Light Crank Pulley

[kimo]

Hi,

I have read about light crank pulley and some is ok, and others say no. Have anyone tried it in the Jazz, and it worth the money.

[08ESE]

why?

[kimo]

What do you mean why


why?

[Jus-10]

No not worth it

[08ESE]

no point lightening the crank pulley when its got a flywheel on the other end thats probably 15 kilos. a few grams from a pulley wont make a difference.

[spoon fit]

what brand?

[wynode]

What do you mean why
Why do you want to change it? You'll get better results with a lightened flywheel.

The crank pulley is there as a harmonic balancer.

[spoon fit]

typeg changed already

[kimo]

What about if the car is auto.


no point lightening the crank pulley when its got a flywheel on the other end thats probably 15 kilos. a few grams from a pulley wont make a difference.

[spoon fit]

even feel better

[wynode]

typeg changed already
That doesn't mean its OK to do!

[spoon fit]

That doesn't mean its OK to do!


i didn't say ok ma :)

[wynode]

i didn't say ok ma :)

:p

[08ESE]

What about if the car is auto.


now theres something i never considered :)

[Zimp13]

if change all the pulleys should be ok....

[bennjamin]

whoever changed the pulleys....please post up when your main bearings fail !

[Zimp13]

does it mean that when u dont change the pulleys the main bearings wont fail????

[wynode]

does it mean that when u dont change the pulleys the main bearings wont fail????
The crank pulley acts as a harmonic dampener. That's why the extra weight is on there on the stock pully. By changing it to a lighter one you are reducing the dampening and as a result the main bearings and crank journals are the first ones to feel the brunt of this.

It won't happen over night.......but it will happen!

[Zimp13]

every mod has its own costs... wear out certain parts faster than standard... this is just my thinking.... plus all depends on the driver's style of driving as well.... if u drive the car hard all the time, something will fail sooner as well.... i just feel that opinions stated in this thread are scaring people away from doing it.... two exact cars have the same exact mod, does that mean that those 2 cars will have the exact problems at the exact time? if not y???? if the answer is the same as mine, thats y i would always use the word "may", "should", "perhaps". Nothing is for certain. Yes, the bearings may fail, sooner than using the standard pulleys, but who knows when?????????????????

[pinklady]

the pulley u guys r talking about..its not cam pulley for the timing belt right?:p

will changing timing belt pulley b no good?

[Tony]

the pulley u guys r talking about..its not cam pulley for the timing belt right?:p

will changing timing belt pulley b no good?

I think jazz uses chain instead of belt for the cam gears. I think they are referring to the pulley that drives the alternater belt.

[kimo]

The crank pulley acts as a harmonic dampener. That's why the extra weight is on there on the stock pully. By changing it to a lighter one you are reducing the dampening and as a result the main bearings and crank journals are the first ones to feel the brunt of this.

It won't happen over night.......but it will happen!


Ok what about the same size but lighter.

[wynode]

Ok what about the same size but lighter.


That's why the extra weight is on there on the stock pully.

[bennjamin]

Unless the entre engine is balanced to the weight of a lighter harmonic balancer - you will no doubt be waiting for perpetual engine failure...

keep it stock and change other bits for lightweight conterparts :)

[pinklady]

found this in option fans mag. it seems quite popular in HK. is this wat we r refering to?? any good? :rolleyes:

http://photos.friendster.com/photos/37/92/11282973/13241302822401l.jpg

[MRFIT]

i read this issue of option fan, they highly recommended the pulley...... I am suprised that so many people on this thread is against the idea of changing pulley.....

[bennjamin]

i read this issue of option fan, they highly recommended the pulley...... I am suprised that so many people on this thread is against the idea of changing pulley.....

If the crank/pulley acts as a harmonic balancer - THEN you cannot change it for a lighter item without running into issues down the road.
IS this the case for newer engines ? IE Jazz engines ? *someone fill us in*

It is better off and safer changing your flywheel for a lighter item , using lightweight wheels or stripping out AC etc long before changing your main pulley :)

[TypeG]

light weight the pulley is not the same as light weighting your car

[TypeG]

i read this issue of option fan, they highly recommended the pulley...... I am suprised that so many people on this thread is against the idea of changing pulley.....

