Connecting Rod D.14.5×D.30×108 mm LB30-2/40-3 (Art. 21132021) — for LB30 Remeza/Aircast Piston Block

The rod’s small (upper) end is articulated to the piston via a 14.5 mm piston pin and moves back and forth together with it. The big (lower) end, with a 30 mm bore, wraps around the crankshaft journal; as the crankshaft rotates, it drives the rod through a combined oscillating and translating motion, transmitting the air-compression force from the piston to the crankshaft. The center-to-center distance between the two ends — 108 mm — defines the geometry of the piston/cylinder assembly and must exactly match the original part.

The distinguishing feature of this specific part is the built-in oil-splash paddle (dipper) on the rod’s big end. LB30 block heads use a splash (bath) lubrication system for the cylinder: as the crankshaft rotates, the paddle on the rod dips into the oil in the crankcase and flings it inside the block, lubricating the cylinder walls, the piston pin, and the crankshaft bearings without an oil pump. This simplifies the compressor’s construction but requires precise crankcase oil level and correct paddle orientation during assembly.

Technical Specifications

⚠️ The exact manufacturing material, weight, and tolerances are not published by the manufacturer in open sources. This part is supplied as a genuine Remeza part — unlike universal connecting rods for unbranded Chinese compressors, here the exact factory fit to the LB30 block family is confirmed.

Design Features

Decoding the designation D.14.5×D.30×108 mm LB30-2/40-3:

Construction highlights:

• Oil-splash paddle on the big end — the key element of the pump-free lubrication system; it dips into the crankcase oil with every crankshaft rotation and creates an oil mist inside the block.
• I-beam cross-section rod shaft — a standard design solution for this class of compressor, providing an optimal balance between bending strength and part mass.
• Single (factory-confirmed) applicability across two block models at once — LB30-2 and LB40-3 share the same connecting-rod mounting assembly, simplifying parts selection when servicing either model.

Installation Recommendations

• Check the oil-splash paddle’s orientation during assembly — this is the single most important point for this part: the paddle must pass through the bottom of its stroke close to the crankcase oil level and fling oil in the correct direction; incorrect installation leads to insufficient lubrication of the cylinder and piston pin.
• Check the crankcase oil level before first startup — with a splash (pump-free) lubrication system, oil level is critical: too little starves the part of lubrication, too much causes excess oil consumption and oil carryover into the air line.
• Check the condition of the piston pin and the crankshaft journal seat before installing the new rod — play or scoring on adjacent parts will negate the new part’s service life.
• Lubricate the mounting surfaces with oil before assembly (compressor oil of the appropriate viscosity) — dry installation accelerates scoring during the first hours of operation.
• Tighten fasteners per the compressor manufacturer’s recommendations — don’t tighten “by feel”; over-tightening can deform the rod’s big end.
• Turn the crankshaft by hand through a few rotations after assembly, before starting the compressor under load — this immediately reveals binding, the paddle contacting the crankcase, or other misalignment.

Analogues and Comparison

Direct compatibility (manufacturer-confirmed): connecting rod 21132021 is used in piston blocks LB30-2 and LB40-3, fitted to compressors of the Remeza, Aircast, AE&T, and Patriot brands — these trade names all use the same Remeza-manufactured compressor head lineup.

Below are connecting rod sizes with similar construction from the same family of Remeza blocks (for reference only; not interchangeable with 14.5×30×108 mm without verification — listed to illustrate the size range):

Before substituting any other size, always check the compressor block marking (LB30, LB30-2, LB40-3, etc.) — unlike universal rods for unbranded compressors, here matching the exact factory block model matters most.

Common Ordering and Installation Mistakes

• Installing the oil-splash paddle with the wrong orientation — the most specific mistake for this part; leads to cylinder oil starvation even when the assembly looks correct from the outside.
• Ordering by the compressor’s outer brand alone, without checking the block model — Remeza, Aircast, AE&T, and Patriot share a common block lineup, but a specific compressor model may be fitted with different blocks (LB24, LB30, LB40, LB50, LB75, etc.); it’s important to confirm the block marking, not just the compressor housing’s brand.
• Ignoring the oil level after replacing the rod — with a splash lubrication system this is especially critical, since the rod’s paddle is the sole source of oil supply to the moving parts.
• Installing without lubricating the mounting surfaces — leads to accelerated wear and a characteristic knock during the first hours of operation after replacement.
• Over-tightening the big-end fasteners — deforms the rod’s big end and can cause it to bind on the crankshaft journal.
• Starting the compressor straight into full load after replacement — a short idle break-in period is recommended.

Application Areas

Connecting rod 21132021 is a genuine part for the LB30 piston block, used in compressors of the following brands (compatibility confirmed per the manufacturer’s parts breakdown):

• Remeza — compressors in the series based on the LB30 block
• Aircast — compressors in the series based on the LB30 block
• AE&T — compressors based on the LB30 block
• Patriot — compressors based on the LB30 block

This rod is also applicable to the LB40-3 block (shared mounting assembly with LB30-2).

Typical uses for compressors fitted with the LB30 block:

• Garage and auto-service compressors of small to medium capacity
• Small production and repair workshops
• Mobile compressor units for construction and installation work

Expert Opinion

Vitali Boluchevski, Lead Engineer, Acvatron SRL, 18 years of experience:

“The LB30 block and its ‘relative’ LB40-3 are among the most common piston assemblies among the brands sold in Moldova under different names — Remeza, Aircast, AE&T, Patriot. The good news is that this is a genuine factory Remeza part with an exact part number, not an unbranded universal equivalent — you can go by the block marking instead of guessing from dimensions. But this rod has a nuance that’s important not to miss during a DIY replacement: the oil-splash paddle on the big end is the sole source of cylinder lubrication in blocks with a splash system and no oil pump. If the rod is installed with the paddle facing the wrong way, or if the oil level isn’t checked correctly after assembly, the compressor may run for only a few hours before the cylinder scores. That’s why, when replacing this part, I always recommend comparing a photo of the correct paddle position on the old and new part before fully reassembling the block.”

FAQ

How do I recognize that a compressor’s connecting rod has failed? The main signs are a characteristic dull knocking sound in the crankcase area that intensifies with rising RPM and load; increased oil consumption due to increased clearance in the rod bearings or the splash paddle not functioning correctly; and a drop in compressor performance and final pressure.

Does this rod only fit the LB30 block, or other models too? Per the manufacturer’s parts breakdown, this part number (21132021) is used in the LB30-2 and LB40-3 blocks — they share the same connecting-rod mounting assembly. For the base version of the LB30 block (without the “-2” suffix), confirm the marking with our sales team before ordering, since within the Remeza lineup there are variants of the same block name fitted with different rods.

How do I correctly orient the oil-splash paddle during assembly? Before disassembly, photograph the paddle’s position on the old rod relative to the crankcase and crankshaft — this is the most reliable reference. The general rule for splash lubrication systems: the paddle should pass through the bottom of its stroke as close as possible to the crankcase oil level, picking up oil with each rotation, and fling the oil toward the cylinder walls, not away from them.

Do the piston pin and retaining clips need to be replaced along with the rod? Not necessarily, but it’s strongly recommended to inspect them before installing the new part — a worn pin or deformed retaining clips can damage the new rod within the first hours of operation and negate the benefit of the replacement.