Rod FAQ

Rods

What is the difference between ARP 625 and ARP 2000 bolts?
The tried, true, and very popular ARP 2000 material is a quench and tempered heavily alloyed martensitic steel with a typical 44-47 C- scale Rockwell hardness and rated at 220,000 psi tensile strength.

The ARP Custom age 625 + counterparts are comprised of a higher tensile strength super-alloy corrosion resistant material, also quench and temper heat treated, to a robust 260,000psi. These higher rated bolts are offered as an optional upgrade from our basic 2000 series provided in all Pauter rods.

Can I order a single replacement rod?
Single rods are available. The information necessary to match the rod weights (reciprocating and overall) of your existing set was in the box printed on a yellow card. If the information is not available, and you purchased the rods directly from us, we should have your rod weights and sizes on file. Contact us for more information..

What is the difference between a forged and billet steel connecting rod?
Forging is a preformed, closely shaped, individual part, whereas a billet is typically formed from a flat rolled bar stock. Forging is designed to take full advantage of manipulation of grain structure throughout the shape of the finished part. Billet processing in rod manufacturing, on the other hand, is the complete machining of a rectangular block of material resulting in a finished part. Our manufacturing methods combine the strength of forging and the consistency of billet steel.

Can I run my rods without a pin end bushing or can the pins be press fit?
Bushings are preferred for ease of assembly and reparability. Typically, we hold our fit to what we consider to be the bottom side of clearance (.0005″ to .0006″ target), since it’s far easier to open the bore than it is to close it. If requested we can hold size to suit specific values noted at time of order.

What bearing clearances do I run with these connecting rods?
This depends greatly on the application, however .0010″/.0015″ per diameter inch is a commonly considered operating clearance standard. Stacked tolerance—the combined tolerances of crankshaft journal, bearing, and rod—of all corresponding parts plays a big role in determining the final clearance. Applying perceived dimensions from specification manuals will rarely match sizes needed to determine true physical clearance, for this reason we recommend actual rod and main bearing clearances be established though the use of dedicated equipment such as micrometers and bore gauges we also suggest contacting your engine builder or our tech department for a personalized recommendation on your specific engine program.

We are sometimes called upon to set specific rod bearing clearances when supplying rods to clients. This procedure is offered as an optional service and only when absolute crankshaft sizes (.xxxx”) are known and bearings to be used are supplied. For more on this, contact our tech department.

What side clearances do I run with these connecting rods?
Favorable side clearance values for crank guided applications are .010”-.012” with a minimum recommendation of .008” per rod. This value should be doubled in shared journal engines (as in most “V” configurations). In assemblies where minimum clearance is to be maintained, groove thrusts should be considered.

How much do your connecting rods stretch?
What is often referred to as rod stretch is actually a result of flex of corresponding parts combined with movement allowed by necessary operating clearances involved within the assembly as well as thermal expansion inherent in the internal combustion engine. Truth is any true physical rod stretch would likely be from deformation of the big and/or small end bores which could in turn lead to serious engine damage. In short, actual steel rod stretch itself should be near zero with exception of thermal expansion but all aspects mentioned above need to be considered during engine planning / assembly stages with regard to rotating and deck clearance minimum requirements.

Can a connecting rod be rebuilt?
Pauter, like most aftermarket rods are manufactured in a way that lends itself to rebuild provided any damage is within accepted repairable means.  Contact us prior to shipping parts for repair

How do separate rod and cap?

Conventional bolt layout:  Unscrew the bolts about a quarter of an inch. Then, holding the cap, tap lightly on the screw heads with a non-marring hammer until the alignment sleeve is clear of opposite face.

Porsche/VW bolt layout: Unscrew the bolts about a quarter of an inch. Then, while holding the beam, tap lightly on the screw heads with a non-marring hammer until the alignment sleeve is clear of opposite face.

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