bridgeporting a street car
 

what are your guys oppinions on bridgeporting a street car? will it be driveable? and is it only reccomended for a turbo or can us N/A guys do it to. thanks.

I wouldn't recommend it, unless you enjoy...

- blowing engines every 30k
- blowing 5k on each engine
- not making ANY torque
- not making ANY useable power below about 4000 RPM
- being heard coming a mile and a half away (LOUD!!!)
- idling at 1.5-2k RPM
- getting 10-12 MPG
- cruising around at 5k like a motorcycle (well, that sounds pretty cool, but...)
- overheating if you don't continually drive the car

So, no, I wouldn't recommend it :D And no, with a bridgeport there's WAAAAY too much overlap for forced induction - you'd be blowing your intake charge straight out the exhaust ports :)

Brandon

what woyuld you reccomend for a street port.. i am looking for a lot of power and i dont mind not to much low end touque. how big can you go with a street port so u will have tons of power uptop.

I know of plenty of people who have run bridgeports on the street and with the exeption of the idle, none of your list of problems have occured for them. This is what I'm building right now, it's just about done and I have not spent anywhere near 5k. None of the bridgeports that I've spoken of have blown up either, with much more than 30k on them. Maybe the engines you were talking about were built incorrectly. I'm not sure but I wouldn't discourage anyone from running a bridgeport on the street. As for noise, dual exaust, two glasspacks and one muffler on each side will provide good noise control and not kill the power. It won't make crazy power but this is the trade off of not going turbo. If money wasn't an issue I'de go turbo. But that's big dollars, and those blow unless you have good detonation control.

well what would you reccomend then i am wanting to warp my tach around 10,000.... thats why im looking into a bridgeport. how much horse do u think i would be running with a good bridge port... will i have to upgrade rotors? obv fuel,air, ..... basicially what horsepower am i looking at and what will i need...

First of all this is my first post.. and would like to say what up to all the fellow rx7 lovers out there.... about the bridge port... ive known many 12a and 13b's with it and it doesnt give any problems...u lose some low end torque but the high end is incredible.. my friend just sold a white 86 wit 13b housings and 12a side housings. bridge port, exhaust porting.. no cats and 2 1/2 exhaust piping, racing beat intake manifold , holley 650 4 barrel with a turbo II hood, and a bronze clutch and he use to run 14.5 constant.. and had no problems... it did swallow more gas.. but it got more than 10-12 miles a gain.. he got almost 210 miles a tank driving in traffic with the idle bouncing from 1000 to 1200 constant... and he never had problems.. the car was solid....

im looking for a redline of around 11000 or 10000 what was your friends and what kinda ##'s were you putting out?

Uh, either these people don't have bridgeports, or there've been some serious advances in the last year or so...

First, you'll save some money, yes, if you do all the work yourself. I'm assuming, since the original poster didn't say, that he won't be. Mazdatrix, Tri-Point, RP, and CCP all quote 5k+ for a well-built (all new parts, lightened rotors, e-shaft mods, hardened gears, etc, etc, etc THE WORKS) bridgeport.

I'd like to know who's gotten more than 30k out a bridgeport... no, seriously, throw some names out :)

As for your exhaust recommendation... uh, are you deef? Glasspacks will burn out in a matter of MINUTES on a b-ported rotary, and with that setup, it'll sound like a pissed-off-Mack-truck-sized-weedwhacker-on-CRACK from about a MILE away. My friend, bridgeports are almost as loud as a rotary can possibly get (with a PP motor only getting louder).

As what's this "It won't make crazy power but this is the trade off of not going turbo"??? Granted, not 600+ hp "crazy power", but 350 RWHP N/A at 12,000 RPM is pretty crazy for a street car.

All that leads me to believe that your friends exagurated (sic) the extent of their ports. Some big streetports require high idles, so that's not a single reliable metric :) Trust me, a bridgeport is NOT streetable, unless you're VERY hardcore. VERY VERY hardcore... :)

Brandon

I posted about this recently an dif you do a search for 10,000rpms you will find it or just search with my my name. you have to do a lot of major $hit to get those kind of rpms. 10.5k is the highest i think you can go without a non-streetable race clutch and flywheel. then you gotta get lightened rotors ($$$$$$$) and all sorts of stuff. just do a search

Justin

At those rpms, I would recommend a scatter shield too. A clutch breaking up at 11000 rpms makes a mess of everything in its way. So I have read!

