World Products (a part of the PBM-Erson family) first began making a name for themselves exactly 30 years ago with the introduction of their modified small-block Chevy cylinder head design. Shortly after their SBC heads became a hit with the masses, World moved over to improving the big-block head architecture; and before they knew it their cylinder head designs were being used in everything from modest street builds to propelling some of the biggest names in professional-level racing.
Building on the success of their cylinder heads, the next evolution for World Products was to take the shortcoming of the small-block Chevy architecture, and develop improvements that would benefit horsepower addicts as a whole. For our small-block Chevy platform owners out there – whether you’re putting together a modest naturally aspirated street build or an all-out boosted LS drag monster – World Products’ Motown series of small-blocks has a solution to suit your needs!
For example, If you’re a classic small-block fan looking to increase stroke to 4.000-inches without reducing valvetrain rigidity or violently introducing your connecting rods to your camshaft, a Motown II version is available with the cam height raised by .134-inch, allowing for big-block cam journals to be utilized. Or if you’re looking for a best of both worlds approach, World’s Motown II LS combines the benefits of the classic small-block Chevy platform and the more modern architecture of the infamous LS. The Motown II LS short-blocks take advantage of the vast aftermarket support and reliability of the SBC bottom end design, and combines it with the modernized and heavier-breathing LS top end.
Through continuous development by relying on feedback from the best engine builders from around the world and trackside research, World Products’ Motown II line is capable of handling more abuse and more power than ever before.
Improvements In Lubrication
The lubrication system of the cast iron Motown II has been completely redesigned from the ground up for greater performance and reliability. Starting with the main bearings, World Products’ engineers realized the abuse that the main bearings are required to take during operation – especially as horsepower and cylinder pressure increases – so the oiling system was rerouted to give priority to the main bearings before any other component. Following the main bearings, the camshaft, lifters and finally the distributor receive oil.
World says this design is advantageous, especially for horsepower junkies, because “if the distributor is improperly fitted or if the O-rings are damaged or missing, an oil leak is inevitable. This leak would now happen only after all the other critical comments have been lubricated, instead of before as in the OE design.”
As any experienced gearhead will tell you, a more aggressive camshaft grind will generally also require stiffer valve springs for safe operation. And as horsepower goals have continued to climb and spring pressures have kept increasing, an issue was discovered with the factory six o’clock oiling hole position, where a camshaft being forced down by a higher spring pressure would essentially seal off these oil passages causing oil starvation related damage. So the World engineers relocated these oiling holes to the five o’clock position to guarantee improved journal lubrication.
In an effort to provide more even distribution of oil to the lifter valley and allow for quicker access during servicing, the oil restrictors have been relocated to the center of the lifter valley. No longer having to remove the transmission and converter or clutch is a real godsend for small-block owners.
Materials And Design
To create a bulletproof casing, the Motown II series relies on the rigidity and durability of a high density cast iron alloy to hold itself together when exposed to levels of abuse that would otherwise make an aluminum or lower quality cast-iron block crack and crumble from the torture. The World team was able to further improve the durability of the SBC architecture by deconstructing the factory small-block design and finding areas where additional material could be added to the casting, creating a stout foundation for any build combination.
The Motown II series also features an extra thick deck, set at a minimum of .600-inch for a strong head gasket seal, at a standard SBC deck height of 9.025 and 9.240-inches for the LS. While the bore can be ordered at either 3.995 or 4.120-inches, World sets the maximum allowed bore at 4.185 for the SBC and 4.200-inches for the LS. And for the forced induction and power adder crowd, rest easy knowing that the cylinder walls have a comfortable .250-inch thickness with a 4.125-inch bore! In addition to expanding the surface area of the water jackets to improve the cooling efficiency of the cast iron block; to eliminate a potential source for coolant leaks, World’s team uses blind-drilled cylinder head bolt/stud holes that do not extend into the water jackets.
For the serious racer looking to shave weight anywhere and everywhere possible, the Motown Pro Lightweight block retains all of the advantages of the standard Motown II, but is a full 20 lbs lighter than a standard small-block, weighing in at just 178 lbs (just the short-block of course)!
What It All Means
If you’re serious about getting the most out of the small-block Chevy platform without risking catastrophic engine failure from components making contact or a lack of proper material thickness and strength for the amount of power being made, World Products’ Motown series of short-blocks (Motown Pro Lightweight, Motown II, Motown II Raised Cam, and Motown II LS) has an option to meet and exceed your horsepower dreams.
For a look at World Products line of engine blocks and cylinder heads, including both the small-block Chevy and Ford, the LS, and big-block Chevy, be sure to check out the full product catalog on their website!