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The Elephant! Building a Stroker Hemi with a Giant Blower for a Dodge Charger

Feb 27, 2020
When it comes to iconic images, very few can even come close to the 426 Hemi, so together with Prestige Motorsports we are

building

one, but with a cherry on top, how about a

giant

old school 871

blower

pushing harder? This is actually a new Hemi. block prestige Motorsports is beginning the process that begins with machining specialist Cody McCleary, machining and verifying all critical dimensions, the camshaft is a solid roller from erson, it is designed to perform well with the moderate boost levels created by the

blower

, but it's still a big boy with On a one-inch base circle, the cam is ground with two hundred and seventy-two degrees of duration at 50 thousand strokes of lift for the intakes and two hundred and eighty-two degrees for the exhaust, all on a 110 degree centerline with a 115 degree lobe separation angle.
the elephant building a stroker hemi with a giant blower for a dodge charger
The original 426 Hemi was first produced in 1966 and Dodge and Plymouth and lasted until 1971. It was nicknamed the Elephant because it was not only powerful but also quite large and heavy compared to engine packages from other manufacturers. This particular engine will go into a 1968 Charger built with its 250,000 four-inch spores and 750k three-inch strokes, the original street version of the 426 Hemi was rated at 425 horsepower and 490 pound-feet of torque. torque, all with a pair of Carter AFB carbs at the top of the course prestige. is going to blow that out of the water not only with the blower but also increasing the total displacement almost an additional 150 cubic inches to a massive 572.
the elephant building a stroker hemi with a giant blower for a dodge charger

More Interesting Facts About,

the elephant building a stroker hemi with a giant blower for a dodge charger...

Similar Larry Broker checks the clearances with the Cleveite V Series main bearings in place once he confirms everything is correct the crank is ready to be snapped into place the crankshaft is a forged unit from Eagle it has already been balanced for the rotating assembly and features a four and a half inch stroke which is 750 mils longer than the original main bolts that They are used instead of bolts because they can provide additional clamping load and are less likely to cause bore distortion to eliminate the chances of scoring the crankshaft journal. The racer does not install the bolts until the crankshaft is secure in the bearing brackets next to the billet steel main caps.
the elephant building a stroker hemi with a giant blower for a dodge charger
They can be snapped into place, it is always better to use a hammer to seat the caps firmly in place than to try to pull them down by tightening the nut, some of the main bolts, the side bolts go next to keep everything from crying. the threads and then under the floor of his garage the racer applies some silicone to each of the rear main caps he used to use an old school rope seal to prevent everything from passing the gap between the side of the cap and the block, but a thick bump of silicone actually works best, simply wipe off any excess after installation, this system uses two slots for the silicone for added security once all the caps are in place and the racer has confirmed that the crankshaft is in play, the mains are tortilla stages to the last 100 foot pounds, while the side bolts are torqued to 75 the connecting rods are also from Eagle they are 100,000 ESP suspended 7-inch H-beam forged connecting rods They use a heavy duty ARP mm cap screw to secure the large end.
the elephant building a stroker hemi with a giant blower for a dodge charger
They connect to a set of custom screws. The pistons are sturdy pieces and are four and a half inches in diameter with a large dome to help maintain compression. tall and the

