What's up everyone, I wanted to start a thread to talk more about going with perfect fit push rods for a new cam installation. I've searched a lot and no one seems to go that route very often here. I know adjustable PR have their place.


I'm about to order woods cams, woods lifters, fuel moto perfect fit push rods for my installation. I also have already order the Rockout rocker shaft inserts. Which is my main reason for going with perfect fit push rods. Since I will be removing the rocker covers and rocker plate assembly, Why fool with adjustable PR.


My question to everyone, Aside from ease of installation of adjustable PR, is there any other advantages of going with adjustable vs perfect fit PR.


After all, its not hard at all to remove rocker covers and rocker assembly. I don't know why more people don't install them. Seems like adjusting push rods to the correct length is a pain. And what happens to an adjustable should your lock nuts back off and comes out of adjustment. Not an issues with perfect fit PR.

 

Because adjustable can be, in theory, adjusted to be perfect.

Perfect fit pushrods are one fixed non-adjustable length.

There are many parts involved in the valve train, all have tolerances (including the fixed length pushrods) and no two parts are exactly the same. All these small differences in the parts in the valve train add up, and from engine to engine can be quite different even with the exact same parts.

Thats why builders prefer adjustable, at least thats how it was explained to me by Fuel Moto. I suppose he's selling perfect fits to you because you want them, not because they recommend them

As far as the adjuster nuts backing out, if you do it right, they wont. I made damn sure mine were tight, no issues in over 16K miles. Some use locktite, but I didnt.

 

Well it doesn't just come down to this. Yes removing the rocker covers isn't that big of a deal but what is more of an annoyance is removing the fuel tank, console, and associated hoses and wiring and those obviously must come off before getting the rockers out. Adjustable pushrods seem to get first timers nervous but do it once with reputable brands and you'll never look back. If adjustable were that bad you'd read about it all over this site.

However, get what you want and I'm sure it will be fine. Contact Woods and see what he reccomends.

 

I did the adjustable push-rods. i also did EVO push-rod tube because they have a bigger opening to get the wrenches in to adjust the rods.

 

I reused my stock pushrods when I put cams in since I was replacing the rocker boxes with chrome ones anyway. Two weeks later I cut them out and put in the SE adjustable ones.

 

I use adjustables to facilitate cam changes in the future if needed. I have one bike with almost 180k miles on it, adjustable pushrods have never backed off and the same set has been in the bike since the first cam change at 15k. I've changed cams 3 times since the first change but same adjustable pushrods. No problems.

 

I have heard one theory that adjustable pushrods can increase ticking/tapping etc. The theory was that because they are a lot heavier, the accelerating/decelerating mass can collapse the lifters a bit. Makes sense, I don't know if it actually happens.

Seems like once a builder knows the length that works best for them the perfect fits would make things simpler.

 

amen to all that

 

The biggest reason to not use adjustable push rods to be is their weight, 3 perfect fits weigh about as much as 1 adjustable,So that weight is on the valve train.

 

Weight on the back side of the rockers arms isn't a deal breaker with a pushrod engine, especially in the rpm range these engines operate.


I'm not saying that it isn't important, just not a big deal in the HD V-twins.


There is absolutely nothing wrong with fixed length stock type pushrods either. There is enough travel in the plungers on the stock type hydraulic roller lifters to compensate for minor variances in the parts used. I still like and use adjustable pushrods for the shear convenience of not having to take off everything above them for cam changes or lifter replacements, etc.......Cliff