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by Jon Mikelonis

In the world of small block Fords, the choice to go with a high
performance aftermarket connecting rod isn't as much a decision about
performance as it is about economies of scale and common sense. With so many manufacturers offering inexpensive forged I-beam rods for most Ford motors, the days of spending time preparing an OEM rod for your 351W or 5.0L block are all but gone. However, if you are unique enough to cut against the grain and build something different like a 351C, 400, or an FE motor, then taking on some old-fashioned rod work can go a long way towards strengthening the rod beam and reducing reciprocating weight. While not as common in the street performance or drag racing scene, the art of preparing an OEM connecting rod is still alive and well in the circle track arena where local classes prohibit the use of aftermarket rods.

Pictured just after tearing down a Ford 400, here are the subject connecting rods for this article.

For this article, I hooked up with Auggie Steinert of Superior Machine in Sparks, Nevada to prepare, recondition, and balance a set of Ford 400 rods that will be used in an engine build I'll be documenting for FordMuscle throughout 2008. Auggie was considerate enough to show me his methods for processing the rods by meeting up with me at Superior's shop on a couple of Sundays this Fall. Determined to do all that I could on my own, anything that didn't take years of experience and machining skill, I took on myself. Unfortunately, this didn't leave me much but the task of grinding and polishing the rod beams using Superior's equipment. When it came time for the special machine operations, I was there to photograph each step so I could share them with you here. In addition to the rod work, the following pictorial sections cover the balancing of the rod and piston assemblies.

Getting Started
There are a number special machine shop processes that need to be performed to any OEM rod and piston assembly before it's ready for engine pre-assembly. These processes sometimes fall under the label of "Rod Reconditioning" and "Rod Preparation" although the procedures and what's included can vary from shop to shop. For example, one shop's idea of inspecting a rod may be purely visual as another shop may take the time to Magnaflux. Furthermore, one shop may use a torch to install a press-fit wrist pin while another shop may do it the right way using a Sunnen Rod Heater that is purpose-built for the task.

While you do not need to know how to "resize the big end of a connecting rod" or how to operate a "cap grinder", knowledge of the rod reconditioning process helps in your communication with and qualification of the machinist. This can be especially important if you decide to take on some of your own rod preparation like I did here. If you do, you'll be working in tandem with the shop. You'll need to be able to communicate effectively and try your best to comprehend the industry jargon. Since each shop has their ways of doing things, it's best to discuss your intentions with them before you simply have your rods hot-tanked, perform the beam grinding/polishing at home, and unload the rods to the first shop you find in the yellow pages.
With that said, here's how I did it working with Superior Machine. Keep in mind that your local engine builder may have a slightly different approach.

After delivering all eight piston, rod and cap assemblies, the pins and rod bolts were pressed out. The rods and caps were hot tanked.
Using this wide belt sander at Superior's shop, I removed the parting lines along the beam of each rod. Notice that I'm removing the parting line parallel to the beam.

The belt sander makes for some fast results. I was sure not to cut into the rod itself by only removing the raised parting line.
Since most of us do not have a belt sander of this caliber, the same work can be done at home with a die grinder and a carbide cutter.

Following the carbide cutter, I used a cartridge roll along the beam to begin eliminating the cut marks left by the belt sander.
This is the rod after finishing up with the cartridge roll.

In three stages, I used an angle grinder and these 3M abrasive discs to work over the beam.
It's best to control the angle grinder so RPM's are not too high. A common mistake is to get lost shooting for a high reflective polish.

The goal is to remove the cut marks still left after the cartridge roll operation. Once at the polishing stage, I approached the rod bolt shoulder to deburr any sharp edges.
Eight rods, two sides each, and a total of five grinding and polishing operations can make for some time consuming work. No sense paying a machine shop to do this kind of work. We need them for their skills not manual labor.

It's best to take on 2 or 3 rods a day to preserve your patience and quality control. Since I was a guest at Superior's shop, I got them all done in about 6 hours.
Here's a shot of a rod after all five operations were performed. Notice it doesn't glimmer, yet all the cut marks are removed and there's no sign of a parting line.

A shot of four rods completed. Take note that I did not touch the rod balancing pads. To pursue absolute minimum reciprocating weight, some people choose to eliminate as much of the pad as possible at this point while still leaving enough material to balance the rods.

Per Auggie's recommedation and since this was a street application, I left the pads as insurance for when it came time to balance each rod and cap assembly.

(Mangafluxing, Shot Peening, Pressing Rod Bolts)

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In This Article...
FordMuscle takes you through the process of preparing, reconditioning and balancing OEM connecting rods. Working closely with Auggie Steinert of Superior Machine in Sparks, Nevada, we show you what steps your machine shop should be taking to "recon" and balance a rod and piston assembly. FordMuscle also shows you what can be done with your own hands to strengthen OEM rods and save some dough.

The connecting rods and pistons used in this article are destined for FordMuscle's feature engine build-up for 2008. We'll be putting together a Ford 400 with the "newish" Edelbrock Cleveland heads. More on that later!

351M/400 Rod Quick Facts

Engine 1975-up 351M
1972-up 400
Part Number D1AZ-6200A
Center to Center 6.58"
Rod Bolts 3/8"
Code 5M
Material Cast Iron

Probe 351C Forged Pistons
For this project, we started with Probe's off-the-shelf .030 over FPS forged piston for the 351 Cleveland. PN P2379F-030

The FPS (factory performance series) piston by Probe is designed as an upgrade over TRW replacements. They are a press-fit design and are made from VMS-75 High Silicon Aluminum.

The Ford 400 and the 351C use the same bore and compression height to allow for the interchange. To accommodate the 400's .975 pin however, the piston's pin bore was enlarged to .975 from the 351C's bore of .912. Also, to reach a 10:1 CR with the Edelbrock 60cc 351C head, Probe machined a dish into the flat top piston.

Probe pistons are available through Coast High Performance.

Connecting Rod Reconditioning, Blueprinting, and More!
Engine Blueprinting by Rick Voegelin is an excellent supportive resource for the procedures shown in this article.

In fact, prior to creating this article and locating the right machine shop in my town, reading this book served as the perfect knowledge base.

You can purchase
Engine Blueprinting
from Amazon for under $15.00


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