That's y Oz is still in development on modifying a car. At least not as crazy as asian countries

[spoon fit]

That's y Oz is still in development on modifying a car. At least not as crazy as asian countries


:thumbsup: :thumbsup: :thumbsup: :thumbsup: :thumbsup:

[asiansquad]

do you ever sleep sunny??

[spoon fit]

haha........u too

[bennjamin]

light weight the pulley is not the same as light weighting your car

Obviously . Better spending money elsewhere first , than on this particular mod tho :thumbsup:


DO fill us in on what the lightened crank does for the Jazz for example tho - ;)

[Zimp13]

Ok what about the same size but lighter.

it is the same size but lighter.... a lighter one would let the pulley spin faster (time wise) and easier (less burden)... effect would b better response

[bennjamin]

it is the same size but lighter.... a lighter one would let the pulley spin faster (time wise) and easier (less burden)... effect would b better response


the pulley turns in exact co-ordination with the entire engine as it is connected directly to the crank - less weight would put it out of spec due to inertia forces ? ( out of balance ?)

[TypeG]

the pulley turns in exact co-ordination with the entire engine as it is connected directly to the crank - less weight would put it out of spec due to inertia forces ? ( out of balance ?)

very wrong indeed
lighter pulley make it spin faster and easier
for the people who develop the pulley have do some research and design on the pulley itself and as well concern on car balancing. moreover, a lot of people used it in HK and not any single one complain on that in HK Jazz forum YET.
Also we will trust what the book said as i am pretty sure they have a better knowledge on car mechanic than us including u.

[TypeG]

however, a warning to all ppl who from HK, the GD1 pulley is JUST FIT GD1 not GD3.

[bennjamin]

very wrong indeed
lighter pulley make it spin faster and easier
for the people who develop the pulley have do some research and design on the pulley itself and as well concern on car balancing. moreover, a lot of people used it in HK and not any single one complain on that in HK Jazz forum YET.
Also we will trust what the book said as i am pretty sure they have a better knowledge on car mechanic than us including u.


no need to get defensive of any claims against a said product - Are you aiming to sell :rolleyes: ?


Seriously, TypeG and others - does installing JUST a lighter crank pulley help at all , or is it a must for midly modded cars + above ?
Ive read up that STOCK cars should not attempt such a mod...

[TypeG]

i hope i can have one only since it is for 1.3L Jazz but if i want to sell this product here, i think my post will be deleted anyway so no pint to talk about this at all.

no mod is need to install this

[Jus-10]

It's a waste, and would probably be the last performance mod you should look at - long after everything else has been sorted out...much better go for the lightened flywheel as already stated.

And I think Bren offers a much more technical explanation and raises valid points as opposed to "a book said so - so it must be right!"

And to be honest I don't believe Australia is underdeveloped in terms of car modification....the cost just becomes too expensive to justify at times.

Look at it realistically. You change the pulley and save 100grams, but you are still running the standard flywheel. OK the engine "might" spin a tiny bit more freely from the lightweight pulley, but the motor still has to turn a flywheel weighing something like 10-12kgs...now you can save 100grams on a pulley, or about 5KGS on the flywheel....think about it.

IMO you would only change the pulleys for the sake of doing a mod...it won't offer any real gains, but will/may have an detrimental affect on the lifespan of the engine.

An exhaust and air filter won't f*ck your engine up like these pulleys can...

[TypeG]

i cbf to argue as i am tired to argue with some people who dun even readlly understand what a light pulley can offer. the gain of the pulley is more than any JDM exhuast.
also it is not 100 g lighter. It is 1-2kg lighter on pulley itself and consider the pulley is not as big as a flywheel.
and price wise it cost like $300 and this price may just enough for u to buy a second hand brand muffler.
"a book said so - so it must be right!"---- depends on comparing to who. If a book vs mod here. I trust the book. Fair Enough?

