Prime Motivation Big Dawg's block, is a 460 D1VE-A casting, hot tanked and bored .040 oversize to 4.400 bore, fitted with stock cam bearings and core plugs. The oil return holes and the casting have been de-burred, eliminating possible stress risers, & maximizing flow. The block contains KB Hypereutectic pistons, (KB137) on stock rods fitted with ultra strong ARP bolts.

Chief mechanic Dave McLain sorted through piles of rods to find well centered forgings. The crank is a stock 100,000 mile 460 crank that was polished lightly , with the clearances on the Federal-Mogul bearings carefully set  throughout. After a season of racing (in BD1), about 80 runs, the bearings look like new, using Valvoline 20w-50 racing oil and a stock CJ (Cobra Jet) oil pump with about 75lbs pressure.

The cam is a Comp-Cams grind, FF-294B-8 with a split profile, 294deg., .589 lift intake and 304deg., .615 lift exhaust with 256 and 266 duration at .050 respectively.  This cam works great with the Dawg's 4000 stall converter and the engine turning at 6500rpm.  With the torque of a 460 & proper gearing, turning stratospheric RPM is not necessary to obtain effective wheel speed. As a result, everything lasts longer, & costs, always an important consideration, stay down.

 The heads are 429  DOVE-C castings.  These are the small port, small valve and small chambered heads. While these heads aren't about to challenge Cobra-Jet castings for breathing supremacy, the actual compression ratio of 11.85:1 using flat top pistons works well on this engine.  To extract every ounce of performance, the heads have been mildly pocket ported and fitted with stainless valves, Speed-Pro retainers, locks and springs.Tucked in nicely below the "Power by Ford" factory valve covers are Crane roller rockers designed for a rat Chevy. They bolt to stock studs & hold down stock Ford guideplates. Speed-Pro pushrods and a Speed-Pro true roller timing chain round out the valvetrain's go-fast goodies.

Induction for the Big Dawg comes from a Predator carb w/2in. spacer seated atop an Edelbrock Torker II intake. "I'll admit I was skeptical about this carb" , said Dave, "but the thing works great!  It runs super and all I've ever done is rebuild it once, for this season" . 

 Last year Big Dawg ran a stock Ford distributor, but this year the guys changed to an MSD distributor. Timing is set at 38 degrees total advance, and Dave degreed the stock damper in the lathe and corrected the TDC pointer.  Autolite 32 or 33 plugs set at .045 gap have proven themselves under the high cylinder pressures.

Big Dawg II also makes good use of an MSD 6-AL ignition box with a 6600 rev limiter chip installed. The limiter proved to be a lifesaver when the 460's brutal torque overcame the inherent strength of the C6 tranny last season

The oil pan is a stock pan that was enlarged to hold about 10 quarts of oil. Says Dave "I feel that this is important because with a big block engine, Ford or Chevy, it's easy to retain alot of oil, mainly in the valve covers and flying around the crank, so a little extra capacity never hurts.  It sure beats starving the crank and blowing her up." Stock Fel-Pro gaskets keep those vital fluids on the inside the mill where they belong.

Gettin' Tricky "Necessity", it's said, "is the mother of invention". When Dave found areas that could be improved upon, he didn't rely on a catalog, he used his head. For example, Dave welded the heat crossover shut to help keep the intake cool.  "Last season," said Dave, " mud would get up there and literally "cook", I figured that couldn't be good for power, so I shut off the heat.  Also, I found a tray that fits under the intake.  I got it from another 460 from the engine pile, you use standard gaskets on the sides and it just goes down the middle to keep oil off the bottom of the intake, it's held in place by the gaskets on the ends."

Simple solutions & common sense thinking have resulted in a powerful, reliable engine that didn't set the Noelke's back a fortune. " This engine has really been a giant killer, built from garden variety parts, but assembled right, it sure has made a believer out of me.  Most people can't believe it doesn't have the CJ heads or nitrous, and that we run gas, not alcohol, but I just didn't feel that this was worth the trouble, loss of reliability or the cost."

