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4.6L Diamond Competition Series Pistons / Molnar H-Beam Connecting Rods Combo

Includes Piston Rings. Available for 2V, 3V and 4V applications.
Pricing: $1,469.00

Customize Your Item

- Select Bore Size -
 * required
- Select Volume / Cylinder Head -
 * required
- Select Wrist Pins -
 * required
- Add Ceramic Dome Coating -
 * required
- Add Lateral Gas Ports -
 * required
- Select Connecting Rods -
 * required
- Add Rod Bearings? -
 * required
- Send in Crankshaft for Balancing -
 * required
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  • Diamond 4.6L Competition Series Pistons 
    • Full Round Forging - 2618 Alloy 
    • 1.220" Compression Height 
      • Approx 0.012" Piston to Deck Clearance with Stock Block 
    • Standard, .010" or .020" Over Bore
    • 2V PI, 3V and 4V Specific Designs 
    • .280" Down Top Ring Land 
    • Moly Coated Skirts w/ Diamond Logo 
    • Includes 1.2mm x 1.5mm x 3.0mm Piston Ring Set 
      • Gas Nitrided Steel Top, Cast Iron 2nd, 3 Piece Oil 
      • Excellent for power adder applications 
    • .180" Wall 8620 Wrist Pins with Round Wire Locks 
  • Molnar Forged 4340 H-Beam Rods -Standard Weight
    • 7/16" ARP 2000 Rod Bolts 
    • Heavier Beam PWR ADR version available as an upgrade
  • Optional Upgrades
    • Lateral Gas Ports - Suggested for 20lbs + Boost
    •  .200" H-13 Tool Steel Pins - Suggested for 800 HP +
    • Ceramic Dome Coating - Thermal Barrier helps with piston fatigue  
This 4.6L Diamond Competition Series Piston / Molnar H-Beam Connecting Rod Combo is an excellent choice for applications all the way up to 1500+ HP with the correct upgrades. The Diamond Competition Series Pistons that come in this kit are available for the 2V PI, 3V and 4V (B,C, Navi, FGT) Heads. Please see the Compression Ratios tab for details.  
Options and features explained: 
  • Moly Skirt Coating - The Moly Skirt coating helps reduce friction and protect the skirts during warmup and cold starts. This is a standard feature. Normally it will come with the Diamond logo printed. Sometimes it will come sprayed on. The only difference is the Aesthetics, as both the screen print and spray on coating serve the same purpose. 
  • Optional Ceramic Dome Coating - The Ceramic Dome coating is optional and definitely not necessary on most applications. It does however, create a thermal barrier at the piston crown and has no negative effects. By having a barrier at the crown, the rest of the piston is protected from the extreme heat of the combustion process. Less heat means less fatigue. Overheating the Aluminum alloy will eventually "Anneal" it and counteract the heat treat which gives the piston it's strength. 
  • Optional Lateral Gas Ports - Suggested for boost levels over 20lbs. The gas ports allow combustion gasses behind the top ring, pushing it out harder against the cylinder walls for better sealing. These work very well with the smaller top rings and will not prematurely wear out the cylinder walls. 
  • Optional  Wrist Pin Upgrade - While you will not break a .180" Wall 8620 Pin at 800 HP or even 1000 HP, we suggest the H-13 Tool Steel Wrist Pin upgrade at 800 HP for one reason...rigidity. The H-13 Pins are more rigid. We have seen plenty of wrist pin flex around the 800-900 HP mark with standard 8620 or 4130 alloy pins. The flexing wrist pin will gall up the pin bores of the piston and damage the pin bushing in the connecting rods. This simply shortens the life of both components. 
  • Optional PWR ADR Rod Upgrade -The PWR ADR Version of the Molnar H-Beam Rods are a good choice for applications that will be making over 1200 WHP. The standard weight rods will do just fine for anything up to at least 1200 HP and will help save some reciprocating weight. 
  • Add Rod Bearings: Both King XP Series and Clevite H-Series Rod Bearings are a good choice. We offer them both in standard and coated versions. King uses their own in-house coating process. We have the Clevite H-Series Rod Bearings coated for us by Calico Coatings. 
  • Send in your crankshaft for balancing: Your crankshaft will need to be balanced to the rods and pistons. We offer in-house balancing and keep extremely tight tolerances. Rod bearings are required for balancing, so you will need to make sure you purchase a set of rod bearings from us when you order if you would like the balancing option. You cover the freight in, we cover the freight out. Includes a 3 Stage Polish and cleaning after balancing. 
Some Pistons in this kit are built to order. Please allow 3-4 Weeks for Delivery. 

Compression Ratios

Compression Ratios Calculated with a 3.620" x .036" Compression Thickness Head Gasket and a .010" Piston to deck clearance. Standard 3.543" Stroke. 


2V PI 42cc  3V 50cc  4V 52cc 
-0.6cc FT - 3V Only    11.0:1  
-1.5cc FT - 2V Only  12.3:1    
-2.0cc FT - 4V Only      10.4:1
-3.5cc Dish 2V / 4V  11.9:1   10.1:1
-5.0cc Dish - 3V Only    10.2:1  
-7.0cc Dish 2V Only 11.2:1    
-7.5cc Dish - 4V Only      9.6:1 
-9.5cc Dish - 3V Only    9.6:1  
-11.5cc Dish 2V / 4V  10.4:1   9.1:1 





Shipping Information

  • Item Requires Shipping
  • 35.0 lbs.
  • W14.0000” x H14.0000” x L28.0000”
  • Free Shipping!

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