{"id":44,"date":"2015-11-16T12:22:00","date_gmt":"2015-11-16T11:22:00","guid":{"rendered":"https:\/\/www.planetzapp.de\/rip\/?p=44"},"modified":"2025-12-05T10:50:53","modified_gmt":"2025-12-05T09:50:53","slug":"ford-flathead-engine-identification-part-1","status":"publish","type":"post","link":"https:\/\/www.rustinpeace.rocks\/rip\/index.php\/2015\/11\/16\/ford-flathead-engine-identification-part-1\/","title":{"rendered":"Ford Flathead engine identification – Part II"},"content":{"rendered":"\n

Part II of the Ford Flathead identification article. After we handled all 21 stud engines, the 60 HP and the monster 337cui engines, we’ll look closer to all 24 stud engines in this part. The american Ford V8 24 stud Flatheads where build from 1938 to 1953. The displacement is 221, 239 or 255 cubic inch. The biggest problem in identifying: all engines look very similar.<\/p>\n\n\n\n

The second problem is that even the Ford literature did not care about the year an engine was build, just which engine will fit in which car or truck. The last problem: World War 2. Ford produced flathead parts for military use and had no civil production from 1943 to 1945.<\/p>\n\n\n\n

Let’s try to divide our table from Part I:<\/p>\n\n\n\n

studs<\/th>cui<\/th>HP<\/th>build from<\/th>build to<\/th>bore<\/th>stroke<\/th>construction details<\/th>model<\/th><\/tr><\/thead>
24<\/td>221<\/td>85\/90
<\/td>		1938<\/td>1942<\/td>3.0625<\/td>3.7500<\/td><\/td><\/td><\/tr>
24<\/td>239<\/td>95\/100\/110<\/td>1939<\/td>1953<\/td>3.1875<\/td>3.7500<\/td><\/td><\/td><\/tr>
24<\/td>255<\/td>110\/125<\/td>1949<\/td>1953<\/td>3.1875<\/td>4.0000<\/td><\/td><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n


<\/p>\n\n\n\n

Different Distributors<\/h2>\n\n\n\n
\"\"<\/figure>\n\n\n\n

21 stud with Divers Helmet or Eggshell Distributor<\/p>\n\n\n\n


The earlier models have, like all 21 stud engines, a so called Divers Helmet distributor (sometimes called Eggshell distributor). This distributor applies to all engines from 1932 to 1941, so for the 24 stud engines we are looking at, all 1938 to 1941.<\/p>\n\n\n\n

The 1942 to 1945 engines had the Crab-Style distributor (see picture below).<\/p>\n\n\n\n

The 1946 to 1948 engines had the round style distributor. All three distributor styles are located on the middle of the front side of the engine.<\/p>\n\n\n\n

All 1949-up engines have a modern style distributor located on the top front of the engine.
<\/p>\n\n\n\n

Water outlets<\/h2>\n\n\n\n

The water outlet design on the cylinder heads was changed in 1949. 1938 to 1948 cylinders had the water outlet in the middle of the head (see right picture below). In 1949 the outlet moved to the front of the engine (left picture). This design was keept till the end of the US flathead production line in 1953.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

<\/p>\n\n\n\n

The Pencil Test<\/h2>\n\n\n\n

All pre WW2 flathead engines, including the 21 stud, will pass the so called „Pencil Test“. This pre war blocks have a tiny shelf above the timing cover. The shelf is deep enough to horizontal lay a pencil on it. All post war blocks will fail the pencil test.<\/p>\n\n\n\n