giant

combustion chambers required by Henry's design. This is the je 1602 forging which provides a good balance of strength and detonation resistance, if the tune ever goes south the dome is 225,000 high and the compression height of this Stroker is of one point three seven zero inches, which is quite tall for a conventional engine, but with the high dome required for a Hemi that compression The height is actually quite short and that means that the pin goes into the old base of the ring that However, it is easily attached using a support rail under the old wing.
The racer gets to work assembling the pistons into the connecting rods. The ring pack is quite thin at 4300 43. and 3 millimeters and the end spaces have been opened up to 32,000 7 inches for the top ring and 35,000 for the second due to the additional heat created by the extra boost once the Pistons are on rods and all rings are properly installed. He performs a final cleaning pass on all cylinders, applies a light coat of engine oil, and begins to move the assemblies into place to achieve proper stretch. The ARP cut bolts are torqued to 75 pounds, although this is an aftermarket block, the Hemi is still a stock platform. 10 inch height 720 miles racer confirms pistons are as intended 5000 send bore once the dual mount timing assembly is connected the ground cam can be checked to confirm it is timed correctly and with that The racer can bolt on the timing cover and start on the long block where the prestige of the oil pan went with one of my half pant loads with a seven quart capacity and a center sump.
This crankcase is made specifically to work in racing applications, so it is designed to use an external pickup system. I can see the pickup at the bottom of the sump, but it connects via a prestigious 12am fitting. welded in place and then to a hose external to the tray. That hose then connects the pickup to the stock style external oil pump, this way there is no internal. pipe to get in the way of additional run or cause wind losses for the external collection system to operate. Prestige is needed to block the internal pickup bracket on the front of the block, which you can see here.
A little extra silicone helps fill the Pro oil. The crankcase gasket maintains a leak-free seal and the oil pan is bolted into place. Now we can turn our attention to the cylinder heads. These are Edelbrock castings designed for Hemi engines when the target horsepower is over 650 and see those beautiful cams. CNC cut and has a 170 CC combustion chamber and 245 CC intake runners to get air and fuel in and out. They are equipped with large tubes, 320,000 intakes and 940,000 one-inch SIGs. All prestige valves use a set of valve springs with 225 lbs. of pressure on the seat and 560 pounds at 650,000 inches of lift, the 426 Hemi is configured so that a row of bolts must be installed on the bottom of the heads which then pass through the bolt holes in the block after screwing in those short bolts.
On the cylinder head deck we also installed the rest of the bolts into the block, but this turned out to be a mistake as we couldn't get the shorter bolts to fit into the block with the longer bolts in place, so the ones are on the block had to come back out while he was there. The racer also installed a pair of unique 60,000 restrictors in this passage in the block that feeds the swing bar. Our particular setup is unique because it prioritizes lubrication by feeding oil to the valve. train both through the rocker brackets and through the lifters and pushrods because the valve train gets oil from two sources, which restricts flow is necessary the original block;
However, only the oils through the rocker board by forced induction put additional stress on the head gasket, so in addition to using Kemetic racer quality MLS steel gaskets, he also gives them a spray coat. copper to further improve combustion chamber sealing and with the head bolts removed from the block, the heads are ready to go. Notice how the head bolts extend through the boss at the top of the block deck, then what is in place, a washer and a bolt can be threaded into the bottom, now the bolts can be threaded Instead through the cylinder heads and into the block runner, a fine type of extreme pressure is applied.
Both ends of the Manton pushrods are ten inches, four hundred thousand, long for the intakes and the 11 inches are 350,000 for the exhaust because they have to reach the opposite side of the cylinder head, they sit on a set of BAM solid rollers. lifters that have already been placed in the lifter holes, as we have already mentioned, this block design has a gallery of pressurized oil that feeds the lifters, that is why the pushrods are hollow and help feed everything to the rockers . The racer also adds the last caps to the On top of the 5/16 inch valve stems, the caps help provide a little extra surface area for the high lift roller rockers to ride on and now we are ready to the famous Hemi rocker arms before the assembly agent takes a moment to thoroughly clean the rocker arm.
The hollow shafts are fed to alter the rocker sprockets, so it is essential that they are completely clean of metal shavings or any other contaminants that may become trapped inside the shafts. The rocker system is from Indy and as you can see some assembly is required but it is simple. sufficient, the purple rocker arm position uses the head bolts to secure them in place, meaning the heads cannot be tightened to the block until the rocker arm threads are in place. Some builders prefer to bolt the rocker brackets onto the heads, tighten everything down first and then assemble the rest of the rocker assembly.
The racer prefers to assemble everything first. The choice is up to you. The racer drops the complete rocker assemblies on each head. taking care to make sure each pushrod cup is firmly seated in the silver rocker ball. The section you see on the outer bracket is where a little clearance was needed to fit the particular valve caps that Prestige uses, then the washers and nuts are threaded onto the studs and everything can be tightened down with the final torque to the cylinder head studs and 70 lbs applied. in three steps and don't forget the bolts that extend into the block, it's impossible to reach them with a socket so the racer uses a dog bone extension on this torque wrench now the rocker arms may be the last person you want the last hot one is 20 mm for the intakes and 24 for the exhausts, to compensate for thermal expansion when the engine is hot, the runner hits 16,000 s when cold and finally it is time to focus our attention on a small forced induction.
