Crate engine package are nothing new to the industry however have been becoming more and more popular over the last few years. Although many factors of the past reputation of going with a crate package include conveyance, affordability, and or reliability many prefer to go this route rather then assembling an engine themselves. As far as performance, many true gear heads scoff at the term “crate engine” referring to them lacking real horse-power or thinking of them as the old “target” replacement engines that replaced worn out work truck engines.
Through modern technology both worlds have met, as the conveyance, affordability, and reliability of a crate engine package has met the standards of the “Bench Racing PHD’s”, in the form of Blue Print engines 420 horse 383cid small block Chevy package.
Based on the poplar “Stroker” engine the 383-stroker combination was first developed by using a 350 block and a 400 crank. A 350 engine has a standard bore of 4 inches while a 400 crank had a stoke length of 3.75. The bore sizes of a 350 block are machined to increase the diameter of the bore to 4.03 inches. However, using a 400 crank means larger main bearing journals on the crank, so the crank needs to be machined to fit the smaller 350 block’s dimension. So to achieve the 383 displacement, one would use a bore of 4.03 inches and a stroke of 3.75 to yield 382.67 cubic inches, round that number up, and you get 383 cubic inches.
After assembly, every Blue Print engine is mounted to an engine Dynometer and ran to ensure that each one lives up to the quality standards set by their engineers. Once its past the test, they’re loaded onto pallets and crated to be shipped to the customer.[/caption]
The stroker engine is of course one of the most talked about engine sizes since they first burst on the scene back in the 1970’s, and were most commonly referred to as “the square motor” as they were know to produce “one horse-power per cubic inch.” As time went by though, this great feat of mechanical wonder wasn’t enough for the gear heads and the supply of donor components became harder and harder to find mainly the 400 crankshafts as GM themselves produced low numbers of 400 inch engines. So over the last few years, efforts have been made by a few manufactures to produce aftermarket parts to fulfill the desire to fit more power in the same package size.
Once we got the crate opened, we wasted no time getting the engine on a stand to assemble the accessories. Not included with the engine package from Blue Print is a balancer from a 400 Chevy, a flex plate, and a starter. A quick trip on Summit racing’s web site made it easy find the parts that we needed and they were shipped right to our door.
The great news is the fact that aftermarket engineers are usually gear heads themselves as is the case over at Blue Print engines, where they produce many different engine packages from the stock replacement 350 work truck engine, all the way to a 572 inch Big Block Chevy that tires fear. While developing their stroker package, the “square motor” was an old idea that left a lot of room for improvement, so they looked into making more horse power and more torque while still offering the reliability, while making it affordable.
When installing the balancer, be sure to wipe some white grease inside and around the balancers neck to make sure that there won’t be any damage to the front cover seal. A hammer is not the right tool to install a balancer. By using a balancer tool we made sure that the seal, and the balancer didn’t get damaged during the install.
Starting with a 4 bolt main cap, 1 piece rear seal block, they are squared and parallel decked. Then the mains are align honed, while the cylinders are honed using computer controlled equipment or “CNC’ed” to within .0002 straightness and roundness. They are also sonic tested for thickness to ensure failure in the wall thickness or to prevent uneven cooling.
While we still had the engine on the stand, we installed Summit Racings’ awesome looking accessory drive system for the Small Block Chevy. The high polished finish looks great, and the easy to adjust serpentine belt makes it simple to adjust the one and only belt, while creating less drag on the engine that means more horse-power![/caption]
Since the engines camshaft is a “Flat tappet” design, we wanted to make certain that proper “break in” procedures were followed. Royal Purple manufactures a line of break in oil that includes special additives that offer insurance to “marry” the camshaft to the lifters. Pouring a quart into the “valley” prior to installing the intake manifold is a good idea, as well as filling the oil filter to avoid any “dry” starts.
The rotating assembly consists of a new cast steel crankshaft, flat top pistons (compression rated at 10 to 1) installed with Hastings Moly rings. Heavy duty “Chevy rods” with 150,000 psi bolts round out the lower rotating parts where they are balanced prior to assembly where a Melling high volume oil pump is installed, giving added insurance to lubricating the flat tappet camshaft. The cam card calls out the specs of 480 Intake / .486 Exhaust & 229 Intake / 230 Exhaust duration @ .050, which is accompanied by a set of long slot, stamped steel rocker arms, plus hardened push rods work in concert through the use of a double roller timing chain.
A bead of sealant was applied to the top of the block on the front and back of where the intake manifold sets into. Next, set your intake gaskets in place. Then the intake manifold was aligned into place.
Topping off the horsepower recipe is Blue Print own version of the small block Chevy cylinder heads. They chose to go the aluminum route and feature many key ingredients for power. The 2.02 swirl polished intake valves partner with 1.60 exhaust valves. Hardened retainers, and 1.25 diameter hardened springs ensure long service as the overall capacity measures 195cc’s.
The final score reads 420 horse power at 5700 rpm with 450 foot pounds of torque at 4400 rpm’s. It calls out for 34 total degrees of timing so 91 octane fuel is highly recommend. Not to leave out two key features of this set up that really can satisfy either the newbie or the bench top master is the fact that all of Blue Print engines are pre dyno’ed and are shipped with the results, while the engine itself carries a 30 month, 50,000 mile warranty.
The torque converter was loaded into the Transmission and aligned with the pump, before the Trans was “mated” to the engine block. Then both of the items were settled in place between the frame rails and set on their mounts.
We recently got our hands on one, and want to walk you through the steps of the installation. Many think that it’s an easy R&R (remove and replace) but there are a few key items that complement the ease of fitment and performance level that this engine offers, so read on as we fire up this stroker in a square-body Chevy.
Moving on to the exhaust, Hedman Headers has just introduced these new “mid” length headers that are wonderful for building torque which stroker engines just love. Shown here with their “High Heat Coating” these won’t chip peal or flake off during use, and insulate the tubing keeping most of the heat in the tube and not in the engine bay.
Blue Print Engines
Text by Marcel Venable
Photos Courtesy of PPC Customs