Send In My Block
Starting at $500
We are dedicated to excellent customer service for our Mail Order Block Machining Service. Our streamline system has your engine block machined to AERA and OEM spec, and cylinder bores matched to your choice of pistons. We are standing by to get started on your project today!
Lower 48 Only - No Exchanges - No Core Charges - We machine your supplied block. (Recommended)
1. Check Your Block First.
Before calling in to place your order, first split and empty your case halves of parts. This way you have time to check your block for obvious damage, and ensure that your case halves are worth putting time and money into. Next, decide on which piston design your project requires, and then contact us via phone to get your price estimate. We will be happy to help design your build over the phone, and email you the final detailed estimate.
2. Decide Your Pistons
There are around 3 options for types of pistons. Factory style pistons, Performance "Hypereutectic" Aluminum Pistons, and Forged Aluminum Pistons. You will hear a lot about Forged Pistons having better for performance, but they can wear much faster (40K Miles) than a harder factory style or Hypereutectic. Your high HP goals may require this type of maintenance, as these soft but tough pistons SWELL with heat. We MUST machine these cylinders with extra "Cold Clearance" to make up for this heat swell. This means we calculate clearance to the between the piston and cylinder as required of the piston manufacture. As the engine warms up, the piston will grow (</>.0025") into proper P/W spec (.0012"). Cast Aluminum and Hypereutectic Pistons (Factory) are highly recommended if you plan on putting miles on the engine. These pistons do not grow and swell like forged aluminum, and have less of a tolerance to extreme heat. Our cylinders are machined to AERA Spec, which is very very tight tolerance. (.0004"-.0012" +/- .0004"). This is TOTAL piston to wall clearance, meaning this is divided by 2, and not multiplied by two when doing piston diameter to bore math. In short, you can add some boost and extra power to Topline pistons, but if you want a figurative number, switch to forged pistons around 375 WHP.
3. Contact Us Via Phone to Place Your Order
Now that you have researched pistons, and you have checked your block out as good; bolt your case halves back together securely for shipping. Give us a call, and we will start building the estimate. We will need your basic information to build the quote like shipping info and email. Our sales staff will start building your parts and service estimate and answer any remaining questions you may have. We can ship you a core box for a $25 rental fee plus freight (around $40) if you do not trust your core engine block to your own shipping methods. During the phone conversation, we will create your service quote via SubaruMachine.com for service, core, and shipping. On a separate invoice you will have listed all of your parts. You will receive the estimates via email, which you can print and send in with your core. If you are packaging the block yourself, please use hard packaging padding like cardboard, and not packing peanuts (they will crush) and the block will be destroyed very easy. We photograph the package as it arrives, and unpackaged every block on video for quality control. Make SURE its packaged tight and does not bounce inside the box. If you rent the core crate, it will arrive shortly with paperwork for return shipping.
4. Core Check In, Ultra-Sonic Cleaning, and Pressure Testing
Once your core has arrived, we check in the block and do our initial visual test for shipping damage. We then measure and record the cylinder bores, main bores, deck height, and line bore straightness. We then make the final decision on what piston oversize to use. Our cleaning process begins at the hot tank and the ultrasonic cleaner; with simple detergents. We then pressure test the block with our custom pressure testing fixture plates. This pressurizes the block to low PSI for a physical pressure test in the coolant jackets to identify a cracked cylinder. We also magniflux the actual cylinders with magnetic powder to check for stress cracks on the cylinder. Once your block passes these tests, it is now deemed good for machining.
5. Vapor Blasting and Fresh Water Rinse
The first step in the actual machining process is surface prep of the cast aluminum block. We first tape off vital main journals surfaces. We then blast away plug sealant, gasket material, white crusty calcium buildup, and smooth out rough edges. When finished, we flush the blocks with water, to rid the block of all blast media. Lastly, we dry and blow out all threads, ports, and gallies with compressed air to ensure no media is leftover from surface prep. We do this process in house, and creates a amazing finish to the aluminum case.
6. Custom Pistons Arrival
Your custom pistons have now been on order, and generally arrive within a week to 2 weeks of checkout. We now measure these pistons and start filling in paperwork. We measure the OD the of the pistons, and set your piston to wall clearance as recommended by piston manufacture, and set our bore gauges for the honing process.
