The D seriesR&D's D16 SOHC creation that drives Bisi Ezerioha's world's fastest D-motor car is built with similar modifications. R&D is getting phenomenal power out of this ignored and unloved motor. This is one D-motor that is not overshadowed by its bigger VTEC brothers. Ezerioha's crank is another one of R&D's 4340 forged blanks stroked a secret amount. The D-motor uses R&D's lightweight rods to minimize reciprocating weight. Again, forged, gas-ported pistons of an unspecified bore diameter are used. The engine displaces 2,000cc.
The block also features millwork to clear the stroker crank and ARP fasteners. Again, buttressed ductile iron sleeves reinforce the Honda's weak cylinder walls and allow a big bore.
The small-port D16 cylinder head received extensive port and combustion chamber work, while also getting 1mm larger stainless-steel valves. Dual valve springs are used with titanium retainers. A special R&D cam of 0.450-inch lift and 312 degrees duration is used. As in R&D's B-series motors, this incredible little engine is squeezing the mixture to the tune of a 15:1 compression ratio.
In this age of high-tech, programmable stand-alone fuel injection systems, Ezerioha's car uses a technological throwback for fueling and spark management. A good old mechanical advance distributor controls the ignition curve, while a pair of two-barrel Weber DCOE carburetors handles fueling! Ten short years ago, these were the premifre way to fuel your racecar. The sight of them brings tears to my eyes! Webers are still no disadvantage in power when it comes to wide-open throttle operation and Ezerioha's car proves it. A Speed Pro EFI system with twin two-barrel throttle body injectors is planned for the near future.
This D-motor is redlined at 8800 rpm and cranks out an amazing 215 hp and 170 lb-ft of torque to the wheels! A de-tuned sleeper street version of this motor can crank 170 hp and 155 lbs-ft of torque; this figure gives respect to the little SOHC base equipment Civic engine that usually gets none. One of these D-motors could rack up the bucks at the street races, taking the money from unsuspecting B-series pilots. Is anyone paying attention here? For turbo and NOS versions of this motor, SanAngelo recommended keeping the displacement down to 1900cc for more strength in the cylinder walls.
The B-seriesCurrently, R&D's most popular combination, the B-series engines are bristling with potential. With similar modifications to the block, crank, rods and pistons, R&D can extract upward of 2400cc from Honda's performance workhorse.
Starting with the bloc, the cylinders are re-sleeved to beef up the B-motor's weak cylinder walls. The sleeves have bridges that butt against the inside of the block to prevent them from walking around under side load, but are open around the top to allow cooling water to flow freely around the top of the cylinder where cooling is critical.
The head is given straightforward porting and makes use of sidedraft throttle bodies driven by a Speed Pro engine management system. The race H-series engines, like all of R&D's full race creations, runs a whopping 16:1 compression. The big thumper manages to spin to an impressive 8800 rpm.
In its current state of development, R&D's B24 is putting out more than 250 hp to the wheels with more than 185 lb-ft of torque. Look for a few of the big names in the all-motor class to be fielding this combination next year. In street trim, the big B-series puts out more than 215 hp and 180 lb-ft of torque. Imagine one of these under the hood of your hybrid Civic with a Hasport conversion kit. Mind-numbing, isn't it?
It is possible to build R&D's engines so they look and sound just like stock engines as they sit idling there innocuously. No clue of their awesome potential is apparent until the loud pedal is depressed.
The AEBS CRXIn direct clashing contrast with the mellow hammers of R&D are the screaming monsters built by the rebel genius of AEBS, Paulus Lee. As AEBS' chief engineer, Lee is a true mad scientist; he speaks in staccato bursts, almost frantically, his powerful brain obviously thinking faster than his mouth can speak. He is animated and enthusiastic in his gestures. His thinking is usually several levels deeper that most people I have met in the racing industry.
The AEBS CRX driven by Rodger Sangco to the championship in NIRA's all motor Pro-Stock Class reflects upon the unique personality of its creator. Unlike the straightforward, no-replacement-for-displacement approach of R&D, the AEBS car bristles with innovation. Lee likes to apply science and fresh, state-of-the-art approaches from other advanced racing venues like F1 and CART. Lee also solves many of the problems associated with very high-revving Honda motors. There is no doubt that the Lee's theories work and that there is method behind his madness. The CRX is fast, with a best pass of 10.95 at 125 mph in the heavier NIRA Pro-Stock trim. NIRA Pro-Stock cars must run a minimum weight of 1,700 lbs. vs. the IDRC minimum of 1,600 lbs.
Let's take a look inside the AEBS engine and explain some of the finer points of its operation. Starting with the bottom end, there are plenty of tricks; the most obvious is the AEBS block. The block uses AEBS' patented spin cast nodular iron sleeves. Spin casting is where the mold is spun at a high speed so the pure dense metal is towards the outside and the slag and impurity-filled lighter metal ends up being on the inside, where it is removed during the final bore to size. This method gives a denser, more homogeneous metallic structure. Nodular iron is better for cylinder liners because of the large amount of carbon granules trapped within the metallic structure. This gives the liner better abrasion resistance and lubricity.
