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Building Performance

By Doug Kaufman

Jerry McLain knows a thing to two about building winning engines. From his background as a Missouri racer competing alongside the likes of Ken Schrader and Russ Wallace (father of the famed NASCAR Wallace brothers) McLain’s time on the track convinced him he was better suited to building the powerplants than racing in the feature event.

Today, McLain and his son David operate McLain’s Automotive in Cuba, MO. The small machine shop does a majority of its work for stock engine applications, but McLain says he builds a number of performance engines for his customers as well.

Actually, the process is very much a team effort, McLain explains. "Dave does most of the engine balancing, dyno testing, and engine assembly. I do the crankshaft grinding and cylinder boring and honing," he says.

But a recent experiment at McLain’s Automotive took the "team" concept to a whole new level.

"Dave told me he had decided to enter our shop in the Popular Hot Rodding ‘Engine Masters Challenge.’ " says Jerry. "Needless to say, I was a little surprised. We would be up against some of the big names in performance engines and I knew most of their entries would be well-funded. One of my first questions was ‘How much do you think it will cost us to build a competitive entry?’ I didn’t know it at the time but Dave was already working on putting together a team over the internet."

Dave explains how it all came to be, and says he wants to give credit where credit is due: "This engine was called the Team 385 entry for a very good reason: it was totally a team effort, put together by people who participate on the Ford 385 series engine forum on the Internet (for more information, check this link: http://www.network54.com/Hide/Forum/85220).

"Scott Johnston at Re-In-Car-Nation Automotive in Tacoma, WA spearheaded the entire team concept and helped to coordinate the whole effort through his business and website. People from around the country contributed money, loaned parts, etc, all to help put together a Ford engine for the Engine Masters Challenge."

The reasons for getting together were easy to understand, from Dave’s perspective. He says the project allowed forum participants to get some firsthand knowledge on various issues: which intake manifold and carburetor combinations work best; which headers are correct, what does the engine like, camshaft-wise, etc.

Much was learned, Dave says. "My contribution was the building of the engine from all of the loaned and donated pieces, dyno testing and developing the combination, and then taking it to the Memphis testing facility at Competition Cams for the Engine Masters Challenge."

One of the first things the elder McLain did was to sit down and carefully read over the rules for the contest. The idea behind this competition is to create a high performance engine that almost any good mechanic could build. The engine displacement was limited to 470 cubic inches. Aftermarket heads were allowed, but the rules spelled out what modifications would be allowed. Particularly, no roller camshafts. "I’m sure this rule was put in to try to limit expenses but it does create a whole new set of problems for the engine builder," says McLain, "As we discovered, the cam profile, spring rate, and camshaft lobe life all had to be very carefully balanced to produce a package that could live.

"The rule that caught my eye was the stipulation that the engine must run on and be tested using 92 octane pump gas," recalls McLain. "I figured that would surely limit the compression ratios the various engine builders would try to use. Horsepower and torque would suffer using a lower compression ratio but again I feel this was done to ensure that this engine could possibly be built as a street engine and survive on fuel available at the pump."

McLain says because his son had already built a number of big block Ford engines he felt sure he would again choose a Ford 460. Although he realized that many of his competitors were likely to choose a high-dollar aftermarket block for their projects, Jerry went a different route for a couple of reasons: "First, we really didn’t have those dollars to work with, and even more importantly in keeping with the spirit of the rules we decided to see what we could find at the local recycling center. Quite often we ‘shop the pile’ at the local metal yard. You never know what treasure you may find on the pile."

Lady Luck certainly smiled on Team 385, says McLain. "We found a 460 engine that had been ripped from its former home by the jaws of the yard crane. The car body had been crushed and the engine tossed on the pile," he said.

Seeing no holes in the block, the McLains made their purchase. "Normally," says Jerry, "we pay between $10 and $15 for an engine off the pile; but on this particular day the owner’s son needed to borrow our angle drill to drill out a broken bolt on his pickup truck, so we did a little bartering."

The McLains stripped their well-seasoned block and, seeing no visible damage, began the cleaning, inspection and machining process. McLain says this step contains one of his performance secrets. "We use a Van Norman boring bar and Sunnen hone in our shop. The procedure for finishing the cylinders is something we have worked out over a lot of years. We don’t talk about it a lot but I will say it involves using six different sets of Sunnen stones."

