EC’s Pinnacle Connecting Rods – Installation & Information Guide
Overview
EC’s Pinnacle Connecting Rods represent the latest advancements in small engine performance and durability. Machined from premium billet or forged materials, these aluminum rods are among the strongest available on the market.
Pinnacle Rods are engineered to clear most large-duration and high-lift camshafts. However, camshaft clearance is also dependent on crankshaft stroke. These rods provide additional oil dipper clearance for long-stroke crankshafts, including our 58mm (2.283-inch) crankshafts.
Important: If additional clearance is required, it must be made to the crankshaft or camshaft, never the rod itself. Modifying the rod may result in premature failure.
Warranty Disclaimer
There is no warranty, expressed or implied, on any racing component, including this connecting rod. Parts that, in our opinion, show signs of installation cannot be returned under our return policy.
Required Tools & Materials
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12-Point ¼” Socket
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Quality Calibrated ¼” Torque Wrench
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Machinist Micrometer
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1–1.5” Dial Bore Gauge or .001–.007” Plastigauge
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Engine Oil (Recommended: Maxima Racing Oil RS 0W-20)
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Oil-Soluble Assembly Lube (Recommended: Maxima Racing Oil Assembly Lube)
Installation Instructions
1. Inspect & Clean Components
Ensure the connecting rod and bearings are new and free from dirt, debris, hot spots, or fractures. Any contamination may lead to improper installation and premature wear.
2. Measure the Crankshaft
Using a micrometer, measure the crank pin in multiple locations (across and around the journal) and mark the measurement spot for reference.
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For Honda or Clone-based crankshafts, the journal should measure 1.180” ± .0005”.
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If the crankshaft measures under 1.795”, it must be replaced.
3. Install Rod Bearings
Remove the rod bolts and install the babbitt rod bearings into the rod and cap. Use clean hands or gloves to avoid scuffing. Align bearings centrally and flush with the edges of the rod and cap.
4. Check Oil Clearance
You can use either a Dial Bore Gauge or Plastigauge method:
4a. Dial Bore Gauge Method
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Assemble the rod and cap with the machined dimples on the same side.
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Torque the rod bolts per the procedure below.
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Use the dial bore gauge to measure the bearing ID.
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Subtract this from your crankpin OD to find oil clearance.
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Acceptable oil clearance is .002–.005 inches, with .002” as the minimum.
4b. Plastigauge Method
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Use the marked location from your crankshaft measurement.
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Place a ¼” strip of Plastigauge across the bearing surface between the rod beam’s oil holes.
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Align with the crankshaft mark and install the rod cap.
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Torque per procedure.
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Remove the cap and measure the compressed Plastigauge with the chart.
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Acceptable oil clearance is .002–.005 inches, with .002” as the minimum.
If your oil clearance is outside this range, contact us at [email protected] or 615.446.6807.
5. Final Assembly
Once oil clearance is verified:
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Apply Maxima Assembly Lube to the rod bearing, crank pin, wrist pin, and piston journal.
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Reinstall the rod cap and torque to specification.
Note: Rod caps and beams are precision-machined as a matched set. Do not interchange.
Rod Bolt Torque Procedure
Improper torqueing is one of the leading causes of rod failure. Follow these steps carefully:
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Align the rod cap with the dimples on the same side.
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Start both rod bolts by hand before seating the cap to avoid cross-threading.
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Apply engine oil to the threads.
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Tighten each bolt to 60 in/lbs.
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Increase torque in 15 in/lb increments, alternating bolts, until reaching 150 in/lbs final torque.
Engine Oil Recommendations
Do not use low-grade oils lacking shear-stabilizers or anti-wear additives. Proper lubrication extends the life of your engine and rod, and can improve track performance.
For most gas-powered engines, we recommend:
Maxima Racing Oil RS 0W-20
Visit our website or contact us for specific oil recommendations tailored to your application.
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