[TypeG]

well, maybe it is waste for u since u even think ARC airbox is a waste of money so well.... what else can I say

[wynode]

i cbf to argue as i am tired to argue with some people who dun even readlly understand what a light pulley can offer. the gain of the pulley is more than any JDM exhuast.
also it is not 100 g lighter. It is 1-2kg lighter on pulley itself and consider the pulley is not as big as a flywheel.
and price wise it cost like $300 and this price may just enough for u to buy a second hand brand muffler.
"a book said so - so it must be right!"---- depends on comparing to who. If a book vs mod here. I trust the book. Fair Enough?
Have a look at the other side of the engine. You WILL notice more of a difference by taking off say 3-4Kgs from the flywheel than say 1Kg from the crank pulley.

Harmonics can destroy an engine........what's trying to be said is that the costs of this mod outway its benefits and there are better bang for buck mods than changing the crank pulley. The idea behind this applies to ALL engines.......not just the Jazz.

[TypeG]

of coz i will notice more different on changing flywheel with 3-4kg off as it is 1-2 kg lighter than lighter pulley. That's is the fact. However, the benefit of these two items are different. I will also agrue flywheel is better than pulley but if they both suit Jazz, i will get both as we always want to max. our benefit.

Again, it has been released for quite a while and i never heard anyone have problem with that little pulley. destory the engine...... let see who destory the engine then...

[civiceg9]

TypeG always in commotion lol :D

Install a llight weight pulley kit and the results usually u get is better throttle response and more power. Light weight pulley is usually made from aluminium billet, making them immensely lighter than their factory steel counterparts. This lower weight yields a large reduction in the rotating inertia of the belt train, allowing the engine to accelerate faster. The effect is similar to fitting a lightened flywheel and is particularly noticeable in the lower RPM range. This is because the power required to accelerate a heavy pulley accounts for a much greater proportion of the available power at low RPM.
By changing the pulley diameters, to a larger one, also reduces the amount of power needed to turn the alternator and power steering pump while still retaining the original serpentine belt.

Honda engine in particular, I think is the B-series where they had problems, the crank main bearing are very sensitive. The Harmonic balancers are a needed component to protect, usually the front bearing of the crank from periodic vibrations that can occur at certain rpm in any engine. Over time vibrations can cause or aggravate wear.
You can however change all the other pulley eg the power steering, a/c and other small pulleys but the crank pulley is a no no. Not so sure about the new honda engines, but I guess they are the same.

Hope this info helps some people.
or email a msg to Spoon CEO, he can tell us to do it or not.
(I think you can sent it in English)

[TypeG]

found this in option fans mag. it seems quite popular in HK. is this wat we r refering to?? any good? :rolleyes:

http://photos.friendster.com/photos/37/92/11282973/13241302822401l.jpg
I am talking on this pulley

[Zimp13]

the pulley turns in exact co-ordination with the entire engine as it is connected directly to the crank - less weight would put it out of spec due to inertia forces ? ( out of balance ?)

to make things simple then.... y would they wanna make something that useless and its been going on for ages now???? i was never told that u needed to overhaul ur internal engine just to fit pulleys.... neither does any magazine from my knowledge....

[Zimp13]

i read this issue of option fan, they highly recommended the pulley...... I am suprised that so many people on this thread is against the idea of changing pulley.....

mrfit.... when they highly recommend the pulley, did they mentioned anything else??? like side effects or whether u have to change anything to suit the pulley????? they must have said other stuff as well.... and wat are these pulleys for anyway???? i mean the ones that they recommend... which pulleys are they?

[Zimp13]

TypeG always in commotion lol :D

Install a llight weight pulley kit and the results usually u get is better throttle response and more power. Light weight pulley is usually made from aluminium billet, making them immensely lighter than their factory steel counterparts. This lower weight yields a large reduction in the rotating inertia of the belt train, allowing the engine to accelerate faster. The effect is similar to fitting a lightened flywheel and is particularly noticeable in the lower RPM range. This is because the power required to accelerate a heavy pulley accounts for a much greater proportion of the available power at low RPM.
By changing the pulley diameters, to a larger one, also reduces the amount of power needed to turn the alternator and power steering pump while still retaining the original serpentine belt.

