Peformance engine building - more art or more science?

General engine tech -- Drag Racing to Circle Track

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Tokyo Torquer
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Peformance engine building - more art or more science?

Post by Tokyo Torquer » Mon Oct 13, 2008 3:59 pm

I am just an old hobbiest trying to learn from those who know more, but I am always struck by the disparity of opinions.

On the science side, there are ton of formulas to help you estimate hp and torque, model valve train action, calculate fuel and air flow requirements, etc.

On the art side, along with the contrasting opinions are those builders with combos them seem to go better than they have any right to, outpower combos that should be making more power, or maybe as simple as achiving the same goal with very contrasting approaches. Cam design certainly seems very much like a black art when I listen to 2 cam experts go at it. I think most every builder/ industry expert would claim he knows secrets that others don't.

I was just wondering what % of this is science and what percent is art in performance engine building. What are your thoughts??

1973 RS Z28: 401ci Dart Little M, Littlefield 8-71 supercharger @14lbs boost, Callies Magnum crank, Lunati rods, JE pistons, 7.8:1, AFR 227 Comp heads, T&D 1.6 shaft rockers. Reed solid FT cam (240/250@.050-.523/.542 lift-112 LSA), QFT 750 carbs

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Post by coolchevy » Mon Oct 13, 2008 4:20 pm

it is a combination of both, sometimes the result defies logics but who cares when you are the one in the winning lane........

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Post by randy331 » Mon Oct 13, 2008 5:04 pm

It's both, and I won't try to put a % on each one.

There are lots of formulas to help you calculate valve sizes/CSA of ports/runner lengths etc, but I haven't found one that will figure the slight little differences in the shape of a ports short turn, that can make the port move 20 more cfm, and be quieter doing it, but I sure know those differences in shapes exist.


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Post by RW TECH » Mon Oct 13, 2008 5:16 pm

I'll say the majority is a science, but there are very few operations out there who have the resources & time to do enough calculation and measurement to develop a robust prodictability model.

Some may argue with this but consider global consumer demand, lack of regulations (gvt. mandated safety, emissions, performance, etc.) and it becomes clear why there are no significant investments to get racing engine technology to that point.

An OEM engine can easily be the result of a $1B dollar investment. The market & all the regulations, warranty risks, liabilities, etc. etc. require that kind of investment. A racing operation could spend something like that but it'd be stretched out over several years because the only thing that drives racing technology is the competition.

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Post by panic » Mon Oct 13, 2008 6:20 pm

It's all science.
Some is based on prediction.
The rest is based on conclusion from past results.

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Post by 67RS502 » Mon Oct 13, 2008 6:26 pm

I think theres more science behind it then most realize,
but then theres the experience, R&D, I've done it and it work (on this combo)
side of it. A scientific formula may not be able to tell you what
carb spacer will work with this or that engine, (R&D / dyno / track will)
but there will be a scientific explanation, and if you understand that,
the reason why it work, not just that it does, you will be a better
engine designer/builder.
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girly rollers on pumpgas:
420 - 641hp BretBauerCam, 1.39, 9.79 @ 137.5
383 - 490hp 224/224, 1.56, 10.77 @ 124.6
502 - 626hp 252/263, 049s 1.44, 10.08 @ 132.7
62 Nova cruiser
383/200-4R/12-bolt w 373s
224/224 HR cam
1.57 10.97 @ 121.2

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Post by beth » Mon Oct 13, 2008 6:47 pm

Science plus testing/R&D resulting in experience with what works is 100%. Experience can also be learned from others.

When people do not understand the science or experience it becomes black art to them. Rather than an art or secret it is simply something they do not understand. This is the reason they can look at the parts yet never see the "secret".

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Post by Keith Morganstein » Mon Oct 13, 2008 7:17 pm

Sure, science is the underlying reason something works.

The art is the attention to detail, the hand involved in the actual work and the experience of the builder, designer and tuner.

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Post by PackardV8 » Mon Oct 13, 2008 8:56 pm

Science is like the sheet music for a symphony. Anyone can buy it. Not everyone can understand it equally well. Musicians are like the parts. Good ones cost more, but work together better. However, it is the conductor/builder who brings it all together. Throw a folder of music and a bunch of musicians in a room and nothing happens. Bring in a good conductor and music happens. Bring in a great conductor and genius happens. Each musician plays better than he/she thought possible. The music sounds better than the composer imagined. The recording defines that particular work sells for years around the world.

Build engines which win a couple of the big races and the name lives on - Clay Smith, Harry Miller/Leo Goosen, Smokey Yunick, Chickie Hiroshima, Lofty England, Harry Westlake, Ernie Elliott, Bo Fields. You've got some heroes and influences who brought art and science together at a higher level. - name them.

thnx, jack vines
Last edited by PackardV8 on Mon Oct 13, 2008 9:02 pm, edited 2 times in total.
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Post by bigjoe1 » Mon Oct 13, 2008 8:56 pm

The biggest thing I have learned in the last 40 or 50 years is what DOES NOT WORK-- this saves you so much time and money. Most people waste so much time on things that do not work--


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Post by MadBill » Mon Oct 13, 2008 9:05 pm

What Joe says is so true, and yet at the pinnacle of engine development, almost nothing works better than what you're already doing; it's really hard for the best to progress!
A top builder could probably pick a cam for my engine that made 30 HP more than my best choice, but who could gain even 5 on a competitive Cup engine?
Felix, qui potuit rerum cognscere causas.

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Post by David Redszus » Mon Oct 13, 2008 9:27 pm

It is entirely science and absolutely nothing else.

That said, recognize that there is good science and bad science.

A great deal of pseudo science masquerades as true science and gives it a bad name.

And that we have not yet learned all that science has to teach us.

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Post by tod85 » Mon Oct 13, 2008 9:42 pm

In my opinion, its science to build the HP, but an artform to make it go fast. 8)

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Re: Peformance engine building - more art or more science?

Post by e-tach » Mon Oct 13, 2008 10:41 pm

Tokyo Torquer wrote: I was just wondering what % of this is science and what percent is art in performance engine building. What are your thoughts??

A little off subject here - but...

My thought is that anyone who is serious about engine building suffers from being

"passionately addicted to a sickness"

At least that is how I feel. And that is not a bad thing. And I am lucky enough to call this hobby my "job".
Now with that said - It takes a whole lot of science - and even some guessing - a lot of skill - patience - fortitude, etc to put all the science into art form.

What I mean by guessing is "trial and error". There are many things we may try, that haven't been tried before (or at least not that we can get any serious input about) that make us better, and make our engines run better :hopefully:

I am with others though, saying this is one of the most difficult jobs out there, (thats if you really care about what your doing)

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Post by automotive breath » Mon Oct 13, 2008 10:43 pm

Clearly a combination of both science and art, based on knoladage of facts
and principles combined with skilled workmanship and techniques.

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