World's Fastest Flathead? (Going to the Bonneville Salt Flats)

believe it or not this video with keith and jeff dorton of automotive specialists has been over a year and a half in the making and that includes three complete engine builds but i hope you'll agree that it was worth it because they have been doing some crazy things with a ford flathead to go set records on the bonneville salt flats believe me it's completely ridiculous [Music] in the short history of the horsepower monster we've done plenty of engine builds punching out a thousand horsepower or more but honestly i'm as or maybe even more excited about this ford flathead build with a target of just 250 horsepower because of all the cool things automotive specialists is having to do just to get there after all the original flathead never produced more than 95 horsepower now this project came about when racer ron cooper decided he wanted to set a record at bonneville now we can all get behind that but specifically he was going after the southern california timing association's xf xfvgc class now that alphabet soup of letters actually means something vgc stands for vintage gas coupe and xf is the engine designation that the scta uses for a classic flathead either ford or mercury from 1932 until 1953 it has to be an oem block and it has to be less than 325 cubic inches simple huh cooper had car builder marshall woolery of thunfield rod and custom built a full fender 39 ford for bonneville and turned to automotive specialists for the power plant keith and jeff determined that 250 horsepower should be more than enough to break the standing record of 132.876 miles per hour the xf class rules at first can seem pretty limiting for example you have to keep the stock deck height and the stock valve arrangement so no arden overhead valve cylinder heads here the engine has to remain naturally aspirated and as i've already mentioned displacement is limited to 325 cubic inches now being crafty old stock car racers keith and jeff both thought they saw areas in the flathead they could exploit so they eagerly took on the project now this is where i'm glad the guys at automotive specialists are confident enough in their abilities that they don't mind me showing the things that didn't actually work after all trying and failing and then trying until you actually find stuff that makes power is what racing is all about i suppose you get that kind of confidence after you've built engines that have won the daytona 500 and hold several world records in land speed racing anyhow remember when i mentioned that this video covers over a year and a half worth of work and three complete engine builds don't worry i'm not going to bore you with a blow by blow of all three builds but for the first build keith and jeff literally threw their entire bag of tricks at the flathead the big one here is cutting off the top of the engine and totally reworking both the intake and exhaust ports they actually reverse the flow so that the intakes are now the exhaust and vice versa plus instead of flowing through the block like stock the exhausts now exit the top of the block through custom headers this both improves flow and gets the hot exhaust gases out of the block so that the cracking problems the plague flathead castings is no longer an issue it truly makes the flat head look like something out of this world unfortunately to achieve this keith had to cut away large sections of the top of the block casting and secure in these plates that rerouted the ports and after a few heat cycles the old flimsy block casting would shift enough that water would start leaking into the oil because of looming deadlines they had to move away from that design but that doesn't mean keith and jeff have given up on it [Applause] [Music] they're talking to engineers and even some chemists to figure out a plan and hope to try again with a few critical updates in the future so stay tuned for that the second build move the exhaust back to the oem ports but they ran into an issue because they used a block that had some wear issues and tried to fix it by sleeving all eight bores that unfortunately cut away too much of the original casting and they again had issues with coolant getting into the oil that brings us to build number three this time around keith and jeff had to find a nearly pristine block which is tough to do considering these things are 75 years old but they finally found a handful of blocks in an estate sale and bought the entire lot so it's build three that's the focus of this video really i just walked you through the history so i could have an excuse to show you that first build with the awesome intake and header combo for the foundation we're using one of the newer flathead blocks made somewhere between 1949 and 1953. it's easy to spot because it lacks the cast in bell housing of the earlier blocks the stock bore was 3.1875 inches and stroke is three and three quarters of an inch making total displacement 239 cubic inches like all flatheads there are only three mains supporting the crankshaft that's too shy of the five and almost all other v8s old henry did this as part of his effort to cut costs and it worked because the flathead was the first v8 affordable to the average guy but that's not so good for supporting the crank especially when you're trying to take the horsepower from a measly 95 to 250 but wait before