Honda engine in particular, I think is the B-series where they had problems, the crank main bearing are very sensitive. The Harmonic balancers are a needed component to protect, usually the front bearing of the crank from periodic vibrations that can occur at certain rpm in any engine. Over time vibrations can cause or aggravate wear.
You can however change all the other pulley eg the power steering, a/c and other small pulleys but the crank pulley is a no no. Not so sure about the new honda engines, but I guess they are the same.

Hope this info helps some people.
or email a msg to Spoon CEO, he can tell us to do it or not.
(I think you can sent it in English)

thats more like it..... i just feel that some people opinions just scaring people away.... u can have ur own opinion, certainly... just dont make them sound like one's opinion is 100% right and other's is wrong... i personally understand that every mod exists for certain purpose.... cant just say that they are useless. full stop. time will tell that for certain. if they are useless, people try, sooner or later no one will buy.....

[bennjamin]

thats more like it..... i just feel that some people opinions just scaring people away.... u can have ur own opinion, certainly... just dont make them sound like one's opinion is 100% right and other's is wrong... i personally understand that every mod exists for certain purpose.... cant just say that they are useless. full stop. time will tell that for certain. if they are useless, people try, sooner or later no one will buy.....


we just want all the facts straight :)

Its no urban legend that the "harmonic balancer" is there for a reason - our logical question still applies.

If you change this side of an entirely balanced engine , SURELY the all other areas will have to compensate ?


Here is a email reply from my Uncle - he works for BHP as lead engineer somewhere rather lol


benjammin,
Pulleys can be made very light even using carbon fibre and drilled alloys like some of the F1 stuff so long as they transmit the required drive torque without breaking. What benefit this would have on a road car is probably so small as to be unmeasurable .
Harmonic balancers are something totally different but most car makers use one item to do both jobs since this is the most convenient and cheapest way to do it.
Balancers are matched to an engine to stop the crankshaft going into self destruct mode at certain frequencies. This means stuffing around with one unless you are really up to speed on the mechanical engineering side of things is not a good idea.

Cheers , pete

[bennjamin]

btw guys n girls - this has gone slightly off topic- but an interestign topic.

Im relocating to the technical discussion area as it applies to all cars :)

[wynode]

Install a llight weight pulley kit and the results usually u get is better throttle response and more power. Light weight pulley is usually made from aluminium billet, making them immensely lighter than their factory steel counterparts. This lower weight yields a large reduction in the rotating inertia of the belt train, allowing the engine to accelerate faster. The effect is similar to fitting a lightened flywheel and is particularly noticeable in the lower RPM range. This is because the power required to accelerate a heavy pulley accounts for a much greater proportion of the available power at low RPM.
By changing the pulley diameters, to a larger one, also reduces the amount of power needed to turn the alternator and power steering pump while still retaining the original serpentine belt.

Honda engine in particular, I think is the B-series where they had problems, the crank main bearing are very sensitive. The Harmonic balancers are a needed component to protect, usually the front bearing of the crank from periodic vibrations that can occur at certain rpm in any engine. Over time vibrations can cause or aggravate wear.
You can however change all the other pulley eg the power steering, a/c and other small pulleys but the crank pulley is a no no. Not so sure about the new honda engines, but I guess they are the same.


Finally an informative post :thumbsup:

This is another reason they are sometime reffered to as under drive pulley(s).

[kimo]

I am talking on this pulley


I didn't know my topic will go that far. Please guys we learn from each other, so we don't have to get pissed off from anyone. The best thing is to ask someone that have it installed in his car, and the results, and we can ask some companies like Spoon, Mugen what they think about the Light Pulley.

Here is some info I got


People are getting their crank pulleys confused with the harmonic dampers found on some V6 / V8 engines. "Harmonic Balancer" is a term that is used loosely in the automotive industry. Technically, this type of device does not exist. The "balancer" part comes from engines that are externally balanced and have a counterweight cast into the damper, hence the merging of the two terms. None of the applications that we offer utilize a counterweight as part of the pulley as these engines are internally balanced.

