The Original BigFoot Engine Build Part 1- Engine Power Season 2, Episode 4

today on engine power Mike and Pat are honored to refresh this 30 year old blown big block Ford straight out of the most notorious truck in the world the iconic original big fly [Music] this year marks the 40th anniversary of the original monster truck there can be only one Bigfoot and it's unheard of that the iconic machines would ever pull into your driveway in need of a little help that's right the truck that started it all Bigfoot one is being dropped off by none other than the great Bob Chandler and business partner and longtime driver Jim Cramer the thing looks awesome want to see what those big tires on there she doesn't race anymore but our team is going to get the chance to freshen her up clean up the chassis and do some much-needed maintenance and more importantly for us we get to rebuild this massive blown big block Ford that was state-of-the-art back in the day first things first get rid of these skinny tires [Music] all right Bob we have Bigfoot one here the original truck it's retired from racing but still does all the praise in it but the rumor is this was your original truck back in 74 personal vehicle yes I ordered from a dealership of course back then they didn't have full guy vehicles so it took six seven months to get it and my wife and I used to take it we'd go camping with it put a camper on the back of it and take it down the river but it went from the dealership to my house and the tires got changed immediately that was the first thing that got changed it ended up being a vicious cycle because I put big tires on it and they weren't big enough for me so I put bigger tires on it then I started breaking axles so you put bigger axles in it and then you run out of power so you got to put a bigger engine it's when I went to a 460 in it but it went that way for probably three or four years where I just kept changing it four decades later Bigfoot is still a worldwide phenomenon running six race trucks at a time three more just for display and even an all-electric Bigfoot but there will never be another original a truck of this stature you know deserves a lot of credit something like the Smithsonian is that something that could be in the future I would welcome it we're still using it right now yeah yeah we hope it'd be great to do I think it would be the highest honor I really do because it in fact started the whole industry of monster trucks which has become a great form of racing and family entertainment and this is the truck right here that there was no other trucks period before this truck came along and this man developed it I mean it starts always it deserves to be in the Smithsonian well now that we've seen the truck for us as engine guys we want to see the important thing let's take a peek at the engine see ya okay let's get a lot of hands in this big boys there's a piece of machinery right here look at this thing yeah well there she is the original huh tell us tell us a little history this is a automotive archaeology for us because this is a things been around awhile it's actually start out life as a boat motor supposed to be and convert it to where we could use it six hundred forty inches I forget the horsepower on it now but hidden us on it and everything how long has it been since its ran probably close to 20 years 20 years really good running engine when it was pulled yes it was I think enjoy this because when you dive into this thing it's like diving in the past yeah you can see how ancient builders did it many years ago I mean you guys are up to everything right now you know all the new technologies and the metallurgy and everything else so these guys had what they have right so it'll be interesting to see what's in there I'm very excited to get inside and we got one of the best in the business and I want to say this too I think Bob you kind of say this if you got a good idea so I make a little bit better you know we're not opposed to making a change here and there we're really not we'll be very kind to it like Mike Mike said we'll treat it like it's our own and we're just very flattered and honored to be part of getting able to work on something like this so oK you've been talking about this though why don't we just quit talking go to work shop say goodbye next we crack open this engine builders time capsule in case you missed it the original Bigfoot engine is here and ready for a complete refresh before it and the original Bigfoot truck go on display for good lucky for us they trusted the powernation crew to freshen up and update this awesome piece of history Pat and I get the engine the original Allen root 640 cubic inch big block Ford being able to participate in this piece of automotive history is way more than an honor it was a dream just as a young child to make it to the local Stadium to see those big blue trucks worn through the air and crushing whatever got in their way now to be a part of the Refresh of the original one that started it all makes that dream a lot larger than life now before we get started Jim and Bob need a few more moments with the power plant that set the performance standard on 66 inch tires there's actually designed for a boat I've never seen an engine like this when this thing rolled in I go ho my god what the hell is this you know I haven't ever seen an engine like this all aluminum block looming them heads look at the manifold tall deck you don't see stuff like this around the Midwest we just didn't have that the guys we ran with didn't have that either they had a big-block Chevy small-block Chevy's of Fords and what's it nobody had a specialized engine that time nobody did putting it back in the truck it's gonna be a kick for me just to see it in their number one but just to be able to drive around it's gonna be spectacular I know we've had people come in the shop time when to buy at night and if it was up to me it's not gonna be sold at times we needed money where we might have thought about it but you know that's Bigfoot that's Bigfoot one right there that's that's where it's got to go back and Bigfoot one that's the only place you can go far as I'm concerned this is a