Project Potent Rodent: Overhead Auxiliary Camshaft Oiler - Trucks 4x4 @ Off-Road.com
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Project Potent Rodent: Overhead Auxiliary Camshaft Oiler
Publish date: Nov 1, 2000
By:  Shawn Spickler
Source: Chevy at Off-Road.com
For the ultimate power plant, you can’t beat the power of a big block Chevy. This engine produces major torque and horsepower which proves there’s no substitute for cubic inches. A normal aspirated big block Chevy "rat" engine can easily achieve over 500hp and 500 lbs. of torque and still be a daily street driver. Despite having gobs of horsepower and torque, the big block Chevy has one flaw that the GM engineers never fixed. It's notorious for chewing up new camshafts. Even with proper break-in procedures, experienced and professional engine builders have camshaft failures with flat lobes. This was actually the case with the first big block that was installed in project Rodent. The big block's poor oiling system and the angle at which the lifters are situated are the primary causes of this failure. Because of this, the camshaft doesn’t get enough oil and may fail at an early stage.

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Bob points out where the big block Chevy engine lacks lubrication. This area is where the camshaft lives.
Fortunately, Bob Cherveny of B.C. Engineering figured out a way to correct this problem which GM should have taken care of years ago. It’s actually a quite simple design. A tube with several small holes is mounted above the camshaft and gives it a constant oil shower. The tube is installed into the last oil gallery that the oil travels. This area is located above the front bearing of the camshaft and an inch towards the passenger side of the engine. The 1/4" tube and some brass fittings are installed in the gallery and held in place across the rocker valley with small tubing clamps. The end of the tube is plugged so the small holes is the only place the oil can go. This will definitely assure a longer cam life of the engine. The kit comes with all the necessary parts to do this plus videotape on how to do the installation. For this installation, the videotape is much easier to understand compared to written instructions. You just can't beat the actual footage of the installation. For most of these photos, we took them off the actual videotape.

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The parts included with the kit are the oil tube, brass fittings, tubing clamps, clamp screws and the instructional video tape was very helpful.
The installation will require the removal of the manifold, water pump, camshaft, lifters, and the oil pump if not already equipped with a high-pressure pump. If the engine happens to be going through a rebuild, it would be best to have this done before all components are installed even though you can install this kit without having to dissemble the entire engine. Just be sure to vacuum the metal shavings from the drill and tap. Installation
  • The first step is to grind the flashing from the 4 window oval-shaped holes above the camshaft. If you're crankshaft, rods and pistons are left in place this step can be skipped. This assures that every lobe on the camshaft will get some oil. Sometimes the flashing can be in the way of the oil.
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The extra flashing is grinded to open up the cam windows a little.

Here's the hole that the oil tube taps into. This oil gallery is located above the front cam bearing and an inch towards the passenger side.

  • Next step is to drill the hole in the oil gallery above the front camshaft bearing and a little towards the passenger side. This is done using a 21/64" drill bit.
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The oil hole is drilled using a 21/64 bit.

The hole is then tapped using a 1/8" pipe tap.

  • After the hole is drilled, a 1/8" pipe thread is used to thread the hole. After the hole is tapped, a vacuum is used to extract the shavings followed by a telescoping magnet and compressed air.
  • The tubing clamp mount holes are drilled and tapped next. The mount locations are found buy placing the tube in the mounts and the tube is placed in the middle of the cam windows. A punch is used followed by a 9/64 drill bit and an 8/32 tap. Two holes are drilled/tapped at the front and rear portion of the rocker valley. Bob notes to be careful tapping these smaller holes since the tap could break and get stuck in the hole.
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The tube clamps are fastened to the block using a 9/64 bit and an 8/32 tap.

The brass fittings are installed.

  • The brass fittings and oil tube are then installed in the tapped hole. A 7/16 wrench is used for the first fitting, then followed by a 1/2" wrench to secure the tube and crush sleeve.
  • The tubing clamps are then installed and the tube is held firmly in place. #8 machine screws are used for the clamps.
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Here's what the tube looks like from underneath.

The tube and clamps installed.

  • Since the high-pressure pump tends to walk the cam towards the rear of the engine, this makes the cam sprocket dig into the block. Bob recommends drilling a .060" hole in the front of the block that makes contact with the cam sprocket. This will lubricate the contact area and reduce friction and wear.

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Bob also points out that a small hole should be drilled in the front of the block to lubricate the cam sprocket.
With the added insurance of the camshaft getting enough oil, we can be assured that flat lobe BBC problem won't ever happen. This is especially important in our case since were installing a "not-so-cheap" roller camshaft soon. Not to mention, this oil kit will reduce friction between the lifters and camshaft, which means improved power and gas mileage. The tape really makes it clear on the necessary steps involved, which means a proper installation. For any big block owner, this should be put on top of your list. Price:
Pre-made tube with fittings: $50
Pre-made tube with fittings and video: $65
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148 South 17th Street
Grand Junction, CO 81501
Phone 970-243-5438
Email: bceng@webtv.net
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Source: Chevy at Off-Road.com, 11/1/2000
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