darin morgan and joe mondello answer BBF's questions

[big block fiero]

I am allways pondering answers to motorhead questions such as the ones we discuss on this forum so the other day I gather up some of our generalized topics and present them to darin morgan and joe mondello.

One of the questions was about the summander grooves. I set up the discussion by pointing out that tests have shown a horsepower gain with these grooves and an increased squish clearence, A resulting wider power band, and that several top engine masters challenge engines are using these grooves.

Now realize that these two have developed an improoved method for wet flow testing and so all roads lead back to their wet flow testing wich we may all come to realize someday is the correct perspective and so the answer is -----------These grooves make gains only when or because wet fuel is somewhere in the chamber that needs to be vaporized and especially if it is on the spark plug. Not about flame kernal, not about flame travel, not chamber shadowing, not an increase in squish dimention, only in cylinder vaporization and nothing else.

So my next topic was the slightly dished pistons used in nascar and if the average overall increased chamber clearence dimention in some way contributes to this gain. ------------The answer was that the squish band is still very close around the perimeter and that as long as the chamber has enough squish to bore ratio then it doesn't mater if the center is dished.

I next described david vizards avenger engine that requires good vaporization and has no squish and A wide powerband. -----------The answer was there must be something else about the build that is being comfensated for and that you should allways run a tight squish clearence----and also from joe "isn't he the guy that races those little mini's?" and then the discusion went on to how super close they run the squish on every engine and that they usually hit a little.

I next described an engine with very good swirl, valve and valve seat shearing, a tight squish clearance and everything that would contribute to good in cylinder vaporization and that this david vizard creation responded better with carboration that delivered larger fuel droplets instead of the smaller droplets. I suggested that the cylinder could be using evaporization to creating a cooling within the cylinder to create this gain. ---------The answer was again that something else within the motor must be deficiant and is being comfensated for. You allways want the smallest droplets to create the most vaporization and then the discusion went on about shearing techniques, ski-jumps in the short turn radious for vaporization (bob glidden), never running a tulip intake valve because the 12 degree has better shearing, pressure recovery dynamics of a 55 degree valve seat creating volocity for vaporization, ect. ------ I then suggested those dimpled golf ball pattern valve undersides, ------- Answer,anything that can help vaporization even if it hurts the dry flowbench numbers a little will add horsepower. Thats all for now, mabe I'll remember some more, if so ill post it.

Matt.

[automotivebreath]

Great set of questions Matt. Did they give any indication that the answers
were a result of testing or rather educated opinion?

[big block fiero]

Originally Posted by automotivebreath

Great set of questions Matt. Did they give any indication that the answers
were a result of testing or rather educated opinion?

Im guessing sometimes its an opinion. The topic of fuel droplet size for example. They have never seen an engine increase horsepower by running larger fuel droplets, but rather then engaging in a debate as to how this could be, they brushed it off with an explination that was so vauge that I wondered how they are able to be on the cutting edge of new ideas without haveing that desire to find out why. Also this issue is very conflicting to their belief that it is best to allways have the best vaporization possible as seen in the wet flow testing.

I am still wondering if a good vaporizing engine can run a larger squish clearence or reduced quench to bore ratio without loosing horsepower wile yet broadening the horsepower curve. I know david vizard has tested things like this but dont know if total horsepower had deminished any from one build to the other and so their could be some penalty for this powerband increase.

[MilesTugoh]

Well done, Matt, I second AB's comments.

[gregory]

Perhaps one day someone will saturate the air so well,that you wont need a wet flowbench anymore..i wonder what they find out with the wet flowbench with injected heads where the fuel enters at the valve..a big gooey mess i bet.

[big block fiero]

Originally Posted by gregory

Perhaps one day someone will saturate the air so well,that you wont need a wet flowbench anymore..i wonder what they find out with the wet flowbench with injected heads where the fuel enters at the valve..a big gooey mess i bet.

