How To Measure Jesel Rockers For Pushrod Length Part 1

Click Here to Begin Slideshow In our last issue, we checked out several different pushrod length checking tools – a set from Jesel , an older (obsolete) set of tools from the late Crane Cams and finally, a set of checking tools from Trick Flow Specialties. There are others available, but this is what I have in my tool box. This time around, we’ll go right into the checking process. Anyone can do it. Here’s the Jesel method for measuring pushrod length: Starting with cylinder number one, rotate the engine until the intake lifter is on the camshaft base circle. This is opposite from full valve lift. Assemble the adjustable checking pushrod to the approximate length. Install the pushrod on the intake lifter and bolt the rocker arm to the rocker stand. Inspect closely for any interference the pushrod may encounter with the cylinder head and correct as necessary. For the more common cup style lash adjuster style, set the rocker adjuster one full turn down from the fully seated position. For ball style adjusters, set the top of the adjuster flush with the adjuster nut. Next, screw out the ends of the adjustable pushrod until they make contact with the adjuster. Select a feeler gauge blade that is equal to the cold lash specification for your camshaft. Insert it between the rocker arm roller tip and the tip of the valve. Tighten the adjustable pushrod. Remove the rocker arm and inspect the pushrod. With the TFS style of pushrod, you can count the number of turns (on the etched scale) the adjustable pushrod has made, or how many turns it takes to go back to zero. This allows you to determine the correct pushrod length. As a heads up, I also make it a practice to measure the “gap” in the adjustable pushrod. Add the “gap” to the closed length of the pushrod and you should come up with same dimension as you have with the number of turns on the scale on the side of the pushrod. This is just a good double check. At this point, you can repeat the process for the next pushrod in the cylinder. Some folks measure one intake and one exhaust and call it a day. I prefer to measure each pushrod. As Jesel points out: “Due to variances in engine machining processes and camshaft grinds, it is not uncommon for pushrod lengths to vary from one bank to another or from one cylinder to another.” Keep that in mind when ordering pushrods. Something you must always consider with a checking pushrods is that they are not sufficiently strong to allow you to rotate the engine with them installed. Case-in-point are the springs used on the engine shown in the photos. Each has a seat pressure of 270 pounds and an open pressure of 775 pounds. As you can well imagine, that sort of pressure will mangle an adjustable pushrod if you attempt to rotate the engine. In the end, dialing in the correct length pushrods for your engine isn’t really a difficult job. It just takes some time along with a couple of inexpensive pushrod length checking tools. For a closer look at the process, check out the accompanying photos: ### Sources: Jesel Valvetrain Innovation 985 Cedar Bridge Ave. Suite 2 Lakewood, New Jersey, 08701 PH: 732-901-1800 Website: https://www.jesel.com Trick Flow Specialties 285 West Avenue Tallmadge, OH 44278 PH: 888-841-6556 Website: www.Trickflow.com Click Here to Begin Slideshow

How To Measure Jesel Rockers For Pushrod Length: Part 1

Click Here to Begin Slideshow

When you purchase a new set of shaft rockers from Jesel(or actually, any roller rocker for that matter) it’s a good idea to check how the rocker sweeps across the valve tip. Sweep is established by way of the rocker stand height. And equally important, you have to accurately determine the length of the pushrod. Dollars to doughnuts, you’ll need new pushrods. Once you have the rocker shaft height figured out (another story), you can investigate pushrod length. This isn’t a difficult job, but you will need a set of adjustable pushrod length checking tools to get it done.

Jesel offers three different pushrod length checking tools – two for cup style adjusters and one for ball format adjusters. Other manufacturers offer similar tools. In the photos that follow, I’m using checking tools from Trick Flow Specialties. These particular tools are marked with a laser-etched alignment line. Each full rotation of the adjustable pushrod represents 0.050-inch. As an example, if you have an 8.800-inch checking pushrod and it’s fully screwed together, if you turn it out one revolution for your setup, then the correct pushrod is 8.850 inches (the standard 8.800-inches + 0.050 = 8.850-inches).

If the pushrod length checking tool(s) you use are not marked, then you’ll have to accurately measure the length of the pushrod by way of a large caliper. Calipers that open to 9 or so inches (or longer) aren’t really that common in many enthusiast tool boxes. Finally, for some engines, such as the big block Chevy shown here, you’ll need two tools – one for the intake rocker and one for the exhaust.

For this portion of the article, we’ll look closely at several different types of adjustable checking pushrods in the accompanying photos. One set from Jesel, one set from the “old” Crane Cams (unfortunately, now obsolete) and one set from Trick Flow Specialties. In the next article, we’ll show you how to actually measure for custom pushrods. The reality is, the entire process is not that difficult!

For a closer look at the checking pushrods mentioned above, take a look at the accompanying slideshow:

Click Here to Begin Slideshow

How To Measure Jesel Rockers For Pushrod Length Part 1

I have several different sets of adjustable pushrods in my tool box. Included in the mix (and from the left) is a set from the old Crane Cams. The set in the middle is from Jesel. Finally, the set on the right is from Trick Flow Specialties.

How To Measure Jesel Rockers For Pushrod Length Part 1

The old Crane pushrod tool adjusts by way of a common 3/8-inch wrench.

How To Measure Jesel Rockers For Pushrod Length Part 1

This is a complete Jesel adjustment set. Included are two ball adjusters, one cup adjuster and sufficient threaded aluminum tubing to make up just about any pushrod length or configuration you’ll need.

How To Measure Jesel Rockers For Pushrod Length Part 1

Here you can see how the Jesel setup assembles.

How To Measure Jesel Rockers For Pushrod Length Part 1

Both the Jesel and the Crane adjustable checking pushrods must be measured with an accurate (large) caliper to determine length. See the text for more info.

How To Measure Jesel Rockers For Pushrod Length Part 1

The Trick Flow Specialties tool also adjusts, but you really don’t need a large caliper to figure out the length. See the next photo:

How To Measure Jesel Rockers For Pushrod Length Part 1

As you can see, the tool is laser-etched with a scale. One full revolution equals 0.050-inch in length. More info in the text.

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