BLOWER tech???

scotch, i was under the impression that the fuel introduced on the top side was also for cooling of the rotors in the supercharger. is this the case? in an efi setup could you inject 1 or 2 on top for cooling and then inject in the port of each cylinder for optimal mixture. seems to me that this would allow more volume to compress since there would be less fuel to displace air in the rotors? obviously it would be complicated, you'd need a custom ecu to drive 10 injectors instead of 8.

tech week rocks, ryan, could we have tech millenium next time?

 

What about running a four or a two hole injector on a Tunnel ram? Now what about turbos and centrfugals? i would like to run one or the other(probably a turbo tho)on my slant six.
-Jesse

 

Here are the pics of my blower setup.

http://members.lycos.co.uk/zackbass/4-71Gallery.htm

The motor feels very strong as it is, but I'm only getting ~5lb boost and the carb is far from tuned. I just got a new 650CFM Holley to put on the motor and hopefully I'll get a smaller top pulley so I can get some more boost. The motor has forged pistons, a strong crank, and beefed up mains so it should be able to take bit more. The motor wasn't built to be a blower motor, it's got a very radical roller cam and an extremely long stroke, but it took to the blower very nicely. The motor has a 7:1 comp ratio. It idles very nicely and the blower makes a surprisingly little amount of noise.

 

flatdog,

whats your estimate on the HP output of that setup? i'm still wiaitng to get joe's book Blown Flathead for some more info. Apart from the main strengthening issues, how would an otherwise stock stroke/bore/heads flatmotor take to being supercharged?

danny

ps. where was the sources for your drive gear parts on the blower?

 

I am hopeing for 300 hp,it made 188hp without blower.It is too early in testing stage to realy know anything yet except seat of the pants,but that feels great.Blower drive parts where made by Ronnie Roadster out off Conn.He also made extened water pump shahts to clear the blower belt it not the first blower drive setup he bilt.

 

Gettinggreasy,

Running mechanical injectors atop a tunnel ram presents it's own issues aside from tuning...which is a problem unto itself. First, I'll tell you why it wouldn't work well if it WAS tuneable, which it isn't.

Mechanical injection is always flowing fuel, just at varying pressures (with rpm). It's been called a "drool" system for this reason. Engineers have placed mechanical injectors close to the intake valve for this reason. The air flowing quickly toward and around the intake valve can pick up the fuel from the drooling jector and keep some of it in suspension in the airstream so it'll mix well. If it doesn't mix well, it won't burn well...(you know that if you toss a lit cigarette into a bucket of fuel, it'll extinguish, right? Trust me on this...).

So, the finer the fuel can be misted, the better. The more fuel that can stay in suspension, the better.

If you were to mount a 4-holer atop a tunnel ram, you'd get a constant flow of fuel into the intake, where it would subsequently puddle up on the floor of the intake and the motor won't run well.

Also, mechanical injection systems don't have accelerator pumps, so there's typically a "lag" wen you floor it, or even casually creep up on the pedal. Remember, these injection systems were designed to be run at WOT, so acceleration smoothness is not a primary concern.

Maybe you can already begin to see how tuning a less-than ideal system like this would be near impossible. Even if you could, temperature and air quality changes (humidity, barometric pressure, etc.) would all affect it, and keep the killer tune out of your reach.

EFI clears up all these issues.

With regard to the cooling effect of gasoline on a blower...

Yes, the introduction of gasoline to a draw-through system does serve to cool the blower assembly, which is trying to heat up due to the friction of compression. However..

Roots blowers were designed to be run "dry", and they don't need the cooling effect of the gasoline to work. In fact, this is one of the reasons "factory" specifications for GMC superchargers are so loose compared to those preferred by automotive enthusiasts. Big clearances exist to account for the swelling of parts and long-term life of the blower when it's used in it's original application (diesel engines).

Car guys prefer tight clearances for higher boost pressures, and with the addition of gasoline this can be done easily.

There are some enthusiasts experimenting with blower EFI systems where the blower is run "dry" and fuel is introduced above the valve. Expect to see things like this on the market in the near future.

Scotch~!

 

I've been looking at FI since I posted a few months ago about my desire to build one with an electric pump. Work causes things to take months instead of weeks, but I found encouragement in air atomizing nozzles. The ones from http://www.spray.com/pdf/b381_Air%20Atomizing%20Nozzles.pdf claim to put out 15 micron droplets. A human hair is 100 microns. The nozzles look just like the tip on a paint gun. I have looked at others where air flow affected fuel which made programming tough, and I have not gotten the specs on these yet, but a Sanden compressor set up to supply air like this http://www.onboardair.com/compressors.htm should supply the air. While finalizing electrical ideas I found http://www.aquamist.co.uk/ who sell water injectors that mimic fuel delivery so if seals are compatible, could be the pump and programming solution. Put all this on 97/Rochester throttle body bases on SBC intakes with plumbing and compressor and offer the pieces for the other engines.

 

phil1934,
whereabouts in jointsboro do ya' live?
i live in hampton,and would like to see some of your experimenting on this subject,if you are doing some that is,and don't mind someone seeing such.
might even do some brainstorming.
pm if interested.
thanks.

 

hey flatdog,

was was his pricing like?

danny

[ QUOTE ]
I am hopeing for 300 hp,it made 188hp without blower.It is too early in testing stage to realy know anything yet except seat of the pants,but that feels great.Blower drive parts where made by Ronnie Roadster out off Conn.He also made extened water pump shahts to clear the blower belt it not the first blower drive setup he bilt.

[/ QUOTE ]

 

Something was said on page one of this thread that roller cams are preferred because it allows for more lift with a certain duration. Actually, that's backward. Roller cams allow for longer duration due to the steeper ramps (quicker opening, quicker closing, meaning the valve can hang open longer).


As for mechanical injection on the street, I doubt it would work well on a stack injector naturally aspirated, but I happen to know some Willys guys doing this on supercharged street engines with good results. I will be using a 4-port on top of my blown 394. There are definite tricks to setting the system up though!