In this thread we will show you what goes into EVERY shortblock build that we do. Every engine is completely balanced and blueprinted, and here we will show you how. This is intended to be a technical thread that shows what goes into a properly built engine shortblock.
------We first start with the engine block, either our customer supplied block, a good core or a brand new one. The first step is to strip it and placed into our soak tank to thoroughly clean it. Used blocks are Magnafluxed inspected to check for cracks and visually inspected for other damage or imperfections. The cylinder bores are measured and also sonic tested to make sure there are no thin spots in the casting. Once the block has passed these tests, a brand new set of ARP main studs are installed and the main girdle is torqued in place to check the align bore. This is to ensure all the crank bore is in the proper alignment with one another from front to rear. ***We've inspected brand new engine blocks and found them to be out of spec and not usable! Once we know that the block is in good shape we can then proceed to machining it.
Now we check over the brand new crankshaft. Every crank is thoroughly washed, Magnaflux inspected, polished, mic'd and checked to make sure that it is straight and within the proper spec. We do not use or sell any "Crank Kits" or under sized cranks. All of our strokers are assembled with brand new cranks and are fully inspected forged steel cranks. Once the crank passes all inspections, it is balanced then final washed for assembly.
First, we modify the oil galley in the front of the block, it is deburred and micro-polished for increased oil flow. This also reduces the level of restriction of the oil caused by the casting flash in the OEM blocks.
The next step in machining the engine block is to square the deck surface. Once this step is complete the engine block is set on a machinist bar that is perfectly level ( >.001" ), it is also secured in place to prevent any shifting or movement. Then a cutter head slowly moves across the deck surface area, thus removing material so that the deck is perfectly square and with the proper surface finish for your MLS head gasket. This is extremely important because the next step, Boring, locates the cylinders off of this surface. If the deck surface area is not square and parallel then the cylinders will also be crooked.
Now we can bore the cylinder walls of block. To do this the block is set on a stand and rolled under the under the machine fixture where it is lifted into position. The "Boring Machine" that houses the cutter head is now perfectly square with the deck. This is why it's critical that the deck surface be squared and parallel with the crank- otherwise the cylinder bores will not be in perfect alignment with the crank. With the block in place, the cutter head will move down through the individual cylinders removing material to the proper spec.
Once the cylinder walls of the block are bored, the cylinder walls are then 4 step Torque Plate honed using ARP head studs. This is where the final wall finish is applied to the cylinders based on the type of piston, rings and also the engines intended application (high boost, race only, N20, etc.). We install the main girdle and ARP main studs, all is then torqued to the proper spec before it is placed into the Rottler Power hone machine. We then install a precision made Torque Plate and the ARP head studs. By using a torque plate this simulates the cylinder head, the cylinder walls will be perfectly round when the head is installed on the block for use. If you were to hone the engine block without a Torque plate, the cylinder walls will distort when the head is bolted down, leaving the cylinder out of round. This will cause a loss of power, poor ring life and over all performance loss. A proprietary series of precision hone-stones are used to achieve the proper cylinder size and wall finish. A steady stream of clean honing oil is delivered while honing the cylinder walls, this is to lubricate and to keep the cylinder walls flushed of materials that has been removed.
Now that the engine block is fully machined, it is once again washed and inspected to make sure that it is 100% free of any contaminants. Then the piston oilers are installed, a brand new galley plug and freeze plugs are also installed, the block it then put on an engine stand to be mocked up. We start by checking the bearing clearances of the connecting rods. The rods are torqued in a special Rod vise to avoid damage and the housing bore is measured with a dial bore gauge to make sure that it is round and within spec. The bearings are then installed and clearances are measured to .0001" and if they are not in spec they are corrected. The piston pin bores are also measured in both the piston and connecting rod with the same dial bore gauge to .0001". Using a Sunnen pinfitting machine we then apply the proper surface finish to both the connecting rods and piston pin bores. The side clearance of the rods is also checked and corrected, if necessary. This is a measure of the clearance between the side of the rod and it's journal. Once the connecting rods are checked, we then proceed to check the main bearing clearances. The main bearings are installed and the main girdle is torqued in place. We also use the dial bore gauge here as well, to measure the inside diameter of the bearings with precise accuracy.
Once all bearing clearances are checked and verified for accuracy, we then disassemble everything for the final cleaning of the rotating assembly. All of the parts are final washed and prepped for the assembly. All components are laid out in the exact order inside of our dedicated assembly room. This is a spotless room where every engine is assembled with no chance of contamination. Nothing enters this room without a trip through one of our washers, including us! The main bearings and the crankshaft are installed and the endplay is measured and recorded on our engine spec sheet per customer. Pistons and the connecting rods are then final assembled. Each set of the piston rings are file fit to a particular cylinder, and clearanced per customer application-intended use, the rings are then installed on the pistons, pistons and rods are then installed using proper lube, the connecting rods are then installed into the engine block using stretch, not torque as this is the most accurate way to tighten these bolts.
We also modify the balance shafts for use in all of our strokers. The shafts are modified for proper clearance.
Now you have a precision machined - Blueprinted shortblock ready for use. If you have any questions, feel free to ask.
