Hi everyone,

I'm getting ready to upgrade my cams. I was talking to my indy (who will be doing the work) and the subject of pushrods came up. I asked him if he would be using the adjustable rods. He told me that he really didn't like using them. His view is that they are thinner (which causes more noise) and there is always a chance that the adjustment will loosen up.

He uses custom machined rods that he finds are better in the long run. Of course this also means that he needs to take the top end off in order to do the cams (which makes it more expensive).

Would like to get some feedback from folks... does he have a point? Or should I insist on using the adjustable pushrods?

 

IMO if you can avoid using the adj pushrods thats 1 less thing to worry about (i.e. adjusting nuts on the rod) unless the labor cost is an issue.
Also, I see you're in Philly...who's doing the work.

 

Take the advice of your indy! There are several ways of doing this and the final cost is likely to be little different to any other indy IMHO. He is recommending something he knows works, which is why we go to indys.

 

Dave @ http://www.jdscycleworks.com/ is doing my upgrades as well as the dyno tune (which he has a very strong rep for).

The only reason I'm wondering is because if you look at the indy videos, almost all of them use the adjustable rods. If the rods where an issue, why would so many use them?

 

Dude..Dave is the man! Trust me, whatever he suggests is want you want to do. BTW ask him to show you his Roadking (145" engine); it puts out 200 hp on pump gas.

 

You're watching too many videos!

Don't think any more about it - either go with your man or find someone else.

 

Why dont you do the work yourself?

 

I too am a little confused by the adjustable pushrod issue.
My understanding is that they were made to allow cam changes or cam chest work without having to remove the rocker boxes. Just cut out the old pushrods with bolt cutters and use adjustable pushrods during re-assembly.

If one is doing a big bore kit, or is not averse to removing the rocker boxes during whatever work he is doing, then why wouldn't you just put one piece push rods back?
Why not re-use the stock ones unless better quality and lighter pushrods are desired.
We are not turning outrageous RPM's with these motors that would require space age materials.
Even with a higher lift cam I would expect there to be enough travel in the hydraulic lifters to accommadate the few hundred thou difference in lobe lift.

Am I missing something here?

 

if he's using a custom rod thats probally a good thing. stock rods bend...have 4 off a bike with 11K miles to prove that legend....and adjustable rods are not trusted...32 TPI rods had aluminum nuts that broke in services and the 24 TPI recent rods are hardend steel which won't break but are heavy. I have the SE adjustsbles and sometimes I hear crickets in the rocker area...it makes me want to take those adjustables out and put stock rods in there.

 

In the context of a straight forward big bore kit upgrade, using the OEM pushrods would be a good choice.

However, there are other variables to be considered if you go beyond a simple big bore upgrade. If the heads are decked, thinner head gaskets used or cams selected that have a different base circle all impact the valve train stack up height. In that situation, one can do the math and perhaps use the H-D Perfect Fit pushrods or order a set of custom fit one piece pushrods in lieu of using adjustables if one is concerned about using adustable pushrods.

The are several reasons there are so many adjustables in use; shops use them to save man hours and get the bikes done and out the door; some guys change cams more often than others and adjustables make the change easier; having the ability to apply more preload to quiet valve train noise are the obvious reasons. In spite of the occasional adjustor not coming loose, there aren't really any issues with adjustables.

There is .200" travel in the OEM hydraulic lifter. The typical pre load setting locates the pushrod about .100" into the lifter, leaving about .100" of lifter travel. However, there is no relationship between lifter travel, pushrod length and cam lobe lift. Regardless of cam lobe lift, .100" will be the starting point for lifter preload. The valve train stack up height tacking in to consideration the amount of material removed from the head surface, the thickness of the head gasket and the base circle of the cam will determine the length of a fixed length pushrod.