Comp Cams XD-A Adjustable pushrods

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David_viny
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Comp Cams XD-A Adjustable pushrods

Post by David_viny » Tue Dec 11, 2018 10:41 am

Anyone use these? Doesn't seem to be much information on them. If they work as advertised that would be an easy way to use stock rockers with a solid roller cam in an LS engine. I definitely do question the rigidity of them being a 2 pc design though.

http://www.compcams.com/Products/CC-%27 ... %27-7.aspx

midnightbluS10
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Re: Comp Cams XD-A Adjustable pushrods

Post by midnightbluS10 » Tue Dec 11, 2018 11:09 am

The late model 4.3L V6 uses that same type of rocker arm, also. Same design and everything, just a shorter ratio of 1.5:1. I assume they would work there, also. To run anything other than an oem cam, you have to switch to an adjustable rocker setup. Using these would allow you to use an aftermarket HR cam with the stock, net lash valvetrain. Correct?
Last edited by midnightbluS10 on Tue Dec 11, 2018 11:09 am, edited 1 time in total.
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arlancam509
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Re: Comp Cams XD-A Adjustable pushrods

Post by arlancam509 » Tue Dec 11, 2018 11:09 am

i am probably all wet, but i think because they are 2 pieces (one sliding inside the other), you are effectively doubling the wall thickness and therefore increasing the rigidity. maybe someone with some high level FEA skills can check it out and let us know. this would have been cool 25 years ago when i was going from a hydraulic to solid cam in my 440 dart.

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CamKing
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Re: Comp Cams XD-A Adjustable pushrods

Post by CamKing » Tue Dec 11, 2018 11:49 am

David_viny wrote:
Tue Dec 11, 2018 10:41 am
If they work as advertised that would be an easy way to use stock rockers with a solid roller cam in an LS engine.
Or you could just order a set of longer pushrods from Manton, and not worry about it.
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Re: Comp Cams XD-A Adjustable pushrods

Post by rebelrouser » Tue Dec 11, 2018 1:12 pm

Years ago I ran adjustable pushrods on a 354 Chrysler hemi, after I got the lock nut to quit coming loose they worked ok but they were a pain. This seems like a gimmick to
me, as camking said just get the correct push rods or have them made. If you run a mechanical solid valve train why would you not want the ability to quickly adjust them? If you run a hydraulic valve train, then just take the time to get the correct length push rods. Not sure how they are made, but I would expect you might have issues getting the pushrods to slide apart to adjust, after they have run in the engine for a while?

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Re: Comp Cams XD-A Adjustable pushrods

Post by CamKing » Tue Dec 11, 2018 1:29 pm

another issue is, these pushrods are only adjustable in .004" increments. You need to be closer then that, for setting lash on a solid roller.
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Re: Comp Cams XD-A Adjustable pushrods

Post by arlancam509 » Tue Dec 11, 2018 2:10 pm

if a fella knew someone with a surface grinder, you could grind the .004" shims a little closer to what you need.

on the other hand, the more i think about these pushrods, the more i think they are a solution looking for a problem.

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