"I feel the CJ heads would be better if we ran more rpm or more cubes, but on a 460 racing in a mud truck, I don't see them as being better. Alcohol seems like a hassle around mud and water because moisture messes it up and it eats the hell out of the fuel system.  As for nitrous, a lot of our competitors run the stuff and they are always saying things like, " the bottle is too hot or too cold" or, " I think I need more fuel pressure", or sometimes "I think I need 8 new pistons!"

Drivetrain Continued Ensuring that there would be no further transmission difficulties was a job that fell to tranny expert Matt Heady. While many of his methods are tried & true, there's at least one little trick will set any mechanic back in disbelief.

"The trans is a Ford C-6 with a manual valve body, K servo cover, Kevlar band, Raybestos clutches and a set of E40D planetarys and drum to give it a 2.72 low and a 1.54 second gear vs. 2.46 and 1.46 in a stock C-6.   These worked out well after curing the shift timing problems that made it twist the splines. right out of the planetarys. This is often a problem in a C-6 because the band wants to hang on just a little too long when it makes the shift to second.  It didn't cause a bog or anything, just instant death for the planetary set!  We also use a TCI 4000rpm stall converter and Mobil 1 oil instead of fluid, another one of Matt's tricks."   said Dave

Backing the C6 is another piece of mechanical trickery. An aftermarket SNS transfer case with a 2 to 1 ratio replaces the old and heavy New Process unit. While the ratio is nearly identical, the lighter weight, and stronger construction make the box a superior choice for the application.

Out back, another 5 link assembly attached to the rear axle, makes use of a T-case mounted disk brake assembly.  The fact that the assembly uses fewer parts (IE, "fewer parts to break") was not lost on Big Dawg II's creators. The reduced weight and rotational mass allows for a lighter, quicker stopping assembly when Big Dawg II clears the pit.

With a beefy  Dana 60 front & heavily modified Ford 10.25" rear, the axles "split ratio" (3.50 front / 4.10 rear) gears effectively transfer the engines brute power to the Interco TSL Boggers in a frenzy of mud slinging acceleration. DUCK!

Lessons learned on the original Big Dawg were incorporated into BDII. For example, why would anyone want to use two such dramatically different gearsets? Traditional thinking says that this would cause drivetrain binding, & parts breakage. While in the majority of cases (rock, hardpack etc.), this is true, the fluid nature of mud changes the rules entirely. "We run a split ratio meaning that we run a higher gear in the front axle vs. the rear. We occasionally had problems when the front end couldn't out run the back and straighten out the truck in the pit.  Once the backend got pitched out a little it would stay that way. By splitting the ratios we cured the problem." said Dave.

Suspension of Disbelief While the stock F-150 has an outstanding front suspension (the TTB), capable of outstanding performance and durability in many off-road environments, mud running is not among them. The IFS is weaker than a solid beam front axle, and is often replaced for serious mud usage; Big Dawg II qualifies. True to form, the Dana 44-TTB was abandoned, and it's solid counterpart was adapted for a 5 link / coil-over  suspension. Utilizing thick wall tubing and spherical rod ends, the 5 link achieves 32" of vertical articulation. Impressive numbers indeed.

"I thought we needed to work on the original suspension in a big way.  It had a setup which consisted of ladder bars and stock leaf springs on the back and ladder bars with some sort of lift kit springs on the front in the stock Ford locations.  Doug had fitted double shocks and stuff and It turned out to be way too stiff.  We tested the roll stiffness and it was almost infinite. I don't know what the spring rates were, but they were high as hell!  We switched over to a 5 link set up by using portions of the ladder bars to make four equal length links & the panhard bar (thus the "5" link).  We knew they had to be strong so they are made from some rod ends from farm implements with a one inch bolt at each end.  The reason for this is because sometimes the truck gets pulled back through the mud and we needed something tough.  We then made a panhard bar for each end and some brackets to mount the shocks/coil over units."  "The coil-overs are really a racing shock with a spring mounted over them.

