Help with crankshaft pulley problem

cot · #1 11-14-2003, 02:09 AM

Hi, I had a timing belt break on my 4G civic, but was lucky and no major damage. As part of the repair, the crankshaft pulley had to come off, and of course that was quite difficult. One of the things we tried was to block the pulley from spinning by putting something through one of the holes on the pulley, but a small piece of the pulley (maybe 1/2"x1/2" or so) actually chipped off.

So I'm wondering how serious this may be in terms of balance of the pulley/crankshaft. It's back together and running, but i'd hate to have problems down the road because of this.

thanks!

crxlvr · #2 11-14-2003, 10:49 AM

that could cause serious problems the crank pulley aint that large to begin with, so that 1/2"x1/2" is pretty big. anyway it could start wobbling after awhile and possibly come off causing tremendous damage, might as well kill two birds with one stone and get an aftermarket light weight underdrive pulley, you'll have your problem fixed, and you'll gain some theoritcal HP.

cot · #3 11-14-2003, 11:59 AM

Thanks! Is there any particular manufacturer of pulley you'd suggest? Given that this is a base model 1.5L engine, I'm not exactly looking for a super fancy (and expensive ) piece, but then again maybe I'd notice a few HP gain even more

that damn crankshaft pulley bolt was such a pita that i'm not looking forward to it, but maybe it'll be easier this time since it's been broken recently. I might just have a shop do it since after all that work i'd rather not mess with it for a while.

RedRacerCivic · #4 11-14-2003, 08:46 PM

Quote:

Originally Posted by crxlvr

that could cause serious problems the crank pulley aint that large to begin with, so that 1/2"x1/2" is pretty big. anyway it could start wobbling after awhile and possibly come off causing tremendous damage, might as well kill two birds with one stone and get an aftermarket light weight underdrive pulley, you'll have your problem fixed, and you'll gain some theoritcal HP.

Buying a lightweight pully will more likely cause more damage to his motor then keeping the one he has on now, lightweight pullies on Honda motors cause premature damage to the main bearings, thats the reason why AEM doesnt produce lightweight pullies anymore. I suggest you find another stock pully that isnt messed up. Thats my 2 cents

Hybrid1990crx · #5 11-15-2003, 01:57 AM

Why do they cause premature damage? Does to happen with other brands of cars as well?

Damn it, your car is so beautiful....

Dumped91Hatch · #6 11-15-2003, 05:24 AM

next time use a Impact gun and you won't have that problem.

RedRacerCivic · #7 11-15-2003, 06:12 PM

Quote:

Originally Posted by Hybrid1990crx

Why do they cause premature damage? Does to happen with other brands of cars as well?

Damn it, your car is so beautiful....

Thanks for the compliment

I havent done much research on lightweight pullies, but i've heard they throw off balance of the crankshaft and cause more friction on the inner bearings or somthing like that. I was going to buy a lightweight pully for my car until I read a huge post(another forum long ago) on how bad lightweight pullies can be on the bearings, he showed pictures of his inner bearings when he took the motor out and they looked pretty worn out compared to the rest. So this is stuff I've heard and I believe it.

FourthGenHatch · #8 11-15-2003, 11:10 PM

Aftermarket pulleys don't have a harmonic balancer so the crankshaft suffers from vibrations and that will wear out your bearings and stuff.

cot · #9 11-16-2003, 05:56 PM

"next time use a Impact gun and you won't have that problem."

Well, that's what we ended up doing, though I have heard that impact wrenches on the crankshaft can actually cause damage to the engine bearings and whatnot, so it's a mixed bag...

and hopefully there wont be a next time, I dont really have time to be dealing with this sort of repair too often.

I guess maybe I'll call some wrecking yards to see if i can find a pulley.

nitrofish · #10 08-04-2004, 03:05 PM

The lightweight pulley's do not dampen the crank which causes excessive crank vibration. THis will cause excessive main bearing wear and trash the crank. Also if you change to a underdrive pulley you will have to change your belts due to the size difference and also change your accessory pulleys for the change. You risk not turning things like the alternator fast enough at idle to charge the battery causing additional undesired effects. Use an OEM pulley with a harmonic damper.

The Honda techs use a Impact wrench to remove the crank pulley bolt. It will not damage the main bearings. If that don't work there is also a crank pulley bolt wrench from Honda (expensive) which mounts to the pulley in the holes and has a t-handle you stick cheater bars in to break the crank bolt loose. You have to use a powerful enough impact wrench though. The standard home quality impact wrench is only good enough for 230 ft/lbs. You need at least 500 ft/lbs to get the crank pulley bolt off. So find a professional grade impact wrench. Getting the bolt loose is a real pain which requires persistence. Use anti-seize compound on only the treads of the end of the bolt (only the bolt do not get any on the washer) when re-installing and it will not be so bad next time.

civic_boy91 · #11 08-04-2004, 07:10 PM

if the pulleys don’t come balanced can you get them balanced?
I don’t see why not...so just get them balanced and don’t worry about it

jeef · #12 08-05-2004, 10:23 AM

i can vouch for the wear of the underdrive pulley... i had an a6 spin a rod bearing with less than 130k on it... and the others weren't doing too well either... but man was that pulley light... under a pound compaired to the stock 7 for the si and the 2 for the dx (which btw doesn't have a harmonic balancer) but yeah any don't do a pulley unless you're only going to put in on for race day, and then you need to get the coresponding alternator belt...

turtlecrxsi · #13 08-05-2004, 10:44 AM

I got Unorthodox Racing pulleys... never spun a rod though *knock on wood* I got the corresponding alternator pulley and belt. The belt is getting old but still looks new. I got two spare Si pulley sets.

nitrofish · #14 08-05-2004, 11:54 AM

"if the pulleys don’t come balanced can you get them balanced?
I don’t see why not...so just get them balanced and don’t worry about it
"

It is not the pulley which needs to be balanced. It is the crank. Mass produced engines are not balanced. Which is why high performance engines must be balanced to stand up to the rigors of racing. Engine balancing prior to assembly is costly and unnecessary unless it is for racing.

itechengineers · #15 08-05-2004, 12:52 PM

i can understand the conecpt of the lightweight pulley and the cracnk wear/tear. how about the flywheel? do you think a lightweight flywheel could casue the crank to experience the wear and tear of a light weight pulley?

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