After a .030˝ rebore and torque plate hone the engine block was put on an engine stand to trial fit some parts that were starting to arrive.

Internal Components
A stock volume Melling oil pump was used along with Clevite rod and main bearings. The cam bearings were Durabond bearings and the oil pump drive was a Dynagear.

The crank was a stock replacement iron crank from Eagle. "This crank is designed to replace the 3Y style crank used by Ford from 1979 on up. It’s supposed to be externally balanced by using a weight on the balancer spacer and flywheel," explains Dave. "The reason it was used was because the counterweights are smaller than the earlier style 2Y crank. It was internally balanced by adding 3 slugs of heavy metal to each end counter weight(six pieces total). This greatly overbalanced the crank and allowed the counterweights to be cut down about .250˝ and shaped round instead of elliptical. They were also rounded somewhat on the leading edges. This was all done to help reduce windage in the crankcase. We were required by the rules to use a pan which fit a production chassis (late model Mustang) and we used a pan and pickup from Moroso."

The rods used were Eagle SIR rods built in the standard 460 dimensions and are made from high quality material that is shot peened. They were fitted with 7/16˝ ARP Waveloc bolts and were bushed for full floating wrist pins. The weight on them is around 800 grams, or within about 10 grams of a stock 460 rod.

Keith Black KB-137 pistons were treated to a coating package by Performance Coatings, Auburn, WA. This package consisted of a thermal barrier coating on the crown, heat-dispersing under the piston top and then a friction reducing coating on the skirts. Nothing special was done to the pistons except for loosening up the wrist pin fit and cutting an additional valve relief for use with the new Ford Motorsport SCJ cylinder heads, says McLain.

The balancer was a Powerbond SFI-approved piece and the Flexplate was a TCI piece, also SFI- approved in accordance to the rules of the EMC.

"A couple of years ago, Jon Kaase was given the task of redesigning the aging Ford Motorsports A-429 Cobra Jet aluminum head casting," explains McLain. "These heads have a terrible exhaust port and a dated combustion chamber layout. What Jon did was move the valve centerlines around and completely redesign the chambers and ports. With very little work, these heads move a lot of air, certainly enough to keep our 460 happy at 6,500 rpm.

"Scott Johnston ported the heads," continues McLain. "He specializes in the porting and development of heads for the Big Block Ford, DOVE-C, DOOE-R and Edelbrock, so he was anxious to get his hands on a set of these new and improved Jon Kaase designed head castings."

The Engine Masters Challenge limited competing engines to one carburetor on a commercially available intake manifold. After testing several candidates Team 385 decided on an Edelbrock Victor manifold with a 4500 Holley flange with two one-inch open spacers. "The carb, which proved to be best in our testing, was a 1200 cfm Holley Dominator modified by Pro Systems. This is A LOT of carb for a 466 cubic inch engine turning a max rpm of 6,500, but this is one of those areas where dyno testing does not necessarily reflect real world operation," McLain says. "A 950 hp Holley tuned by Competition Carburetion, Sparks, NV was in second place in our testing, and would have been an excellent choice if the engine were used in a real world street application."

Contest rules limited the valvetrain to a flat tappet profile. In this engine the team used a Lazer Cams solid lifter grind. “The cam specs are: 261-261 duration at .050˝, .685˝-.685˝ lift with 110 degrees of lobe separation in the engine on a 106 intake centerline,” reveals McLain. “Notice that it’s a single pattern camshaft, not a split pattern cam that might normally be assumed to be correct in a Ford engine: remember the notoriously weak exhaust ports. Recommended lash was .030˝ intake .032˝ exhaust, but it ended up running the best cranked down to .026˝ and .028˝ after some testing. This camshaft is a VERY aggressive profile and a roller camshaft would make a lot more sense in an engine like this one.”

Pushrods were from Competition Cams and the rockers were a pedestal mount style from Yella Terra. McLain said this rocker design eliminated the need for guideplates, studs and stud girdles. Competition Cams locks and titanium retainers and Isky springs, as well as the stainless Ford valves which came stock in the SCJ heads, were used.

