AMC V-8s
(Quikc history of AMC V-8s.) |
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AMC made their own V-8 engines. The company did use a few parts from other manufacturers, namely transmissions, carburetors, and electrical systems (distributor, alternator/generator, starter, etc.). Many people see a similar displacement (327, 390, etc.) engine with a Delco (GM) or Autolite (Ford) ignition/starting/charging system on it and assume the engine was purchased from GM or Ford. Anyone real familiar with GM and FORD V-8s would immediately know they were looking at a different engine at first glance though. | AMC made their own V-8 engines. The company did use a few parts from other manufacturers, namely transmissions, carburetors, and electrical systems (distributor, alternator/generator, starter, etc.). Many people see a similar displacement (327, 390, etc.) engine with a Delco (GM) or Autolite (Ford) ignition/starting/charging system on it and assume the engine was purchased from GM or Ford. Anyone real familiar with GM and FORD V-8s would immediately know they were looking at a different engine at first glance though. | ||
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AMC only purchased one V-8 from another manufacturer. That was the Packard 320 V-8 for the big 1955-56 Nash Ambassador and Hudson Hornet models. These were equipped only with the Packard Ultramatic auto trans. AMC and Packard were supposed ot have had a "gentleman's agreement" to cross purchase parts. This was partially to establish a working relationship between the two companies for a possible future merger. As it turned out, Packard felt it was doing AMC a favor by selling AMC V-8s. Packard sent a few bids in to AMC, but rejected them all as too high even though AMC was paying a premium for the Packard V-8s. | AMC only purchased one V-8 from another manufacturer. That was the Packard 320 V-8 for the big 1955-56 Nash Ambassador and Hudson Hornet models. These were equipped only with the Packard Ultramatic auto trans. AMC and Packard were supposed ot have had a "gentleman's agreement" to cross purchase parts. This was partially to establish a working relationship between the two companies for a possible future merger. As it turned out, Packard felt it was doing AMC a favor by selling AMC V-8s. Packard sent a few bids in to AMC, but rejected them all as too high even though AMC was paying a premium for the Packard V-8s. | ||
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All three engines can share the same components except for pistons. All 250 models use solid lifters, the 287/327 are hydraulic. These engines were used by Grey Marine for boats in the late 50s and early to mid 60s. All the marine engines used solid lifters as well, regardless of size. | All three engines can share the same components except for pistons. All 250 models use solid lifters, the 287/327 are hydraulic. These engines were used by Grey Marine for boats in the late 50s and early to mid 60s. All the marine engines used solid lifters as well, regardless of size. | ||
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By the mid 60s the heavy Gen-1 V-8 was becoming dated. AMC engineers didn't rest once the Gen-1 was introduced though. They had been working on a thoroughly modern light weight V-8 to eventually replace the Gen-1. The Gen-2 engine was introduced in mid year 1966 as a 290. The only thing it shares with the Gen-1 is the bore spacing. This was done so that existing boring tooling could still be used. Everything else about the Gen-2 was totally unique an new, even the bell housing bolt pattern was changed. These engines are similar to a small block, but have a larger bore spacing similar to a big block. Many people call them a "mid block", but it's just the AMC Gen-2 V-8 -- AMC only made one V-8 design at any given time. | By the mid 60s the heavy Gen-1 V-8 was becoming dated. AMC engineers didn't rest once the Gen-1 was introduced though. They had been working on a thoroughly modern light weight V-8 to eventually replace the Gen-1. The Gen-2 engine was introduced in mid year 1966 as a 290. The only thing it shares with the Gen-1 is the bore spacing. This was done so that existing boring tooling could still be used. Everything else about the Gen-2 was totally unique an new, even the bell housing bolt pattern was changed. These engines are similar to a small block, but have a larger bore spacing similar to a big block. Many people call them a "mid block", but it's just the AMC Gen-2 V-8 -- AMC only made one V-8 design at any given time. | ||