The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley that looks similar to a harmonic damper. The elastomer in the OEM pulley serves as an isolator, which is there to suppress natural vibration and noise from the engine itself, the A/C compressor, P/S pump, and alternator. This is what the manufacturers call NVH (Noise Vibration & Harshness) when referring to noticeable noise and vibration in the passenger compartment. It is important to note that in these applications, this elastomer is somewhat inadequate in size, as well as life span, to act as an effective torsional damper. If you look at the pulleys on some of the imports there is no rubber to be found at all. We have samples of these, mostly from Acura/Honda, the Nissan Altima, 1.8L Eclipse, 2.3L Fords, Chrysler 2.2L's, and 1.8L VW's, to mention a few. This is not to say that with our pulleys you will hear a ton of noise or feel more vibration from your engine compartment. Most who have installed and driven a vehicle with our pulleys will notice the engine actually feels smoother. This is a natural result of replacing the heavy steel crank pulley with a CNC-machined aluminum pulley. NVH is variable and unique to every car. NVH will increase with the installation of an aftermarket intake and/or exhaust, for example. Think of OEM intake systems in newer cars, they use baffles and resonators in the intake to quiet all the intake noise. Aftermarket intakes eliminate these resonators and create dramatic increases in engine noise from the throttle opening and closing. So to most tuners, certain types of NVH can make the driving experience more enjoyable.

The purpose of a traditional harmonic damper is to protect against crank failure from torsional movement. This is not necessary in most modern engines because of the many advances in engine design and materials. Factors such as stroke, displacement, inline, V configurations, power output, etc., do determine when and how these harmonics and torsional movements occur.

Again, there is a lot of internet hearsay about the pulleys. When engine problems occur, too often people are quick to blame the pulley first, rather than taking the time to look logically into why there was a problem. We hope that after reading this you will understand the crank pulleys better.



This is a fear many prospective owners have and is a valid concern since we are dealing directly with the rotating assembly. Fortunately it is another urban myth with no basis in fact. The fact is that our pulleys have the opposite effect on engine bearings. The combination of tight tolerances, quality control, perfect balance, and dramatic weight loss versus the stock pulleys reduces stress loads on your engine, extending the total service life you can expect from your engine. Engine bearing problems are purely associated to poor engine maintenance, use of heavier than factory recommended oils, improper engine building practices (which includes poor balancing), excessively revving engines when they are cold, and owners expecting their factory oil pumps to handle engine power outputs beyond 3, 4, even 5+ times the stock power levels.

[PhatSol]

I suggest searching honda-tech.com, you will find many examples of what happens to B series motors when you put a solid pulley on them......

[Boost]

crank pulleys do dampen a lil. but not like true harmonic dampers.
True Harmonic dampers (fluid or elastomer ) do not have grooves on them to drive belts connected to accessories (p.s, alternator, a.c.). Harmonic dampers, whether they are fluid/viscous damper or elastomer are installed for only one purpose and that is dampen torsional and rotation imbalance of the crank and nothing else.
The crank shaft imbalance is caused by the rotation of a mass which causes it to vibrate at one of its many natural frequencies. All mass / matter has many natural frequency (modes). There are harmonic dampers out there that are able to dampen the virbration at all modes. But the elastromer dampers can only dampen vibration up to a certain frequency.
Hope this help guys..

[smoknhothonda]

I have an unorthodox pulley set for my accord.

*edited out plug*

[kimo]

I have an unorthodox pulley set for my accord.

Ok is it a crank pulley and what is your comment.



*edited out plug*

[smoknhothonda]

I placed a link to a site but one of the moderators must have deleted for some reason....?

Well basically I stated to check out unorthodox racings website, they have a shit load of pulleys available, and its all great stuff, that is well engineered, but is pricey.

But thats what you pay for products that have plenty of R&D work put into the products that are designed and engineered for each individual application. (just like HKS, Trust or any of the other big name Jap stuff)

[bennjamin]

I placed a link to a site but one of the moderators must have deleted for some reason....?



that was me matey - just as it wasnt entirely relevant to the discussion - try and quote info from the site to aid in our discussion :thumbsup:

[yfin]

Ancient thread I know - but I was doing a search on pulleys as I am interested in knowing more about them for the Euro.

