Pros & cons hydraulic vs. solid tappets

[luske74]

hi again dudes
whats ur point on tappets ??
i prefer the hydraulic ones due to their less workingnoise but what have u guys in ya motahs

Luske74

[fourthgear]

I use solids in all of my personal scoots , the older hyd. just don't seem to be reliable to me . The newer hyd.s are pretty good from what I hear . The other problems with the older hyd. are who( what country) makes the replacements. I know when I set up solids( correctly) they will not have to pump up or pump down when ever they want and some times you don't know if they are all the way pumped up or not . Solids do make more noise even when adj. correctly , but its no big deal. I also believe solids help starting . my two.

[PanPal]

question

If you are running solids on a long trip. What do you hear first when your motor gets hot and should cool down?
Today's traffic lights seem to take much longer to get through before you are on the move again.

[fourthgear]

If you start to here your lifters( Hyd. ) on a long run , you have other problems than a hot engine . HD's run in parades all the time , yes with solids too , and thats longer than a trafic light . When Hd motors get hot they let you know it in a number of ways , preignition, slugish throttle response among other things , you got to know your motor . Hyd. lifter noise can be a number of things , low oil flow ,wrong oil for conditions ( wrong weight ) bad or worn lifters , worn oil pump ect. I could go on for a while. I'm not riping Hyd. , I 'm just not a fan of the older systems.
, they just tend to colapse at the wrong times.

[PanPal]

I prefer hydraulic tappets at this point. I may have oil problems and my tappets let me know. If I run solids (and I do in my modified pan). I become aware of my oil problem because of heat expansion through out the motor. By time the motor is not responding to the throttle, I have run the motor closer to the point of seizer and started to prematurely wear bushings, bearings, pistons etc. (Cringe) With my hydraulics, my oil light will not come on, but my hydraulic tappet tells me it's time before throttle response problems or preignition occur. It also lets me know there are some issues with the oil flow that need some attention. I have had no cold or hot start problems with the hydraulics, so I can not comment.

I believe solids may be great and most times necessary when building a higher performance motor, but you are probably doing your motor a disservice if you put them in because you can't figure out why your hydraulics drop out.

Fourthgear,
I have not had my bike with solids on the road yet. It is good to get some idea of what to expect. The previous owner said he was having heat problems.

[fourthgear]

Having heat problems can be a lot of things , Timing and the dreded EVIL manifold leak are some ,air cooled motors do run kinda hot anyway. I put a set of solids in a guys bike , per his request of course , and he came back about a week later and wanted his hyd. back in because he said it didn't sound or idle like a Harley , even though he said it never ran so good . What ever turns ya on . Its a personal choice as we know and yes they probably do attack the valve trane system some what. I personly have run them and have had no problems with them at all . I do adj. them every season cause its something I do at the start of every year, like alot of other things. As far as starting , when you have a lifter that does not pump up , you will find starting is some what differant than your used to . there are those that say there is not any performance diff. by changing to solids , I for one believe there is , it may be minor .
but, Its very dificult to tell if your lifter is pumping all the way up or not . to me its one less thing to trouble shoot when a problem comes up and I am talking about older HD's. I have had HD's with hyd . and ya can't complain about they way they run when tuned properly.

[Cotten]

IMHO,
Your choice of cam determines your choice of lifters.
(Beware of manufacturers that lie. Or at least stretch the truth to the point of your disaster.)

I have had better luck with Japanese hydraulic units than modern Eaton replacements (the OEM manufacturer!).
The jury is still out on the D I Y units.
If running solids, it is prudent to replace the tappet rollers with every top end. Especially if you like to run them loose.
If running hydraulics, keep your oil clean!

[65flh5326]

Hope I can explain this about lifters OK.
Cams with higher lifts acompish this by having a smaller base circle, that is the lifter actually drops deeper in the tappet bore in operation on higher lift cams.
Since the tappet drops deeper, it many times will drop below the oil feed hole in the tappet block.
The tappet itself can be modified by carefully grinding a notch so it wont starve for oil when its at its lowest point. That is, raise the oilgroove on the tappet at the area of match up to the oil holes in the tappet block.
If one compares a spendy Jims unit to a stock unit it will be apparent.

Don

[flash]

That's a Big blanket statement. It may be true the some aftermarket cam makers use a smaller base circle. But not all. Andrews for one, uses the same base circle as OEM. measure them & you will see.
But I will agree about the lifter groove mod..Better oiling.

[65flh5326]

Better remeasure yourself, Andrews most definitely uses the small base circle, very little can be gained other wise. Simply not enough room.

Don