Whats the difference..Is it only called an ironhead when they put a shovelhead in a sportster?

 

In short, yes. Shovelhead big twins have aluminum cylinder heads. Older Sportsters (1957-1985), despite having rocker boxes which resemble the Shovelhead had cylinder heads made of cast iron, instead of aluminum, hence the term, "ironhead" for a Sportster.

 

Iron heads usually refer to Sportsters made before the aluminum engines. Shovelheads usually refer to some of the coolest Harleys ever made...

 

So the heads are different but rocker boxes the same?How bout the jugs etc?

 

Dude, an ironhead is a Sportster. A Shovelhead is a big bike. Finito...

 

Nope, the rocker boxes only look the same. They are completely different engines. Sportster is a "unit" - engine & tranny share the same cases. Shovel, and all the other Big Twin iterations, have separate engine and tranny cases.
Sporties have 4 cams; note that the pushrods are parallel. Shovels have 1 cam; note that the pushrods come off the cases at various angles, and are not parallel to each other. Ironheads all have generators, while '66 - '69 Shovels used generators; '70 up used alternators. '57 thru '71 Sportsters were called 900, though the engine was actually 883cc; '72 and later Ironheads were called 1000, though the displacement was 997.5cc.

 

And the new Sportys are still Evos. Right?

 

Evo Sporties as opposed to Evo Big Twin. Most times when someone talks about an Evo they are referring to the BT model.

 

when they made the shovelhead, they copyed the ironhead,sportster head design,but the two have nothing in common besides looking kind of similar. sportster evo rocker boxes are different then the bigtwin, but are interchangeable if you wanted to.(i had a buddy that used sportster boxes just for the look on a softail chopper)..

any one know if the newer rubbermounted sportys are still considered evo?

 

Back in the day before 1985, all Sportster heads were cast iron . FYI, they were never refered to as Iron Heads prior to the Evolution design.
Though the rocker boxes looked similar, the Sportster has a notched rocker box look.

1973 Sportster




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