The Little Engine That Couldn’t

It’s situation normal on the engine side of things in indycar world. A decision a few years ago is biting them in the rear and there’s not much they can do other than wait out the contract cycle. Ask anyone involved with the series and they will tell you: the number one request is more horsepower from the engines.

This topic comes up on a weekly basis in Robin Miller’s mailbag and always seems to have legs whenever someone on a forum or on twitter wants to ask the question of: why no more horsepower? The current 2.2 liter turbocharged engine formula produces between 550 in speedway trim and 600 in short oval trim. That number is limited by turbocharger pressure purely for safety and engine longevity reasons.

I like pressuring engine manufacturers to make a more reliable engine to contain costs in the long run instead of finding means to make it cheaper right now. Less power means less stress on an engine and on an engine near the redline at full power for two h ours could use some stress relief. However, I think we would all like to see some more speed out of the chassis at places like Indianapolis, California and Milwaukee.

The question of driver safety inevitably follows, and if speed must be limited to make the show  feel safer, I would rather it be done with power reductions instead of wing limits. Limiting speed through drag created the spectacle that was open-wheeled pack racing and I respect the need not to see that again. But watching 250 mile an hour bullets shoot into turn one at Fontana would be an awesome sight to behold.

All of this makes sense to me, and the power deficiency is apparent when the drivers are turning right. The engines were making 700 horsepower until push to pass was implemented by lowering base power by 5 or 10 horses. This is just not enough oomph for circuit racing, plain and simple.

Drivers want more power and fans absolutely want more power, but the engines can’t even create much more over the 700 already available from the small displacement engines, even if they wanted to. At the current RPM limit, the engines are nearly maxed out in their ability to create power out of 2.2 liters no matter how much fuel or boost you add.

The ironic part of this whole story; the detail that makes the series look aloof, is originally displacement was quoted at 2.4 liters. The series and manufacturers agreed to the engine shrink because it would be easier from an engineering standpoint to further decrease displacement from  2.2 liters to 1.6 in the future if that was deemed desirable in the next generation of engine formula.

Had the series and manufacturers stuck with the larger displacement engine, we could have made more power for next year instead of being stuck with an underpowered engine whose only developmental future is to become even smaller and more underpowered. Poor planning, considering big speed and big horsepower numbers is what always set American open-wheel racing apart from Formula 1.

Pop shots at the series aside, there is another way to increase power without forcing a complete redesign of the engine block. The 12,000 RPM limit was set because of the use of traditional metal valve springs. The rev limit is in the upper range for what is possible with the traditional alloy springs.

The introduction of a pneumatic valve system would allow the engines in their current configuration rev higher and produce more horsepower. Cost was specifically mentioned as the reason such a system would not be used in indycar. I can partially believe this from the Chevy side, but Honda has made both Formula 1 and Moto GP engines using such a setup, not to mention the technology has been in use in F1 for some 15 years.

In the long run, the cost of developing a pneumatic system would eventually be offset by a more reliable unit. The weakest point of a traditional valvetrain is more often than not the metal springs. When one goes, valves start dropping and the cascading engine kablamo follows in very short order. Once you take the springs out of the picture, the piston connecting rods become the weakest point of the system; a much stronger weakest link. A definite good thing if the series and manufacturers wish to continue this line of engine development into the future.

However, we do know that Honda, Chevy and even Judd/Lotus have developed the highest reving direct injected engine in the world, and I have no idea if the simultaneous introduction of pneumatic lifters would have made initial developments costs astronomical. But we are way past initial development.

Increased revs would not only unleash precious more power, but they would change the sound of the engine. One of the very few complaints I have with the new engine is they don’t really sound like an indycar. The engine note is throatier, and not as piercing as one would expect from a top level open wheeled monster. The addition of the turbochargers were, in theory, supposed to produce that distinctive turbo scream, but because of the low boost produced that whine never really comes through.

As with most of my “ideas” floated on these pages, this is totally pie in the sky and I think there is a better chance that Lotus will win the 2013 500 than the introduction of pneumatic valvetrains anytime soon. I can totally live with 700 horses but still would love to see a hundred or so more added in the near future. The current engine formula is a wonderful platform to perform real engine development on, something that has been missing from the series for far too long. Lets hope we don’t have a five year long engine freeze.

Eric Hall