(AFCO racing products - Boonville IN) .  They have been very tough units for racing in the mud, I don't think they would make it for the street, but for us they have really done the trick.  They attach with a half inch Hiem joint at each end, pretty simple really.  The coil overs and the rod ends  are the only parts of the suspension that we didn't build ourselves. We used a scale and figured the weight at each wheel and then got the springs that Bill Workman at Afco recommended.  This year's springs are 350lbs front 200 rear which seems to be about right.   Everyone told us they wouldn't work, but last year when the track got rough, we were tough to beat in the old Bronco.  Tube Tough With the drivetrain secure in it's maniliness, attention was turned to reinforcement of it's backbone. While the F-150 sports one of the strongest frames in it's class, the combination of Big Dawg II's 460 bark & it's 5 link / Bogger bite, can add up to some seriously bent parts. BDII's frame was become a well triangulated maze of round & square tube steel, eliminating unwanted flex, and providing a secure mounting location for all important items like the "bed" mounted fuel cell, & radiator / trans cooler. Desert technology strikes again!

Tubular steel also fits the bill for  "Rules Required" driveshaft safety loops. Crossbraced between the framerails, the units add a bit of structural integrety. In this sport as tough as mud racing, there's no such thing as "too much" of that.

Giving the Dog some Direction in Life All that high-tech wizardry wouldn't mean much if the Dawg gets unruly. To make sure, it remains a docile creature when the chips are down, a hydraulic steering ram works in concert with a thick-walled tie-rod to eliminate bump steer with the long travel / high lift suspension. Standard issue crimped hydraulic line ensured the reliability stays high, while the costs stay down, while spherical ball joints mounted to the "panhard" bar ensure a solid axle placement, with no unexpected "suprises" when things get ugly.

Interior Decoration The BDII's cockpit is all business, with all the factory comforts removed in the interst of weight reduction, and simplicity. Encased behind blue foam padding rests the all important 2 x .120 wall roll cage, which is now a structural part of the chassis. The mounting system of the cage serves several purposes, including mounting the cab to the frame. This arangement makes for a cleaner installation, and an easier clean-up after a run. Where the factory mounts gather and hold the heavy mud, the new mounts are easilt accessed and blown clean. RCI bucket seats provide an added measure of safety & control over the Big Dawg, keeping the pilot & co-pilot firmly secured at the controls. Aditional safety comes from an interior fire extingusher & another old time desert favorite, window netting.

"We have already had lots of laughs about the nets but I figure if it keeps your arm inside instead of outside in a rollover it's worth it!" said Dave. 

Shift, oil warning lights, switches & guages are housed in an aluminum diamond plate dash, designed for ease of access & readability. The Temp & oil pressure guages are wired with safety lights, which provide a visual warning in the event of an engine failure. A B&M Megashifter was mounted in a raised position, putting it in easy reach. The normally floor mounted shifter was designed for a car, which has a lover seating level. Thanks to a Morse cable, the shifter can eacily relocated to nearly position in the cab.

Less Weight = Less Stress BDII lost a lot of it's original weight when the factory front clip was replaced with aftermarket fiberglass. Several hundred pounds of shed weight are very noticeable in the performance dept, but the biggest improvement comes from reduced parts breakage. Extra weight means extra stress on the drivetrain. If it's there, you gotta' pull it. If it isn't, you don't. It's that simple. Further dieting occurred in the box, where the interior "bed" was removed to make way for the aforementioned fuel cell & radiator.

Without question, Big Dawg II is sure to raise hell at it's official unveiling at the track later this month. With solid construction, a fantastic power to weight ratio, and a team willing to experiment with other (than traditional mud racing)   technologies, BDII is bearing it's teeth, ready to take a bite out of the checkered flag.

Off-Road.com would like to thank Dave McLain, from McLain's Automotive in Cuba Mo. for all his assistance in making the feature possible. Be on the lookout for Big Dawg II, Doug and Brenda & Dave, coming soon to a mud pit near you! Tell'em Off-Road.com sent you.

Contact info for Big Dawg II

Dave McLain - McLain's Automotive
Cuba,  Mo  65453
573-885-3920
E-Mail - frd427@fidnet.com