The liners also feature a very beefy, flex-free deck surface, which would make them ideal for a turbocharged engine or one running nitrous oxide. The thick deck butts solidly against the outer edges of the block, giving the sleeves a very solid base of support to keep them from shifting under side load.
Digging a little deeper, we see some real innovation; a thick aluminum plate, TIG-welded to the top of the block, extends its deck surface upward an unspecified amount, allowing the use of a very long connecting rod. This is a unique AEBS innovation. You may have noted that we have been predicting that Honda tuners would work to optimize an engine's rod/stroke ratio for several years. AEBS is the first tuner that we know to address this issue head on.
The engine has a bore and stroke of 84mm x 95mm for a displacement of 2106cc. The exact length of the connecting rod is secret, but we were told that it is longer than 165mm. That would give us a stroke-to-rod length ratio of more than 1.7 to 1-excellent for a Honda. The higher the rod ratio, the slower the piston dwells around TDC, helping Volumetric Efficiency (VE) at high rpm as well as aiding combustion efficiency and reducing mechanical stress on the engine. Pretty cool stuff. This is the exact opposite of the way that R&D gets around high-rpm VE issues by using ultra-high compression
Looking into the bottom end, we found a fully counterweighted billet 4340 AEBS stroker crank. Lee was quick to point out that he is careful to keep the weight of the counterweights correct; many highly stroked Hondas can have trouble with the oil pump breaking, due to crank harmonics. This is amplified by the fact that many top builders of naturally aspirated engines cut down the crank counterweights, knife edging them to lighten them and reduce windage losses. It is worth pointing out that both the AEBS engine and the R&D engines have fully counterweighted cranks. To further control torsional crank harmonics, Lee showed us he is running the harmonic balancer off of a B18B engine, which he believes is the heaviest, most effective balancer.
Ultra-trick, ultra-light Cunningham titanium connecting rods hold the AEBS-designed, Ross low-silicon pistons to the crank throws. The rods feature 220,000 psi bolts and are super light. These were selected to combat harmful harmonics from enhancing bending and twisting loads on the crank. Lighter rods also mean lighter counterweights are possible, a way to safely reduce power-sucking reciprocating mass. The Ross pistons have H11 tool steel pins and Total Seal rings. The pistons are hand massaged to a high, but still conventional, 13.5:1 compression ratio and are coated with Polymer Dynamics Teflon coat on the skirts and thermal barrier coating on the domes.
Lee has to use a more conventional compression ratio than SanAngelo because of the AEBS engine's controlled and optimized piston speed, as well as the smaller displacement that better matches the flow capabilities of the head. Again, an opposite approach to R&D's engine-building practices.
To improve head gasket seal and strengthen the bottom end, all of the block's structural fasteners have been replaced by an AEBS stud kit featuring 180,000 psi tensile strength studs. The block also has threaded oil passage plugs, a deburred interior and the usual signs of good engine prep. Stock Honda bearings are used for the crank and rods. The unique innovation of a decent rod ratio, harmonics control and light reciprocating weight without sacrificing strength, allow the AEBS engine to produce power to a screaming 10,000 rpm.
The folks at AEBS were proud to point out that the engine ran the entire 2000 season without a single failure. The valve cover never came off and the only things checked were the plugs. This is not like many of the other all-motor competitors who were plagued by failure during the year. Lee pointed out that the engine was still in excellent condition, with good compression and leak down numbers. The engine was just pulled to freshen it up, as it will be sold to another competitor to be replaced with one of his even more radical creations.
The cylinder block has a block-off plate and adaptors to run a trick AEBS full-flow electric water pump that moves water at a rate of 20 gallons per minute. The pump frees about 6 hp by eliminating parasitic losses present in a crank-driven water pump. A stock Integra Type R oil pump was used for its additional flow capacity.
Looking at the all-important cylinder head, we find more of AEBS' engineering innovation. The combustion chambers are welded and reconfigured so they are in a cloverleaf pattern instead of a pentroof. This was done to increase quench and to create turbulence in the combustion chamber for a more homogeneous, stabilized burn. By taking away areas for end gas to linger, the engine's propensity to detonate is reduced, as end gas areas at the periphery of the combustion chamber are where detonation usually starts. The high turbulence also improves combustion efficiency.
Lee checked on a flow bench that the welded areas of the chamber did not cause valve shrouding by interfering with the flow around the valves. He also hand massaged the piston domes to clear the piston's quench areas. The pistons, exhaust ports and valve faces are coated with Polymer Dynamics thermal barrier coating to prevent the loss of heat from the combustion chamber.