we get too far this is a really cool build but a lot of it is way out there and i'm also assuming since the flathead is so old many of you aren't familiar with how unique and really how cool it is so if you're interested i shot a flathead build with automotive specialists a while back that's much more traditional if you aren't familiar with how the stock flathead goes together you may enjoy watching this video first so you can appreciate just how cool this race build really is i'm not trying to give you extra homework but you know anyhow a link to that video is in the description and if i say so myself it's worth the time to watch anyhow back to it here you can see how the intake and exhaust ports lead into the block just above each of the cylinder bores there are no moving pieces in the head itself the hot exhaust gases go down into the block and exit out the sides here the cylinder boards have been opened up to 3.375 inches which keith says is just about as far as you can safely go one issue with the flathead is there are no rocker arms the valves are actuated directly by the cam lobes so however much lobe lift you have that's exactly how much valve lift you're going to get and you can't make the cam lobe just as big as you want because of physics or maybe it's geometry either way you cannot slide a cam lobe into the block that's bigger than the hole it must go through and then the hole for the cam bore gets even smaller on conventional engines when you drive in the cam bearings to maximize available lobe lift keith went with a trick used by modern pro stock drag racers this is a tool steel billet cam but notice the clam shells these hold the cam bearings in place on the camshaft instead of driving the bearings into the block automotive specialists jaisal and comp cams all work together to develop this camp shaft the idea is by clamping the roller bearings to the camshaft and sliding it all into the block as a unit the lobes can be larger notice how the lobe is just as tall as the od for the bearing clamshell the flathead prioritizes oil to the cam first and then everywhere else in the engine so this groove on the outside of the clamshell allows oil to flow around it to get to the mains this is actually the second billet cam made after determining that the engine could handle even more lift and duration than originally thought here we have 270 and 280 degrees of duration at 50 000 tappet lift for the intakes and exhaust lobe separation is 110 degrees and gross lobe lift is 470 thousandths of an inch also notice there is no clamshell at the rear of the cam that's because no lobes need to go through that housing bore so the roller bearing is simply installed into the block keith adds plenty of lube to the cam and then slides it into the block the o-rings around the outside of the clamshell are necessary to seal that gallery of oil flowing around the cam and keep pressurized oil moving through the rest of the block the small bolts are threaded into place to lock the bearings into position this way they can't spin in the bore this also by the way sets the cam thrust so that the cam can't walk in the block with the cam in place we're ready to move on to the crank and rotating assembly the crankshaft is a billet steel unit from scat that bumps the stroke up from the stock three and three quarter inches to 4.375 justin bryson roughs in the balance on the crank by cutting select counterweights on a lathe once he gets it close enough he'll dial it in the rest of the way by hand using a grinder now this takes a lot more time than the more common method of drilling holes in the counterweights and balance the rotating assembly but those holes can catch oil and increase power robbing windage this method keeps the counterweight smooth and helps keep all the available power moving out the end of the crank and toward the rear wheels before laying in the crank keith preps the block original flatheads had to make do with a leaky rear main seal made from rope we'll be running dry sump oiling and pulling a vacuum in the crank case so an old school rope seal is obviously a no go for this engine instead keith has cut away a large portion of the rear of the block and machined this adapter plate that will accept a modern rear main seal made for a small block chevy he also installs and adds assembly lube to the two and a half inch main bearings from federal mogul [Music] [Music] this big passage you see is for the oil pump which mounts in a cavity at the back of the block keith is running a dry sump system with an external oil pump so he came up with a way to block off this passage to the oil pump but keep the oil flowing to the rest of the engine these two aluminum plugs press into the passage with a light coat of loctite to make sure they seal up tight if you look closely you can see the gallery in the side of the hole which must remain open that's the reason for the plugs both above and below it with the plugs in place the lower half of the adapter for the rear main seal can go in place as well as the custom billet main caps these cnc cut caps are after market and seat the main bolts down into these pockets you have to use a socket head cap screw because the hole is too tight to fit a socket down in there that means you also can't use a main stud and thread a bolt onto the cap key says on version two of this engine he'll have his own caps made