Remanufactured Cylinder Heads

Cylinder Head Machine Shop The Capital Reman Exchange cylinder head department is equipped to machine all manufacturers of diesel and natural gas remanufactured cylinder heads. Our capacity includes small rebuilt cylinder heads up to CAT 3600 series heads which can weigh upwards of 500 lbs with a seat diameter of over 4 inches. During our remanufacturing process of rebuilt cylinder heads we disassemble the cylinder head, perform a magnetic particle inspection and pressure test using our state of the art Newclear tester checking the casting to look for leaks.

We then offer a wide variety of repairs that include: injector tube replacement, valve seat and valve guide replacement. We repair damaged bridge pin bores along with resurfacing the decks and the exhaust manifold surface. We can repair cracks in the casting and we can repair damaged cam bushing bores along with repairing damaged exhaust manifold stud holes. Once all repairs have been performed we then assemble the remanufactured cylinder head and check valve heights and vacuum check the seal between the valve face and the valve seat. The complete 13 step process for remanufactured cylinder heads is below.

General Machining Services

Capital Reman Exchange is extremely well equipped to service various industrial components. Whether it be tool making, surfacing, boring, crack detecting, polishing, grinding, or roll grinding, we are set up to handle the task. We provide consultative machine shop solutions and understand the demands of the industry and how urgency and service are paramount.

Our machining centers, lathes, welding and heat treating oven allow us to repair components that many other machine shops would not attempt to salvage. Our machinists’ knowledge and experience ensures quality and reliability for all of our remanufactured cylinder heads.

13 Step Cylinder Head Remanufacturing Process:

We take a meticulous approach to remanufacturing cylinder heads. Our process for rebuilt cylinder heads has been pioneered and refined over 40 years. We have developed a 13 step process for remanufactured cylinder heads which ensures the highest quality rebuilt cylinder heads are ready for our customer’s needs.

Step 1: Tear Down Process for Remanufactured Cylinder Heads

The first step for remanufactured cylinder heads is the initial tear down process. Our technicians remove all of the valves, guides, seats, springs and injector cups. We then visually inspect each part as well as run quality control and structural tests to see if any of these parts can be re-used. For example with our valves, we inspect the entire valve to see if there are any erosion pits. We later regrind to the proper angle and then regrind the stems.

Step 2: Initial Cleaning and Magnafluxing

The second step in cylinder head remanufacturing is the initial cleaning and magnafluxing. Cleaning the rebuilt cylinder heads is a very important step during the remanufactured cylinder head process. Often times used cylinder heads arrive at our facility with dirty, grime, oil and lubricants embedded on the cast iron. In order to properly indentify cracks and evaluate structural integrity the remanufactured cylinder head must be completely clean. At this stage we also measure the surface thickness based upon OEM specifications. For example the OEM specs for the Caterpillar D334 remanufactured cylinder heads are as follows: New Height is 3.400” and the Minimum Height is 3.3940”. This gives us a tolerance of where we need to grind later on in the remanufactured cylinder head process. If the height of the rebuilt heads is below the minimum height when we receive it, we replace the entire cylinder head as it is deemed to be unfit for cylinder head remanufacturing. We also check the warpage, compression and water port seal area.

Step 3: Deep Cleaning All Rebuilt Cylinder Heads

Diesel Cylinder Heads The third step in the cylinder head remanufacturing process is the deep clean. Once we remove the initial dirt and grime from our rebuilt cylinder heads we employ one of three deep cleaning processes. We can place the rebuilt cylinder head in a hot tank, a steam clean tank or a wash tank. The hot steam tank heats up the remanufactured cylinder heads to over 200 degrees Fahrenheit and literally burns off any component that is not part of the rebuilt cylinder head. Once the deep cleaning is complete we tap all of the bolt holes and repair as needed. We strongly believe in thoroughly cleaning our remanufactured cylinder heads because even a miniscule amount of dirt can hamper the grinding or crack repairing process.

Step 4: Pressure Testing the Remanufactured Cylinder Heads

The fourth step for our remanufactured cylinder heads is pressure testing the unit for further structural integrity. We place the rebuilt cylinder heads in the Newclear Pressure Regulator Machine for 20 minutes. The Newclear Pressure Regulator Machine will subject the remanufactured cylinder head to 60psi at 200 degrees Fahrenheit. What this does is it pulls water through any cracks that may be present. Our quality control manager will check the guide thread in and around the seats and in-between the valves. After the rebuilt cylinder head is removed from the Newclear Pressure Regulator Machine we inspect the remanufactured cylinder head for additional warpage and shrinkage which would be later removed during grinding.

Step 5: Researching Remanufactured Cylinder Head Parts

The fifth step to manufacturing rebuilt cylinder heads is to determine what parts need to be replaced. We then verify the quantity and part numbers. We either use our own internal OEM certified remanufactured parts or replace with brand new parts from any of our part suppliers if requested by the customer. Typically, we replace worn seats, guides and valves for all of our remanufactured cylinder heads.