It is purported in this thread below that the K series engines do not use a harmonic balancer so changing the pulleys on K series engines is less of an issue. Perhaps it is the same on the Jazz?

http://tsx.acurazine.com/forums/showthread.php?t=27876&highlight=pulley+harmonic

ps - people are getting quite decent results across the rev range for the K24. Any idea how much the install cost would be?

http://tsx.acurazine.com/forums/showthread.php?t=30103&highlight=pulley+harmonic

[juzz]

hi,
i too have been interested in the lightweight pulley as i intend to buy one, however having read in this thread, that the pulley could have a detrimental effect on the engine, i've since become reluctant to get one. My Question is however, if i install a lightened flywheel (Spoon) and also install a lightened pulley (Summit) will this be ok?...Will it still have a detrimental effect on the life of the engine?.

Also Yfin, for my dc2 vtir, i was quoted 320 to fit my flywheel and $70 EXTRA to install the pulley.
I'm not sure whether it would be cheaper or more expensive to fit the pulley on its own, But i am planning to fit both components at the same time.

[JasonGilholme]

What i can't understand is that theres all this camotion over the balance of the engine because they remove weight from the crank pulley.

Wouldn't removing weight from the flywheel have the same effect??

Cause really, both the flywheel and the crank pulley are connected to the crank shaft. If removing weight from the flywheel is ok why isn't it ok to remove weight from the crank pulley seein as tho they are both attached to the same thing???

[aznsiko]

lightweight pulleys are suppost to give you more torque.. so either way i think its should be effective in some way..

[blk_shadow]

be careful of installing lightweight pulley, that means removing the harmonic balancer in your engine.

this can cause problem in the long run. the harmonic balancer is what causes all the weight. aftermarket pulley removes this plus using lighter material, the result is very light pulley. but missing an important 'ingredient'

[nigs]

be careful of installing lightweight pulley, that means removing the harmonic balancer in your engine.

this can cause problem in the long run. the harmonic balancer is what causes all the weight. aftermarket pulley removes this plus using lighter material, the result is very light pulley. but missing an important 'ingredient'

Lol I think this was covered over the last 6 pages.....

I've used one made by GFB (Go Fast Bits). It was on a built and fully balanced motor though. So I had no troubles except running my water pumper harder than usual, thus wear.

For some motors (EJ20) they offer a full kit, maybe to offset the difference in size. So the motor can still spin in harmony.

The BFG item is much much smaller than the OEM part (SR20) and about 4-5kg lighter, maybe more!
This mod will be the same as doing a light flywheel. IMO not really worth it's coin unless everything else attached to the crank is balanced too (But we do it anyway, hehe).

The response derived from depressing the pedal is bliss.
Balanced motors FTW.

[blk_shadow]

i c :zip: i didn't read the last 5 pages

[JasonGilholme]

Sorry for my stupidity but what makes it ok to remove weight from the fly wheel but not from the crank pulley?

Essentially they're both apart of the 'balanaced' crankshaft. Aren't they not?

[STOCK]

Ive got a underdrive lightweight pulley on my car and have had it on for the past 40000kms and have not had an issue whatsoever. Gains were minimal though.

[blk_shadow]

Sorry for my stupidity but what makes it ok to remove weight from the fly wheel but not from the crank pulley?

Essentially they're both apart of the 'balanaced' crankshaft. Aren't they not?

flywheel main objectives is to make the engine more stable during acceleration and decceleration.

[aaronng]

On some motors, the crank pulley forms part of the crankshaft balancing. For the K series, it isn't and we can change pulleys as we wish. For your L series, I think you should find out first. Claymore said that it isn't, and if it is 100% confirmed, you can use a lightweight/underdrive pulley.

[aaronng]

It has been 100% confirmed over and over and over again. Just look at any Jazz/Fit sites starting with the online HONDA manual or any of several sites and Hondas own specs. The "L" series engines are INTERNALLY BALANCED and the pulley and/or flywheel, or flex plate are NOT PART OF THE BALANCE PACKAGE you could run the "L" series engines WITHOUT A PULLEY OR FLYWHEEL if you could fix a snout starter to it. Where did you "confirm it 100%" for your "K" series do the same for the "L" and then maybe you will be convinced.

tsx.acurazine.org and k20a.org, both forums for the K-series. I know about the K, but not the L, that's why I don't dare to make a statement saying that the L does not rely on the pulley to be balanced. You're the L expert, if you say doesn't need the crank pulley, then I personally am inclined to believe that it shouldn't.