Remember this is a street bill that is primarily going to burn pump gas, so the goal is not to generate stratospheric amounts of boost, but a big 871 blower just makes sense in a Hemi Elephant Prestige works with many engines. blower and generally depends on BDS for its blower configurations. This particular build is no different. It is the polished BDS intake manifold that provides a stable base for the blower drive. There are sixteen fasteners that secure the manifold to the heads and, like the main covers and cylinder heads, use prestige bolts in this application. Here's a look at the bottom of that big Box 8 71, the 871 is the largest blower BDS makes for this application, it features all polished components, twisted rotors for great strength, billet support plates and a upgraded billet case and even eight-millimeter belts and pulleys, but before the racer can attach the massive blower belt. drive, the accessory drive system should be in place, the water pump and front drive system are from Eddie Motorsports and it is their S Drive system, like all the components on the BDS, they are all polished aluminum.
Brooker also brands the MSD Pro Billet distributor accordingly. everything in place to check for clearance issues and here's a look at the external dash twelve oil pickup line all connected it's a little hard to see but the oil pump is a standard volume pump to send by mail. Note that the line stays hidden in a nice, low spot. He said it won't get caught in any of the belts or pulleys or can't even come into contact with the heads at this point, we have the big Hemi set up on the engine dyno that we're going to power this. four cylinder twin carbureted beast from quick fuel technologies, they are both a thousand twin pump 50 CFM and quick fuel B series and that just means they already have boost reference.
Notice the black vacuum lines coming out of the joining carburetor bodies. into a tee and then connect it to a fitting and to the intake manifold plenum. This is the reinforcement reference we mentioned. Allows theCarburetors continue to feed fuel and air to the engine even if the air pressure inside the intake manifold is higher than the atmosphere. The carbs are fed through a hardline kit supplied by BDS and it's actually quite attractive and doesn't take away from the look of the blower setup like a conventional large diameter fuel stick stick. The adjustable throttle linkage also came from BDS after checking. over the rocker system for the last time, the cast aluminum valve covers are bolted on and the auto light plugs installed through the spark plug tubes, the ignition controls are handled through an MSD six BTM box will retard the timing from our 31 degrees, all in one degree timing. per pound of boost, in other words, at nine pounds of boost it will run 22 degrees of time and here's a look at the belt drive system.
Eddie Motorsports' front-wheel drive accessory system fits well on the Henry, but it's not purpose-built for performance. on a blower setup, so Percy had to machine some spacers to get the blower drive setup to fit in front of the accessory drive serpentine belt, but honestly, that's all that was expected on the custom primary, after breaking up we made some carburetors to dial in the air fuel ratio and were ready to start pulling, we started with the pulleys arranged to produce the least amount of boost which meant a 59 tooth pulley on top and a smaller 52 tooth pulley on the crank producing an insane bottom view and here's the tire just look at that flat Kansas torque curve, we're talking over 600 foot-pounds from 3500 to 6400 rpm.
Maximum power was 760 8.3 at 6400 rpm and that was with relatively low boost, in fact the boost never exceeded 3.4 pounds. In this graph, the numbers for the horsepower and torque readings are along the y-axis on the left side of the graph, while the numbers for the boost ratings are on the right, but they are impressive, as that that group was actually just a base of the engine. and we confirmed that everything was working correctly, then we changed the two pulleys creating a slightly overdriven setup and some improvements. Since enough is never good enough, we removed the 52-tooth top pulley and installed a 50-tooth one which improved the gear ratio over the stock. 0.88 to 1 driven ratio under 21.18 to 1 over driven, so let's see what that produces this time, we saw a big increase in power, the shape of the horsepower and torque curves were basically identical, only much higher on the graph, the average torque across the range was incredibly 100 better, while the average power improved by 95 with a peak of eight hundred and seventy-nine point seven at 6300 and that's all thanks to the greater boost produced by the police, as you can see, this time we hit a peak boost of nine point four at 6400 which was pretty impressive, but Prestige wanted to do one final test.
Almost all dyno testing is done without an air filter installed because there are a lot of variables when it comes to what the end user might choose, but we wanted to see how the air intake and the two perform. Which air filters fit inside affect engine power, so we installed the assembly and made one last comment with the air filters and air intake in place. We did, as expected, lose some power, the average torque and horsepower decreased across the range by 28 and 27 respectively, however the engine still makes a ton of power with a peak of eight twenty-eight point. eight horsepower at 6,400 rpm and that is due to the fact that the additional restriction created by the air filters or the fact that air can only enter the engine from one direction across the blade instead of 360 full degrees as before reduces the amount of boost the blower can produce.
It's as simple as less air to the engine means less power produced. One thing the engine dyno cannot do, however, is replicate. air flow into the engine at speed, even though we had a little bit of power, that scoop is probably pretty useful in real world conditions, after all at highway speeds it should help trap air and get it into the engine Either way, this 572 cubic inch Hemi is just as strong as this

elephant

head site, not only does it have great power, but it also looks amazing and sounds even better, as always, thanks for looking.
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