that will accept a stronger main stud setup in the meantime these half-inch bolts are torqued to a hundred pounds combined with the three-inch 375 thousandths bore and the 4 inch 375 000 stroke that will make total displacement for this engine 313 cubic inches [Music] to help add a little extra support for the center main cap and keep the crankshaft from flexing keith fabricated these one-inch steel bars that bolt to the block with nine fasteners each and then they also bolt to both sides of the center main the goal is just to help tie everything in the block together just a little bit more rigid here's another look at the exhaust ports that exit through the block if you look at the block from up top the two center valves are both exhausts so we have a pair of exhausts dumping through the same port in the center of the block this can cause big time heating issues and cracking if you aren't careful to make sure the blocks stay properly cooled this exhaust port design also causes an issue because as you can probably see they're pretty restrictive and don't flow a ton of air jeff and keith have already hand ported the exhaust and open them up as much as they dare plus the cam duration is 10 degrees longer for the exhaust than the intakes to try to help move more of the exhaust gases out more efficiently before he finishes up the rotating assembly keith installs the front drive system so he can connect up the crank and cam with the timing belt that's because the cam has to be properly timed up or else some of the lobes will wind up hitting the connecting rods automotive specialists work with jaisal to develop this one-of-a-kind system all centered off this big quarter inch machined aluminum front cover now notice how it covers the water inlets for the coolant on both sides of the block so this plate deletes the original water pump mounting points we'll get into it more later but for now it's just worth remembering for a bit as you can see the front cover already incorporates the torrington bearing setup for the cam drive the sides also include places to bolt up the engine mounts to the frame but the car builder will do that once the engine's in the car for now keith is just using these bolt holes to help hold the front cover tightly to the block so the silicone can properly seal up once that's bolted up the timing belt drive can go on a good timing belt compared to a moored conventional timing chain or even gears is more efficient and will absorb more of the harmonics to protect the valve train with that done we can finish up the rotating assembly the pistons are a set of flat top foragings from molly with their iconic graphol anti-friction coating on the skirts other than that they aren't very exotic the flathead has a really tall deck i think it's nearly 10 and a half inches but you can't stroke it much more than keith already has because the architecture of the bottom of the cylinder boards is pretty limiting the connecting rods are already quite long so there's little point in squeezing the pin boards up into the ring lens of the pistons to try and get more rod length these rod forgings are from scat and they are a surprising seven inches from center to center the big end is chevy rod size and they've been outfitted with coated acl chevy sized bearings but they had to be narrowed down on a lathe to fit these aren't the beefiest connecting rods in the world but they don't need to be after all the flatheads architecture is too limiting when it comes to naturally aspirated power the piston rings are from total seal and quite thin to help minimize parasitic drag the top ring is tool steel while the second is a ductile iron napier both are just eight tenths of a millimeter thick and the ring gaps are set at just 18 thousands all 24 head studs have already been installed on each side of the block and keith obviously didn't want to remove them so instead of using his usual tapered ring compressor he swaps out a ratcheting style to install these pistons and rods he begins with just the number one piston so he can degree in the cam shaft and once that's confirmed the other seven rods and pistons can be dropped into place what's interesting is that the number one cylinder on the flat head is on the passenger side even though the first cylinder on the driver's side is forward of it just another of this engine's many quirks by the way here's a shot from an early mock-up session where we discovered that the deep bores and long connecting rods wouldn't even allow the extra inch of a stroke to four inches 375 thousands so the bottom of every bore had to be notched as you can see here once he confirms the cam is correctly degreed in and keith can be sure that none of the cam loads will be hitting the connecting rods as they swing by he can finish installing the other seven rods and pistons the cap screws are tightened to 55 foot-pounds which achieves the desired 5 thousandths of an inch of stretch the dry sump oil pan is completely custom fabricated keith purchased the three pickups from steph's fabrication specialties but everything else even the billet in pieces were fabricated in-house later on on the dyno you'll probably notice that we're only using two of the three pickups that's because with the original design keith was able to fit a four stage external oil pump with three vacuum stages but when we had to go back to the stock style