mrz udp

[andrew383]

well well well i think i have started an up roar all good info thanks. now im P.O.ed that i have to change the timing ring back

[CNCguy]

Well said Geoff. As I have always pointed out in the past, if GM could eliminate the dampener without causing problems, they would do it in a heartbeat. They are always cutting costs any way possible.

I try to stay out of these UDP/dampener debates as they almost always turn into an argument. I have strong negative feelings about not running a dampener and have refused to make UDPs until I can work out a way to incorporate a dampener. Sure it would be nice to make a cheap one to compete with the others but not when I know it isn't the right way to do it.

[andrew383]

i dont want any arguements here just info

[34blazer]

I think the biggest thing is people are confusing is balance with dampening. Yes the 660 is internally balanced. It is almost perfect. A 60 Degree V6 produces a primary and secondary rotating couple. The primary couple is simply balanced out with counterweights at the ends of the crank. The secondary couple only amounts to about 220LBs/ft at 4000rpm so it is not noticeable. And is left alone. A 90* V6 produces such a large secondary rotating couple that it is noticeable and most use a balance shaft to cancel it out. In case people are wondering this force is never balanced it still exists on the internal parts but the balance shaft masks it. So if you don't care about smoothness then ditch your balance shafts.

Anyways onto the the real function of the damper. Don't visualize a crank from the side. Visualize it from the end. Staring at the damper. Off of the center comes each crank throw and of course off of that comes the rods and pistons. Every time a piston fires it produces a huge force that pushes down on the crank throw and this forces is transfered to the center of the crank creating a twisting motion on the center of the crank. This force winds up the crank like a spring and the crank fights back by returning to its natural state. Now imaging just this one springing motion on every throw times 6 throws several times each second. All of this causes vibration in the crankshaft, completely independent of the pistons and rods, but around its axis. There is only 1 way to take care of these forces and that is with something to absorb them and transform them to something harmless. In this case, heat. That is the job of the damper.

So what happens without a damper? Well your crank bearings will not suffer like many think. What does suffer is rod bearings, piston pins, timing chains, valvetrain components and distributor gears.

You will not find a single car manufactured without one. You will also find the same is true for any form of endurance racing. Drag racers get away without one because the engine is usually built to mammoth proportions and the engine is looked at after every run.

Yea your street engine might last a good while without one. But you wont ever notice a problem until these forces do enough damage to push things beyond specifications where enough slop exists to cause a noise. Plus if you chug along around 2000RPM and never really work the engine hard then you may not arrive at these damaging results quite as fast.

The last benefit of a damper is POWER. Since having one dramatically improves smoothness in the valvetrain and distributor (if you have one) resulting is more accurate valve and ignition timing. I have never herd of anyone on this site reporting power gains from the UDP maybe the above is an answer as to why?

well said

[loner666]

well either way its staying on my car..if it does cause the crank or something to go then o well..more reason to build it they way i want it but i have a few years left on that

[andrew383]

has anyone had one of these cause a failure??

[PCGUY112887]

I don't think anyone has been 100% sure if they caused a failure but I look at it like this...

Your engine may be fine for quite a long time without a a dampener, however GM designs engines to last 100k+ miles. So the underdrive pulley may be fine for years then one day, something cracks due to harsh vibrations in the engine.

When I did my built, I planned on this engine being in a daily driver car... a car that I will probably keep for a very long time. I wanted it to last, so I used the stock dampener that was on my 3100.

Reliability > performance on street cars for me. Unless you have plenty of time and cash to throw around in case anything goes wrong.

[19Cutlass94]

If you put a UDP on a race engine, that engine would blow up quickly. Especially one with high compression and a huge cam. Pushing more air and fuel and a bigger bang, more pressure on the crank, no balancer, and boom... there goes your engine.



On a stock, factory engine you can get away with it, but who knows for how long.

[IsaacHayes]

Lots of people run them however. Anyone feel a big increase w/the MrZ since installing it? It is lighter than the FDP one.

[19Cutlass94]

I know when I put my ASP pulley on I felt a difference. But at a stoplight I drop to about 10-11v...

[andrew383]

ok new question, are all the 3100 pulleys the same? i found the asp one but its for early years

[andrew383]

they have one for 3400 to http://www.aspracing.com/frame.htm but looks like it doesnt have the rubber eeither

[andrew383]

Lots of people run them however. Anyone feel a big increase w/the MrZ since installing it? It is lighter than the FDP one.

engine response is better prob picked up a few ponys,revs faster

[IsaacHayes]

The older 3.1 is not a 3100 and would lack the 24x timing wheel or provisions to put it in. I've heard of people modifying the ASP one to accept the ring but I don't know what this requires.

[andrew383]

i had to swap the ring on my mrz udp. has any one swapped one over? or wound the 3400 one work??