Engine Maintenance and Modification Bradley Artigue
FIAT 124 Spider Engine Maintenance + Modification - Artigue.com
FIAT 124 Spider Engine Maintenance + Modification - Artigue.com
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FIAT 124 Spider<br />
<strong>Engine</strong> <strong>Maintenance</strong> + <strong>Modification</strong><br />
carburetor are collectively regarded as “boat anchors” <strong>and</strong> are always c<strong>and</strong>idates for<br />
replacement. Simply replacing the carbureted 2000cc head with one from a 2000cc fuel<br />
injected or 1756cc engine will provide some improvement in efficiency.<br />
The Spider 1756 head began life as a clean head, nearly identical to the 2000 FI head<br />
described above. The 1756 head has smaller combustion chambers than the 2000<br />
heads but is otherwise the same casting. By 1978 they had adopted a camshaft-driven<br />
air pump <strong>and</strong> several emission control valves on the intake manifold. Unlike the 2000<br />
carbureted head the 1756 never had the EGR port squishing the combustion chamber<br />
<strong>and</strong> with little work any of the 1756 heads are desirable. One of the Lancia heads, the<br />
1976 Monte Carlo (Scorpion) head, has larger ports than the other model years. The<br />
1756 intake manifold is also desirable for the ADL, ADF, ADFA, DFEV, <strong>and</strong> DMSA<br />
carburetors.<br />
The Spider 1592 head was designed for, <strong>and</strong> mated to, the 1592cc engine used on the<br />
1973 model year only. It is not laden with any specific emission control devices <strong>and</strong> is<br />
really a clean head. If your vehicle has the 1592 motor (many were replaced with<br />
1756’s) <strong>and</strong> you wish to maintain originality then this is the only head you can use. It is<br />
otherwise not desirable for use on any other Spider.<br />
The Spider 1608 <strong>and</strong> 1438 heads are clean heads with few or no emissions control or<br />
other power-sucking devices added to them. They are slightly different that the later<br />
series heads <strong>and</strong>, for the purposes of interchangeability (as described below), should<br />
probably be kept on the engine they were designed for.<br />
11.1.4 Interchangeability<br />
The interchangeability of cylinder heads between the 1756 <strong>and</strong> 2000 Spiders is a true,<br />
do-it-yourself, instant improvement. A clean 1756 head installed on top of the 2000<br />
block (carbureted or fuel injected) results in a compression increase. Although not as<br />
dramatic as the installation of high compression pistons, this can be done without pulling<br />
the engine <strong>and</strong> requires the same amount of work as replacing the head gasket. The<br />
difference being when the head gasket goes on the new head goes on top.<br />
The 2000 FI head can also be installed on the 2000 carbureted engine. It will not alter<br />
the compression ratio but will improve performance just by nature of a better, cleaner<br />
design.<br />
Other model years can be interchanged as well. The 1438 head is somewhat restrictive<br />
<strong>and</strong>, with some minor welding on one of the coolant ports, can be replaced with the<br />
1608 head. Experience has shown that most owners of these older Spiders are not<br />
doing these upgrades as the performance gain is minimal. More suitable is the<br />
installation of high compression pistons or other engine upgrades.<br />
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