rare opportunity to step back in time and see what was state of the art and performance technology back in the mid 1980s its automotive archaeology at its finest Plus this combination has some unique parts specific to the application like the predator carbs the BDS blower the MSD Magneto and an external oil pump and we'll cover those as it comes apart before monster trucks swapped over to injected engines they all ran predators they're known to be the best off-road carburetor and have great characteristics like throttle response excellent low-end torque and a unique look that says performance the only problem that arose with them was from inexperienced tuners these things haven't seen the light of day in 20 years we're gonna be as careful with disassembly as we are with reassembly of this engine we all know it has serious historic value and we want to preserve every bit of that whoo that is not your typical for Braille right there and there seen the inside of one see these plates they don't particularly move it's a it's a variable venturi type deal which it just goes on air demand it's a unique setup it's uh there's not a lot of stuff that flops around in there not a lot of moving parts in it so very cool to keep track of where everything goes we're taking photos so we know what the untouched piece looked like all right got a linkage there yeah that's very important this will insure us the orientation of the plumbing and the exterior of the engine will go back the same way we're also bagging all the parts and pieces for each component this keeps the hardware from getting mixed up and costing us time later trying to figure out where things go we roll one two three here these predators are extremely important to Bob us too they look great on the outside and all the linkage functions perfect but we will give the internals a refresh things a little dry yeah yep sure is this brittle 20-year old dust in there too what's cool they got the catch screen for any parts that come off up top can't get into the blower rotor the car base is a two-piece design we have to remove the upper car plate first to gain access to the fasteners that secure the base to the blower now the custom NOS nitrous assembly can be removed we're not sure what the horse power level was originally now this engine will make gobs of power blown amazingly they never needed to use it with the blower belt removed will feel how well the blower turns over it feels good but there are a couple spots on the rotor that concern us and it's an obvious sign of repair the blower studs are aluminum and made to break away during an engine failure if that happens the restraint plate straps keep the blower from leaving the engine bay BDS has been in the supercharger business for decades this is one of their 71 units which is standard on a monster truck and we'll be sending this one back to them for a complete refresh the history lesson continues coming up we are back and ready to dig deeper into our automotive artifact now this is the original Allen root 640 cubic inch big block Ford that set the monster truck world on fire back in the 80s now we've got it down to Long block form but it's not going to stay this way for long the tall Dec cast aluminum manifold was built for performance with nitrous bungs for a wet kit and a blow-off plate in case of a Leanback fire this thing was ready for serious power now we're starting to see the effects of it sitting for 20-plus years the cylinder head was ground for push rod clearance then epoxy was added to ensure water would not leak into the engine from the thin spots it's obviously showing his age by separating from the aluminum aside from that everything else looks pretty good up here now we can remove the dry rotted plug wires and the NGK spark plugs finally the MSD magneto can be removed a magneto is a combination of a distributor and generator built into one unlike a regular distributor a magneto creates its own spark energy without external voltage they're used in engines that require high spark energy and can produce up to 20,000 volts this engine came to us with the unique Allan root valve covers that were specifically made to fit his cylinder heads now the Hemi style is an eye catcher and we're leaving them untouched it's their time to be removed and we can't wait to see what's underneath them oh man that's cool wonderful yes it came off in one piece this is a gasket you cannot buy down in an auto parts store it's unique to the the Allan root setup this is a Ford part number but it's all Allan root and it's very unique but it all looks good the valvetrain is specific to his design as well let's start with the intake side it's a shaft mounted rocker that rides on a needle bearing fulcrum and has a large diameter roller tip to handle the high valve spring pressures now that large diameter roller also helps distribute the load due to the large amount of sweep on the lash cap because of that big cam what that means is there are more needle bearings riding on the roller tips axle to distribute load that equates to less friction and greater durability the roller tip has a significant amount of movement on top of the lash cap and it's under as much as a thousand pounds spring pressure keeping that big wheel rolling also keeps the valve guides from wearing out by not pulling on the valve and bending the stem inside the guide the stands are billet aluminum and made to a custom height which sets the valvetrain geometry for this ratio which is one point seven two to one the rockers are also offset to allow port placement in the cylinder head the exhaust side uses the same type of shaft mount but they have a slipper foot on the valve tip because there wasn't enough material down here to put a roller and retain the strength now the reason they're so long it's the only way to get proper push rod angle because of where the valve is placed in the combustion chamber we're going to mark every piece of the valve train so it goes back where it belongs during reassembly to do this we'll use our Dremel which is much more gentle on the parts than hitting them with a stamping hammer oh she's that is not supposed to have a half inch of lash