Truck / SUV
Jeep®
Restoration
Stock Replacement
Late Model Muscle
Tools
Gifts, Clothing, & More
Circle Track
Street Rod
Powersports
Paint & Body
Marine
Jr Dragster
S&S Cycle M8 128 in. Big Bore Kits
2017+ M8 Models 4.250in Bore 4.500in Stroke Cylinder Kit - Wrinkle Black w/o Highlight
See More Specifications
|
Check the Fit
Estimated Ship Date: May 14, 2026 Would you rather pick it up?
Overview
Brand:
Manufacturer's Part Number:
910-0685A
Part Type:
Product Line:
Summit Racing Part Number:
SSY-910-0685A
Cylinder Included:
Yes
Pistons Included:
Yes
Piston Material:
Forged aluminum
Piston Rings Included:
Yes
Wrist Pin Included:
Yes
Wrist Pin Bearing Included:
No
Head Gaskets Included:
Yes
Base Gaskets Included:
Yes
Cam Chain Tensioner Gaskets Included:
No
Exhaust Gaskets Included:
Yes
Valve Cover Gaskets Included:
No
Quantity:
Sold as a kit.
Notes:
Cylinders are wrinkle black with no highlights.
S&S Cycle M8 128 in. Big Bore Kits
The S&S Cycle 128 in. big bore kits are for Harley-Davidson® Milwaukee Eight engines to allow you to upgrade your M8 motor to the largest bore size possible—and without required machining of your cases. So ... go big or go home! These upgrade kits are as simple as big power gets!
S&S Cycle 128 in. big bore kit features:
* 114 in. to 128 in. big bore kit
* Bolt-on kit, the largest cylinder bore possible without requiring machining of the crankcases
* Cylinders are constructed from premium aluminum castings wit cast-in iron liners
* Wrinkle black finish in highlighted and non-highlighted fin versions
* Easy installation; no need to bore or split existing cases—just swap the cylinders!
* 4.250 in. bore, 4.500 in. stroke
* Forged pistons
* 11:1 compression ratio
* All necessary gaskets and hardware required for installation included
Applications
Loading...
Loading...
Questions & Answers
Ask a Question
What type of question would you like to submit?
I have a Customer Service question
(order, shipping, returns, protection plans, etc.). Customer Service Question
(order, shipping, returns, protection plans, etc.). Customer Service Question
- OR -
I would like to ask other customers
a question about this Product. Product Related Question
a question about this Product. Product Related Question
Loading...
Reviews Write a Review
Some parts are not legal for use in California or other states with similar laws / regulations
Modal Header
Call To Order
This is a custom order part. You can order this part by Contacting Us.
Email this page
