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Injector Angle??????

Posted: Thu Feb 05, 2004 10:56 pm
by fourwhls
You guys have got me thinking, and thats a scary thing.

The whole injector angle situation has intrigued me, and I would like some more information.

Most cars with either a fuel rail or direct port injection use a high pressure system to supply the fuel. The fuel atomized coming out of the injector.

What kind of pressure are we looking at with the Cdale?? Is the fuel atomized or is it merely pissing out?

If it is a low pressure system, then Cannondale's original design would be warranted. The fuel would bounce off of the cylinder wall and create a more turbulent flow, therefore igniting faster.

Has anybody ever compared the before and after effects of realligning the injectors and only the injectors?

A lot of people have had this done in conjuction with numerous other enhancements. What percentage of the increased HP was due to the injectors?

I know Wade was the first to start this. I wonder if he did any testing to prove his theory.

Posted: Thu Feb 05, 2004 11:21 pm
by Jaybr
All good questions for another deep discussion.

I'm no where near being an expert in this subject, but here is what I have learned

The fuel pressure at the pump is 42psi, don't know how that compares to cars.

Talking with Mike at FDO, he said it looked like the fuel hits the wall and at least some of it just kinda drips down into the cylinder. He's pointing them directly at the valve on his reangle, not sure how his compares to others.

I have heard that the reangle helps it start alot easier and does away with plug fowling problems. No proof here, just hearsay.

Posted: Thu Feb 05, 2004 11:44 pm
by Bags
I know that I can really tell a better throttle response. Mine still starts hard and will flood if you touch the throttle while starting it.
It makes more sense in my mind to have the injectors spraying the fuel into the cylinder and not against the walls. I believe that the engineers had them angled in that way to help with clearance problems with the radiator and all and also to help with connecting the two injectors together.
I know that on our airboats, when we put injection on the aircraft engines, you can really tell a BIG difference between the injectors installed just in the intake tube somewhere before the head and the injectors that are installed into the head spraying into the cylinder.
I also know that this spraying of the fuel directly into the cylinder and onto the piston made some of the engines run a bit cooler head temperature.

Posted: Fri Feb 06, 2004 4:04 am
by J. Delaney
40psi is the ball park where most automotive fuel injection systems run with multi port fuel injection (where you have an injector per cylinder). It is much lower with a central fuel injection system (where you have one or two big injectors sitting atop the intake manifold like a carb).

Posted: Fri Feb 06, 2004 7:36 pm
by btolenti
my 02 SVT lightning runs 42 pound injectors....

Posted: Fri Feb 06, 2004 7:45 pm
by Swampdale
Technically the standard is 3 bar or 3x14.5 psi=43.5psig. Pressure in the 42-45 psig range is generally acceptable.

Posted: Fri Feb 06, 2004 8:40 pm
by claas900
..This is kinda off topic,but what you guys know about the fuel pumps? Iv heard of ppl getting one out of Summit,to replace the stock one..Iv been looking for a more compact aftermarket pump with the regulator built into it. so i can put it under the plastic were the air filter is..Problem is the the Cannon regulator has a vacuam hose on it,im not sure how to get around this?
Also anyone know anything about putting different injectors in them,or is there no performance to be gained by changeing them?..

Posted: Fri Feb 06, 2004 9:22 pm
by Swampdale
I'm investigating the same too. There are several pumps on the market which will work. The stock crossover is a Walbro or Master for around $80. The Accel from Summit is more expensive but more resistant to vibrations and heat. Have not seen one with a built in regulator yet???? You may want tocheck with Diamond Racing, QuadShop, or ABBOTTS???

Posted: Fri Feb 06, 2004 9:50 pm
by J. Delaney
btolenti, your 42lb injectors flow 42 lbs of fuel per hour, not 42 psi.

Posted: Fri Feb 06, 2004 10:09 pm
by btolenti
oh yeah..........duh.........sorry.......... smile.gif