and any discoloration so we have to investigate that further come on with it we're gonna remove the rocker arms in Paris at each individual cylinder when they have no spring pressure this applies to every engine they come apart in a fairly unique way by removing the Allen bolt the chef slides out of the assembly and the rocker arm can be taken off now that the stand bolt is accessible we can remove it from the head no it's I just met in the end or so we thought it seems twenty-year-old Loctite is a force to be reckoned with to round in and out I'm gonna mess something up right there so the arms and the rods are priority again keeping them organized we also found the culprit of all that excessive valve lash the number-8 intake valve is hung open indicating it's seized in the guide with a long breaker bar we can remove the mass of 9/16 chintz head stud nuts in the reverse order they were originally torque to with only 10 in the head they have to be large to keep the head clamped down to the block under high cylinder pressure situations with a few swats of the rubber deadblow the 20 year old seal has been broken in the driver side head can be removed and it looks good there's no signs of Burns leakage it was doing its job it looks like the passenger-side did its job - not bad for 29 year old automotive artifact in continuing with the original Bigfoots power plant now just like us you're discovering racing technology from over 20 years ago now a lot of parts on this engine are obsolete and just flat-out unable to get so we'll be calling on some of the top guys in the industry who would have had their hands on engines like this back in the day to help us revive this piece of history this mile it and crank driven water pump is one of those long-lost parts it's a cast aluminum piece that was found on performance engines in cars and boats now the pump can be pulled off the coupler and it can be removed next the crank bolt is taken out to remove the coupler drive these countersunk bolts retaining the blower pulley are being stubborn and won't come out so with little backyard ingenuity is in the works that's a proper term for a torch wd-40 and an impact directly heating the head of the countersunk bolt will help loosen the lock tight due to the heat the wd-40 is drawn into the void for extra lubrication under the head of the bolt and the shock of the impact is doing its job to remove them that was a little nerve-racking using our Matco balancer remover we can pull off the timing wheel remove the supply line to the oil pump and the original a v8 pump comes off followed by the magneto drive housing now the Dooley enterprises oil pan comes off to expose the cylinder case and at first glance were really impressed back up front the blower belt tensioner and bracket can go followed by the timing cover specific to this engine design oh yeah that's cool which reveals this highly specialized gear drive now timing gears are very accurate because there is no chain to stretch for reference during reassembly we're turning the engine to TDC and documenting exactly where the alignment marks are now the entire gear drive can be removed the camshaft is the next item to be disturbed it's a solid roller from Howard's now it'll be upgraded to a more modern lobe design to give us more power and torque where it's needed in the power band the rotating assembly is the foundation everything is built upon we were lucky enough to get handed a folder containing the original build sheet giving us the specs and manufacturers of all the parts in this engine the rods were built by crowler's so we know they're strong they're a forged and machined eye beam design the big block Chrysler rod bearing which is smaller than the stock big-block Ford translates to more strength at the big end and less bearing speed which reduces friction the Pistons are custom Ares flat tops with two small valve reliefs these gave this engine of seven point five nine to one compression ratio with an 84 CC combustion chamber in the heads the ring pack is an old 43 top 16 second and 3/16 oil ring if you're new to the engine building scene instead of spiral locks or Ron wire locks these wrist pins are held in place by a free-floating aluminium button this is not common practice anymore and will be replaced the custom forged for 750 stroke crank is held in place by extra beefy splayed 4 bolt main caps plus a bolt hole in the center for this an easy and safe way to remove them with a slide hammer they're made of aluminium and hard anodized they not only keep the crank in place they add structural rigidity to the bottom of the block here's an oops we discovered too long a flywheel bolts were installed at some point and they self clearanced on the back of this cap and block the fix after these bolts were removed required helicoidal to the crank the crank shaft is a unique piece from Arnold forging sand has a cool story behind it Larry Arnold designed the dyes and had the forgings all done in Japan the forging weight 156 pounds raw and could make a big-block Chevy big-block Ford and a Hemi crank between a 3.6 and a 4 750 stroked the quality of this forging was so far superior that their competition faded away from Pro Stock and Top Fuel making this the backbone of the most powerful engines in its day so do we have any question what we're doing with this engine nope Jim's orders made it pretty clear I really want to see it run really bad you know once I want to see it get back in the truck I know Bob Shannon would love to have this thing in the truck and I like just to see that happen for him to get this thing going and get in the truck and make the truck complete like it was like it should be again and this is this is the piece right here just gonna make that happen in the weeks to come that's what we'll do see you then

Channel: POWERNATION

Views: 2,065,425

Rating: 4.8032393 out of 5

Keywords: Automotive;, Cars;, Vehicles;, How-To;, Auto, News;, Howto;, How, To;, DIY;, Car, Tips, Monster Trucks, Trucks, Engines, Nitrous, Aftermarket, BigFoot, Entertainment, History, Automotive History, powernation, v8

Id: lrI03FVYbvQ

Length: 18min 42sec (1122 seconds)

Published: Fri May 03 2019