NASCAR Chevy SB2 V8 Turned Into a Racing V6!?Feb 27, 2020
racingmakes the best stories and i want to share with you one of my favorites. It may look like your standard small-block Chevrolet, but what you're actually looking at is the world's best-disguised 660-horsepower v6 engine. Now the trick. it's that if you want to get full power you have to do a lot more than just unplug the back to plug in the wires now Keith was willing to show us everything he's done and I think it's fascinating to see the way he thinks when he builds these motors to break records and stand out from the rest.
There's honestly very little reason to go to the trouble of building a high-speed v6 using a NASCAR SB as a base, unless you're talking about finding an edge in a
racingworld and that's exactly what engine builder Keith Automotive specialist Norton is doing it here after a long career building stock car race-winning engines including the Daytona 500 Jordan has become a major player in land speed racing where a the thin Rule book allows for more creativity The Hoodlums Hot Rod Racing Team plans to use this engine to break Bonneville's current speed record of 228 point seven miles per hour in the gasoline rear-engine Toaster class with an engine displacement of less than 261 cubic inches the problem with building a naturally aspirated v8 that is so small, you still need a lot of diameter to fit r big valves for plenty of airflow but that in turn leaves the stroke so short it's hard to build compression and if that's a bit confusing I'll just let Dorton explain himself so the question is why would someone take a v8 and build a v6 from it.
Well this goes to the bottle for land speed racing and they have different classes based on cubic inches. This particular class is limited to 261 cubic inches actually. at sixty point nine nine and if you do that in a v8 there's so many cubic inches of super fuel per cylinder that it's hard to get compression now that we've done that and we've been successful with most comparisons The ression we get is about eleven not even quite 11 to 1 so i figured one office did it b6 and that way we would have another 12 super silver cc and could keep 13 to 1 compression so we did it the simplest way.
The way I found to do it was to just remove two silvers in the one block experiences we've done with 90 degree V-sixes in the past where they were cluttered with a lot of vibration and we didn't want that for an endurance guy like us. would be doing out there so we just limited the silver back to the cylinders we found right at 259 cubic inches and about a 13 to one compression ratio now to assimilate the v8 we make a way to go on a song of crank boat like connecting rods would and we've already read this engine so this is a rebuild and it was just smooth running like any v8 you've seen now and it has a unique sound it's also kind of a cross between a v8 and a v6 vacation by the time I got involved with this engine bui Old Keith was almost done with the short block but I think I can get you up to speed.
The basis for this build is an SB race engine previously built by Hendrick Motorsports and raced in the NASCAR Cup Series and no, I don't know what car. or track Dorton likes the sp2 architecture for dirt racing because it breathes so well and puts out tons of power in the upper rpm ranges the crankshaft is a Bryant billet piece with three and a quarter inches of stroke attached to the R6 Carrillo connecting rods that are six-inch 350-mil Sloan and a half-dozen custom moly pistons finish the rotating assembly in the Valley Dorten riser is pressed into these machined aluminum parts to seal the old galleries that feed the riser bores for the part. cylinders this will help maintain proper oil pressure throughout the rest of the engine and also seal the lifter valley for cleaning by the multistage dry sump oil pump.
Here's another look at those molybdenum pistons. the pistons are not new at TDC the pistons are flush with the block cover to maximize compression and at the same time in the valve pockets they are absolutely as small as possible while the cam is a big boy in every way of the word crane cam ground from a piece of billet steel specifically for this build the camshaft is 55 millimeters in diameter to resist twisting because even the slightest twist can ruin valve timing events it is a solid roller and also it has been gun-drilled to lighten it up a bit being a race cam and a grind he has worked hard to develop Norton prefers to keep much of the detail on this cam to himself however as this motor is designed to running at 9,000rpm and up we know duration is huge, over 270 degrees at 50,000 speed for both intake and exhaust valves exhaust, once it is in place, a racing belt drive system is used to control timing because it is more resistant to stretching than timing chain since there has been machining done to the deck of both the block and Dorton cylinder heads check piston valve clearance before final assembly turns out to be the tightest intake valve is 70mm clearance and exhaust is 170 mil that includes the 40,000 thick head gasket now that its pretty tight for intake but doable also check the radial clearance in the valve bores its right against the bore wall of course the intake valve needs to be a few thousand higher in the bore and the wall leans back a bit so the clearance is actually more than machinist would suggest no rods or pistons on most rear cylinders those are numbers 7 and 8 after First of all, including the pistons would only add friction inside the engine, so Dorton designed a machine with this weight that clamps over the groove of the crankshaft connecting rod, simulates the weight of the two connecting rods and the pistons, and exactly how. he came up with the exact mass to keep the engine balanced, he keeps to himself that the cylinder head is a high flow sp2 model that has already been ported by Hendrick Motorsports note the plaque above the combustion chamber at the rear that is simply an aluminum cover that was bolted in place and machined flat with the rest of the head the combustion chamber and ports have also been capped with epoxy for three chamber operation in each head however the intake valves are two-inch 180 mils in diameter with a 6-millimeter stem, while the exhausts are 580-inch with a thicker 7-millimeter stem to help them withstand the high heat of the exhaust fumes escaping that gold color on the intakes is a coating to help strengthen the soft titanium they are made out of and here's a look at the intake manifold this is an edelbrock high rise intake with a large chamber to help maximize high rpm power if you look at the manifold you can see the plate that was placed to help prevent air fuel from getting into the unused runners after it was fired, the gaps around the edges were sealed wit h The engines of high revving silicone requires very stiff valve trains for this engine.
