MAKING MORE HORSEPOWER...IS IT TRUE?

[Corzette]

OK, I was just told by a racing guru here in Angelo that if I cut a piece of screen door screen the size of a Carb gasket and put it in between the carb and intake, silicon it for a proper seal and torque down the carb, it will get better throttle response and AF mixture. This is because the squirters will then not just shoot raw gas straight into your intake but rather hit the screen and fan out more. Has anyone every tried this? Also you woundnt have to worry about dropping anything in the intake thru the carb. Any input or experience. Its sounds reasonable to me....

[Guest Nic-Rebel450CA]

I have heard that as well, but the explanation is a little off. The carb does not shoot raw gas straight into the intake. The carb squirts the gas in the carb body and it starts atomizing by the time it gets to the top of the intake manifold. The screen idea is supposed to be somewhat helpful as it does help with the atomization in a couple ways. First, it conducts heat through the wires of the screen and warms the air in the path of the AFM and helps atomize. Second, it does help slightly in the dispersion. However, I have heard that the gains are negligable as it does slightly decrease airflow, and does pose a risk to your intake valves unless you routinely take the carb off to confirm the condition of the screen.

[Corzette]

Roger that....

[660Z]

I tried it a few years ago and it does work for normal driving but it hurts WOT performance so I took it out.

 

Mark

[RPMS]

If you're as hamfisted as I am, the screen might also prevent small objects from being dropped into the intake tract.

 

I think y'all are right about the restriction, though. I was thinking about putting a screen in on similar advice, and I experimented by blowing forcefully through a section of screen. Yup, there was significant restriction, so the screen stayed off.

[Guest Nic-Rebel450CA]

If you're as hamfisted as I am' date=' the screen might also prevent small objects from being dropped into the intake tract.

[/quote']

 

That was mentioned, but, the screen itself becomes an object that can enter the intake due to deterioration. I'd say it may be a decent trade-off in some cases.

[Tim240z]

Well...I definitely wouldn't "silicone" it in place. Gasoline eats up silicone. Maybe Hylomar or something similar.

Usually, when the engine is warm the fuel atomises fine without any modifications. It's only in colder areas that there may be some benefit.

Tim

[Guest Vince]

I've seen intake manifold gaskets with screens on them, i think in a Summit or Jegs catalog.

[denny411]

David Visard touches on this subject in his book, "How to build Horsepower"

He specifically talks about the intake manifold gaskets with screens in them, and the benefits of fuel atomization.

I don`t recall his mentioning any adverse effects or air restrictions. I`ll read up on it this weekend and post his specific comments.

[waynekarnes]

back in the late 70's early 80's, one could buy a plate that had 4 little strainers in em, that went below the carb, between the carb and manifold. the idea was, better dispersion of the atomized gas and air, would produce better gas mileage/ hp. for the most part, it was proven to be bogus, and the product faded away.

 

guess the hula hoop, slinky, and frisbee are back in style. next it'll be magnets, copper pellets, the tornado

 

if any of this stuff worked, it's cheap and easy, the auto makers would use em on regular production cars.

 

wayne

[grumpyvette]

The screens under the carburetor or the intake gaskets with the screens in them, are one of those rare instances where it's kind of yes and no deal.

at low RPM's the screens do in fact help the breakup of the fuel droplets, which helps the cylinders get a better burn and can very slightly increased your fuel mileage. Provided of course that you can keep the engine below about 2500rpm-3000 rpm, but as the engine RPM's increase, that screen in the intake port or under the carburetor becomes a major restriction, I happened to have seen testing they did, in one of the magazines on those several years back, they picked up three horsepower and 1 mi. per gallon if and only if the driver The engine below 3000 rpm at all times, if the driver drove the car like most of us do would occasionally got 4000- 5000 rpm range he noticed a very large drop in performance almost as if there was a rev-limiter built into the engine. If I remember the article correctly, they tried it on both the 350 Chevrolet and a 454 Chevrolet the 454 Chevrolet with a large rectangular port heads, having much larger cross-sectional port's, was able to pull slightly higher in the rpm range before the restriction took effect, but in both cases the drivers felt there was a net loss not a gain in overall performance, I suppose if you are driving a taxi for a living, picking up an extra mile per gallon and spending most of your time and traffic, it would be a good idea.

Not on something totally different

on some single plane intakes, people install what they call it turtle, a turtle is basically a lump of carefully shaped metal, in the floor of the plenum, that redirects the airflow, the engine displacement ,the carburetor and the intake itself, plus the port size and cam timing, effect how the pulses from the intake port cross that plenum at different RPM's, if you're familiar with most dual plane intakes you'll notice of the divider wall, below the carburetor, on single plane intakes, that divider wall is normally removed, or very small,Occasionally, you'll find an engine combo on which some cylinders run much richer than others. I have found that making a turtle, which in this case I make out a folded aluminum sheet metal can redirect those pulses, and equalize the flow. the reason I bring this up, is that I normally make that sheet metal turtle from perforated aluminum sheet(screening of a sort) because it tends to break up fuel droplets and re-disperse them better than a solid sheet of aluminum forming a partial divider wall(turtle) in the floor of the plenum

[Corzette]

Thanks for the advice guys. Grumpy good to hear from ya!

[RPMS]

if any of this stuff worked' date=' it's cheap and easy, the auto makers would use em on regular production cars.

wayne[/quote']

 

Port matching would cost them almost nothing, yet they don't do it. So would tube headers, 3-angle valve seats, improved rod angles, porting heads, efficient exhausts, halfway decent stereos, etc. Some of these, they're starting to do thanks to popular pressure. Others they won't do because it will cost them $5-10 per car, and they're cheap bastards. Just because it's cheap, easy, and effective doesn't guarantee the factory will do it.

 

Anyone else have ideas that the car makers SHOULD do that they DON'T?

[Guest Perry]

here's one they are doing.

read the last 2 paragraphs of this one:

http://www.autoweek.com/cat_content.mv?port_code=autoweek&cat_code=carnews&loc_code=index&content_code=06906182

then this one:

http://www.focaljet.com/

Perry

[RPMS]

Now THAT'S a hybrid! I LIKE!!!

 

The first link, though was typical of much of Automobile's reporting. I paraphrase it like this: "We're going to make more power in the future. We're going to make more power, and make it in our cars. Our cars are going to make more power. Cars. Power. More. More powerful cars are going to be made, and we're going to make them." *barf*.

 

It takes real talent to take a 15 word concept and extend it to eight paragraphs. HOW are they going to do it?