The problem with your redline figures is the flywheel rpm's. You'll need a scattershield and a tilton 5in. clutch/flywheel setup to spin 11k. You can do it but its not nec. Get a lightened steel flywheel for the street and that will be good enough. No stalling the motor at stopsigns. Power at the flywheel with a brigdeport will vary with the type of intake and exhaust you want to run. Webber downdraft carb and an open exhaust will get you 280 fwhp approx. This is not streetable though. The exhaust noise would be far too loud. Use the exhaust I mentioned before and now you;re looking more at 250hp. At the fly. Those carbs are pretty touchy so you might want to go with a Holley setup which will further sacrifice power to approx 240hp. It all depense on what you're comfortable with running. Is this a toy? Use the Webber setup and a louder exhaust. Is this a daily driver? Use the holley setup and muffle the crap out of it. As for the people that I speak of, one has a early 70's RX3 with the holley setup and the same exhaust I'm running. I'm not sure of his power output but his 1/4mi. times are 13.1 at 112. Pretty good if you ask me. I've ridden in this car and it sound good and has a very smooth idle, about the same as SoulAssasins car. A little smoother. Oh yea, he gets 22mpg!!!! He works for Motorsports Dynamics if you want him to build you one. He has reasonable prices. The other guys that I know of that have bridgeports on the street are a little closer to what that guy was speaking of but these engines were built as toys and not to be taken seriouly as comfortable or daily drivers. These were cop ditchin, donot doin, streetdraggin, neighbor pisser offers. And yes some of them didn't even last a month. But you dont have to build this type of motor. Let me know if u need any more advise or help. Theres plenty of it on this forum. Good luck.

Most of you guys are wrong!!!! You will not blow an engine every 30k unless you get Fred Flintstone to do the bridges. There are lots RX-7's here in Puerto Rico that are bridge Ported for daily street use. I used to have a 1979 RX-7 it was bridged ported, Racing Beat header and Intake manifold, holley 650 cfm a pair of jaycobs ignition coils and many extras. I had it with me for 4 years, no trouble at all!!!!! Plus it had A/C. Just got to make sure that the person who makes the porting does not do a shitty job that will eat your side seals.

OOpps, before I get slammed let me clear up the redline thing. The steel flywheel will let you spin up to 10.5k, maybe but with a street setup for intake/exhaust you'll taper off your power at 9.5k. That's high enough. Keep it under that for the street and you'll be much happier. If you really want to spin it to 10.5k you can but I would'nt do it very often if at all. Esp. for longivity sake.

Thanks Angel.

If they want to spin spin that hard they better have a good rear end :D

Ok, Thanks for your input Brandon, that's great.
As for names I'm not at liberty to put out my friend full name out on the internet fo anyone to see but if you'de like to talk to one of them go to Motorsportsdynamics.com contact Todd. And as far ass(no typo) the sound of the exhaust, it will or it does, have you ever actually heard this setup or are you just using your imagination together with your years of exhaust fab experience, Hey what would a Buick GNX with a hooker muffler out of a 3in. pipe sound like? Could you give me a example of that. 12k on the street is crazy sure but 350hp is not and no I'm not hardcore.

A bridge port would definitely be streetable, and unique in a 2nd gen. I say go for it... something that you may want to look into is what is known as a partial bridge port... thats when you street port the primaries and bridge the secondaries... kind of a best of both worlds... you get a bit more low end, still have the AWESOME idle sound, makes good power (you could prolly hit 240 or so rwhp), but top end doesn't suffer too much... true, anything over 10k would be pushing it, but thats about where a partial bridge (or half bridge) tapers off anyhow...

and about the statement about a bridge port having too much overlap for forced induction... just talk to Soul Assassin... he is running a huge turbo (T51R I believe, might be wrong on that though...) and a bridge port. Makes good power (I think he is getting up around 520 rwhp).

Do it. Bridge port it... or partial bridge. I am going to be putting a partial bridge port in an RX3 with a 60-1 this summer (thats the plan)... should SCREAM!!!! 10 second street car.

Heh. In the end, it's all up to him, but I still don't think a bridge would be worth the gutless low-end :) I guess I just like some torque...

