssion built in and are set up for chaindrive. You don't get that with any car engine.

Kentetsu

I don't remember who it was, but there is a company building rotary engines. You can purchase them (if they are actually producing them yet) as a single, double, or triple rotor engine. I think the power output for the single was something like 100 hp, but I'm not really sure. Maybe someone will pop in with the link to their website....

milton

thanks guys, and 100 hp is great for this b/c we r looking at weight to be hopefully under 1000lbs with driver. and it is an auto-x type course. i think we might just do a bike engine but i dk yet. thanks for the help and keep it coming.

milton

o yeah we r allowed to manufacture our own turbo or super setup, i was figuring that a single rotor with and air to air intercooler (only thing allowed) would put out more power then a bike engine, mind you we cannot use a turbo on an engine if it comes stock with one. any other sugestions?

Rx7_Nut13B

iTrader: (1)

http://video.google.com/videoplay?do...&q=Rotary+Kart

This is a 50 +/- hp rotary

13BT_RX3

Rotary displacement is rated in an odd way because it fires every revolution. Haven't seen what the rules say about this, but it would probably be the same thing as using a 2 stroke engine. You may be limited to 305cc, not sure.

Also, don't you need to run an 18mm inlet flow restrictor? If so, that is where a lot of the design should start. If you could make an engine with 100% HP sustained between gear splits with minimum friction loss you will be doing about as well as possible. Basically HP running on the flow restrictor to peak at the start of each gear and be flat from there. The only thing you could do after that is reduce weight.

Cornell made a lot of power in the past with a small turbocharged motorcycle engine. May be a good idea to look at previous HP leaders and improve on that type of setup.

What are the rules about alternat fuels and direct injection? Using cutting edge technology may get you more recognition and sponsors.

Find the creative ways to cheat the intent of the rules but not the letter of them.

milton

well we have a 20 mm restrictor if we use regular gas 94 or 100 octane, and a 19 mm restrictor if wwe use e-85. but the restrictor if paired with a blow-thru turbo ( i think that is the right terms) allows the air to be entering the turbo at a very high velocity thefer decreasing lag and giving some hp gains. also if the engine normally comes with forced air induction, we are not allowed to use that turbo or supercharger set up we have to design our own. direct injection i am not sure. i would prefer to use a deisel if we could do that but we dont get to use deisel oil.
here is a link to the rule book:
http://students.sae.org/competitions...aseries/rules/

thanks guys

RXBeetle

sorry to poop on your parade but rotarys are banned in FSAE
I don't think you would get any more HP per cfm from a rotary engine than a pistion engine. Rotarys are not efficient engines. (the lack of valve components and volumetric efficiency does make up for some of this) They make a lot of power for their displacement because they displace it fast. Put a restrictor in the mix and a bike engine has you spanked, granted I know of a FSAE car with a megasquirted Briggs mower engine with a snowmobile drive that competed last year... You don't have to assume that the bike engine is the only way to compete. The weight on the other hand? 1000lbs? I think most of the cars were around 500-650lbs last year. Tell your driver to lay off the burgers and beer, stick with whiskey and beans

13BT_RX3

I though the turbo system had to draw through the restrictor. Blow through wouldn't work as a restrictor because more boost would give more massflow. Restrictor needs to see atmosphere on the inlet.

GT12 or GT15V may be a good fit. The GT 12 has an ~31mm inlet from what I've seen. They may have a smaller trim available. In this link "turbotwig" explains how to get a free turbo from Garrett for your SAE car.
http://fsae.com/eve/forums/a/tpc/f/1.../m/41410016521

Turbo Maps and Drawings (2.6MB):
http://dot.etec.wwu.edu/fsae/HostedP...t_pictures.zip

CAD models can be found here:
http://fsae.com/eve/forums/a/tpc/f/1.../m/70610838821

milton

thanks guys, i am going to email sae to see if a rotary will work b/c a rotor can be considered as a realux triangular piston as opposed to a cylindrical, so i need to get a lil more info. o well i was just ball parking the weight we havent competed in almost 2 decades, also right now we are very low on funds, so if anyone knows of businesses that would like to sponsor marquette universities fsae car, in the milwaukee area or anywhere, we could sure use the help

rotaryinspired

iTrader: (3)

You might contact Atkins. I know there were building single rotaries for marine applications.

BLUE TII

iTrader: (9)

Yeah, if that restrictor was allowed anywhere it could be 20mm right at a P-port (w/ a larger face for timing) and w/ 100 octane and 30+ psi boost it would be 300+ hp easy.

What rpm are possible w/ a well balanced lightened rotor 1 rotor? Shorter shaft has less flex...

the_glass_man

iTrader: (2)

http://www.freedom-motors.com/
http://www.rotamax.net/

milton

can you expand on this some more please?

milton

after some searching i found an old arctic cat panther w/ a 303 wankel in it.
http://cgi.ebay.com/ebaymotors/VINTA...QQcmdZViewItem
this may verry well become the powerhouse of our fsae car.

BLUE TII

iTrader: (9)

Quote:
Yeah, if that restrictor was allowed anywhere it could be 20mm right at a P-port (w/ a larger face for timing) and w/ 100 octane and 30+ psi boost it would be 300+ hp easy.


can you expand on this some more please?

P-port is a more efficient port than stock side port.

If you put the restrictor right at the entrance to the engine and properly shaped it (venturi) and positioned it (angle of discharge) it would increase intake velocity which would help fight reversion at low rpm and enhance overlap effect at high rpm.

You can't just have a 20mm port face though as the port timing is dictated by size of opening, it would have to be a transition.

W/ 100 octane fuel, the limit of boost is basically where the turbo compressor drops significant efficiency and w/ the new GT line that is in the mid 30psi range.

Anyways, probably mute as restrictor likely has to be at intake to atmosphere.

milton

http://students.sae.org/competitions...ules/rules.pdf
page 113 has how the restrictor can be used with a turbo.

speedturn

iTrader: (1)

http://www.uavenginesltd.co.uk/index.php?id=402 these people sell very lightweight UEL air cooled single rotor engines made for aircraft - and they are only 40 horsepower, and they need a lot of air blowing over them, and they do not have a transmission.

It will be VERY hard for you to beat the weight per horsepower of a 4 cylinder 4 stroke motorcycle engine which already has a clutch and transmission designed and built into it.

cabaynes

iTrader: (4)

You will not be allowed to use a rotary engine in FSAE, I was on a team at school a few years ago and we also asked the same question. Find a motorcycle engine and modify it within the rules and you'll be fine.

Rhode_Dog

Ah thats too bad. You could have made use out of a Norton F1 (588CC Rotary Motorcyle)

https://www.rx7club.com/showthread.p...Norton+NRV+588