singleshot

10/20/2000
SONIC TECH NOTE SERIES:
After market Light weight crankshaft pulleys
Condition:
Flywheel/harmonic dampener and crank bolts coming loose, engine bearing problems
Never remove the factory crank pulley on any engine to replace it with a performance pulley or light weight performance pulley. To replace the factory engineered pulley with something made by a person or company that does not understand the complete engine design will hurt the performance/reliability of your engine not help it.

Toyota and many other manufactures such as BMW, Porsche, Mercedes all use dual mode damper pulley designs in all their engines. I have also received a similar tech note on crank pulley's from Dinan Engineering (BMW performance).

The factory stock pulley is designed to absorb both torsion and bending lateral vibration from the crankshaft. This helps the crankshaft deal with high vibration in the 400 Hz range after the #1 piston fires. Overall this has many benefits on the bottom end. It helps the crank deal with high continuous loads as well as overall bearing life, not to mention overall engine life. Also the drive-line will have a more pleasing sound with very little 400Hz vibe's setting up.

See the following jpeg pictures from a Toyota engineering book discussing this!!

Also see:
http://www.supras.com/~riemer/sonic...tech/dinan.html

A number of times I have personally seen bad side effects on street and track cars using these after market crank pulleys. Avoid them, there are other good performance upgrades that will not hamper the reliability of your nice engine.

I understand that this topic has seen many flame war's back and forth on all of our supra club mail lists and other car lists around the country. I personally don't mind this at all, I feel it is my responsibility to tell our members about correct and documented information such as this topic regardless of the flame wars it could result.

Please send any flame comments with regard to this directly to supras@home.com email address so as not to bog down the list servers with this type of email.

There has been too much disregard the past year on all of our club web sites with regard to erroneous information being given to many car club members around the world.

Our sites should only offer good upgrades for Toyotas. Upgrades that will not hurt the reliability of the car.

Please forward any questions or typo reports to rcts@home.com


Regards


Reg Riemer

Written by Reg Riemer Copyright Sonic 1997 (free to distribute and copy in this original format)



here is the original post with some pictures that explaining the dual mode harmonic balancer that the article says toyota uses.. not sure if scion uses them.. but it's still worth the read..

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hotbox05

hmmmm i don't know seems like a manufacturer gimmick.

singleshot

could be. but why would a manufacturer who isn't trying to sell anything to you put something out to prevent you from spending money on someone elses product?

hotbox05

tehy look down upon many many things that aren't stock and are always willing to cut a warranty claim. who knows

MattyRattyPoo

Yeah i really dont belive in this. I have many friends with pulleys in their scions and other cars as well and havent come across any problems what so ever. And speaking of BMW, ive got a froend with a 600hp M3 and has 20,000 miles on his lighten crank pulley and hasnt had any problems.

jrv2000

Id tell your friend to take that pulley off. Read this......

http://www.dinancars.com/whitepapersFile.asp?ID=5

Straight from the mouth of Steve Dinan... You know, the guy behind the most respected aftermarket tuning company for BMW's. This information found in the link goes for our cars aswell.

islandromeo81

ok im not trying to start any problems but this info is incomplet because now all crank pullies cond engien vibration it depends how the engine is balanced from the factory wether it is externaly balanced with a harmonic dampener or internaly balanced where all the engine internal componants piston rod crank and macth to eliminate any vibration an example of this is pro drag car they spand alot of time builind engines run in without harmonic dampeners for better power and higher RPM now im not sure of the scion but my 1992 mustang has a harmonic dampener but the crank pullie is removable and a whole seprae piece so changine it for a power pully has no effect on the engine balance but because the acesories have been slowed down the water pump turns slower which can cause the engine to run a bit hotter but changing the thermostat can easly fix that problem i have seen for sale pulleys for the xb and xa that are same size at stock just lighter im just not sure if toyota inernaly balances there 1.5l but i am assuming so because the fact that the engien run at high RPM at most time like going 60MPH@3000RPM it would make sence for them to internaly balance it to improve engine life and perfomance so i think some people (not refering to any one here) should look more into a subject befor write about it where it might worry some one that hasnt learned about it i am not trying to be all knowing but i have spent alot of time working in engine mechine shops and have learned alot over there years i still am learning till today with the scions and with my family race car my 1992 mustang

jrv2000

our scions use an external harmonic damper. They are not internally balanced.

singleshot

Don't know. That last BMW article was nice.


I enjoy reading this stuff.. Better to know boths sides then it is think you know and spout opinions.

I'm a good faith type of person. I would be more inclined to beleive the story of someone who wasn't trying to sell a product to me, rather than someone who was. Besides, how does it benefit a car manufacture to suggest not using something that "could" shorten the life of your motor?


I've spent the cash having one engine professionally built. It was spun balanced/blue printed and matched ported. Basically all bragging rights after the motor was finished. They guy who built the motor still suggested a standard fluid harmonic balancer for the set up. He even matched the crank pully (which on a chevy, bolts right to the front of the harmonic balancer).

food for thought


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Chimmy3

I read most of the debate before I put on my perrin lightweight pulley.

AFAIK, There are several things that don't really apply when it comes to our scions. If you do a search, I'm pretty sure you'll find the thread where this debated initially on this forum.

The major differences are:
1. Most people aren't using underdriven kits, though I believe there is one out now. A lot of the concerns raised had to do with underdriving the accessories.
2. Our crank pulleys are not harmonic dampers. as far as I can tell they are just metal.

Once you take those two things away from the argument... there's very little left. Only thing that can be argued is whether there will be balancing issues due to weight.