exhaust ports the header and the oil pump wanted to be in the same spot so keith and jeff switched to a three-stage oil pump with just two pickups in the pan that center pickup is simply plugged off to provide a flat surface for the oil pan to seal to keith and jeff also machined up these aluminum spacers that match up to the steel girdle supports and go on all four corners of the block he says if he gets the opportunity to do this again he'll probably just go the extra trouble to machine the girdle support so that it goes all the way across and the spacers aren't needed regardless there are no gaskets on the market to fit this setup so all the surfaces are machine smooth and ultra gray silicon will work to provide a good seal making the pan as wide as possible helps reduce windage so the walls of the oil pan extend beyond the pan rails plugs in the bottom of the pan allow access to get a nut on the studs obviously the last thing you want to have happen is to lose a nut inside the pan during assembly so a small squirt of extreme pressure lube helps hold the nut inside the socket until it's properly threaded on the cool thing about epl is it melts once the engine warms up on the dyno and basically just dissolves into the oil then it's all gone after the first oil change automotive specialists and jaisal teamed up to make these one-off solid roller lifters for the flathead that's them on the left and for comparison a more stock style flat tappet is on the right the bolt in the top of the lifter actually serves as a lash adjuster that's a 3 8 20 bolt with an interference thread so it's not easy to turn notice those two bumps in the side of the lifter body those are actually keys that will keep the lifters from rotating in the lifter bores most roller lifter valve train setups use a link bar between the intake and the exhaust pair that keeps them from rotating but because the valve stem and the spring fit right on top of the lifter on the flathead there's simply no room for that here that's why it's conventionally assumed that the flathead is stuck with the older style flat tappet keith and jeff didn't want to give up anything when it came to airflow in the engine so they came up with a way to actually cut key ways in the lifter bores to allow the use of these keyed roller lifters with the lifter boards buried down inside the block like this cutting keyways in there and getting it right is a lot easier said than done but now they have a dependable way to properly orient the roller lifters let's take a second and back up so i can make sure i'm able to accurately share with you just how much innovation is going on here so here's the stock style combo or cartridge or whatever you want to call it you can see how the valve the spring guide valve seal retainer and locks are all bundled into a unit it's then inserted in the block and held in place with a spring clip retainer this setup works but it also has its limitations besides the keyways cut into the lifter boards a second critical change is the valve guides have been pressed into the ports in the block now that the valve guide no longer has to be removable more attention can be paid to shaping everything to increase airflow into and out of the block they've also installed copper beryllium valve seats and cut the seats approximately 125 thousandths larger than stock to accept one inch 625 thousandths diameter valves both the intakes and the exhaust are the same size we'll get to the valves a little bit more in a minute first the custom rollers need to be dropped into place notice how the lifters fall all the way inside the lifter bores when the lifter is on the base of the cam in a flat head you want to keep the lifter short because that creates more room for a longer valve stem and a taller installed spring height which allows more lift next keith slides the lightweight titanium valves from exodine into place this isn't final assembly this is just an opportunity to rough in the valve lash things will get a lot tougher once the springs are in position but since they aren't yet it's easier to pull the lifters back out and rough in the lash with them out in the open you can't really see it here but keith is using a fixture that grabs the lifters and the gaps on the sides so the vise won't damage the lifter bodies and here before things get too crowded you can see how the lifters and valves work in two of the intake ports the valve springs are a dual nested setup i can't share the spring specs because i don't know them but keith did tell me these are basically the same type of springs nascar cup teams using their restrictor plate engines on the super speedways and these retainers are ultra lightweight titanium now the valve is lifted out of the way so that the valve spring can be compressed enough to be popped into position you may need to reorient your thinking here but on this engine the retainer is on the bottom of the spring and not the top like you're probably used to to compress the valve spring enough to get the locks in the groove and lower the retainer in place keith had to design this valve spring compressor that's capable of reaching down into the flathead and getting underneath the retainer obviously there's nothing on the market suitable for a job like this if it looks a bit familiar however that's because this thing started out its life as a carpenter slide clamp before