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DHM Ported Cylinder Head for the 2022+ Honda Grom / Monkey


This ported cylinder head provides HP and Torque gains across the entire RPM range by optimizing the port shape and flow. It includes stiffer valve springs and has clearance for any aftermarket cam on the market. Expect noticeable power gains when adding this head to any setup. 

  • 25mm intake port for use with the stock throttle body
  • Flush valve guides for optimized port flow
  • Ideal intake port flow to maximize velocity
  • Compatible with any piston and/or big bore kit on the market
  • Compatible with any Grom cam on the market
  • Requires additional ECU tuning or Standalone ECU adjustments
  • Includes upgraded valve springs and retainers

Pairs well with either our S1 or S2 Camshafts!

Customer Reviews

Based on 3 reviews
Adam Jones
Stock Valve Ported Head

Backstory- Stock valve ported heads were not in stock for some time. Wrote to David to express my interest in purchasing one and If he could please keep me in mind once they became available for purchase. Of course David responded quickly and stated something along the lines of- no problem, its been noted and I'll keep you in the loop... Sure enough, he sent me an email few weeks later that they were back in stock, so I purchased one! Port work looks great! I will be pairing this with the DHM 149 Gen2 big bore and S1 camshaft... Highly recommend.

Kirk Russell
Excited waiting

It was sent through US POSTAL SERVICE . I’m anxiously awaiting, but haven’t received it yet (been 10 days, & still not showing it out for delivery). I have high hopes things will be great

Michael Ivory
New Years up grade

Have not installed ported head yet or the 27mm throttle body, aracer, af2 all going on in January, will be glad to rate it then.