A non-VTEC engine block has...
A non-VTEC engine block has one of the larger crankcases in the Honda lineup, making ideal for stroking. With the combination of pistons, rods and crank, Crower was able to eliminate modifications of the crankcase.
It was only a matter of time before one of the big boys in the domestic market developed a stroker kit for Honda enthusiasts.
Most would wonder, "Why a stroker kit for the LS and not the 1.8 VTEC DOHC." Crower's marketing director Brian Crower said, "Although VTEC and the Honda badge go hand-in-hand, incorporating our new kit in the LS block is much more cost effective for the consumer. For one, it's much harder to track down a GSR engine than it is an LS due to the popularity of the 1.8 VTEC. Two, the LS block runs a significant amount of space in the crankcase to compensate for the larger stroke." So what does it take to stroke a motor? There are two different ways of increasing displacement. One, you can bore the cylinders out and stuff larger pistons in the cylinders. Or two, change the crankshaft for a model with a longer throw.
Crower offers two different...
Crower offers two different types of cranks with their kit. A factory redesigned crank can be incorporated with the piston rod combo that nets a 95mm stroke. With the billet model, the stroke can be custom tailored to almost any spec. Note that a custom stroke requires modification of the engine block.
Changing the size of the piston creates more room for fuel and air by widening the combustion area. In our case, the non-VTEC engine displaces 1834 with an 81mm (3.189-inch) bore. With the given formula, bore x bore x stroke x .7854 x # of cylinders, let's punch out our engine one full millimeter (.040) making the bore go from 81mm to an 82mm (3.23-inch). The new displacement comes out to 1877 which is 43cc larger than factory. By punching out the engine, the gain of cc's can be achieved but it is limited by how far the already delicate Honda cylinder sleeves can be punched out.
Unlike boring the cylinders, gaining cc's through a bigger stroke can also net an increase in displacement. In the case of the Honda's B18A and B18B engine, this requires a crankshaft with the longer stroke than the factory and a set of specifically-sized connecting rods to go with it. By changing a motor from a stroke of 89mm (3.50-inch) to 95mm (3.74-inch) without effecting the rod ratio, the piston's wrist pin boss has to move higher up into the oil control ring. The Crower kit addresses this by including custom JE pistons. Now if we apply a 95mm stroke rather than an 89mm our new displacement checks in at 1958cc which is 124 cc's more than factory. By going with the stroker route we not only gained more displacement we also gained the option to bore out the engine for even more displacement.
The rods are not like the...
The rods are not like the common Crower 1.8-liter non-VTEC units. In fact, the rods are reinforced on the big-bore end and narrowed on the small-bore end. The I-beam connecting rod is not only much longer and thicker than the factory rod, it is also 40% lighter than the narrow OE model. They utilize a bronze bushed small-bore end to reduce friction between the boss of the pistons and rods.
Crower offers its kit in two different packages. You can either purchase a redesigned Honda crank out of an older-generation Prelude or a brand-spanking new billet steel crank. Both kits come complete with a rod and piston combination.
If the buyer purchases the factory-redesigned model can easily be upgraded to a billet crank later. Considering the cranks are steel rather than cast-iron is a big plus. Regrinding a factory crank is by all means not a bad thing. If anything, this is much more cost effective to the consumer. The only down fall to the regrind Prelude crank is it is limited to a 95mm stroke.
The pistons are JE forged...
The pistons are JE forged units built to Crower stroker specs. One of the major differences to the JE/Crower-spec piston is in the wrist pin boss. To accommodate for the longer rod JE had to move the boss up into the region near the oil ring.
The billet crank kit would be considered, "the mother load of stroker kits." For years now, companies have had billets available for almost any V8 application you can think of. Now, Crower has done the same for the Honda market. The billet crank is ground to perfection from 4340 steel. For the wild and crazy Honda racer, Crower can also produce a more aggressive stroke, within a reasonable tolerances. With the billet model, one also has the option of building a short stroke kit for a high-reving turbo application. One thing you might want to take in consideration, if the stroke is extented the engine block will need modification to clear the rotating assembly. So tell your local machine shop to warm up the mill or have the die grinder ready because notching the block to clear the rods and crank is a must.
The pistons in the kit are made by JE but these particular models are only available through Crower in this kit. Crower will stock a few of the common compression ratios and bore sizes but as far as custom compressions and bores go, they can be tailored to the customer's specification. The pistons come with JE's normal high-quality performance and the units are forged aluminum with the necessary valve relief's for stock or larger-diameter valves. High-quality rings are also provided with the pistons.
The job of designing a rod that will not break under extreme engine speeds and still clear the crankcase is one of the most critical challenges when it comes to stroking the 1.8-liter. Crower has a substantial chunk of R&D time invested in these particular rods. The finished product is an I-beam rod with a reinforced big-bore end. The rods are made of 4340 steel, rod bolts are of H-11 tool steel and the bush on the small-bore end is made of bronze to reduce heat caused by friction. Compared to the stock 1.8-liter rod one can easily see the stroker rod is longer that the stocker. This ensures a better than factory rod ratio as well as a good torque output.
The non-VTEC billet stroker kit is just the beginning. Two different types of kits for different levels of achieving horsepower. The redesigned Prelude crank offers more displacement for less money while the billet model offers an almost unlimited amount of stroke variance. By the time this feature hits the stands, the B16A 1.8-liter stroker kit will be available and Crower is in the process of building billet cranks for most popular Mitsubishis and Toyotas. Stay tuned, as Crower provides different strokes for different folks.