Airframe and Powerplant

Motor Men of Mena

May 1, 1997

Ultimate Engines aims to be the choice for Bonanza and Baron owners

It's said in medicine that if the general practitioner isn't dead, he's at least not feeling very well. Maladies beyond the very simple or very vague always seem to warrant a trip to the "specialist." Such specialization — or niche maintenance, if you will — may not be as rampant in aviation as it is in medicine, but it most certainly exists. You've got shops that work mainly with tube and fabric airplanes, for example, and engine builders who vastly prefer one make over another. In many cases, the expertise gained while working in one very narrow field eventually leads to an emphasis on one type of product and then to specialization, to the exclusion of other products. It's a case of knowing more about one type of engine and not caring (or being able) to keep up with the other makes.

The trick is, of course, to pick the right specialization. A small shop may well succeed in catering to the Navion crowd, for example, but for long-term success, it's better to back your wagon up to a corral with lots of horses. That's the theory in Mena, Arkansas — the home of Ultimate Engines and Capehart Industries. The latest of Terry Capehart's several overhaul shops — all of which offered various levels of "performance" improvements to the engines — Ultimate Engines is staking claim within the vast Beech Bonanza and Baron market. Today, the company does nearly all its work with the big-bore Continental engines and the venerable Beech airframes. Recently, with Capehart's selling the company and taking on an advisory role, Peter Lo Bello, who comes with a background at a Beech factory service center, has taken over the reins in Mena.

What Lo Bello has brought to the mix is an increased emphasis on all-around Beech service. Where Ultimate used to be known primarily as an engine builder, the company under Lo Bello strives to be a one-stop service for Bonanza and Baron maintenance, repairs, modifications, and major engine overhauls.

Ultimate's facilities at the Mena Intermountain Municipal Airport are tidy and efficient, though certainly not large. The engine shop is a short drive into the wooded outskirts of Mena, and it, too, reflects a dedication to neatness. Naturally, a clean shop is not necessarily an indication that the product will be first-rate, but we saw no evidence of rushing to meet deadlines or hurrying to slam an engine together. Frenetic mechanics are often not meticulous and happy mechanics. At the time of our visit, Ultimate was producing about 50 engines a year; Lo Bello hopes to quadruple that number over the next few years.

The Ultimate shop includes a handful of buildup stations, as well as some impressive machinery. A fully instrumented flow bench helps to determine the amount of port grinding that must be done to match cylinders. There is equipment to dynamically balance crankshafts, as well as highly accurate scales and fixtures to determine both the weight and weight distribution of such items as connecting rods, pistons, piston pins, and so on. Basically, Ultimate attempts to closely match the weights of all reciprocating parts, with the goal of producing a smoother-running engine. (Indeed, the owners of Ultimate engines we talked to all mentioned that their engines were much smoother than stock.)

Two questions surface whenever the subject of internal balance comes up: One, why doesn't Continental (or Lycoming) try to balance the engines as accurately, and, two, doesn't the movement of oil in the engine pretty much negate any careful balancing of the components? Speaking from a production standpoint, the engine makers say that the weights of the components aren't all that important, and, anyway, it would greatly increase production costs to have to group parts by tight weight limits for assembly in one engine. Capehart, on the other hand, says that the oil movement isn't an issue and that it's only the right thing to do to have the component weights as closely matched as possible. Of course, Capehart and Ultimate can charge for the extra time it takes to carefully match these components.

Capehart says that experience from all his years of fiddling with aircraft engines in general and the big-inch Continentals in particular has gone into the current line. He readily admits that some of the performance tweaks he tried before were a bit aggressive. "We attempted some things that in the long run didn't work out," Capehart says. Part of the Capehart philosophy still at work at Ultimate involves improving and balancing air flow through the cylinders. The motive is sound — make all cylinders breathe alike. One of the great compromises in this endeavor is to improve airflow all across the usable power band. The uninitiated often open up the ports and get really impressive flow numbers, only to find out that the engine doesn't need that much flow and that it actually produces less power in the normal cruise range than before. These are hard-won lessons that every high-performance engine builder, Capehart included, must learn and remember in order to remain successful.