Boxer_Rebellion

That Dinan article is excellent. It's cool to have an basic primer of the physics involved.

I wonder, however, if issues like crankshaft failure are really pertinient to our little 1.5L motors (vs. 600hp M3 ones)...

islandromeo81

(no offence) only wanna ask not putting no one down
when your engine was built where u given the option for a ZERO balance because with my mustang there are 3 diffrent balance style 50oz 28 oz and 0oz and with the 0oz they balance everything inside just as i stated befor then at that point u use a netral flywheel and crank hub that has no weights on it to reduce harmonics there so much i could write about this but i dont wanna boar every one im not saying anything to what was in the artical online at the BMW page im just saying that we all should no more about the car we are working on befor messing with somthing that could potentaly mess up the engine im gonna poke around my xb im 95% sure toyota internaly balanced it because of the high RPM while cruzing

singleshot

i don't remember being given an option on different balances. I think I would have remembered that if he had offered. Possibly the shop that did your motor had more modern equipment that offered those options. And I had the 383 built almost 10 years ago, so that equipment may have been too new or too damn expensive for this guy.

I agree whole heartedly about your statement on knowing more about our engines before we go messing around with them. I personally have no desire for the lightweight pulleys. I've done what I'm going to do to this little motor. And I don't normally mess with the rotating assembly unless it's a rebuild. I say, let her breath and let is run...

Course the little I've done to this motor has reaped me about a $100.00 a horse. That's way too much for what little benefits I've received.. I think I could have stopped at the muffler and been just as happy at this point..

Not to change the subject, but it just makes me kinda laugh.. I've put roughly a grand into exhaust, intake and header for a grand total of just shy of 10 hp (now that is paper horse, I have never dyno'd). After that I spent another $250.oo on dynamat extreme to sound deaden the interior. That added 50 lbs. to the car.

Heres a little math for those of you who are HP freaks..

xB's curb weight 2395 lbs. @ 108 hp = 22.17 lbs. per horse.

I've added a several items and have taken off mulitple items, but my curb weigh has probably been in the ball park of the same except the dynamat extreme. A total of 50 lbs of it to be exact.

2445 lbs now @ what I guess't-mate to be 118 hp = 20.72 lbs. per horse.


a net increase of about in HP/lb of 1.45 lbs... not saying much is it...

Now think of all those folks who have monsterous subs, amps, monitors and yards of cable powering all that.. Yes it all adds up... = more lbs. per horse.. = slower car.

evosky

soo ... what's the take on doing the pulley swap on our xB's ? is it a go or no go ? i'm aware that a lot of people have already done the swap and have had no problems whatsoever.

oh, i also personally know the son of one of the founders of dinan. he has a pretty sweet 325.

Kilo6_one

most guys with $25,000 to $30,000 blown chevy crate motors run pullies and never had a problem.....
I for one have always done underdrives on my trucks and never once had an issue, I think people tend to forget as well that most issues related to pullies are longevity issues at milage over 160,000.

islandromeo81

True but with almost all v8 have a seprate harmonic dampener and the pullies are a whole other piece modern car's have been making one peice balencer and pully what why the BMW site has a problem with people putting them in .i run a blower i still have the stock pully only because i choose no to change mine because my personal belife if that althought a lighter pulley can make more power because it drives the acessories slower the ends dosnt justify the means a slower turning alt means your battery wont charge as well and a slower turning water pulley means the car cant cool effecently im not bad mouthing any produce as some people have run the perrin pully with no problems because is its a power pulley its the exact same as stock its just lighter all the accesorys turn the exact same ratio as stock it just has less rotating mass

superfreestyle

wow!!!!! over 45,000 miles on my xB now and over 30,000 miles with my perrin lightweight crank pulley and i have had no problems whatsoever, I'm almost positive that if i would hurt the motor then after 30k miles of my foot sunk into the floor barking gears left and right and going out of state almost every weekend, that my motor would have rod knock like a mother f***er.....

if you guys want then we could start a timer on the homepage here of how long my motor has lasted with the aftermarket pulley, if it ever causes a problem we can stop the timer and mark it a point in history!!!!

this sounds like the people that have said a C160 will not fit the xB, which is not true, and that a C52 lsd will not interchange, and it will, some people just wanna be so much smarter than everyone else, all i can do is shake my head in dissapointment that this thread even exists

flame away!!!

islandromeo81

nah i would worry about flaming here if u read what i wrote i belive the reson u dont have any problems is because the perrin pulley is because it is not an underdriven pulley and that i truly belive that our 1.5's are internaly balanced and do not need to be externaly balanced

Kilo6_one

Island....
I hear you there, its not something i dont think people should be instantly worried, but pullies, S/C's turbos or any other mods then stock can have some sort of negative effect at some point in time on a car, its just up to the owner and there level of being comfortable with mods.
Im not terribly worried about it, i dont plan on keeping my Tc longer then 2-3 years max, maybe not even that long......

islandromeo81

yeah i noticed alot of people are getting worried and there isnt anything i belive bad the companys that make these products test every thing befor selling it look at the time its taking for some turbo kids for the xb its all about R&D and alot of company's due there homeowrk i guess the bottom line is if u feel uncomfortable with some part dont buy it . just dont complane that a car dosnt have enoughf power if u arnt willing to do what has to be dont to better your car and hopfuly ever one here know i am not picking on any one just my 0.02cents as for me i plan on keeping my xb for a while as it is the family car and 100hp dosnt bother me dosnt mean im not gonna try better it but if i want power i drive my mustang plane and simple and no offence to any one