Dorton wants to use large, half-inch diameter pushrods that are incredibly stiff, but large diameter pushrods like this simply won't work with many high-end roller lifts because the tie bars limit the diameter of the pushrod. thrust as you can see here so the block has been lined to accept keyed risers notice the slots in the top of the riser bushings these have a keyed riser that has no tie bar the key can see them on top of the Risers are slot guided to prevent the roller riser from spinning in the bore and now you have virtually unlimited push rod clearance for these bad boys.
Norton wants to make these key elevators work. the outer surface is extremely hard and with a diameter of 937 mils, they are also significantly larger than the standard 8:42 riser size, allowing the riser roller wheel to be slightly larger and reducing stress . In the valvetrain as a whole, multi-layer steel gaskets were chosen to help seal the combustion chambers and are 40,000 thick when the heads are fully bolted on to match Crane Cams' long-lasting roller. Jordan is using a nested valve kit. pack springs are 160 lbs of seat pressure and 600 open by the way total valve lift will be in the range of 800 mils for inlets and 850 for exhausts retainers are tool steel Machined for minimal weight.
You can see here where the valve springs for the rear cylinder have been left to prevent oil from dripping into the combustion chamber. The valve guide has been tapped in and then sealed with small pipe plugs. a pain because it's designed specifically for racing it just won't work with standard head bolts in some places you have to use bolts with the SB in the ports they were given priority so you have to bolt the head through the intake ports in a couple of locations then add a plug later and the plugs are also not interchangeable because the bottom has been ground to match the specific shape of the input port.
By the way here you can see the bolt extending slightly from the port floor now this really isn't an impediment to power due to how the RPM levels with a full flow SB cross the port top another quirk is that some of the outer bolts are directly under the exhaust flange and a crows foot on the torque wrench is required to tighten it. This is an engine that definitely requires patience to build. We've already mentioned that Dorten will be using ultra-stiff, half-inch-diameter pushrods to limit flex. He ended up using 8-inch 825,000 shots. Eight-inch 875 pushrods for the exhaust because the valve stems are very narrow to reduce the overall mass of the valvetrain.
Tab caps should be added to each valve stem to provide a little more diameter for the rocker arm roller tip to slide on. Typically through the full stroke sp2 rocker arms used by NASCAR Cup teams in the past we are not adjustable and you had to use shims to adjust the valve lash. problems in bonneville where you are always in a time crunch so dorton works with tnd for this set of aluminum rockers with adjusters on the pushrod side of the rockers the aluminum tendis are super stable with a mass minimal so they don't hurt the taller ones Engine rocker arm ratio rpm performance is 1.8 to 1 for the inlets and 1.95 to 1 for the exhaust and as we mentioned above the overall lift is in the range of eight thousandths of an inch for the intake valves and 850 for the exhaust valves.
Cold lash is set to eight and ten thousandths for the intakes and exhausts when the engine is warm both will grow to about ten thousandths of an inch the sp2 architecture uses a separate valley cover and two totally separate intake manifolds the hot engine coolant air and fuel charge flow through the intake and again you can see the plate blocking the two rear ports inside the intake and here's another trick the NASCAR guys came up with that Dorten likes to take advantage of. This is a sixth stage. Auto Verde dry sump oil pump that draws everything from both the dry sump pan and Valley riser to virtually eliminate any energy-robbing wind.
The old pan is cut from a piece of billet aluminum and sealed against the main caps to create chambers under each crankshaft. via a pad under each, the oil is pretty much sucked out of the engine as fast as possible, the distributor is used only to route the spark to the proper spark plug at the front and the MSD crank trigger is mounted to the housing ATI damper to control ignition timing. He may have noticed a different black carburetor earlier in the video. At this point Norton has already done some testing and determined that the 216 cubic inch v6 works best with a n 1150 CFM Holley Dominator carb, yes you heard right, v6 with a bolt-on top Dominator car, that's because of that land speed racing is all about the flow ofMax air, we don't even care how the engine runs below 6,000 rpm, this bad boy won.
They don't even start up until most engines have already exceeded their redline the first time this engine was built. Dorton modified the distributor to fire it up only six points instead of the usual eight, but the race team was never able to get the system to work properly with his setup. on the race car so this season is letting the ignition system think it still works on a v8 for testing we just ground the two rear plugs and wires against the dynamics which is a pretty good athenian fire but an uncontrollable spark in a race car isn't Not exactly a good idea so he also made this canister out of aluminum that will hold the spark plugs and not allow any gas to get to the spark so let's burn some gasoline from race again, no one will really need conv. turn a perfectly good v8 into an ultra-high rpm v6 unless you're trying to find some kind of racing edge, but if you love horsepower engines you can definitely appreciate the ingenuity here, Dino pull nor It didn't even start up to 6,000 rpm and when we pulled the handle at 92,000 rpm we still hadn't reached full power with peak torque of 393 point 3 pound-feet at 70,300 rpm and 663 point 3 horsepower at 9,200 rpm this engine It's an unbelievably little beast that's over two and a half horsepower per cubic inch in a naturally aspirated engine and we were working on a 97 degree day here at South Dorner reckoning says the hot thug racing team rod should have more than enough power to absolutely break the current record of 228 points seven miles per hour at Bonneville will make more power, but 9200 rpm is simply the norton redline assigned to the mot Or to ensure your health during those massive 5-mile long bursts of acceleration and acceleration through the salt, hey, thanks for watching.
I'll try to update the results after Bonneville. They will let you know how this engine worked and if you enjoyed this video please hit the like button and consider subscribing for more. future engine building videos thanks again
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