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New Harley-Davidson No-Weld 4.250 Bore Head Gasket Kits

Thursday, February 07th, 2019

New Harley-Davidson No-Weld 4.250 Bore Head Gasket Kits
Harley Davidson Milwaukee 8 Engine - Wikipedia

If you or your customers are interested in installing a 4.250” big bore kit on a Milwaukee 8. Cometic has just made this project a whole lot easier and taken some of the cost out of the project. Cometic is always looking to improve their products and they did it in a big way for the M8. The original design for the Milwaukee 8, 4.250” big bore head gasket could only be used if the oil hole in the head was plugged or welded. For some shops, this isn’t practical and priced the job out of reach for some customers. Now with the newly redesigned M8 head gasket welding that oil hole up is no longer necessary.

You might ask how that was accomplished? The Engineers at Cometic put together a new design that allowed for a 4.250” bore to fit into the bore embossment while keeping enough room for a separate embossment for the oil hole. Making this application a true bolt-on project. Since the majority of the Milwaukee 8 engine out there is oil-cooled and 4.250” is the biggest bore you can install without boring the engine cases this is a huge breakthrough and pretty much makes the 4.250” big bore kit, the go too bore size. The 4.250” bore kit will make your stock 107cu engine a 124cu engine, not bad for installing a cylinder and piston kit. If you have a CVO model that started out as a 114cu or a 117cu this kit will make your engine a whopping 128cu, that my friends are a lot of bolt-on displacement!

Please contact for any technical questions.

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