being heavily modified to suit its new job and here is how it looks once the springs are installed we've already roughed in the lash but now that everything is installed fine tuning the latch is a little bit trickier remember the holes in the top of the lifters this fork tool has two pins in the end that slide into those holes so that keith can keep the lifter steel while he uses a wrench on the lash adjuster you'll have to forgive me keith needed to get both hands down in there to do the job right and space was already tight so these are just about the best shots i could get without getting in the way too awfully bad now you see why maximizing the lobe size on the cam was so critical it's that 470 thousandths of lobe lift minus the 14 thousandths worth of lash that gives us a net valve lift of 456 thousandths of an inch of course the odd valve arrangement of the flathead also means that valve lift has a weird relationship on power normally on an overhead engine adding valve lift as long as you time everything so you aren't crashing a valve into a piston is nothing but good for power however in a flat head both the intake and exhaust valves open up into a valve pocket in the cylinder head that valve pocket is a fixed area so if you want more valve lift to improve flow into and out of the combustion chamber you have to make the valve pocket bigger and when you do that you guessed it the compression ratio goes down that's why keith and jeff were constantly checking valve clearance they needed to get it as tight as possible but you can't make the valve pockets so tight that they're just barely big enough to fit the valves into because then you shroud the valves and you get no airflow and that hurts power all over again by the way this is an old already compressed head gasket a new cometic will go on for the final build anyhow that yin and yang between valve lift and compression creates a strange balancing act to try and find exactly what combination will create the best power there's just really no way to know what the right mix is without lots of actual testing that's why if you look closely you'll see a couple different cylinder heads used in this video the brand doesn't really matter anyway because keith and jeff welded them up and created their own designs and in fact they think they may have found a little bit of an edge here as racers to the core they asked me not to share it that's why you really haven't seen the business side of the cylinder heads here i'm respecting them and i hope you will too anyhow that bead of weld on the leading edge of the head is just to make sure they've got plenty of coverage over the head gasket and a cooling hole that extends just beyond the head studs incredibly the flat head has 24 head studs per side for comparison the 351 windsor only has 10 per bank it seems like a bit of overkill considering the original flathead have somewhere between 6.15 to 6.8 to 1 compression over the years [Music] after torquing each of those head studs to 60 pounds each keith uses this cool old whistler gauge which gives a very accurate compression ratio reading and it comes out to 9.2 to 1 not much at all by modern standards but still a big improvement over the original another issue is the spark plug holes are oriented right over the plugs to keep the spark plugs from extending too far into the valve pocket and limiting valve travel they machine these pressed in spacers then move the plugs just a little bit higher in the heads ignition timing is handled by a small diameter msd crank trigger wheel and a pickup from moroso gesso worked out a system to use a drag racing style distributor that's driven by a belt off the cam shaft which routes the spark to the appropriate cylinder now the belt driven distributor is useful because one there's no distributor gear on our custom cam but two the narrow cog belt is very efficient and sucks up less power to spin than a traditional geared system keith hooks up the three-stage barnes external oil pump for the oil pan that's a dash 12 scavenge hose the oil tank will be mounted in the car and has a 3 gallon capacity all that extra volume is there to help keep the oil cool during long full throttle runs remember way back at the beginning of this video when i pointed out that the front drive plate covered up the water pump inlets on the front of the block yeah we're back to that now in the car there will be an electric water pump mounted remotely and it'll feed into both sides of the engine block right here where keith has drilled and tapped the block to accept the pipe plug this location isn't accidental this is the area just beneath the exhaust port where the two center combustion chambers empty into and a critical area of the block to keep cool about the last thing left to install now is the intake keith and jeff knew there was nothing currently on the market that would work so they set out to fabricate their own now from previous bills for bonneville competition they know that you just about cannot give a land speed race engine too much plenum volume so this one is downright huge remember we aren't worried about throttle response here the flathead isn't what anyone would call a high revving motor so the target here is to help the maximum power in the range of 4500 to 6000 rpm that's why the intake ports are longer than you might expect at first the top of the intake is