A Conversation with Jim McFarland

Jim McfarlandWhen you want straight talk from an industry insider it's always best to ask someone who has been around a long time and is fully comfortable with voicing his opinions. That would be Jim McFarland, career engineer, long standing member of the SAE and a man with impeccable performance credentials who is wholly at ease conversing with industry giants or entry level enthusiasts.

Jim McFarland was one of this writer's earliest contacts in the performance industry more than 35 years ago. At that time he had already served as editor of Hot Rod Magazine and was currently Vice President of Engineering and R&D for the Edelbrock Corporation. In that capacity he was the innovator of the single plane intake manifold (Edelbrock Tarantula), a fundamental performance component that changed virtually every form of racing in this country and still remains a core component of most racing efforts. McFarland has always been an engine man and this writer's go-to source for the low-down on any particular engine performance question. I well remember standing in his upstairs offices asking novice questions and trying to comprehend the concepts he drew out for me on the blackboard. His patience and easy going manner put me immediately at ease and into a comfortable learning mode.

That has never changed as McFarland progressed through a brilliant career as an ambassador for the performance industry; pioneering many of the industry's efforts to accommodate government oversight. He has served as  a technical consultant for SEMA, working primarily in the area of state and federal environmental and regulatory issues. With his engineering background and 25 years of experience working directly with both the U.S. Environmental Protection Agency and California Air Resources Board certification staffs, Jim continues to contribute a vital technical perspective to the Government Affairs office. He is a well regarded automotive journalist and has served on multiple SEMA committees, three consecutive terms on the Board of Directors, and is a former SEMA Person of the Year and a member of the SEMA Hall of Fame. Among his current activities he also authors an authoritative monthly column on engine technology for Circle Track Magazine.  All that and he is still the same self confident, soft talking Texan willing to make time for anyone with a question. I am proud to call him friend and grateful that he still makes time for me whenever I call. I recently queried him on a number of contemporary performance issues.  His responses are presented here for the readers of hotrodenginetech.com.

Topic: Discussion on the current and future state of race engine planning and design


HRET

Twenty years ago race engine builders claimed they were nearly maxed out and lucky to find two or three horsepower. Today many of them are up a hundred horsepower or more with significantly better power curves.  What factors do you think contributed most to the steady advancement of power levels and how much do you think is still on the table? 

JM
I believe several factors have contributed to this progress, not the least of which are engine simulations and parts integration software that has helped engine builders enjoy the benefits from parts manufacturers who have refined their parts development skills.  Today, I think there is far more emphasis on parts “systems” function and a more global view of what makes engines packages work.  Plus, as parts technologies (CFD, and related analysis programs) and development tools (Spintrons, etc.) have evolved, new concepts about how to make power in the face of greater parts demands have also been in the mix.You need only look at where F1 has come in the past few years to get a sense for how technology has unlocked power from heretofore overlooked sources

HRET
How much do you think advanced coatings have contributed now that the science has matured? 

JM
There’s little question coatings have played a role, both in parts durability and power levels.  Further, I don’t think we’ve come to an end-point in how these materials will continue to evolve.

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HRET
Turbocharging and supercharging have really come into their own with truly amazing power levels.  Is this the result of precise electronic fuel injection and engine management or a combination of both with better superchargers and hardware? 

JM
This goes back to my point about integrating technologies and techniques.  In particular, advancements in turbocharger capabilities (some spawned from the OEM and some from motorsports) and the software that controls them has advanced.  Coatings have played a role here as well.  However, the fact that turbochargers can be designed and evaluated using dynamic computer models has enabled very fast (and more economical) means to final designs that any prior method that required hard parts to evolve a given design.

Spintron valve train tester

Spintron valvetrain tester
courtesy of Comp Cams

HRET
The Spintron has contributed greatly to camshaft and valve train development.  Could you shed some light on the current trend toward reducing spring mass and using shorter, stiffer pushrods to maintain valve train stability at extreme RPM? 

