Project STurdteen: Building the SR20DET Engine

The crank and main bearings were placed in the block and the main caps were loosely assembled. We will get into why in a bit. Next, the rings were compressed with a special ring compressor tool and tapped into the bores.

The rod bolts were torqued down but not the main caps. After the rod bolts were tight the main girdle and main caps were removed so we could install the windage tray and crank scraper.

The crank scraper was tapped into place on the main studs.  We would have to hand fit the teflon blade part of the scraper to the crank counterweights and the rods for minimal clearance.

The Teflon scraper blade must be trimmed so it just touches the crank counterweights and just misses the rods and rod bolts.  This way it can strip as much oil that is whipping around the crank as possible and return it to the pan.  This reduces friction, oil temperature, reduces oil consumption and gets rid of a lot of entrapped air in the oil.  We have seen the oil temp drop 10 degrees in other racing SR’s we have built when we added the scraper and windage tray.

You can see how close the scraper comes to the rods and rod bolts here.


  1. For competition engines, I prefer not to use them because they are torque to yield and they stretch and take a set. They can only be reused maybe once and it’s a good idea to change them every time on a serious engine.

  2. for the mains, did you guys use arp’s torque spec or something else? I always thought it was a bit high

  3. Are you modifying the upper oil pan to clear the windage tray or did you find/make a spacer? the jet nuts on my tray touch the upper pan and require me to mod my pan.

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