studs<\/th>cui<\/th>HP<\/th>build from<\/th>build to<\/th>bore<\/th>stroke<\/th>construction details<\/th>model<\/th><\/tr><\/thead>
24<\/td>221<\/td>85<\/td>1938<\/td>1940<\/td>3.0625<\/td>3.7500<\/td>Divers Helmet distributor, water outlet on center of cylinder head, passes pencil test<\/td>81A\/91A\/01A<\/td><\/tr>
24<\/td>221<\/td>90<\/td>1941<\/td>1941<\/td>3.0625<\/td>3.7500<\/td>Divers Helmet distributor, water outlet on center of cylinder head, passes pencil test<\/td>11A<\/td><\/tr>
24<\/td>221<\/td>90<\/td>1942<\/td>1942<\/td>3.0625<\/td>3.7500<\/td>Crab-Style distributor, water outlet on center of cylinder head, passes pencil test<\/td>21A<\/td><\/tr>
24<\/td>239<\/td>95<\/td>1939<\/td>1940<\/td>3.1875<\/td>3.7500<\/td>Divers Helmet distributor, water outlet on center of cylinder head, passes pencil test<\/td>99A\/09A<\/td><\/tr>
24<\/td>239<\/td>100<\/td>1941<\/td>1941<\/td>3.1875<\/td>3.7500<\/td>Divers Helmet distributor, water outlet on center of cylinder head, passes pencil test<\/td>19A<\/td><\/tr>
24<\/td>239<\/td>100<\/td>1942<\/td>1945<\/td>3.1875<\/td>3.7500<\/td>Crab-Style distributor, water outlet on center of cylinder head, passes pencil test<\/td>29A<\/td><\/tr>
24<\/td>239<\/td>100<\/td>1946<\/td>1948<\/td>3.1875<\/td>3.7500<\/td>round distributor, water outlet on center of cylinder head, fails pencil test<\/td>69A\/79A\/89A\/ 59A (Mercury all years)<\/td><\/tr>
24<\/td>239<\/td>100\/110<\/td>1949<\/td>1953<\/td>3.1875<\/td>3.7500<\/td>modern style distributor, water outlet in front of cylinder head, fails pencil test
<\/td>		98BA (’49) \/ 8BA (’50-’53)<\/td><\/tr>
24<\/td>255<\/td>110\/125<\/td>1949<\/td>1953<\/td>3.1875<\/td>4.0000<\/td>modern style distributor, water outlet in front of cylinder head, fails pencil test<\/td>CM (all years)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n


It’s important to know that the cylinderhead marks can be differend from the engine model. For example 81A cylinderheads were used from 1938 to 1942. The same periode trucks used 41T cylinder heads. 99T heads were used on trucks in the years 1939 to 1941.
<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Crab Style Distributor on Ford Flatheads 1942-1945<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Round Style Distributor on Ford Flatheads 1946-1948<\/p>\n\n\n\n

<\/p>\n\n\n\n

Part III will follow\u2026<\/p>\n","protected":false},"excerpt":{"rendered":"

Part II of the Ford Flathead identification article. After we handled all 21 stud engines, the 60 HP and the monster 337cui engines, we’ll look closer to all 24 stud engines in this part. The american Ford V8 24 stud Flatheads where build from 1938 to 1953. The displacement is 221, 239 or 255 cubic inch. The biggest problem in identifying: all engines look very similar.<\/p>\n","protected":false},"author":1,"featured_media":113,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,4],"tags":[],"class_list":["post-44","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-engine-talk","category-history"],"_links":{"self":[{"href":"https:\/\/www.rustinpeace.rocks\/rip\/index.php\/wp-json\/wp\/v2\/posts\/44","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.rustinpeace.rocks\/rip\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.rustinpeace.rocks\/rip\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.rustinpeace.rocks\/rip\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.rustinpeace.rocks\/rip\/index.php\/wp-json\/wp\/v2\/comments?post=44"}],"version-history":[{"count":9,"href":"https:\/\/www.rustinpeace.rocks\/rip\/index.php\/wp-json\/wp\/v2\/posts\/44\/revisions"}],"predecessor-version":[{"id":232,"href":"https:\/\/www.rustinpeace.rocks\/rip\/index.php\/wp-json\/wp\/v2\/posts\/44\/revisions\/232"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.rustinpeace.rocks\/rip\/index.php\/wp-json\/wp\/v2\/media\/113"}],"wp:attachment":[{"href":"https:\/\/www.rustinpeace.rocks\/rip\/index.php\/wp-json\/wp\/v2\/media?parent=44"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rustinpeace.rocks\/rip\/index.php\/wp-json\/wp\/v2\/categories?post=44"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rustinpeace.rocks\/rip\/index.php\/wp-json\/wp\/v2\/tags?post=44"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}