Mopar 440 Wrist Pin Size: Length and Diameter
The 440 engine wrist pin size and pistons are often asked. Let’s answer, what size wrist pin and pistons are in a 440 engine?
The 440 wrist pin is 1.0935″-1.0937″ diameter and 3.555″-3.575″ long. The pistons are made to fit a 4.320″ engine bore size.
Continue reading below for more of the 440 engine pistons, rings and wrist pin specifications.
Mopar 440 Wrist Pin and Piston Size: Bore Size, Length and Specs
| 440 Pistons & Pins | |
| Piston Bore Size | 4.320″ |
| Piston Rings | 3 Total (2 compression/1 oil) |
| Wrist Pin Type | Press fit in rod |
| Wrist Pin Diameter | 1.0935″-1.0937″ |
| Wrist Pin Length | 3.555″-3.575″ |
The factory compression ratio changed more than once for both the high performance and standard 440 engines.
Check out my article which covers the ratio for each year and engine, Mopar 440 Compression Ratio.
440 Piston Rings
The factory pistons have three rings. The top two are compression rings and the bottom is an oil ring.
The oil ring is a 3-piece design. It has two chrome plated rails with a stainless steel expander-spacer.
- The compression ring width is .0775″-.0780″
- The compression ring gap is .013″-.023″
- The oil ring steel rails width is .025″
- The oil ring steel rails gap is .015″-.055″
440 Wrist Pins
- Wrist Pin type: Press fit in rod
- Diameter: 1.0935″-1.0937″
- Length: 3.555″-3.575″
- Clearance in piston ( light thumb push @ 70°F): .00045″-.00075″
- Interference in rod: .0007″-.0012″
Other Mopar Engine Piston and Wrist Pin Articles:
If you have any questions about the 440 pistons or wrist pins, send us an email found specifically on our contact page.
For the past 40 years, I’ve been studying and researching Mopar engines including Six Pack pistons. I installed my first Six Barrel pistons and rings 38 years ago while building my first 440 Mopar engine.
More Mopar Engine Articles
Mopar 440 Compression Ratio: Standard and High Performance
Article Resources
- Chrysler Service Manuals: 1969-1971
- Google Books: Chrysler Engines 1922-1998
- Wikipedia: Chrysler B engine
- Stellantis: 100 Years of Dodge