[bennjamin]

Even though there is claims of 100% etc , It would be interesting to follow any L series engines with light weight pulleys , over time to see IF there is any detrimental effects IE premature worn bearings etc.
IE when these engines are approaching 150-200,000ks

[bennjamin]

No controversy at all.No brainer or not ~ its a simple idea to check on these Jazz engines , over time and see if they are mechanically ok.
Not 1.5 years , but say in 3 or 4 or 5 years time ( or say 50k or 100k time etc). Lets keep an eye out.

[muhhan]

What's this counter weight balance hump you speak of? I'm guessing it looks pretty obvious once you're looking at one. Where can I find out if the D-series engine are internally or externally balanced? The crank pulley on my D16Y4 was a solid single piece from memory but I remember that the mitsu magna I used to drive had a 2 piece harmonic balancer that was joined together by a piece of rubber. I remember this well as it separated on me just as I pulled into my driveway one day!

[koldfire]

...yet another concern makes me wonder to add to this threat...

It seems there are two similar but different critical mechanical vibrations generated at the crankshaft. Imbalanced rotational mass and torsional vibrations. A harmonic balancer and a torsional damper are used to reduce crankshaft vibrations respectively.

Info found: -
1. http://www.epi-eng.com/BAS-TorVibInt.htm
2. http://www.epi-eng.com/ET-PistonExcit.htm
3. http://www.grapeaperacing.com/GrapeApeRacing/tech/dampers.pdf

After analysing, It looks like lighten crank pulley for honda is highly unlikely a harmonic balancer. However, the need for torsional damping and the effect of lighten crank pulley for and on honda engines need further clarifications... Hope a someone knowledgable in this forum can answer this...

I have one installed and it seems slightly increases NHV and rev. response but i'm starting to get abit worried regarding the torsional damping effect.

[TODA AU]

FWIW, we don't use lightweight alloy pulleys on high output engines.
What we do use are dampers by "Fluid Damper" & "ATI Performance Products"
Both are extreemly effective removing torsional crankshaft vibrations.
See these sites: http://www.fluidampr.com/ and http://www.atiperformanceproducts.com/
I won't say that one is better than the other as they are both top shelf products.
I do like the 360deg lazer etched timing marks on the ATI damper, as it makes cam timing a breaze.
Though more so on nissan engines than Honda engines due to difference in camshaft set up procedure etc (Sorry - I have digressed)

IMO, if the engine is near standard.
There is little to be gained changing to an alloy pulley.
Give it a go if you must...
But be aware, you may simply be convincing yourself in your mind that this was a worthwhile modification. When in actual fact there is little to no gain at all. That is, IMO the perceived gain would be quite difficult to measure is real terms.
Example. What time is it worth on the 1/4 mile?
I'd say 0.05 ~ 0.1sec if you're lucky.
Should that be the case, is it really worth the bother?
Also of note... Alloy pulleys are banned in import racing in USA.

[bennjamin]

IMO, if the engine is near standard.
There is little to be gained changing to an alloy pulley.
...........
That is, IMO the perceived gain would be quite difficult to measure is real terms.
.........................
Should that be the case, is it really worth the bother?


Would it be correct saying this is comparable to mods of similar benefit?
IE are only useful "...in the owners mind" ? Mods that do not increase power at all but increase power to weight ratio or mechanical response such as light flywheel or CF / fibreglass hood or panels , or smaller rims etc ?

[koldfire]

i'm using a lighten alloy crank pulley and improvements are very minimal even on my worked top n bottom B16. Motor responsiveness noticable improvement only on low to mid rpm. I'd say money better spend elsewhere and should be at the bottom end of the shopping list.

I'm interested to hear anyone who are using a crank damper...also as to what extend a modified motor needs a crank damper?

[LoiBoi]

http://www.importtuner.com/tech/powerpages/0702_impp_honda_fit_performance_modifications/unorthodox_crank_pulley.html

interesting...