Honda Grom Big Valve Head

DH Motoring

Regular price $414.00

Shipping calculated at checkout.

Customer Reviews

Based on 2 reviews
If you need headwork DHM is the place.

I ordered a stock valve, street port with ti retainers for my 143cc big bore, I was honestly blown away from the performance that I got from his headwork. It pulls so hard compared to the stock factory head. Im gonna have him make me another with larger valves for my other 143cc Im building and I can't wait to see the difference between the stock valves and larger!

Awsome head to wake up your Grom

This is a great product, made a Hugh performance difference on my bike. What Makes this a great service is the multitude of options on the head, ie, size valves, porting options and matching to what intake you have. I highly recommend this item.

DH Motoring Big-Valve Honda Grom Cylinder Head

These heads are OEM Honda heads that have been modified with larger intake and exhaust valves. All heads come with a DHM street port, but can be modified with a race port as well. All heads also come with upgraded valve springs with titanium retainers as an option. Prior to shipping, each head has the valves thoroughly lapped to the seat, and all OEM defects are removed from the chamber when it is smoothened. We also install NEW viton valve seals that have less friction and more flexibility than the OEM seals. 

27/23 - This head has only been confirmed to work with DHM pistons and the TB 186 and Koso 170 pistons. If you would like to use it with a different piston you can send in your piston and we can modify it. This is the largest valve head that will work with the stock bore. 

**Each head includes an NGK CR9E spark plug with the spacer necessary to clear the piston.

        Info about our portwork:

Street Port:

Our street port reshapes and enlargens both the intake and exhaust port, which helps with power across the entire rev range. It is especially helpful on bikes with aftermarket camshafts and/or big bore kits. This is a great option for bikes that see a lot of street riding that still want to maintain bottom end torque and still gain some HP up top.

Race Port:

Our race port is an all out reworking of the intake and exhaust ports. The race port is aimed at maximizing high-rpm horsepower. In many cases we will cut the valve guides and raise the intake port to maximize efficiency. The chamber and shrouds will be modified as well. This is the portwork that we use on all of the race bikes. It has won multiple championships and is the only option if you want to have the most power possible from your 2v Grom head. 

**Allow 2-3 weeks for each head to be built before shipping