Step 6: Inventory Management Process for Rebuilt Cylinder Heads

The sixth step in the cylinder head rebuild process is to fill out a materials requisition form for our parts department. Our inventory management system directs our cylinder head rebuild management team to make the best decisions regarding what parts to use for our remanufactured cylinder head process.

Step 7: Surfacing the Deck of the Remanufactured Cylinder Heads

The seventh step regarding cylinder head remanufacturing is to surface the remanufactured cylinder head as needed. We use the Berco Grinding and Milling Machine on all of our remanufactured cylinder heads. The Berco Grinder uses a carbonate cutter which uses the flat cutting technique. We mill the top completely off our rebuilt cylinder heads which is referred to as “surfacing the deck”. We do both metal stitching and hot welding techniques to repair cracks in the rebuild heads. Metal Stitching involves boring a series of holes completely removing the crack, threading the holes with pins/plugs and then resurfacing the raised surface on the rebuilt cylinder heads.

Hot welding involves placing the entire remanufactured cylinder head in our hot oven, heating up the cast iron to 1100 degrees Fahrenheit and then doing an arc weld while the entire head is hot. After arc welding we place all of our remanufactured cylinder heads in a sand pit for 24-48 hours so that metal contraction occurs at the same rate in an insulated environment. Remanufactured cylinder heads rebuilt using the hot oven technique must be cooled in the insulated environment so the various metals in the cast hold the weld.

Step 8: Installation of Injector Tubes Back Into the Remanufactured Cylinder Heads

The eighth step in the cylinder head remanufacturing process is to install the injector tubes. We typically replace our injector tubes during the cylinder head remanufacturing process. We use either brass, copper or stainless steel injector tubes. We use a punching machine to seat injector tubes correctly into the injector holes. The injector tubes purpose is to seal out coolant passages as well as seal the combustion chamber. Some rebuilt cylinder heads have O-Rings seated around the injector tube, others do not. The type of injector tube we use depends on the cylinder head composite metal and what the OEM specifications call for. We can use OEM or Aftermarket injector tubes depending on customer preference.

Step 9: Pressure Test the Rebuilt Cylinder Heads a Second Time

The ninth step in the cylinder head remanufacturing process is to pressure test the rebuilt cylinder heads for a second time using the Newclear Pressure Regulator Machine. It is important to pressure test all completed remanufactured cylinder heads a second time to make sure the hot weld or cold weld procedure has maintained its integrity. We check for any leakage using both visual inspections through a glass magnifying screen as well as measurements of water underneath the cylinder head. The transparent pressure plate provides 360° rotation capability which allows for an adjustable center of gravity for the rebuilt cylinder heads. The system also contains an in-line heater system for both cold hydraulic and hot hydraulic testing on remanufactured cylinder heads.

Step 10: Prepare the Remanufactured Cylinder Heads for Assembly

The tenth step for remanufactured cylinder heads is to prepare the head for assembly. Once our rebuilt cylinder heads have been surfaced and pressure tested it is then time to reassemble the cylinder head. We wire wheel all ports and surfaces. We then grind lap valves & seats. After that is completed we check valve recession. Checking for valve recession is critical. The valves need to be flush as the piston strikes up +.001” or -.001”. Our quality control department inspects and if necessary immediately fixes valve recession issues on all of our rebuilt cylinder heads.

Step 11: Final Wash of All Finished Rebuilt Cylinder Heads

The eleventh step during the remanufactured cylinder head process is to steam clean or use a wash tank. The steam clean process takes our remanufactured cylinder heads and pre-washes it in a steam bath. The steam bath removes additional grime and solvents that may have accumulated during the grinding process. After our remanufactured cylinder heads are cleaned we stamp the serial number on the rebuilt cylinder heads as well as the estimate number and the employee’s initials.

Step 12: Paint and Package All Remanufactured Cylinder Heads

The twelfth step for rebuilt cylinder heads is to assemble the entire package. We reassemble the seat keepers, then paint or Cast Blast and package. All of our remanufactured cylinder heads are painted to OEM specifications using industrial paint. The paint we use helps prevent rust and is durable enough to withstand environmental changes.

Step 13: Rust Prevention Measures and Preperation of the Remanufactured Cylinder Heads for Shipping

The thirteenth and final step for rebuilt cylinder heads is to spray with a rust preventative oil and package again. We supply custom boxes per each remanufactured cylinder head then we wrap in plastic and place the entire remanufactured cylinder head in a wooden box for shipping.

1 Year Warranty Program

REMANUFACTURED CAMSHAFTS, LIFTERS/FOLLOWERS, CONNECTING RODS, CRANKSHAFTS, CYLINDER HEADS, CYLINDER BLOCKS, ENGINES
Capital Reman Exchange, LLC warrants its remanufactured products to be free from defects in material or workmanship and provides a warranty that includes 12 months unlimited miles of which the first 6 months will include parts and labor. The second 6 months will include replacement parts or components either new or remanufactured to OEM specifications. Read about our entire warranty process here.