i just want to know about the UR problems and hp and tourque gains. what all went wrong and why'd it happen? i like to know things. haha
some people with the ur pulleys experienced oil pump failure!the stock pulley has a two part design that comes together as one inner and outer ring with a hard rubber in the middle separating the two. it is this rubber insert,that everybody is saying makes the stock pulley a harmonic damper.
the nature of dampers on most motors esp.v8s is to compensate for rotation assembly vibrations(crank)and natural vibrations (resonance)that will occur at certain frequencies that a rotating crank and engine combo gives off)
this is my personal feeling now, though it has some merrit that the rubber insert helps with vibrations on a motor thats designed to spin 8.5k,i think it can cause slightly more vibrations but nothing to talk about.
as for oil pump failure,i dont think so.most of the cars that had pump failure were heavily modded cars,and some even had more solid than normal engine mounts.
if the mounts were too solid,the natural vibration of the 2zzge and its harmonics would have vitually no place to be dissipated!thus compounding the problem.i have the ur pulley kit and had only one problem(my battery was dead and it stayed long to charge)
when people started having problems with the pulleys,i asked my tech guy what he thought,at first he was pissed that i bought the pulleys and didnt check to see if the stock was of the damper type(he said i should have known better!)
but when we actually took the pulley off,he was like, i thought you said it was a damper!(i know a great deal about cars,not blowing my horn)but this guy works on hi performance drag cars,boats and bikes! and after he examined the pulley,the tensioner along with the belt system came to the conclusion,that it will cause a slight increase in vibration but nothing to cause the massive oil pump and pre mature engine failure!unless other factors come into play.
an intersting thing to note also,is
1)the fact that my stock pulley did not have balancing holes drilled into it,
2)some of the pulleys that was replaced had as much as four holes drilled into them.
3)and the rubber insert looked thicker in some.
4)some people had difficulty getting the pulleys on the snout for the crank(mine was the easiest crank pulley off/on i have ever seen,the one with no holes drilled) i am of the opinion that all the pulleys should be the same and maybe some of the motors depending on the year,or what ever were offbalanced and the pulley with the holes were used on them to bring them back to tolerance
.this would pose a serious problem if you were to replace that pulley with one that is not balanced in a similar way!
my question is: WHY WOULD SOME CRANK PULLEYS HAVE THAT MANY BALANCING HOLES AND SOME DONT HAVE ANY AT ALL!
it would mean that some of the rotating assemblies are out of tolerance and were balanced by the pulley and those that had no holes were ok.
or it could be the other way around,a shit load of pulleys were nanufactured and were off balanced and those guys just drilled them to get them balanced.
or,it could even be my motor is off balanced and i should have had a pulley with the holes drilled into it and i'm due for some kind of failure !
(true if you look at it from all unbiased angles)
in any case,some thing is up! pulleys with/without holes for balancing,and the fact that they limited the rpm band in some years, when first it was higher then put it back the following year!