One aspect of volumetric balance that an Ultimate overhaul does not address, however, is the inherent imbalance in the induction and exhaust systems — some installations are better than others, but few manage to provide each cylinder with exactly the same intake-air and exhaust-gas flow characteristics. But as with the balancing issue, Capehart says that you should do what you can with the items you can control — that is, to balance as best you can, even if the final outcome isn't perfect balance with all systems in place. To deal with fuel-flow imbalances in the Continentals, Ultimate has started shipping every engine with a set of GAMIjectors installed (see " Airframe and Powerplant: Balance of Power," October 1996 Pilot).

Until recently, Ultimate used standard new Continental cylinders as the basis for its overhauls. Today, the company is really pushing Superior Air Parts' Millennium cylinders ("Airframe and Powerplant: A Superior Solution, July 1995 Pilot). These investment-cast cylinders represent some significant improvements over the standard Continental sand-cast parts, including greater wall thickness in areas prone to cracking and the promise of better structural stability because of the casting method's reduced porosity. In addition, the Millenniums come with through-hardened barrels as opposed to Continental's method of treating the steel barrels to a surface nitride hardening process. (Ultimate will, at the customer's request, install the new and improved Continental cylinders recently released under the TopCare program at the same price as the Millenniums.)

To further improve performance, Ultimate will install a camshaft that was developed jointly by Capehart and RAM Aircraft in Waco, Texas. This cam features a profile that better suits the low-speed operation of these aircraft engines. Capehart says that the stock Continental 520/550 cam really hits its stride only at the top of the engines' rev range; the new cam improves torque at the mid-rpm settings used during cruise. The cam, along with all the other cylinder tweaks, leads Ultimate to claim that the 520-series engines will produce 9 percent more power than stock — or about 311 horsepower. Though we haven't seen any hard numbers to prove this claim, Ultimate's customers uniformly note speed increases. Of course, nothing is free, and the Ultimate engine can be expected to burn more fuel at equivalent power settings; the firm says that at like speeds (and therefore true power output), the Ultimate engine will realize a 3-percent fuel savings.

Ultimate sweats some other details in the Continentals. All Ultimate overhauls include case dowels — small sleeves around eight of the case-half through bolts — that are said to greatly reduce crankcase cracking in these engines. This is common procedure in Lycomings — in fact, Ultimate uses Lycoming parts — but is not done on standard Continentals. (Perhaps not coincidentally, Continental has begun using case dowels on its top-line Platinum engines.) Other case work includes line boring, stress-relief, and resurfacing of the case-mating areas, as well as a specific process to accurately center the crank in the case halves. Ultimate also makes some oil-passage alterations to improve oil flow.

Capehart and company have also brought some new-to-aviation technology to these engines. Until recently, Ultimate's sister company, Capehart Enterprises, was building roller-bearing rocker arms for the Continentals; it has ceased production of these parts pending a better component. According to Ultimate, the next option will be a new articulating-slide rocker arm (with roller bearings around the pivot shaft) that will both reduce the rocker-shaft wear common to these engines and relieve side-loads imposed on the valve tips by conventional rocker arms. (In fact, a properly ground rocker arm will not impose great stresses to the valves, but few seem to have the right profile right out of the box.) Also, you can order ceramic coatings to be applied to the piston crown and exhaust-valve face. Ultimate says that the coatings help to keep these components from soaking up as much heat as the standard components. But the heat has to go somewhere, and Capehart admits that you can expect to see slightly elevated CHTs with engines so treated. (You might ask how such a modification can be done to the engines legally. Capehart simply wrote the process into the company's overhaul manual for the engines, so the change is approved by the FAA as a process rather than as add-on parts.)

Ultimate's installation of the big Continental in the Bonanza and Baron aircraft takes steps to reduce engine temperatures, whether you opt for the coatings or not. With every installation, you get new baffle material and repairs as necessary to the existing metal baffles. Ultimate also provides as part of every installation a small sump heater — even if you live in Florida — as well as a Beech firewall cooling-duct kit, new engine mounts, new hoses, and a dynamic prop balance (overhaul of the prop costs extra).

Befitting a product that its makers unashamedly promote as top of the line, the Ultimate overhaul is not cheap. It is comprehensive. For your basic IO-520-B, the total cost is $26,000. A factory reman runs almost $18,000, but then you must add the cost of installation, hoses, and all the other options that come as part of the Ultimate overhaul. (The company figures that a factory-reman engine installed will run a bit more than $23,000 if you account for all the options; however, it has figured shop rates at $39 an hour, lower than is typical in many parts of the country. Your mileage may vary.)