Haha! :rofl: yeah, but with a turbo that big, he won't be making full boost (all 14 lbs?) until, what, 3700, 4000 RPM? Heh, by that time the overlap times will be too small to matter :) I still think that with something like a T04B or E running 16-18 psi you'd be blowing your boost out the exhaust in the midrange... :)

Brandon

(Not a guru, I just play one on T.V. :p: )

my friend was revvin 10 grand constant with bridge port and no ecu... no ecu means no rev limiter.. so there u go.. and to add to angel guard racing team.. in puerto rico they are many bridge ported 1st gens or rx3's runnin as daily driver.. some even peripheral port..... no lie..

thanks for all the info guys... keep it coming. i was going to get s ahop around here to build it for me, he builts racing engines for rx's... i was intrested in the 1/2 bridge port.. anybody have this or have heard of anyone running this setup and what kind of numbers were they producing..

If you actually knew what you were talking about you could make some informative posts. now lets put the record straight.

BP engines will not BLOW every 30K.

You wont spend any more on a rebuild of a BP than you would on any other high HP properly prep'd motor.

BP's make MORE TORQUE than a street ported motor can achieve at any rpm ablove 4500.

You can make usable power below 4000rpm, but how many street ported motors do you know running REAL sized turbo's that make truely usable power below 4000rpm? most street ported motors are only spooling the turbo at around 3500........

It all depends on the exhuast system you run, a turbo muffles the sound particurly well.

a BP will idle sweetly at 1200rpm, my extended port motor idles sweetly at 1200rpm - NO DIFFERENCE

Add a turbo and you'll make well more than you would with a street port

as i said YOU HAVE NO CLUE!!!!!!!!!!!!!!

If you want a car that makes a lotta power, is still somewhat streetable, goes like a cut cat and is uneekly different get a BPT

aharrrmmmmmm - Soul Assasin made 500 and something rwhp with a T04e at 20psi.............

now what was it you were saying????//

rotary's are ment to be revved, you see to make good HP outta any small capacity motor you have to be able to get the volumetric efficency over 100%, you get this how? by having large overlap and pulling LOTS of RPM to get the 'natural' supercharging effect going

I thought I would mention it since no one else has.The stock n/a computer has a fuel cut at 8500rpm(or the 89-92 does,the 86-88 may be lower) so you have to something to it or you'll never spin past 8500.I don't know if any of the aftermarket chips remove this or not.If not you'll have to go with either a stand alone ECU or a carbeurator.Personally I would go stand alone if I couldn't get the stock one reprogramed.Also to continuosly run rpms above 8k the motor needs to be balanced and the rotors and rotor gears race clearanced which is what will drive the cost up.I personally think a bridgeport would be cool and may build one myself one day.

You must not have ever seen Soul Assasin's car,because as others have mentioned it has a bridgeport and it kicks ass.

Use a 1st gen dist. setup. MSD box and you'll have your redline set.

I'd like to hear more from Brandon, he seams to have a handle on this whole triangle thingy.

People read Felix Miata's FAQ on porting and assume that BP's or PP's are no good for the street or for turbocharging.

anyone who tries to run a bridge port on the factory ECU weather it be turbo'd or n/a deserves all they get, a bridge port requires VERY different fuel maps and VERY different ignition timing than a stock port motor which is what the ecu's are designed to run

maybe we should link to the write up on crispeed's car which is making 608rwhp at 32psi using an engine wtih BRIDGE PORTed secondary ports...........

Another thing you guys are leaving out in regards to the 10,000 rpm thing..When you get to about 10,000 or a little less... your eccentric shaft begins to flex quite a bit, which can cause you to but up an apec seal.... In order to get your street car past 10,000 you will have to get some sort of custom one made...although it is entirely possible...

well i was in a shitty mood till i seen this! this is hilarious ! 14lbs of boost on a t51? you surely have no clue what the hell you are talking about!
well to set the record straight take it for what it is worth
1. a bridgeport is fully streetable
2. i am running a to4R with a 1.15 a/r
3 10k is possible but i shift at 9k
4. currently making 520rwhp at 20 psi at 6k soon to be about 600 when i run 30 this spring
5. a bridge motor does not cost 5k maybe 600-800 more than a regular motor depneds how freaky you want to get with it
6 i drive my car everyday to and from work in about 6 inches of snow right now!
7 you WILL make twice as much torque then a sideported motor
8 no problems with over heating
9 loudness depends on your exhaust sytem i have removeable silencers for everyday cruising
i completly agre with HWO views on this subject

i have seen at a few placs for chips claims to add 25% more horsepower 25% more torque and increase the redline to 9500... only with a chip... so.... i dunoo....

