Interesting observations: Comp Cams roller rockers with new Smith Bros adjusters

[drdano]

Greetings FEnatics.  I wanted to share some photos of the new Smith Brothers adjusters I just finished mocking up.  I got these adjusters as a recommendation from a fellow in Europe on the other forum.  The adjusters that come with the blue Comp Cams roller rockers just suck from all directions.  The ball side of the adjuster on many of mine had a burr around the edges where they cut the end off the ball and a few chew up the cups in my $8/hit pushrods.     Also, on the opposite end, they use a 1/8" allen on the adjuster, which likes to strip out easily if you're not super careful.  Lastly, the lock nut is 9/16ths nut, but it doesn't fit the recess in the rocker well at all and so you end up with lovely little shards of aluminum you get to pick out of the top of the rocker.   Lastly, on this rant of how much I hate these things, if you inspect the drilled oiler holes on both ends of each one you'll find more chunks of aluminum from the machining process that is just waiting to escape.  Ok, rant over.  I hate these things and as soon as they die I'll never go back to them again.

On with the photos:

Photo of the two adjusters, courtesy of Kimmo.  Smith on top, Comp on bottom.  Easy to see how the bottom of the ball is machined off, I'd say the last 1/4 of it or so and it leaves a nice rough edge that will chew up your pushrod cups if you dont smooth it out somehow.  Full finished ball on the Smith units, no seams or edges at all.  Smith Brothers part is BAS338-14 (add -16 to the part number to buy the whole kit ~$75 as of when I'm writing this), 1.4" length, 3/8-24 threaded with 3/16 allen hole.


Top view, Comp adjuster on the left, Smith Bros on the right.  The Smith Bros unit takes a beefy 3/16ths allen and has a 14mm 12 point lock nut that is smaller on the outside diameter than the oem unit and fits into the rocker better without chewing it up.  You can easily see on the right side rocker where it was chewed up by the lock nut before.


Installed height from the top of the rocker face to the top of the adjuster when setup with preload on the same length pushrod:

Comp adjuster:


Smith Bros adjusters runs .040" shorter for better valve cover clearance


Front view.  Comp on the right.  Here is where things get different.  Same pushrod length for both, but no visible threads (just barely) on the Smith Bros unit.


Side profile.  Non-visible threads on the Smith units, but the pushrod is in the sweet spot right where the rocker is clearanced where it should be


As a test, I mocked in some -.100 length pushrods (8.2" E.L.) to see how the geometry would look with the new adjusters.  Got 2 visible threads now, which is good...but the pushrod is now out of the sweet spot and into looking like it's a tad close to the rocker on the ball cup.


Now at max-lift on the lobe.  I can see light around the back side of the pushrod, but not very much!  It doesn't touch, but I'm not sure I'd trust it...


Ok so given the same pushrod length, we see no visible threads using the Smith Bros units.  I could run the -.100 pushrods, but I know already the contact pattern on the valve face is darn near perfectly centered indicating proper pushrod length and it also puts the pushrod cups dangerously close to the rocker body with the short pushrod.  I'm going to run the same pushrods and and see how they behave, even though there are no adjuster threads visible.  Anyone see any reason to not do this?

Ok, end of the photo essay.  I'm very happy with these adjusters and with Smith Bros in general.  They also replaced all of the cups on my pushrods, not just the damaged ones, for $16 flat.  Cant beat that!  I'd recommend these adjusters in a heartbeat. 

[afret]

The length of the pushrod should not have much effect on the contact pattern of the roller on the valve tip on FE engines.  Probably better to use the longer pushrods since I assume those are the ones that worked with the Comp/Dove adjusters and not have the adjusters stick out too far.

[e philpott]

I agree with afret , your valve tip to roller is determined by the rocker shaft stands .... looks like your Comp adjusters are wore out , but the Smith's will still be nicer than new Comps

[drdano]

You are correct guys.  Since the fulcrum point is fixed on the FE, the pushrod wouldn't have influence on the valve tip wear pattern like you see with stud mounted rockers where the pushrod length influences the fulcrum point.  Good catch there, thanks.  I'll run the longer pushrods since it will tuck the cups up a bit where they should be.  It is a violation of the "2-3 exposed threads" rule of thumb.  I'll inspect everything periodically and report back if I get a ticket for violating the rule.   

The first photo from Kimmo shows his adjusters that he emailed me for comparison.  I don't know how much runtime was on his.  However, after 2hrs of runtime at less than 3000 rpm, mine look just as worn out.   

[Kerry j]

I'm not sure if this relates, but I had to use a .25" shorter than stock push rod with my Edelbrock heads and Dove rocker set up. The stock length push rods would contact the bottom of some of the rocker arms. With the .25" shorter push rods, the adjuster was far enough away from the bottom of the rocker that I had good clearance.

I'm running a Comp 294S cam and dumbell lifters.

Don't know if that has anything to do with what you're doing, but I sure would check that before I ordered push rods.