Jerry Branch Ported Cylinder Heads



I keep viewing ironhead Sportster heads on Ebay - and the seller describes them as "Branch heads" and they aren't...not even close.  Branch heads (at least all the one's I've seen):

1. Have numbers stamped near the intakes (on the bottom)
2. Have micro, knife edge cut valve seats
3. Have mirror polished ports (both intake and exhaust) 
 Later heads have a smooth intake, but unpolished as much...
4. The head gasket surfaces AND rocker box surfaces 
are both surface ground (parallel)
for straightness and squareness

2 comments:

  1. KevinFriday, March 27, 2020

    Do you have any info/thoughts on those tiny valve seats? I would think you would want wider cuts for a more gradual corner, but obviously Jerry Branch knew about airflow...

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  2. NootMonday, March 30, 2020

    They don't last as long, but it's all about the flow most likely? I know a bit wider seat on the exhaust valve (some-say) helps to carry some heat away from the valve itself while it's shut(against the seat on the head).

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