Hey soul assassin, I just bought a bridge ported engine. I have your soulbridgeidle.wmv file. I hope mine idles like and, maybe even runs like yours! I'll let you know.

What is your "warmed-up" idle speed?

Mike

MikeL:

so, you gonna be running a t-66 full bridge engine? you getting RP to tune it for you? I hear that a bridge is a bitch to tune.... but I've never done it, so who knows.

...then you're more hardcore than I am...

he won't be running a turbo

he won't be running a turbo, and therefore will most likely be shifting at all of 10k-ish. How long do you think an engine continually shifted at 10k will last? ...and don't say "He'll pussy-foot it around town." A ported 13B at full scream at 10k is FUCKING AWESOME. He'll want to show it off ALL THE TIME. Unless he's got WAY more restraint than I've got :D

he won't be running a turbo

you're in Japan. what are "extreme" engine mods here are 'commonplace' there (e.g. bridgeporting). A well-built bridgeported engine will require the use of NEW rotor housings, rotors, hardened stationary gears, probably new (though perhaps lapped) side housings, modified e-shaft oiling and oil injection system (unless he goes premix). Not to mention the extensive rotor and e-shaft balancing and hardening required for 10k RPM operation. Carbon apex seals are required as well. He probably won't be installing it himself. I stand by my $5k estimate, and that's low, IMO.

...then you're more hardcore than I am...

yeah, at 7000 RPM! What do you estimate his torque numbers to be at 2800 RPM? 3500 RPM? Where he'll be used to doing all his street driving? He'll have to tach around 4k to make useable power, and thus, his gas mileage will suffer. Hell, I tach about 2.8k in my STOCK 89 TII. Like I've said before, prehaps I'm just a sucker for torque.

and I'll bet you ballocks to a barnyard you're not running anywhere close to a stock-size radiator. Anyway, mea culpa - a std. bridgeport doesn't cut into the water jacket, so okay, I stand corrected.

he won't be running a turbo. and I'll bet your removable silencers are like those sold by Apex'i - good for a dyno-proven 75 hp loss (damnit, now I'm going to have to bug Jay in Pensacola for dyno charts... just take my word for it, okay? :) ). And anyway, how loud is "streetable" anyway? I consider my stock 89 TII to be pretty loud for everyday driving, esp as compared to my Camry.

Comments? I'm not too arrogant to admit that I know next-to-nothing about turbos or their effects on a highly-ported engine - but it's a moot point, since he won't be running a turbo. I'd like to see some port numbers for your engine, Soul; specifically, port duration numbers. I'm always willing to learn...

Brandon

The term "bridgeport" can mean a lot of things.&nbsp I've seen everything from a "half-bridge" to a monster "J-port" called a "bridgeport".&nbsp Very small bridgeports could easily last a long time, but larger bridgeports drop engine life (cracked bridge) dramatically.

SPZ510 mentioned "Todd" at Motorsports Dynamics; although Todd doesn't work for MD anymore, I know his RX-3 pretty intimately when I used to life up in Sac.&nbsp If it wasn't for this car, I would probably still be calling a BP motor "unstreetable"!&nbsp I won't drop all of this BP RX-3 secrets (anyone who has ran into this car can ask the owner himself), but it does run a pretty sizable bridgeport and regularly sees 9,500RPM; the car does run consistent 13.0-13.1 @ 105 (Sac Raceway) and has put down an honest 220-230hp to the rear wheels (on a DynoJet).&nbsp The thing that scares me is that the car is VERY QUIET and VERY STREETABLE.

Now, as for turbo'd 13B's running bridgeports, this is something I don't recommend for most street cars.&nbsp Overlap kills (low-end) power, and most street cars don't (stay) rev'd high enough to take advantage of the increased overlap.&nbsp Soul Assassin is justified cause he lives in Japan - the Japanese bridge EVERYTHING! :D

Personally, I don't listen to anything that HWO says, cause a lot of his posts are regurgitated from stuff other people; I haven't seen proof he has done any of the work himself.&nbsp HWO, you should listen to yourself..."by having large overlap and pulling LOTS of RPM to get the 'natural' supercharging effect going" - WHAT natural SC effect?&nbsp The only SC effect I know of is early closing of the intake, which is also known as the Miller cycle; increased overlap is totally opposite, as you end up blowing the incoming intake charge back into the exhaust - or are you implying that the exhaust blow-by your increased intake "pressure"?



