V6 Chevy 90 degree engines
(→Firing orders) |
(→Firing orders) |
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All the Chevy V6 90 degree engines share the same firing order of 1-6-5-4-3-2. The two smaller engines, the 200 cid and 229 cid, have what is called a "semi-even fire" sequence which alternates between 132º and 108º. This comes about due to the "slipped disc" crank pins; each pair of rods are offset by 18º. The design of the crank required the connecting rods to have 0.050" narrower ends to fit onto the available rod journal space due to the material added to the cranks for strength. | All the Chevy V6 90 degree engines share the same firing order of 1-6-5-4-3-2. The two smaller engines, the 200 cid and 229 cid, have what is called a "semi-even fire" sequence which alternates between 132º and 108º. This comes about due to the "slipped disc" crank pins; each pair of rods are offset by 18º. The design of the crank required the connecting rods to have 0.050" narrower ends to fit onto the available rod journal space due to the material added to the cranks for strength. | ||
| − | The cam and distributors are specific to the 200/229 cid engines and they cannot be interchanged with the 4.3L V6 engine. Distributor bodies used on the V6-90 are identical to the one used for the Chevrolet small-block V8 except for the pickup coil and pole piece assembly. The main difference between the semi-even fire series (200/229) and 4.3L distributors is the 4.3L distributor pickup coil and reluctor wheel has six equal points, one every 60 degrees (6 x 60 degrees = 360 degrees). Also, a majority of the distributors used on the 4.3L has a small distributor cap, same as used on the 2.8L V6 60 degree engine. The small cap/external coil ignition system is commonly used with the TBI and CPI motors. The 1985-'86 4.3L engine used in Chevrolet trucks, vans (including the Astro/Safari) used the traditional large-cap HEI on the RPO LB1 motor. Marine applications used a unique small-capped distributor not interchangeable with those used in automobiles (with the exception of the GM small cap distributor similar in design to the passenger car/light truck small cap variant commonly supplied with the Delco Voyager ignition kit). | + | The cam and distributors are specific to the 200/229 cid engines and they cannot be interchanged with the 4.3L V6 engine. Distributor bodies used on the V6-90 are identical to the one used for the Chevrolet small-block V8 except for the pickup coil and pole piece assembly. The main difference between the semi-even fire series (200/229) and 4.3L distributors is the 4.3L distributor pickup coil and reluctor wheel has six equal points, one every 60 degrees (6 x 60 degrees = 360 degrees). Also, a majority of the distributors used on the 4.3L has a small distributor cap, same as used on the 2.8L V6 60 degree engine. The small cap/external coil ignition system is commonly used with the TBI and CPI motors (the distributor is also used with the Delco Voyager ignition kit for marine and industrial applications). The 1985-'86 4.3L engine used in Chevrolet trucks, vans (including the Astro/Safari) used the traditional large-cap HEI on the RPO LB1 motor. The LB1 distributor (with a 5 pin module for electronic spark control) is a rare find in salvage yards where the pole piece and pickup coil from a 1974-88 Chevrolet 250 or 292 inline six (some 250s manufactured between 1981-85 may have a 5 or 7 pin HEI module - usually for California applications which is similar in design to the ESC distributor used with the LB1 or 81-86 Chevrolet 305s with ESC) are usually swapped in place of the Chevrolet V8 pole piece and pickup coil. Marine applications used a unique small-capped distributor not interchangeable with those used in automobiles (with the exception of the GM small cap distributor similar in design to the passenger car/light truck small cap variant commonly supplied with the Delco Voyager ignition kit). |
From the 2007 model year until production ended, the traditional distributor was eliminated where coil packs were phased in. | From the 2007 model year until production ended, the traditional distributor was eliminated where coil packs were phased in. | ||
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