piston with pin side view

Chevy Piston Pin Heights SBC

Chevy Piston Pin Height

(Compression Height)

piston with pin side view

Chevy Piston Pin height is the distance from the pin to the top of the crown of the piston this does not include any domes or dish.

This has been a much misunderstood fact that can be very important when buying pistons. Often pistons are sold under the name re-builder pistons which often means they are a bit loose and shorter Chevy Piston pin height. This can lead to low compression and too large of a quench distance. With the stock deck height small block that the pistons normally set .025 down from the top of the deck. The re-builder type of pistons will allow the piston to set up to .030 lower so the piston my be below the deck by .055 which with normal gasket thickness of .050 can result in a large loss of compression. Also making the engine more prone to knock as the quench distance has grown so much larger in the process.

Compression Height

Lunati formula for checking deck height,

Compression height = block height – rod length – (0.5 X stroke)

 

An example would be 3.48 x .5 = 1.74

9.025 – 5.7 – 1.74 = 1.585

1.585 – .025 = 1.560″ which is stock Chevy Piston Pin Height for 350

 

OEM piston Chevy Piston pin height. Deck height for sbc is 9.025″

3″ stroke engines

  • 265, 283, 302 with 5.7″ rod = 1.8″
  • 265, 283, 302 with 6″ rod = 1.5″

3.25″ stroke engines

  • 307, 327 with 5.7″ rod = 1.675″
  • 307, 327 with 6″ rod = 1.375″

3.48″ stroke engines

  • 267, 305, 350 with 5.7″ rod = 1.560″
  • 267, 305, 350 with 6″ rod = 1.26″
Note: that since the 350 is so popular they sell pistons with varying compression heights. 1.575″ and 1.585″ is very common with 5.7 rods and other variants are out there that also can help work with stock deck blocks. Be sure to keep a look out for lower than stock pistons as these can adversely effect performance.

3.75 stroke engines

  • 383 with 5.7″ rod = 1.425″
  • 383 with 6″ rod = 1.125″
  • 400 with 5.7″ rod 1.425″
  • 400 with 6″ rod = 1.125″
Note: the 383 is a very popular upgrade to the 350 engine. They have many combos of pistons that are available but it is not uncommon to see 1.440″ pistons for 5.7 rods.

3.875 Stroke Engine (After Market 396/400)

  • 396 with 6″ rod = 1.0625″

I’m sure there are a few combos I missed. From here you should be able to figure out just about any engine out there. With a little measuring and calculator time. Will fill in the other combos as time permits.