-Ted

Ted, I'm not too familiar with the Miller Cycle. I know it differs from the Otto cycle in that its "phase durations" are not of equal time - it would seem that the rotary would be conducive to a Miller Cycle-type design, due to the fact that the durations of the various phases can be altered much more than is possible in a reciprocating piston engine. Do you have any good links to Miller Cycle Engine info or thoughts about what a "Miller Cycle rotary" would consist of?

Brandon

I don't remember all the details, but the gist of it is that the engine closes the intake a tad earlier than normal, which allows the intake charge to pressurerise slightly in the intake tract before being allowing into the combustion chambers.&nbsp A supercharger is used to heighten the effect - Mazda has gotten 10%-15% more power doing this with their Millenia S models.&nbsp With the release of the Millenia S, there were wild rumours that a Miller Cycle rotary was in the works; Mazda has not confirmed nor denied these rumours - it would make for a very nice running rotary!



-Ted

Me???? I'm just looking for more port than previous.

Kurgan, I haven't seen the inside of the engine but, I soon will. I bought it from someone that I don't know so, my local engine builder is gonna take it apart.

It will be used with my T-66. The only change from my current setup(376 rwhp) is the port and a 17lb steel flywheel. I can't afford a BB CHRA right now. That will come in a month or two.

I figure this:

I was pretty happy with the lag before, with a street port and no BB turbo.

-The lighter flywheel will help the lag on the street.

-When I can get it, the BB turbo will help even more with the lag.

Here's a video of me punching it at about 25 mph in 2nd gear. It takes about 7 seconds to hit about 100. I think I'll be quicker with the bridge, flywheel and BB turbo.

http://brfoundation.com/RX-7/video/MikeL5.mpeg

Where is Soul Assasian. I thought he had a Bridgeport. That car is nice:)

James

damn you guys always go nuts while i am sleeping! lol! ok lets get back to the topic
my warmed up idle is about 1500-1700 bounce since i have no cold start my cold idle is a 5lb sledge on my gas pedal! lol (i'm not kidding either)

ok well here are some hardcore numbers from my last dyno run
peak torque at 6297 rpms
peak hp at 6767rpm
now granted i don't make much power below 4k but why do you need 500hp at anyhing below 4k? hell i don't even launch at the track that low
if you need 500 hp or even 300 hp below 4 k for crusing in traffic and stop and go driving i think you are retarded, if you want to play around race do what ever it is you do all of it will be done most likely above 4k after 4k it skyrockets straight up
just get over it and accept that a bridgeport is streetable! :D

Argh... I couldn't quote you.... so I'll have to go over some stuff manually :)

You only need carbon seals if you want to go over 8500. Since a well done bridge or peripheral port can and will increase torque over a BRAD RPM curve (I've seen a shart floating around here that shows marked improvements in VE at everything over 2000, and that's just where the chart began) then if you tune the ports for the midrange you will still get great improvements without needing to rev over 8500. (Mazdatrix's drag 20B has bridge ports and an ~8500rpm max because of 1-pc steel apex seals)

All NSU production engines were peripheral port. They were tuned for midrange power. An NSU 10A-sized engine was making 120hp at 5500rpm, when at the same time a side-ported Mazda 12A made 100hp at 7000. The peripheral/bridge port is a MUCH more efficient port. The problem is that "traditional" peripheral/bridge engines made out of Mazda parts are tuned strictly for high-end power. Well you can do that with a side port too... you can make a side port that doesn't begin to make power until the tach needle twists off. (It still won't be as efficient as a bridge though)