JM
As you know, valve train components designers have long sought to “stiffen” the overall way of converting cam lobe actuation of the remainder of the valve train.  Obviously, valve springs are “energy absorbers and releasers” and need to move through this cycle with a minimum of kinematic losses.  Mass reduction creates a corresponding reduction in kinetic energy within the system.  Pushrods are “shock absorbers” that operate in an environment that cannot avoid a range of compressive/extension movement that includes the effects of harmonics.  The stiffer (or shorter) the pushrod, the less kinetic energy transfer cycles are involved, all of which may be counter-productive to the harmonic ranges of the valve springs.  The outcome of this conflict includes valve train instability (at high rpm), potential parts damage and a net reduction in power.

HRET
You always stress the importance mixture quality and charge management to enhance combustion efficiency. What steps are engine builders currently investigating to optimize mixture quality with today’s modern combustion chambers? 

JM
In a carbureted engine, fuel atomization is a mechanical process, the success of which is exacerbated by an environment (total inlet air path that includes the combustion space) laced with pressure excursions (non-steady-state and multi-directional) that work against maintain small fuel particles and homogenization of air/fuel charges.  Various mechanical means can be used (inlet path surface textures, dynamic inlet air pressure distribution with the inlet path, and similar fuel-suspending techniques), the success from which can be gauged by a study of brake specific fuel consumption data.

HRET
The benefits of hot honing are well documented.  Do you see more people starting to employ it, or do most builders still find it just too messy and troublesome? 

JM
Any engine builder who deems this not worthy of the time and expense required is probably the same builder who seems stuck at about the same power levels.  I suggest you contact Dennis Wells (Wells Racing Engines), tell him I suggested you call and ask him this question.

HRET
Could you discuss briefly the value of power band placement and shaping to suit application specific requirements and how that is accomplished on any particular engine? 

JM
I cannot overemphasize the importance of “selective” power positioning, within the rpm range.  This is clearly fundamental to making the most of any engine package but only if the remainder of a given powertrain (transmission, rear gear, wheel/tire size, etc.) is matched to the rpm range targeted.  Since torque and volumetric efficiency are unavoidably linked and, further, inlet and outlet flow performance is a function of intake and exhaust systems (even though other areas of an engine can contribute somewhat), matching the performance of these two systems (relative to target rpm ranges) is where I’ve always focused my efforts when “shaping” power curves.

HRET
With vacuum pumps, honing techniques and superior ring technology is there anything left in the cylinder package for engine builders to find?

JM
I think lubricants play a role here.  All of the techniques you listed are intended to reduce fresh air/fuel charge contamination prior to and during combustion while, at the same time, creating the best possible pressure seal and minimizing frictional losses (pumping friction) is included.  I also believe further steps to reduce piston skirt friction, especially at high rpm is worthwhile.  Once again, I think lubricants are important to consider.

HRET
Do you think many engine builders outside the professionally engineered ranks actually do the math and plan their combinations to accommodate mathematically derived flow path dimensions? 

JM
I think as more of these rank-and-file engine builders become aware of modeling techniques and the means to do this becomes more affordable, we’ll see a growth in this approach.  Unfortunately, integrating parts from manufacturers who are simply trying to optimize the performance of their particular component outside an operational environment that represents an optimal parts combination prevents a builder from doing anything but modeling and assembling the best package with the parts that are available; each not functionally optimized for the balance of the package.  But, to your question, more of these builders probably should than do.  Today, they seem to explore the Internet to see what the “fast guys” are running, rather than stepping out on their own for what best suits their specific needs.  However, this “me too” approach has characterized the industry, almost from its beginning.

HRET
Is there much power in modern lubricants or is their chief value seen primarily in enhanced durability and thermal stability. 

JM
I touched on this earlier, and yes I do think there’s some power to be found.  This is not totally unlike the power that can be found by using a reverse-flow cooling system vs. and standard-flow version.  In and of itself, reverse-flow systems don’t create power, but they do “enable” other engine modifications that, in fact, to boost power

HRET
Is there any single area where you see top engine builders devoting a lot of time and testing? 

