The Super Efficient engine project- 40+ MPG- 110HP!

dstar · Post by **dstar** » Fri Apr 08, 2005 9:01 am

BRAVO Bill, BRAVO!

What ever happened to, "AMERICA, By the
PEOPLE, for the PEOPLE" ?

Don

HAM Inc · Post by **HAM Inc** » Fri Apr 08, 2005 9:32 am

I vote against any sitting politician I can. If I could vote against them all I would. The "R" or "D" after their name means nothing to me.

Should have known the fuel economy issue would turn political!

Guest · Post by **Guest** » Fri Apr 08, 2005 9:36 am

HAM Inc wrote:I vote against any sitting politician I can. If I could vote against them all I would. The "R" or "D" after their name means nothing to me.

Should have known the fuel economy issue would turn political!

BUWAHAHHAHAHAHHAHAHA!

OK, OK, I remove it!

Don

davygrvy · Post by **davygrvy** » Fri Apr 08, 2005 9:40 am

HAM Inc wrote:Should have known the fuel economy issue would turn political!

So I just read there's this bill in congress to extend daylight savings time because it is expected to save 10,000 barrels of oil a day..

Umm.. like WTF? How does shifting the clock save petroleum?

Plastermaster · Post by **Plastermaster** » Fri Apr 08, 2005 9:41 am

Calm Down Don! LOL

I think voting D or R can be stratigally done to maintain a healthy gridlock. With gridlock they cant screw things up a easily.

Back to the subject, This engine will produce alot of Hp for the amount of fuel used. What kind of BSFC numbers would you expect? Is it possible to get it down into the 30s?

Ron

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Fri Apr 08, 2005 9:50 am

I don't get involved in politics at all. I don't have enough time to watch TV and see what the "Liar of the day" is saying to glorify himself...

Due to this I am not an informed individual enough to even make a wise decision when casting a vote- So I don't and never ever have.... Is that wrong? I don't think so simply because I'm politically ignorant and haven't the time to sleep, much less watch Fox news, CNN or CSPAN and listen to lies from people that spend millions of bucks to be elected to make 1/5 of that in return from their "Position"... Doesn't make much sense to me.

One more political post on this thread and I'll lock it up.

This forum is about engines, not politics.

As for BSFC numbers I don't see 30s at all, hell a Super Efficient modern Diesel operates in the 30s!

mike373 · Post by **mike373** » Fri Apr 08, 2005 2:55 pm

AMEN!!!!!!!!!!! Hopefully that response wont shift to a religious discussion.

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Fri Apr 08, 2005 3:17 pm

If it does, I'll lock it and throw away the key!

jarbutt9 · Post by **jarbutt9** » Mon Apr 11, 2005 6:18 pm

that pretty much killed the thread. oh well. maybe next time we start talking fuel efficiency we can mention God? what do you think jake? great idea for the engine. i'll watch for the T4 version.

jas

Poor Realist · Post by **Poor Realist** » Tue Apr 12, 2005 1:50 pm

I think engines should only be offered with sequential FI -- none of this batchfire stuff.

914fan · Post by **914fan** » Tue Apr 12, 2005 2:25 pm

Jake,
I think you said that you were going to try and have a smog clean or legal engine. (could have mis read) Have you thought of shortening the piston crowns. I believe that this decreases the total chamber volume (although not usually calculated) but also decreases the area that does not contribute to a compleate burn. The mixture above the top ring and below the top of the piston does not get burnt compleatly. (again I believe) I read somewear that the newest engines had moved the top ring up to clean up emissions. I think it made a significant differance.

914fan

raygreenwood · Post by **raygreenwood** » Tue Apr 12, 2005 4:21 pm

Well..decreasing the chamber volume can lower compression. It will affect NOX...but unless lots else changes...will generally raise hydrocarbons. Unless evrything else is designed just right for it...lowering the compression lowers the efficiency.

As for sequential injecton, I also believe sequential would help in certain areas. But...I base that from a long series of injection timing related observations and experiments over 20 years.

