Connecting Rod Boring Machine MB-98 Chinelatto - 0.59-3.86in Capacity

The connecting rod boring machine is used to bore the internal holes of engine connecting rods, correcting out-of-roundness and wear in the holes where the piston pin passes through. The MB-98 Chinelatto works with connecting rods from 0.59 to 3.86 inches (15 to 98mm) diameter, using interchangeable tools of 0.24, 0.31 and 0.47 inches (6, 8 and 12mm). It's essential in engine rebuilding to ensure proper dimensional precision between connecting rod and piston pin, avoiding excessive clearance or inadequate fit.

The MB-98 has boring capacity from 0.59 to 3.86 inches (15 to 98mm) diameter, with connecting rod center distance from 3.15 to 12.6 inches (80 to 320mm). The tool holder spindle runs at 1,140 rpm, with automatic feed of 1.77 IPM (45mm/min) and manual return. 0.5hp motor, 220V three-phase power. Includes centering device for connecting rods, expansion fixture for 1.85 to 3.86 inch (47 to 98mm) rods, and three tools (one 0.24 inch and two 0.31 inch). Weighs 342 lb (155kg) net.

The MB-98 accepts connecting rods with internal bore from 0.59 to 3.86 inches (15 to 98mm) diameter and center distance from 3.15 to 12.6 inches (80 to 320mm), covering small to medium engines. Includes special fixture for connecting rods smaller than 4.33 inches (110mm) between centers and expander with three sets of blades for secure clamping of 1.85 to 3.86 inch (47 to 98mm) rods. Works with connecting rods from car, truck, some tractor and generator engines, both gasoline and diesel.

The main difference is in tool feed: the MB-98 has automatic feed of 1.77 IPM (45mm/min), ensuring uniform finish and constant speed, while manual machines depend on the operator to control speed. Automatic feed reduces human error, improves dimensional precision and increases shop productivity. Return remains manual for operator control. Automatic machines are ideal for machine shops that handle higher volume of connecting rods.

The process starts by clamping the connecting rod in the expander and centering with the fixture and dial indicator. The cutting tool spins in the chuck at 1,140 rpm while automatically advancing at 1.77 IPM (45mm/min), removing material from the internal bore. The operator controls final diameter using the measuring device with dial indicator. The MB-98 allows precise adjustment of interchangeable tools according to connecting rod size, ensuring smooth finish and exact measurement.

Basic maintenance includes regular cleaning of guides and lubrication of moving points. Cutting tools need periodic sharpening or replacement according to use. Check alignment of centering devices and calibration of dial indicators. 0.5hp motor is simple and reliable, needing occasional electrical service. Chinelatto provides technical support and replacement parts. With proper use, it's a durable machine for engine rebuilding shops.

The MB-98 is quoted on demand, and pricing varies with each customer's needs, including accessories, tooling and optional features. With in-house technology developed by Chinelatto in Brazil since 1962, you can count on responsive support from our technical team. Spare parts: many are kept in stock and the others are manufactured within a reasonable lead time. Request a quote at chinelatto.com.br/contact — our sales team will contact you very soon.