Once the crankshaft is straight...
Once the crankshaft is straight or straightened, a series of steps take place in preparing the crankshafts. The unit is placed on the lathe, the centers are re-cut while pre-grinding the journal 40 thousandths in order to remove any factory heat treatment off the crank. The crank is then taken up front where the counter weights are deburred and once again checked for straightness. If the job requires both rods and main journals to be grinded, the crank will be placed in an oven where it will bake overnight in a process to relieve stress.
Not your typical run of the...
Not your typical run of the mill kitchen oven, this crankshaft-baking tool runs for a three-hour stand. With the metal still smoldering at 975 degrees Fahrenheit at the time of completion, the crankshaft is left in the oven to cool overnight. "If you suddenly decide on pulling them out of the box, the oxygen will hit that metal and oxidize, forming a scaly residue. We leave them in the oven overnight for the temp to come down. By the time we pull it out of the box, the metal temperature will still be in the 250-degree range," explains Castillo.
If the crankshaft is a custom...
If the crankshaft is a custom stroker unit that requires re-welding of the main or rod journals, the piece is put on the crankshaft welder where Castillo carefully welds up the journal then sends the unit back to the v-blocks in order to straighten the crank once again, due to the likelihood of being bent from the welding process. Once restraightened, the crankshaft it is ready to be rough ground and placed in the oven to be stress relieved. After the cool down process the crankshaft is put back in the grinder and taken down to 20 thousandths oversized.
Once the custom stroker crank...
Once the custom stroker crank has been stress relieved, Castillo's cleans out the oil holes once they are protected with carbon plugs during the welding process. His staff deburr and clean up any excess welds that might have formed on the top of the journals. Once the process has been completed the crank is hand carried to the finish grinder. With the crankshaft completing its process in the finish grinder, Castillo takes the unit and grinds the rods, mains, and chamfers the oil holes. Nearing the final stages of the crank, the journals are polished using a hand held polishing machine.
Recently serviced by Castillo,...
Recently serviced by Castillo, this factory 86 mm RSX Type-S crankshaft was stroked to 88 mm and has undergone a series of modifications including knife edging, opening of the rod journals, and ion treatment. Ron Acevedo, owner of IPS, asserts that for this engine setup along with and this crankshaft will be stroked to a new 2240cc displacement.
Depicted on this image are...
Depicted on this image are two rod journals for the K24 from its initial weld process to a rough-finished journal (post weld).
We asked Joe for the secret to his success. He smiled a big grin and said, "Do it right the first time so you don't have to come back to fix your screw-up. The biggest thing in my life is there's a procedure of doing things. You follow that basic procedure and fundamental in machining and I don't think you'll ever have a problem. You'll have a problem when you start taking shortcuts and deviating from your goals in order to get the job done faster. It will catch you in the end and cause problems, turning things into a big mess. Ultimately it's the customers who dictate your reputation. But that's how your quality of work stands up to your competitors. Any crankshaft we service for any customer gets the same treatment. For twenty years, all the crankshafts have been ground the same and treated the same whether it's a top fuel dragster guy, Honda guy or an individual looking to repair his crank on his minivan. The grinds are the same, the procedures are the same. We don't take any shortcuts. It doesn't matter who sends us work. We don't give any preferential treatment. And that's the way we've always done business. Once that crankshaft comes through that door it receives a work order and it gets done."
Here's a close-up of the tear-dropped...
Here's a close-up of the tear-dropped and chamfered oil galley performed on the crank. Chamfering is a process often used to relieve the sharp edges on the oil galleys and thus allows the oil hole to flow at an improved rate. This process is also used to reduce the chance of scoring or damaging the bearings during dry startup or when encountering high rpm. While this crankshaft is still in its processed stage, IPS has requested Castillo to modify the rod journals by widening them to 0.948" to accept 5.572" Cunningham Ti rods that have the F20/22C/H-series big end width (0.938").
Once the crankshaft is complete,...
Once the crankshaft is complete, they will either ammonia gas or ion treat it. Ion gas treatment will bring the metal's Rockwell (surface hardness) to approximately 55, while ammonia gas ranges from 42 to 44. With only a thirty-dollar difference in cost, it's more logical to choose the ion treatment as it's a cleaner process that promotes less warpage, depending on whether the metal has any stress in it. Additionally, ion gas treatment has less growth at a tenth of a millimeter or two, while ammonia gas treatment has two or three tenths. After it comes back from the treatment facility, Castillo pre-polishes the whole crank because of the chalky residue from the treatment forms. The unit is placed back onto the v-block for straightening; cleaned; rinsed off; and, after being coated in oil, is ready to be shipped off or picked up by the customer.
Weight measurements were taken...
Weight measurements were taken on a factory K20A2 crankshaft which came in at 38 pounds. The modified crank weighed in at 34.5 pounds prior to opening up the rod journal width and final balancing which obviously contributes to further lightening of the crankshaft. Typical turnaround time for a K24 crankshaft undergoing knifed edging and the full treatment will usually take about three weeks. If it's a welded stroker, Castillo says expect to wait six weeks due to the welding process, roughing, extra machining and grinding that needs to be performed. If the crank is in need of a simple knife edged process, the wait time is a one week turnaround that also includes balancing.