JM
I’m probably not sufficiently qualified to respond to this question because I’ve been away from direct involvement with this level of engine builders for a time.  I would only be speculating and that’s not a good way to form authoritative answers to any question.

HRET
Do you see anything truly exciting on the horizon? Any design breakthroughs or do we just keep chipping away at it little by little. 

JM
Based on work I’ve been involved with the past few years, I believe EFI will become the next threshold for not only power gains and improved on-track fuel efficiency, but an opportunity to manage fuel curves like never before with a carburetor.  I also think that the influence of induction system design has a chance to play a major role in the collateral benefits of EFI.

HRET
If Smokey Yunick were still with us how do you think he would characterize the technical progress that has been achieved to date? One suspects Smokey had already figured most of it out years ago. 

JM
I spent some time with Smokey just a short time before we lost him.  We talked about many subjects, not the least of which was where he saw racing and racing engines going in the near- and long-term.  Of his comments that I recall, one reflected on the fact that if racing continued to keep its head stuck up its rear, it would probably muddle along with marginal gains in both engines and race tracks.  He obviously pioneered the “safe wall” we know today but had some other thoughts as well.  He said racing was far too late embracing alternative fuels, grain and cellulosic alcohol being just two possibilities.   He also said, because of his orientation to NASCAR, that unless or until they opened up opportunities for EFI and related onboard electronics, the “dinosaur age” would continue.  Bottom line, for someone who single-handedly developed his “hot vapor” engine decades ahead of his time is pretty clear indication (at least to me) that he had “figured out most of it” well in advance of anyone else.   I once commented to him about that and, as I recall, his response was, “Hell, I never asked anybody to understand all this crap, I just wanted them to accept it for what it was.”  I still miss him.

HRET
And finally… could you reflect briefly on some of things you have participated in or observed during the course of your career that you recall as truly exciting, revolutionary or extraordinary. 

JM
There’s no way I could list all of these for you.  But here are some representative examples.

Edelbrock Tarantula Intake manifold

Edelbrock Tarantula Intake

When we developed the original Tarantula, single-plane manifold for street and racing,  it was the first such manifold to be used for high performance street and outright racing.  There just weren’t any others.  In your experience, over time, how many different versions of single-plane manifolds have you seen or heard about?  At the risk of sounding boastful, I think it was a benchmark and has lasted until today, some 38 years later.

In the mid-to-late 70s, the Edelbrock engine dyno facility (and its staff) was clearly the most prominent and capable such operation in the automotive aftermarket.  With Vic’s “sorta” permission, we initiated a program whereby prominent racers and engine builders from around the country streamed through that facility, many of whom got their first glimpse of the power being made by their engine packages.  The political overtones were dramatic.  Never before nor since (to my knowledge) was there a parade of racers and builders who had been and still were competing with each other.  As an example, the first year of NHRA’s Pro Stock category (just prior to the Winternationals that year) we assembled an entourage that included Bill Jenkins, Wally Booth, Dick Aarons, Paul Blevins, Don Nicholson, Dick Maskins and Bill Blanding’s “Mimi” cars.  There were a few other, but I don’t recall them now.  We almost needed a bleachers in the dyno room.  Looking back, it was an incredible experience that was never repeated again.  However, we continued the process by later having Benny Parsons, Waddel Wilson, Mark Donahoe, Bobby Allison and other notable NASCAR teams who spent time on the dyno, many for the first time.  I don’t this such an activity was ever repeated, anywhere in the country.

Then there was the very early period  (in the available electronics technology community) when we developed the first aftermarket EFI system.  The events leading up to its conclusion are too numerous to list here, but we ended up running it on E10 “gasohol” and driving to and back from an “energy rally” in Washington, D.C.

This could go on ad nauseam and I’m sure you have better things to do than to read through my recollections. Thanks for a chance to share a few thoughts and responses to your questions.