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The 290 and 343 used cast cranks and rods. The 390 was always intended for high performance and was made with a forged crank and forged rods. AMC stated that the primary reason forgings were used was to get the engine to market quicker -- they didn't have time to thoroughly test cast components and intro the engine when they desired to. As a result, the AMC Gen-1 390 doesn't have the problem of breaking rods at high rpm that the big three small block 400s have. Worked over AMC 390 rods are good to 7000+ rpm, whereas the other makes require replacement performance rods. A lot of work also went into development of the head. AMC heads were some of the best flowing heads on the market at the time. A typical AMC head flowed as good or better than other makes high performance heads. | The 290 and 343 used cast cranks and rods. The 390 was always intended for high performance and was made with a forged crank and forged rods. AMC stated that the primary reason forgings were used was to get the engine to market quicker -- they didn't have time to thoroughly test cast components and intro the engine when they desired to. As a result, the AMC Gen-1 390 doesn't have the problem of breaking rods at high rpm that the big three small block 400s have. Worked over AMC 390 rods are good to 7000+ rpm, whereas the other makes require replacement performance rods. A lot of work also went into development of the head. AMC heads were some of the best flowing heads on the market at the time. A typical AMC head flowed as good or better than other makes high performance heads. | ||
| − | AMC made some improvements in the Gen-2 design for 1970. This resulted in different block and head castings and slightly larger displacement. The only change to the block was adding approximately 1/16" to the deck height and increasing the stroke accordingly. The 290 became a 304, 343 a 360, and the 390 a 401 (with a little extra stroke in the crank than the 390). The 401 wasn't introduced until 1971. The 390 was kept for 1970 only by using a special piston -- the pin height was altered to keep displacement at 390 inches. The head casting was changed to create a slightly larger "dog leg" exhaust port (Gen-2 heads have rectangular exhaust ports) to improve exhaust flow. So there were four Gen- | + | |
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| + | AMC made some improvements in the Gen-2 design for 1970. This resulted in different block and head castings and slightly larger displacement. The only change to the block was adding approximately 1/16" to the deck height and increasing the stroke accordingly. The 290 became a 304, 343 a 360, and the 390 a 401 (with a little extra stroke in the crank than the 390). The 401 wasn't introduced until 1971. The 390 was kept for 1970 only by using a special piston -- the pin height was altered to keep displacement at 390 inches. The head casting was changed to create a slightly larger "dog leg" exhaust port (Gen-2 heads have rectangular exhaust ports) to improve exhaust flow. | ||
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| + | So there were four Gen-3 sizes: | ||
1970-79 304 | 1970-79 304 | ||
1970-91 360 | 1970-91 360 | ||
1970 only 390 | 1970 only 390 | ||
1971-79 401 | 1971-79 401 | ||
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The AMC V-8 finally went out of production when Chrysler halted Jeep Grand Wagoneer production at the end of the 1991 model year. This make the 360 by far the most numerous AMC V-8. It can easily be built to produce over 400 hp on pump gas. It's as modern as any other make V-8 of the time, and has as much potential. There isn't as large a selection of performance parts, but the parts still available are the ones known to work well -- nit a lot of junk to wade through. The parts cost a little more than the more common small block Ford and Chevy parts, but no more than any other make. Cost to build is partially offset by the very good heads. The typical SBC or SBF really needs better aftermarket or now hard to find performance head to be equal to the AMC V-8 heads. | The AMC V-8 finally went out of production when Chrysler halted Jeep Grand Wagoneer production at the end of the 1991 model year. This make the 360 by far the most numerous AMC V-8. It can easily be built to produce over 400 hp on pump gas. It's as modern as any other make V-8 of the time, and has as much potential. There isn't as large a selection of performance parts, but the parts still available are the ones known to work well -- nit a lot of junk to wade through. The parts cost a little more than the more common small block Ford and Chevy parts, but no more than any other make. Cost to build is partially offset by the very good heads. The typical SBC or SBF really needs better aftermarket or now hard to find performance head to be equal to the AMC V-8 heads. | ||
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