7. Squaring Up the Block to the Crankshaft Centerline
Before we work the cylinders, we send the case over our surfacing machine. We square up the deck surfaces parallel to centerline of the crankshaft, and not the parting case halves; with a special fixture that holds the block on the main bore. We match how much we cut from each side, so the case cubic liter displacement matches on both banks. We use a 3/8" round CBN insert, on balanced fly cutter, which results in a low RA finish. This way you have the smoothest surface possible for MLS head gaskets.
8. Boring and Torque Plate Honing of Cylinders
Now that we have a squared block, we can start machining cylinder bores. We start the process in our Van Norm boring machine. This is where we bore out 85%-90% of the actual cylinder, leaving around .003" of material for the honing process. We then move the block to our Kwik Way Power Hone, where we install the torque plate, and proceed to our 3 step precision honing process. If .25mm or less material is taken from the cylinders, they are simply toque plate honed; and we skip the boring process all together, because there is not enough material to bore. We start honing the cylinders with a roughing stone, and work our way to the final finish stones. Our cylinders are concentric within .0001", along with cylinder straightness top to bottom, is within .0001".
9. Case Deburring and Oil Galley Porting
The Subaru blocks have oiling gallies and coolant passages that can be improved with minor hand porting. During this process we port the casting in a few spots for oil windage drainage. and coolant flow. We also hand chamfer the case halves sharp edges around the decks and bell housing.
10. Engraving Data and Final Wash
After we have finished all the machine work listed above, we hand engrave the data onto the case, and give it a hot soapy water wash. We remove all metal shavings, honing residue, hand prints, pipe cleaner all galleys, and air gun dry. Following this process, we coat the cylinders with light fogging oil to prevent flash rust during shipping. This oil must be washed off before assembly.
11. Spec Sheets and Quality Control
No project is complete without proper quality control. Final ID Bore Spec, OD Piston Diameter, and Piston to Wall Clearance are among the many measurements documented at Q/C. All of the information pertaining to the project is documented and inserted to project folder which is included with every SubaruMachine.com project. In short, we document that the block is pressure tested, hot tanked, vapor blasted, bored, torque plated, honed, decks are diamond surfaced, block is individually numbered, and to AERA / OEM / Manufacturer specifications.
12. Packaging and Shipping
The block is now placed inside our double shipping box, lined with 2" of styrofoam. This is to comply with Fed Ex shipping insurance policy, that all packages must have 2" of padding between the product package and the shipping package. Our product package contains the already bagged case, which is inserted in another poly bag and expanding foamed into place. The case is now securely packaged and will not bounce around inside the box while in shipping. Pistons and documentation is inside the shipping box securely in place. Our shipping, packaging, and machine process are designed to eliminate all headaches and risk involved in ordering a specialty item online, and we strive for zippy turn around and excellent customer service!
13. Arrival and Unpacking
We saved the best for last! When you open the box and check out the goods. We package all of our paperwork away from box opening so you will not cut the paperwork in half. The block will have warranty tags attached about washing oil galleys and pre assembly washing. DO NOT DESTROY or DISCARD PACKAGING. You may need this if you find the block was somehow damaged in shipping or needs returned for any reason. Read and follow all unpacking and block prep instructions before you begin your build; as gapping rings or inscribing on parts can void returns, even if there isn't an issue with the block itself. Our blocks are guaranteed to be in spec as advertised, and you can read more about all of our warranty information online and is included within the paperwork included with the shipment. You are now ready to build your Subaru engine, and we hope you enjoy using our services for your project!
Service Turn Around Time
In conclusion, the turn around service times only vary slightly. All blocks are completed within 2-3 days in the shop once we have the pistons here and the block properly tested and cleaned. We stock Topline and Manley Performance pistons a variety of sizes for many of the Subaru blocks, to help streamline our efficiency.
Mail Order Subaru Machining and Conversions
WE ARE OPEN AND TAKING ORDERS - Call Today!
4 Week Turnaround Service No Additional Charge
2 Week Express Turnaround Service Additional $100 Charge
VIP Core Shipping Box Service
If you do not want to package up your core, we have this special VIP Indestructible shipping crate. We can ship this container to you empty, and you can ship it back with your core securely inside. We require a deposit for the container, which can be refunded towards your project when returned with your core.