This is exactly why I think some of this wet flow stuff is perplexing. For these guys to say that anything you do, to a point, to increase vaporization, do it, even if there is some loss in flow. So now a flow bench without wet flow is fairly inefective. 30 degree valve seats are out (alltho they average more flow for many applications) because 55 degree seats have more low lift vaporization due to velocity from the restriction. Any mod (other than a vaporization mod) that anyone has ever reported to be a gain is now in question because it can be said that that gain may only have been because there was somehow increased vaporization.

And so now on to your point that a super carborator that could solve all this means that the flow bench is now again significantly important, We can run 30 degree seats, valve movements as aggressive as we want, and whatever connecting rod to stroke ratio's that we want. some could even start advocating the old school polished intake ports again, (ok, maybe this is an exageration). In summary as much flow as we can find anywhere in the opperating cycle.

So then it appears that smokey was right with his hot air vaporizing engine, long connecting rods, ect, but then why is this so important now rather then back in 1984. The only difference being that smokeys vaporization occured more upstream and at 450 degrees which reduced intake air density. mondello and morgan,s vaporization occuring later and comparatively colder for more air density. Or is this because joe didn't even ever have a flow bench till 1997 and it took him till 2001 to reinvent the wet flow testing imageing and then to establish this philosophy.

David vizard has allways in the past outlined ways to increase vaporization but has generally stopped short of things that would measurably reduce cfm. perhaps his carborator mods have generally allways had more vaporization.

These clues all seem to be fitting together untill davids motor and others that Ive seen, that make more power with larger droplets are considered. The only way I can make this all fit the picture at this point is, as I surmized by darin morgan, to assume that these engines on smaller droplets have wet flow problems that create a vortecy at the plug that wets the plug. Then wile running larger droplets the vortecy changes location or mannor due to the centrifugal force within these droplets, within the vortecy, which then dosen't wet the plugs as much. An intresting test would be to run this motor with the small droplets but then try a dished valve, flat valve combination to move the vortecy somewhere else within the chamber so as to dry up the plugs. Any comments david vizard?

Matt

[gregory]

What you gotta think about is this..

There are a lot of people out there that whether they know it or not,relate everything that they see,in terms of wet flow,dry flow,upside down flow,and insideout flow,to a average size fuel droplet that comes out of a holley..
Now you can do things to get those droplets smaller,and i think that this will lead to a much higher ratio of air saturation,that will go a long way to determing what you see in the terms of wet flow,or what you dont see in wet flow..so,the thing is....are current head designs related to a certain or average size fuel droplet? what were to happen to those designs if the air saturation to ALL cylinders was increased by 50%?

Do current winning enigine designers and head porters experiment with fuel droplet size? because this is where the circle begins once the engine is designed and built.

[shrinker]

I think a big problem is the rules for drag racing etc. american rules are very protective of the home environment. There is a whole world of choice out there that american racers are not allowed to use because it says in the rules only holley or BG or american production. How restrictive is that, that attitude inhibits other areas of development.

I first started wet flow testing in 1993 with a bench I built and designed my self, just like the one I designed & built for Darin Morgan at Reher Morrison.

Mondello did'nt reinvent wet flow testing. While attending the AETC conference in Colorado Springs, Colorado I, Lloyd Creek mention to Joe that I had an idea for a wet flow bench.

We decided to form a Corporation called Mondello/ Creek Flow Management, Inc.

From that I designed and engineered the WFB-2000, WFB-1500, and Dart's WFB-2800.

Just wanted to set things straight, seems like the real story gets buried these days

Lloyd Creek
Creek Flow Management

[gregory]

Hi Lloyd,
When you have done flowing on your wet flow set-up,do you play around with the droplet size of the liquid that you add to the airstream,and if you do,what trends do you see when you go smaller,larger?
Do you try and replicate the fuel droplet size that comes out of a generic holley?
On a typical pro-stock deal,do you see the fuel droplet size from their carbs any smaller?