Although the EMC rules dictated what could be done to the engine, the exhaust system allowed McLain to get creative. "The rules stated only that the exhaust had to exit through a max pipe diameter of three inches and that two commercially available street style mufflers be used,” says the younger McLain. “The exhaust system consisted of a set of Hooker Super Comp headers built for an early ’70s Torino chassis exiting into a set of 3˝ “bullet” style mufflers. Just connecting the muffler directly to the header was something I wished to avoid because doing so changes the tuning of the header and can really hurt performance."

To maximize peformance, McLain says he applied a technique he found in an article by Engine Builder columnist David Vizard on how to build an exhaust system that’s muffled yet loses little to no significant horsepower.

"Basically the exhaust system uses a chamber in each pipe that’s large enough to allow the positive pressure wave to collapse properly allowing proper header function as if it were running with open exhaust," explains McLain. "It worked: testing with and without mufflers showed a difference of only about four horsepower in back-to-back testing."

According to both McLains, the engine they built was a very straightforward, simple and low buck motor when compared to others in the contest. "I had lots of ideas that would have been fun to try and might have helped our score, but there just wasn’t the funding to allow some of those ideas to happen," says Dave. "Instead, we concentrated on making the best of what we had."

The Test Phase
After I got the engine assembled I spent many nights and weekends working at my dyno trying out the various parts combinations. In case you’re wondering, dyno testing takes more time than you could ever imagine!" says Dave McLain.

Once the team arrived at Competition Cams’ test facility in Memphis, TN, McLain said things happened fast. Because some other teams needed time to make last minute repairs, Team 385 was invited to "bump and go" early.

"We had the 460 up and running on the Superflow 901 in about an hour or so," Dave says. "The rules required a warm-up period where the engine coolant temp was at 160° F and the oil in the sump, 200° F. Then we were required to do three warm-up pulls at 600 rpm/sec from 3,000 to 6,500 rpm one right after the other." McLain says he was confident about his team’s chances because the Comp dyno was about 8 percent more liberal than his dyno.

"Next came a twenty-minute period where we could do whatever we wanted to the engine. A check of the air density showed nearly identical weather conditions to what we had experienced the day before back home, so we made no changes," he says.

The actual competition pulls consist of three pulls in rapid succession from 3,000 to 6,500 rpm at 300 rpm/sec. It was during these pulls that McLain says he began noticing a problem with the engine.

"In our own testing we had had some valvetrain stability problems above 6,000 rpm with our original spring package (125 lbs seat, 330 lbs open). After upping the spring pressure to 140 seat and 370 open all seemed to be well," he says.

"The new spring package had been on the engine for about 30 pulls worth of testing, but they decided to lay down right when we needed them to be at their best!" recalls a disappointed McLain. "Looking at the power graphs we could clearly see the power peaking at 6,000 rpm, dropping slightly and then recovering at about 6,400, then taking a real dive! Since the contest is scored by taking the average torque and average horsepower from 3,000-6,500 rpm this hurt our score in a BIG way!"

Still, Team 385’s engine finished fourth overall (out of 50 national participants) in Memphis. "It didn’t blow oil all over the dyno cell or detonate itself to bits, so we were happy," says McLain.

"Still, after I got home, I put the engine back on my dyno where I tried one more spring package, one that we would have tried if we had more development time, 185 lbs on the seat and 440 lbs open pressure. This is pretty serious spring pressure for a flat tappet cam, but it proved to be worth about 25 hp over our best previous number. The engine made 600 hp on my dyno and that would have been about 630 hp on the Competition Cams’ dyno. This engine made a very flat torque curve and excellent overall power."

The McLains acknowledge that’s how things go sometimes. "I tried to cover all the bases in my testing, but the one thing we speculated about but didn’t get to test bit us right in the butt!" says Dave. "Better luck next time, no. Better preparation, yes!"

Jerry concludes: "I think the engine made a great showing in the engine contest. Dave has since torn the engine down for inspection and to package up the parts that need to be returned to their rightful owners. The engine looked great inside. The camshaft, one of our major concerns, looked great. Our 466 Ford was truly an engine that could be built by any good engine builder and one that could survive on pump gas!"

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