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OVERVIEW ON HARLEY DAVIDSON PERFORMANCE HEADS

?      HARLEY DAVIDSON SE HEAD

These are good set of heads and work well in most applications. They are a lot like our SCOTTSMAN series head. The early sets of these heads came without compression release holes. All current heads come already drilled for releases. These heads use a 1.900 intake and a 1.625 exhaust valve. Port design is good, which yields good air-flow. These heads have been decked to .060 and in most cases yields a 78cc combustion chamber. Recommendations  use mild cam and a cast flat-top piston. Look in our flow library on air-flow comparisons.

?      HARLEY DAVIDSON HTTC non-CNC ported

I think these are a neat set of heads in many ways. They have our VORTEC intake port design. These heads have a 2in intake valve and 1.550 exhaust. This was done for TDC lift issues on certain cam shafts. With these heads you need to HTTC pistons and HTTC intake manifold. These heads have a unique  combustion chambers with many different squish ramps and angles. In most applications these heads are to yield 10.5/1 compression ratio. I use a COMETIC .030 head gaskets with these heads. My thoughts, I would like to see 1.900-1.940 intake valve and 1.610 exhaust valve. There is a ridge left in intake port that should be ground out to enhance air-flow. See picture

I have welded up combustion chamber on some builds and have used flat-top pistons kits. Our flow library shows more details on these heads.

?      HARLEY DAVIDSON CNC PORTED HTTC

I was really surprised to see Harley Davidson offer a CNC ported head. The workmanship is top notch on these heads. On a flow bench these heads really whistle. Have very high flow numbers. The problem I see with heads they do not work well on small engines. Complaints I have heard is no low-end with heads. I have to agree, there is excellent air flow but the port velocity has been diminished, due to port size. My recommendation use on 103 and larger engine builds. I have also welded up the combustion chamber on these heads, so a flat-top piston can be used.

?      Harley Davidson SE 103 PRO

I have only had one set of these at our shop. A dealer sent them for us to fix valve guide. As of this time I have not been able to flow test or port a set of these heads. My personal view on these heads are. The combustion chamber and piston set up makes no sense to me. The 2.080 intake valve is to big for this size engine. I feel a 1.940 intake should be used on SE103 build. I want to note, in years past I did use a 2in intake on many SE103 cylinder head builds.

Final thoughts on HARLEY DAVIDSON SE HEADS. I think it neat to see the factory offer these different head packages. The problem I see is this, I wished the dealers would think things out before they build. Most cases to much compression and too radical cam for rider application. Think it out before you build!