Bridge/peripheral engines have 1 disadvantage... poor efficiency/economy at low load. That's a tradeoff that many people are willing to take. I used to drive a lumpy idled 429 that didn't like to run below 2k... I'd get anywhere from 2-10mpg in the city. (Out on the hgihway where it could get into its powerband it'd get 23 or so MPG) Other people I knew at the time had wilder combinations and drove them daily as well. Just because one particular person's idea of "streetable" means things like smooth, low idle and super-high MPG doesn't mean that's everyone's idea. Personally smooth low idles annoy the crap out of me, it sounds like some sort of granny car :)

the velocity of the intake air keeps going 'forward' even when the rotor/piston is past TDC and starting the compression phase, this is how you achieve over 100% VE, only once the intake ports are closed does intake air stop going into the chamber, this is achieved easier on a rotary than on a pistom engine

sweet :)

as a point of reference my last street port had a cold idle of 1900-2100 bouncing (brap brap brap) and a hot idle with all accessories off it'd idle between 900 and 1100 bouncing slowly, turn accessories like lights and the electric fan on it'd idle down to as low as 700. I usually held the idle up to about 1500 at stoplights. it also made good torque at all RPM, lots more than stock, but the real meat of the powerband didn't start until 5500, and it felt like a turbo spooling up. (This being a non turbo car)

Hey, I've got this porting stuff figured out...

A bigger hole lets more gas and air in. Pulled-in ok, pushed-in even better. More gas and air makes a bigger bang (probably the loud sounds you guys were talking about). Bigger bang makes more power.
See, it's simple:)

Steve C.
Marietta, Georgia
>Carbide wins

Pulled in? What do you mean?

Air is always pushed in to the engine. At atmospheric it gets pushed in to the intake manifold at 14.7psi at sea level, under boost it gets pushed in at 14.7+boost pressure (10psi boost (psig, gauge pressure) is 24.7psi absolute (psia).

Once inside the manifold you get into things like resonance tuning effects, imagine the air pressure wave moving in the manifold is a big Slinky moving back and forth - if you can time it so the pressure is highest right before the intake port closes you can force even more air into the engine. That's where goodies like the way the intake manifold is shaped come in to play. Rotaries' secondary side is shaped like it is to actually use the closing of one intake port, which makes a big pressure wave Slinky-ing around, to force more air into the other rotor. Of course this can only be tuned for one specific RPM, but by changing the length we can change the RPM it happens at - this is where VDI comes in.

The port overlap period is more fun. With proper exhaust tuning you will end up with lower pressure on the exhaust side than at the intake side during the critical overlap period. (Same Slinky effect works on the exhaust side too!) The pressure in the intake manifold (remember there is no such thing as vacuum, just pressure below atmospheric) forces the exhaust gases out of the chamber for a more complete fill. Bridge and peripheral ports have a much nicer and better-shaped overlap period so this happens more readily (large street ports to a very small extent, too) which results in better chamber filling at whatever RPM you tune the resonances to occur.

Notice, whatever RPM you tune it for! People who just open the ports up as big as possible and put enormous-diameter short-runner exhausts on are going to only make decent torque at sky-high RPM. If you TUNE the SYSTEM for a lower RPM band, you're going to get shatteringly good results without having a "peaky undriveable" engine. Porting must be done intelligently and with the intended purpose in mind! Of course if you order a race peripheral or bridge port engine it's only going to make power at sky high RPM, because most builders will assume that it's a race engine that needs to make maximal power and forget the rest of the RPM band because the engine never goes that low.

This is only for boosted engines.&nbsp You're actually losing velocity in an NA engine due to the fact that you're allowing the intake charge to enter the combustion chamber in a much larger winder.&nbsp Remember, velocity is delta distance over delta time; you're increasing delta time so velocity decreases.


It depends on who you're talking to.&nbsp Changing duration and overlap is as "easy" as swapping out the camshaft(s) on a piston engine...



-Ted

You're only losing velocity if you open up the runners a huge amount! Only open up the parts that are a restriction and leave the rest alone, and get max velocity with minimum volume. Then you start making stupid-big power at decent RPM!

The window of the port isn't critical to velocity... it's more critical as it relates to opening and closing timing. Look at it this way, the airflow is going from high velocity in the runner to very low velocity/large volume when it actually gets in the chamber, you're going to want to make that as smooth a transition as possible so you need to open up the port window BESIDES the obvious benefits from increased port timing. With a good Bridge or a Peripheral the air has more of a straight shot into the runner versus the two or three right angles that the air must make with a stock port or even some badly done street ports.

On a list of Mazda rotary engines I did see they have a model designation for a Miller Cycle rotary! I have to learn to bookmark stuff more though :-(

Wow! I never thought I would say this, but Ted you are incorrect. The Miller Cycle engine DELAYS the closing of the intake valves further into the compression stroke and depends upon a strong S/C to provide compression and stop reversion. Typically Millers are 15% more efficient per displacement.

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