Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: kev-yorks on December 02, 2006, 09:27:06 AM

Title: Rotary mass flow rates
Post by: kev-yorks on December 02, 2006, 09:27:06 AM
In general the calculation for a turboed piston engine is 9.5 to 10.5 lb/min of flow per flywheel horsepower. Has anyone any idea what the figures are for a turboed rotary?
Kevin
Title: Rotary mass flow rates
Post by: sdminus on December 02, 2006, 03:42:19 PM
1.92 CFM per 1 RWHP
Title: Rotary mass flow rates
Post by: MikeLMR on December 02, 2006, 03:50:44 PM
at what pressure and temp is that ? volumetric flow rates are fairly meaningless.
Title: Rotary mass flow rates
Post by: dubber91 on December 02, 2006, 05:08:01 PM
my thaughts exactly ;)

volumetric flow rates are also dependent upon rpm and throttle configuration; hence, volumetric efficiency

Steve
Title: Rotary mass flow rates
Post by: kev-yorks on December 02, 2006, 05:13:50 PM
There will be some sort of general figure out there though, which is all i was after. No engine runs the same day to day,i was just after a ball park figure which it looks like Scott has come up with.
Kevin
Title: Rotary mass flow rates
Post by: MikeLMR on December 02, 2006, 05:16:48 PM
CFM isn\'t a good measure though as it will vary through the engine whereas massflow is almost constant from the air intake to the exhaust.

whats it all for anyway Kev :)
Title: Rotary mass flow rates
Post by: Mave on December 02, 2006, 06:08:24 PM
Rotary engine is going to be pretty much the same as a piston engine, maybe a bit higher as the engine is less efficient. If you went for 12 lb/min I doubt you\'d go far wrong.
Title: Rotary mass flow rates
Post by: dubber91 on December 02, 2006, 06:27:10 PM
i concur.
Talking about stock motors of course.

:)
Title: Rotary mass flow rates
Post by: sdminus on December 02, 2006, 06:28:37 PM
well a
GT42R flowing 84 lbs a min in a stock port rotary flows 1234 CFM this equates to 643 whp ish.

stock twin flows about 50lbs of air at peak flo = 382 whp

This and these formulae work for the rest of the world so i cant see a problem with them in the Uk !

 good luck with your project what ever it is
Title: Rotary mass flow rates
Post by: MikeLMR on December 02, 2006, 07:03:06 PM
about 6 - 7 lbs per hp from those examples then (well at the rear wheel)
Title: Rotary mass flow rates
Post by: stuart wizy on December 02, 2006, 07:27:53 PM
Quote from: kev-yorksIn general the calculation for a turboed piston engine is 9.5 to 10.5 lb/min of flow per flywheel horsepower. Has anyone any idea what the figures are for a turboed rotary?
Kevin

why the question , are u making custom inlet manifold for lots of flow??
pp even
Title: Rotary mass flow rates
Post by: kev-yorks on December 02, 2006, 07:36:53 PM
Lets just say there\'s a lot of little bits being played about with. Due to the nature of the beast a lot is trial and error so i\'ll be posting up next year when its all sorted as to what\'s been done and what has/hasn\'t worked.
Kevin
Title: Rotary mass flow rates
Post by: sdminus on December 02, 2006, 09:03:28 PM
the figures i quoted are for 2 rotor
Title: Rotary mass flow rates
Post by: stuart wizy on December 02, 2006, 09:26:59 PM
Quote from: kev-yorksLets just say there\'s a lot of little bits being played about with. Due to the nature of the beast a lot is trial and error so i\'ll be posting up next year when its all sorted as to what\'s been done and what has/hasn\'t worked.
Kevin
same goes for me mate, heres what my t45 will be flowing through:yes
Title: Rotary mass flow rates
Post by: arrouk on December 03, 2006, 12:46:51 PM
i think if you take the figure for a piston motor and divide by 1.3 it gives an approximate figure for a rotary, so 50 lb/min=500fwbhp/1.3=385rotary fwhp

matt
Title: Rotary mass flow rates
Post by: sdminus on December 03, 2006, 02:10:37 PM
No that is incorrect. it would be 380 ish atw.. rotarys have a differant BSFC to piston engines and differant VE depending on the port and the effictive port duration creating a differant BMEP at X boost.
Title: Rotary mass flow rates
Post by: Glenn Butcher on December 03, 2006, 05:07:34 PM
Great post guys - getting technical!  :)
Title: Rotary mass flow rates
Post by: oldone on December 03, 2006, 05:14:34 PM
Some time ago,I posted,asking for a cfm flow bench .........was shot down in flames:2Rolleyes ...seems it is all relevant to finding what you are looking for guys.Now please believe me it does work.!!!!!!!!! :cool :D  Yes I know........
Title: Rotary mass flow rates
Post by: Carl on December 03, 2006, 05:53:37 PM
For Era\'s eyes only
Special secret figures for ERA.
122 and 90 and 4
All in metric.
For that top secret special project we are going to do!!
Regards
Carl
Title: Rotary mass flow rates
Post by: oldone on December 03, 2006, 06:03:28 PM
Quote from: CarlFor Era\'s eyes only
Special secret figures for ERA.
122 and 90 and 4
All in metric.
For that top secret special project we are going to do!!
Regards
Carl
Thank you kind squire for relinqhishing that valuable information in my favour....:Thumbsup!
Title: Rotary mass flow rates
Post by: arrouk on December 03, 2006, 08:51:02 PM
Quote from: sdminusNo that is incorrect. it would be 380 ish atw.. rotarys have a differant BSFC to piston engines and differant VE depending on the port and the effictive port duration creating a differant BMEP at X boost.

well i was close:wave
Title: Rotary mass flow rates
Post by: dubber91 on December 04, 2006, 07:38:33 AM
if you need to get your hands on a flow bench why not google \'build your own flowbench\'. There are somne great...and cheap, designs out there.

Steve
Title: Rotary mass flow rates
Post by: sdminus on December 05, 2006, 01:15:26 PM
Quote from: CarlFor Era\'s eyes only
Special secret figures for ERA.
122 and 90 and 4
All in metric.
For that top secret special project we are going to do!!
Regards
Carl
LOL :Typing

FAO Gary ( K1HKS )

special numbers for you my friend

   9 11 15 31 42 46 and  27

Remember you have got to be in it to win it. I love all this play ground talk makes me feal all grown up LOL LOL LOL
Title: Rotary mass flow rates
Post by: K1HKS arse on December 05, 2006, 08:36:00 PM
Quote from: sdminusLOL :Typing

FAO Gary ( K1HKS )

special numbers for you my friend

   9 11 15 31 42 46 and  27

Remember you have got to be in it to win it. I love all this play ground talk makes me feal all grown up LOL LOL LOL

Thank you kind squire for relinqhishing that valuable information in my favour