Moreover, Ultimate says that its engines have a 2,000-hour time between overhaul (TBO). That sounds great, but it really carries no legal might; Part 135 operators with Ultimate engines still must get TBO extensions to run past Continental's specified TBO of 1,700 hours, and Part 91 operators are not obligated to overhaul by any set of numbers. At least Ultimate's warranty is based on the longer TBO, and it is a generous one — full warranty for 520 hours, then prorated at 20 hours a month to the 2,000-hour Ultimate TBO. We spoke with owners of Ultimate engines who have had early problems — face it, every engine shop makes a mistake now and again — and they all said that warranty service was superb. One owner added that in his experience, the standard Continental warranty might as well not exist for all the trouble he encountered in an attempt to get satisfaction.

There are other engines on the Ultimate overhaul roster, and it isn't necessary to have the installation done in Mena. For example, a TSIO-520-series engine runs $34,995 installed, or $29,500 on a ship-out basis; the IO-520/550 costs $21,500 sans installation. Ceramic coatings add $1,600 to the total for any of the engines, and the cost of the rocker arms will be determined in the next few months. All Ultimate engines come with Capehart's nifty billet aluminum replaceable-element oil filter.

The truly conservative no doubt are muttering that there's too much new, too much untried in the Ultimate engine for it to be a good long-term engine. And yet Ultimate's customers are, by our research, a happy bunch. Even so, we'll be able to tell you just how good the Ultimate tweaks are, how well they hold up in day-in, day-out flying — our own A36 Bonanza has just been through the Ultimate mill. At press time, the engine was still in the break-in period, so it's hard to make any early assessments. The pilots who have flown the airplane report that it is unusually smooth on the ground and perhaps a bit better in flight; again, these are very early impressions. Given how quickly our Bonanza racks up the hours, it won't be long before we will have significant firsthand experience with the handiwork from the specialists in Mena. We'll let you know.


Terry's Turbine Adventure

Capehart joins the "whoosh" crowd

Terry Capehart is unquestionably better linked to piston-engine tweaks than to endeavors in the turbine marketplace. Even so, Capehart's next big thrill is to run Extex, a firm that has begun to produce components under a Parts Manufacturing Authority (PMA) approval for Allison 250-C20 and -C30 engines. Actually, Extex — the name denotes the high infiltration of ex-Texans in the shop — is a combination of Capehart's new company and the remains of Superior Turbine, which the Phoenix, Arizona-based firm purchased last year.

Superior started producing PMA'd parts for the C20 engines in 1992, quickly expanding its line and creating some serious competition for Allison on certain parts. Predictably, Allison dropped prices for the parts also made by Superior. Extex started in 1995 and by the next November had its first 30 parts approved for the larger C30 engines. Two months earlier, the principals at Extex had purchased the stock, PMAs, and ancillaries from Superior Turbine.

It is Capehart's goal at Extex to carry on the best aspects of the Superior tradition — that is, to make better parts at lower prices than the OEM. In particular, Extex has gained approval for a new first-stage nozzle for the C20 that is made of stronger materials and that, with some very slight alterations of the airfoil shapes, will help to improve internal air flow. The nozzle's trailing edges have been increased in section to help prevent erosion problems that are common with the OEM part. Capehart says simply, "We know how to make these parts better, and we're going to do it."

Unlike Superior, though, it's not Extex's intention to radically undercut Allison's prices. Capehart says that he would rather compete with a better product that is available instantly — it's said that many of Allison's parts are difficult to get in a timely fashion — than to start a price war. "We're a much smaller company than Allison, and we're not in this business to make enemies," he explains. — MEC


Extex is located at 6001 South Power Road, Building 15, Mesa, Arizona 85206; telephone 602/988-2000; fax 602/988-1012.


For more information, contact Ultimate Engines, 106 Elk Drive, Post Office Box 807, Mena, Arkansas 71953; telephone 501/394-5422; fax 501/394-4048; e-mail ultimate@ultimate-engines.com ( www.ultimate-engines.com).