Pushrod question for HDWRENCH

[TalonChief]

Steve,

You mentioned in a thread across the street your dislike for quick-install versus through the rocker box adjustable pushrods. I am curious what issues with the quick-installs drove your preference for the other type.

Thanks.

[Berserker]

Not Steve, but got a few minutes. Posting the link would have been nice.

I kept stock, for $, and one less thing to have to do when build. Also once in a great while they come loose. I think due to lack of loctite, and incorrect install.

I would have to read the thread at VTF again. But I thought Steve didn't like the quick or easy install SE ones, can't remember exact name, cause they are made to fit the SE cam. I thought he was ok with certain adjsutable ones.

When I did build he had me reuse mine. Which was fine with me, cheaper. fixed length are lighter also. Thats why you can buy various length pushrods.

Only thing I would have like the adj for is realigning oil pump. If you go gears they cover the alignment holes. I took the gears off and put them back on, not the easiet thing, and not hardest. Need to be careful not put a valve in your piston too.

[TalonChief]

Not Steve, but got a few minutes. Posting the link would have been nice.

Link concerning quick-installs (http://www.v-twinforum.com/forums/showpost.php?p=1251513&postcount=17)
Link concerning Perfect Fits (http://www.v-twinforum.com/forums/showpost.php?p=1251658&postcount=27)


I kept stock, for $, and one less thing to have to do when build. Also once in a great while they come loose. I think due to lack of loctite, and incorrect install.
Shaved heads may preclude using stock rods. Perfect Fits could be used if one happens to end up at dimensions with a length they make.


I would have to read the thread at VTF again. But I thought Steve didn't like the quick or easy install SE ones, can't remember exact name, cause they are made to fit the SE cam. I thought he was ok with certain adjsutable ones.

Yes, the Perfect Fits are designed for known SE cams. He said he was not a fan of quick-installs, but preferred through the rockers.


When I did build he had me reuse mine. Which was fine with me, cheaper. fixed length are lighter also. Thats why you can buy various length pushrods.

If I end up having a significant amount shaved off the heads, the stockers are out. If I get into a dimension where perfect fits ain't perfect, then adjustables are a requirement, unless I have custom rods made, which would be kinda' silly cost-wise in a mild street application.

I just want to know what issues he's seen with quick install type pushrods that lead him to favor the alternate type.

[Berserker]

Ya you could buy exact fit rods. But if you are going to spend money, I would probably get some type of adjustable.

Curious what the best is.

I got .30 head gasket, and 37, with .510 lift and used stock. Dropped them in the hole and forgot about them. Steve sells adjustable and could ahve tried to sell me some, but didn't.

[springer-]

Perfect fit come in +-.030" and +-.060". The stock length obviously being in the middle. Even though stock cylinders vary in length and other dimensions also vary they are within a tolerance. the factory uses the same length pushrod for all new engines. The lifter is hydraulic and designed to compensate for these tolerances. If you start with a stock engine and make known changes to the stack height of the engine, you can calculate what size perfect fit pushrod to use. For example, if you change from a stock .045" head gasket to a .030" MLS head gasket, the stack height is now .015" shorter. Since the hydraulic lifters have approximately .100" of travel in either direction from the stock pushrod, the .015" stack height change can be considered acceptable for use with the stock pushrod.

If the .030" MLS gasket is used and the heads are shaved .015", then the stack height is changed .030" total. In this case it would be good to go to the .030" shorter perfect fit pushrod.

Given that +-.015" is acceptable in the stock pushrod length before it should be changed to the next size, the perfect fit pushrods will cover ALL stack height changes of +-.075". For example, if the heads were milled .060" and the MLS .030" head gasket was used, the stack height change would be -.075". The -.060" perfect fit pushrod with a +-.015" "range of use" would cover anywhere from -.045" to -.075" and therefor could be used.

The perfect fit pushrods are not designed specifically for use with SE cams. They can be used with ANY cam that uses stock base circles and known changes in stack height. They can even be used with different base circles if the math allows them to fall into the correct length range.

[LittleBear]

Problems with quick install pushrods.
Heavier that stock pushrods, more load on the cam bearings and cam components.
Larger diameter of the rod can rub the pushrod tubes and make noise. I had to shave the top tube on the front cylinder exhaust on my EVO to keep it from rubbing.
The adjustment can come loose and really screwup a motor if not caught right away.
Not always true and straight due to the way they are made. I had to buy 2 sets to get 4 straight ones to use. Took the bad set back to dealer.
Not as rigid as a one piece rod.

Despite all that, I run them in both bike without any issues.

Advantages:
Can change cams and lifters without taking off the rocker covers and rocker arms.

[TXCHOP]

Little Bear and springer got it...The only other thing too add is the quick install type has a longer threaded section that a non quick install type. This by design would make it a little weaker, but forums make them sound like failure is going to happen with those. They are not bad for mild builds at all and i wouldn't hesitate to use them. The ones GMR markets now are made by smith brothers for him...

[route66paul]

Little Bear and springer got it...The only other thing too add is the quick install type has a longer threaded section that a non quick install type. This by design would make it a little weaker, but forums make them sound like failure is going to happen with those. They are not bad for mild builds at all and i wouldn't hesitate to use them. The ones GMR markets now are made by smith brothers for him...

Exactly. Most builds are fine with stock pushrods. Non-adjustable is the best bet, stock will work with just about any aftermarket cam that is a slide in cam, and also many high lift cams. If you have a special grind or modified rockers, or shaved heads, you should try something else.

Adjustable pushrods in a mild build are just fine. Many will choose to cut the stock pushrods to save labor. Most street builds rarely see 4500 rpm, much less 6000. I don't think that they are better, though.

[Friday1]

[The adjustment can come loose and really screwup a motor if not caught right away.
Not always true and straight due to the way they are made. I had to buy 2 sets to get 4 straight ones to use. Took the bad set back to dealer.
Not as rigid as a one piece rod.

Adjustable pushrods have two designs and if you are not careful, you will not get them to lock properly after adjusted. You have to look at the way they are threaded so you are locking the proper pieces. I have never seen a pushrod come loose if it was properly locked. No locktite is needed-just locknut tightened properly. Most adjustable pushrods are not straight. Put a new set in the lathe and they will wobble. I have talked to ANdrews about that problem. They were not concerned. Friday

[Berserker]

This is why, when doing my build, first time, I used stock rods. My brain was full, I learned to much and had no more room. Now that the pressure has released, I am curious.

How hard is it do to do my yourself? And we are still left with the question what to use?

Still, I want to do cam my new bike, but when I do it, I will probably do heads at the same time, and just reuse.

The only real reason I am thinking about them, is so I can realign oil pump on m y 01. Not even sure how often it needs to be done, if at all.

Only other thing I can think of would be changing lifters on the road. Which I am not sure if that happens.