removable so that keith and jeff can easily test both single and dual carb setups notice that both the base of the plenum and the intake are an inch thick the purpose isn't strength those slabs of metal especially at the base are so thick to give them room to hand work the transition from the porch to the intake runners so they match perfectly and so it's finally about time to get this beast on the dyno and see what it can do [Music] in this shot you can see how the exhaust manifold kept keith from running a four-stage oil pump like he'd originally planned also notice the coolant line that feeds water into the block just beneath the center exhaust port i don't want to bore you with all the different testing combos so i'll just let you know that we made best power using a pair of holley 750 cfm double pumpers they're sitting on one inch open spacers but that's mostly just so that the linkages will clear the top of the intake plate [Applause] that's about it let's go after the break-in process we were ready to start making some pulls but honestly this is a highly strong engine and not exactly easy to find the big issue was the carbs seemed to run rich no matter what jets were used so keith had a suspicion what was happening but he wouldn't tell me instead he asked me to mount one of my cameras directly over one of the carbs and this is what we saw the signal through the intake and to the carburetors was so strong that it is literally pulling fuel right from the squirters so that took a little testing to find the right combo jeff thornton eventually found the right mix using tiny number 18 squirters on the front half of each carb while blocking off the rear squirters altogether again this is not an ideal setup for streets but for land speed racing the main consideration is to be able to get from idle to wide open throttle without bogging and then leave it there until you fly past the finish line the rest of the changes were more incremental we wound up with all in timing at 35 degrees before top dead center we were burning sunoco 110 race fuel and after multiple jet sweeps jeff settled on number 82 jets on all four corners of both cars so here's the results 257.5 foot-pounds of torque at 4700 rpm and 249.4 horsepower at 5300. almost to their target 250. considering keith and jeff were not allowed to change the valve locations alter the deck height could only burn gasoline and had to keep the engine naturally aspirated this is really impressive remember the most the flathead was capable of from the factory was 95 horsepower that's a 263 percent improvement if my math is correct oh and they did want to make sure their custom intake was actually making power so they did do a test with the biggest cast intake manifold they could find fitted with an 830 cfm four barrel carb i wasn't there when they tested this so i don't have any photos or video but they did share the dyno graph and the engine was basically down on power at the peak by a little more than 50 horsepower plus the power had rolled over by 4 800 rpm 500 earlier than the fabricated intake so we took that as a sign that the fabbed up intake is an improvement normally this is the point that i sign off on most of my videos but this time around we've got a special treat for you the flathead left automotive specialist and went straight to the shops of thunfield rod and custom where it was dropped into the 39 ford that had been built just for land speed racing then racer and car owner ron cooper and his crew took the car to el mirage for a shakedown test jeff dortmund went also serving as the engine toner and he provided me with these photos first of all check out that car is it absolutely gorgeous or what now if you aren't familiar with el mirage it's a dry lake bed in california and the racing surface is dirt or more really a really fine dust as you might expect it can get pretty dusty out there so to protect the engine this air cleaner setup was fabbed up there isn't a lot of room between the top of the carbs and the hood so this is what they were able to make work even though it obviously has to hurt power production now that's okay because el mirage was just a shakedown test there aren't the same issues with dirt on the salt flats so the air cleaner will be removed from bonneville anyhow the team made three shakedown runs on the one mile el mirage course and actually achieved a top speed of 125 miles per hour even though they had shifter issues on their final and best run that leaves them only 10 miles per hour short of the mark which should be easy to make up on bonneville where they have a three mile race course the crew are pretty confident the record is well within reach at bonneville and once they've run i'll leave an update for you in the description of this video hey thanks for watching and we'll see you next time with more great videos [Music] [Applause] [Music] you

Channel: The Horsepower Monster

Views: 632,520

Keywords: bonneville salt flats racing, Land Speed Racing, VGC/XF, 1939 Ford Coupe, Flathead race engine, Automotive Specialists, Keith Dorton, Jeff Dorton, how to build a flathead, ford flathead race engine, Jeff Huneycutt, The Horsepower Monster, Comp Cams billet camshaft, Jesel flathead, custom flathead engine, flathead, flat head engine, flathead v8, bonneville, ford engine

Id: sJWtjChXbOw

Length: 38min 26sec (2306 seconds)

Published: Fri Jun 17 2022