Why???
Tourer
Joined: Aug 2010
Posts: 320
Likes: 24
From: Hudson Valley
What wasn't as good about the evo lifters?
Can you explain what is different internally between evo lifters and twin cam lifters?
HDF Community Team
Joined: Jun 2006
Posts: 12,763
Likes: 2,597
From: san antonio
djl, you stated "One reason why the service manual recommends replacing lifters at 35K mile intervals." Exactly what service manual are you referring to? I had someone tell me that pushrods should be replaced every 25K miles and said the "service manual says so" and still cant find that one. This was for an EVO motor. I am by no means a mechanic but I do try to understand the best I can. thanks!
HDF Community Team
Joined: Jun 2006
Posts: 12,763
Likes: 2,597
From: san antonio
Originally Posted by inverse121
Okay, if the OP is adjusting to what the two of you are calling zero clearance, its going to be a really noisy valvetrain if it runs at all. The lifter should actually be compressed past zero lash approximately half of its travel or .100"
Originally Posted by djl
You can try taking them down another half turn or even another full turn. Some adjust from the bottom up by bottoming out the lifter travel and backiing off a full turn. Try re-adjusting, more preload on the lifter and see if that helps.
A lifter plunger has approximately .200" of travel and a properly adjusted pushrod should be set at the center of the plunger travel. This adjustment will allow for expansion of the engine components and shortening of the distance from the lifter to the rocker arm as the engine comes up to operating temperature and/or other manufacturing measurement inconsistencies all the while maintaining a zero lash = zero clearance valve train condition. As I pointed out in my post #2, some adjust push rods by bottoming out the plunger travel to .200" and backing off a half or full turn leaving approximatley .025" of travel at the bottom of the lifter. Not a practice I subscribe to but one that many do subscribe to.
So, if the OP has not adjusted the pushrods in accordance with the manufacturer's instructions, that would certainly explain the noise.
Originally Posted by inverse121
Also, on our twin cams if you pull your tappets you'll noticed that the sides have flat areas on them. The tappet anti-rotation device goes against these flats to keep the tappet from turning in it's bore. Sometimes you will get some noise as the from the factory tappets if the flat does not extend down far enough as the body hits the anti-rotation device at full lift.
HDF Community Team
Joined: Jun 2006
Posts: 12,763
Likes: 2,597
From: san antonio
1. TC roller diameter is smaller.
2. TC lifter body smaller in diameter on the Evo; shape different.
3. Not sure but bleed rates are different.
You also have to be careful when generically stating that TCs use "Chevy" lifters now. The small block chevy lifters will work but there are many suppliers of small block chevy lifters and the quality varies considerably from one manufacturer to another. If considering small block chevy lifters one should verify that the supplieris Delphi; if not by Delphi, don't buy.
Tourer
Joined: Aug 2010
Posts: 320
Likes: 24
From: Hudson Valley
Also, on our twin cams if you pull your tappets you'll noticed that the sides have flat areas on them. The tappet anti-rotation device goes against these flats to keep the tappet from turning in it's bore. Sometimes you will get some noise as the from the factory tappets if the flat does not extend down far enough as the body hits the anti-rotation device at full lift.
This is possible but in the rare event that it does, it would most likely be the result of manufacturing tolerances. This would be the last place that I would look for valve train noise. There are several HD cams with lifts over .600" and nowhere in the SE Performance catalog is it recommended or suggested that OEM lifters will not work.
Next time I pull a set of TC lifters, I will take it apart and take some pics for those that think the twin cam lifter is really different from an evo lifter.
All of this being said, I just don't seem to have witnessed the valvetrain noise or adjustable pushrod problems that seem to pervade the members of this forum. Of course if anyone wants to hear valvetrain noise, I'll ride my solid lifter pan next to them. for a while.
HDF Community Team
Joined: Jun 2006
Posts: 12,763
Likes: 2,597
From: san antonio
Originally Posted by inverse121
Next time I pull a set of TC lifters, I will take it apart and take some pics for those that think the twin cam lifter is really different from an evo lifter.
All of this being said, I just don't seem to have witnessed the valvetrain noise or adjustable pushrod problems that seem to pervade the members of this forum. Of course if anyone wants to hear valvetrain noise, I'll ride my solid lifter pan next to them. for a while.
All of this being said, I just don't seem to have witnessed the valvetrain noise or adjustable pushrod problems that seem to pervade the members of this forum. Of course if anyone wants to hear valvetrain noise, I'll ride my solid lifter pan next to them. for a while.
Having said that, sometimes I think there are those that think a Harley should be as quiet as a Honda. However, an air cooled, vtwin pushrod engine just makes noise.
Picture of dis-assembled lifter attached compared to small block chevy lifter that some use in lieu of Harley lifters.
6th Gear
Joined: Jun 2008
Posts: 13
Likes: 0
I have experienced valve train noise; noise so loud that it made riding the bike unpleasant. Chased it for months; finally installed a set of Woods new directional lifters, problem solved.
Having said that, sometimes I think there are those that think a Harley should be as quiet as a Honda. However, an air cooled, vtwin pushrod engine just makes noise.
Picture of dis-assembled lifter attached compared to small block chevy lifter that some use in lieu of Harley lifters.
Having said that, sometimes I think there are those that think a Harley should be as quiet as a Honda. However, an air cooled, vtwin pushrod engine just makes noise.
Picture of dis-assembled lifter attached compared to small block chevy lifter that some use in lieu of Harley lifters.
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Road Warrior
Joined: Apr 2010
Posts: 1,832
Likes: 3
From: North Georgia
I know it's an old thread...however, I learned a lill sumptin when I did my project that I'll share with those who "wanna know."
The adjustable pushrods have a larger dia hole for the oil passages. Larger hole equals more volume. More volume equals more weight (Force.) This may amplify the "hammering" effect on the valvetrain...by product is increased noise.
While this may not be harming anything...it may become annoying.
Leason for the day...
Don't be lazy and go ahead and pull your tank so you can access your rocker covers. Use your stock pushrods since there is absolutely nothing wrong with them.
Or...cut your stockers and put your adjustables in. Try to get them set "just right," and wonder if they'll ever back off. Then you can ride while listening to that wonderfull hammering goin' on between your knees.
Choice that each has to make for themselves....choose wisely!!
Just sayin'
Beav
The adjustable pushrods have a larger dia hole for the oil passages. Larger hole equals more volume. More volume equals more weight (Force.) This may amplify the "hammering" effect on the valvetrain...by product is increased noise.
While this may not be harming anything...it may become annoying.
Leason for the day...Don't be lazy and go ahead and pull your tank so you can access your rocker covers. Use your stock pushrods since there is absolutely nothing wrong with them.
Or...cut your stockers and put your adjustables in. Try to get them set "just right," and wonder if they'll ever back off. Then you can ride while listening to that wonderfull hammering goin' on between your knees.
Choice that each has to make for themselves....choose wisely!!
Just sayin'
Beav