In a lot of cases.....it may be a lot of trouble for small benefit. In my experiences, the engines that benefit the most ....(and these high fuel milage high efficiency engines Jake is planning may just be some of those that can benefit)......injection timing on banked and paired injection becomes an issue from idle up to about 1700 or so rpm (depending on the engine combination). It can adversely affect fuel mixture at idle. Not ugly...just noticable. That...obviously affects emmissions. After a certain rpm....the time factor becomes so compressed that the variance is negligable. Not non-existant mind you....just negligable....on the average engine.
It (non-sequential injection) keeps you from fully excercising really delicate control of the fuel...because it disturbs the spray pattern... partly....and partly because more of the fuel is hitting port wall surfaces on a closed valve cycle...instead of staying in micro-droplets in a moving airstream flowing into an open valve.
Of course...its very hard to get a full handle on whats really happening at that point, because there is a lot of turbulence going on at high rpms due to reversion waves....BUT, inspection of a lot of paired and banked manifolds will show you just how much fuel gets baked onto the port walls whose injectors are out of time to the valve opening point. This is mainly an issue of complete...or at least even....atomization.

Some cases in point. D-jet and CIS. Both of these systems are reputed to idle more happily slightly rich. This is not actually true. The D-jet...actually can idle perfctly with the fuel mixture just right...but...the exhaust will smell a little rich (even though it is not actually receiving too much fuel).....and...the two out of time plugs will actually show to be a little lean. Thats because the fuel entering the two out of time ports is poorly atomized, poorly stirred and homogenized...and due to the in built exhaust overlap of the cam....a lot of unburnt fuel gets exhausted before it can burn. It also makes the muffler run hot due to combusting in the J-pipe and muffler. But.....adding a little more advance can help that....because not only does it start the ignition process sooner...it advance the injection on those two cylinders as they are slaved to the distributor. The downside...is that... lets say just for experiments sake...if you keep really advancing the timing at idle....it will start disturbing the timing of the other two cylinders. Now all 4 are out of time to some degree. It gets ugly.

CIS on the other hand....sprays all the time. All of the ports have excessive fuel spray in them. In order to run exact correct fuel mixture while under way, the car idles rich ....BUT... the actual fuel mixture settings are a little lean. It constantly makes up about 10% of what the injectors are NOT giving it at any particular instance...with what it scavenges off the port walls.

In sequential...a very close tie must be made to ignition advance.....because....and keep this in mind.....as you are accelerating, to a certain extent, the pulse width relation is increasing....then... should start decreasing slightly. During the stage of injection duration increase....the injection trigger point must start advancing......to inject before the actual valve opening point starts...in order to complete a full injection...before the valve slams shut. If the injector has not finished its pulse on a sequential engine...before the valve closes.....that "inhalation".....will be lean.

Also, you do not have to start injecting exactly at the instant the valve opens. It just must be at some time while the valve is open...so the micro-droplets are injected into a moving air stream. THIS is the point wherein they are actually atomized...not at the injector tip.
In fact....from some of my observations...it may not be exactly advantageous to inject exactly the instant the valve is starting to open....as the turbulent air from the last reversion wave must change direction, flow toward and consolidate...to be a useful vehicle for moving fuel droplets while touching as little as possible with that fuel. If you then have to have really advanced injection timing to jeep ahead of the valve opening point.....at some point there wil be a point of dimenishing returns...as you are injecting too much when the valve is still closed. How that will work when its only closed for a couple milliseconds or so more...i'm not sure yet. Sorry for the length. Ray

914fan · Post by **914fan** » Wed Apr 13, 2005 9:00 pm

Good points Ray. What do you do for a living?

One question. Dosent decreasing the chamber volume increase the compression?

Jake,
Should compression be measured with volume for the crown gap? I know that this will not increase compression, It will actually decrease it right? So what way do I do it? I'm going to see what kind of differance it makes.

Can anybody give me a crown height, cylinder boar, and piston boar combination. I would guess that the crown is about 3mm and that the cilinder boar is .25 larger than the piston. Are these close?

raygreenwood · Post by **raygreenwood** » Wed Apr 13, 2005 9:39 pm

Yep...meant to say...increasing the chamber volume lowers compression. I gathered...and I may have mis-understood....that it was suggested to shave the top of the piston down...Did I mis-read? Ray

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Wed Apr 13, 2005 9:43 pm

Yep, to get a 100% complete CR reading you need to measure the volume all the way to the top compression ring. This is typically 1 +/-cc or so for most 96mm bores and more for larger bores.