Anyone try Comp Cams XD-A pushrods?
Thread Starter
On The Tree
Joined: Oct 2012
Posts: 198
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Anyone try Comp Cams XD-A pushrods? https://www.compcams.com/xd-a-7-320-...set-of-16.html
These are two piece pushrods that you put shims in to adjust the length. I've read a few people on the internet have used them and liked them. I would use them with Rhoads VMax lifters instead of adjustable rockers, I think using these with stock style rockers would have some advantages. Just curious if anyone has used them and what your thoughts were.
These are two piece pushrods that you put shims in to adjust the length. I've read a few people on the internet have used them and liked them. I would use them with Rhoads VMax lifters instead of adjustable rockers, I think using these with stock style rockers would have some advantages. Just curious if anyone has used them and what your thoughts were.
TECH Fanatic
Joined: Jul 2007
Posts: 1,800
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From: Wilmington, De
It's an interesting design. I hadn't heard of them until this thread, and found this article about them: https://www.enginelabs.com/engine-te...e-ls-pushrods/
I know they designed them for LS engines, but I immediately thought that these could be used in older small blocks where additional stiffness is desired, but there isn't enough room beyond a 5/16" pushrod without going to a shaft rocker setup. For your typical hydraulic roller LS setup, the only real benefit I can see is saving time because you don't need to measure, order, and wait on the correct pushrods. Otherwise, if you have the ability to either wait or have multiple sets of pushrods on hand, these don't really serve a purpose because you can simply order 3/8" or 11/32" pushrods and be golden.
I know they designed them for LS engines, but I immediately thought that these could be used in older small blocks where additional stiffness is desired, but there isn't enough room beyond a 5/16" pushrod without going to a shaft rocker setup. For your typical hydraulic roller LS setup, the only real benefit I can see is saving time because you don't need to measure, order, and wait on the correct pushrods. Otherwise, if you have the ability to either wait or have multiple sets of pushrods on hand, these don't really serve a purpose because you can simply order 3/8" or 11/32" pushrods and be golden.
What I like about the design is that it allows you to play with lifter preload by changing your pushrod length relatively quickly. And if your not comfortable with the multi-piece pushrods in the engine after you’ve covered your bases and nailed down the exact pushrod length, for that ultra-quiet LS valvetrain, you pull them out and measure with a caliper. Give Manton a call and order your exact length or lengths most of the time. Nailing down a pushrod length is easy at room temp. Allowing for thermal growth and adding that into your pushrods….that’s the tough part. These adjustable rods make that pretty seamless…no pun intended.
