Putting a crank pulley on a Lathe, Good Idea???
 

Can i lathe off the ac/ps pulley off my crank pulley? No need for it and it would save some rotating mass.

http://i33.tinypic.com/f1ytkk.jpg

No. That's part of the harmonic balancer. Cut it off and the balancer will no longer work as designed. In short, it won't work at all. Just take it off and put an aluminum one if you want to reduce weight on the crank and break your OP gears.

Ok scratch that...

If you look closely at the pulley, the p/s portion can be cut off without touching the harmonic balancer what so ever, and poses no threat to your oil pump gears. It doesn't save much weight, but it is certainly cheaper than buying a new aluminum one, and doesn't shatter your oil pump gears. The 'nose' to the pulley that is left once you cut off the p/s portion can but faced off, however at that point you're cutting into the harmonic balancer. You're not completely removing the harmonic balancer, only some of it. I've taken off the p/s part , and I have seen someone on this board face off the 'nose'. I have no proof, good or bad, that shows any effects from taking half the harmonic balancer off.

Oh goodie! Conflicting statements... I love a good debate.
So curly your saying that the front pulley can affectively be cut off with out messing up the harmonic balancer because it is located closer to the crank and under the alt/WP pulley section?

Rebuttals?

I 100% disagree with curly. I stand by what I said. But hey, it's not my engine...

oh yeah, that sounds like a great idea.

You virgins should get together and go on a retreat.

If you all you got out of that was what you bolded, no disrespect, but your reading comprehension is a little laking. What you bolded only refers to when you try and face off the front of the pulley and doesn't apply to removing the p/s portion. If you remove the PS portion you are leaving the harmonic balncer untouched.

????

The entire assembly IS the harmonic balancer! The pulley is integrated into it. The unit is still the balancer though. If you cut on it, you're cutting on the harmonic balancer. Why is that so hard to understand? You do anything to it and you'll ruin it. Pretty simple. Drill holes in it to lighten it up, cut part of it off, turn it down, grind some of the rubber out, etc etc. Anything you do to it will ruin it.

Curly did contradict him self multiple times in his post. Can't blame hustler for making fun of him.

" If you look closely at the pulley, the p/s portion can be cut off without touching the harmonic balancer what so ever"

And then, "The 'nose' to the pulley that is left once you cut off the p/s portion can but faced off, however at that point you're cutting into the harmonic balancer."

So according to Curly, you can cut some of the part without cutting the balancer.

Yet then he says, "You're not completely removing the harmonic balancer, only some of it."

And finally, "I have no proof, good or bad, that shows any effects from taking half the harmonic balancer off. "

Twice he states you can cut off half the harmonic balancer without actually cutting on it, then twice he states you're cutting into the harmonic balancer.

ok ok, i won't do it. Thats why i asked. I would rather take a little guff and get the correct answer before trying it on my car and screwing something up.

ok. if thats how you want it to be, your choice. do you honestly think i cant bribe rick for your ip adress? everyone has a price. im on 2 grams of test a week and a gram of tren. do this a couple months back, ok i mightve let it slide, now, someone so much as looks at me the wrong way and theres gonna be probs, lucky for me they always back the fuck down so i dont gotta get my hands dirty. i know youll try the same when shit hits the fan but dont think ill be so linient, cause i wont. dont say i didnt warn you.

WTF are you talking about? I honestly have no idea what you just said. Oh and Texas is for steers and queers. :fawk:

The following is a rant with 4 apologies
 

I apologize (1)for not chiming in sooner, and for any misleading information.

The power steering portion of the pulley can indeed be parted off (meaning I used a parting tool, not a facing tool) without touching the harmonic balancer. Please looking closely at your pulley, before making any assumptions about the harmonic balancer.

I did say that the 'nose' can be faced off, which at that point would be cutting into the harmonic balancer. Let me be clear: taking the p/s portion off does not affect the harmonic balancer (see pic #1, apologies(2) for my oil leak). In this picture, you can also see the 'nose' of the pulley left over once you've removed the p/s portion. As you can see I was unsure what affect it would have if I faced it off, so I chose to leave it. In the picture, you will see a thin rust color ring on the inside, which is where the p/s portion was parted off (clean surface = rust, probably should have painted that) then there is a thin black rubber ring THIS IS THE HARMONIC BALANCER this rubber goes through the entire depth of the pulley, you can see it from the back. you can face off this nose, leaving enough meat left for the water pump belt groove. This, as I said, would cut into the harmonic balancer, however it is just a rubber ring, using the heavy hunk of metal that is the pulley to counteract any harmonic forces applied at the crank.

pic #1
Attachment 210558

pic #2 is a diagram drawn up quickly in paint, for the 3rd time, I apologize, this time for the sloppy drawing. I hope I labeled everything clearly. You can see that the part which holds the P/S belt is an L shaped piece which does not connect to the harmonic balancer.

pic #2
Attachment 210559

These final pictures, #3&4, are of an uncut pulley, and the same P/S section that I took off the pulley from picture #1. Hopefully this will give you guys an idea of what I'm talking about. This post was written in a slight rage from being called wrong, and as you all know, no one can resist arguing on the internet, so, my apologies(that's four)

pic #3
Attachment 210560

pic #4
Attachment 210561

Yeah, no hard feelings man.

For one, it's apparent 1.6 and 1.8 harmonic balancers are of different construction.

On a 1.8 (the one the OP has and the one he pictured), you can NOT cutoff any piece of the pulley as it is part of the harmonic balancer. If you disagree, fine.

If your 1.6 A/C / P/S pulley was attached to the "hub" of the front pulley assembly directly to the steel center part that bolts to the crank then cutting it off wouldn't matter. If it attached to the outer part that was suspended by rubber then yes, you cut part of the balancer off. I can't tell from the pics or your diagram.

Damn, all that time to write the post, and we more or less agree. I was hoping for more of a fight...

Anyways, all this information is kaput, cause I have no experience with 1.8's, and this information only applies to a 1.6 pulley!

believe me, I did the cutting myself, taking the p/s portion off doesn't affect the balancer. Of course it also doesn't remove a very large amount of weight.

If you want a fight, go open a thread in the engine forum on "compression ratios and forced induction" and read. Be sure to put on your flame suit and bring your ego if you forget your common sense.

haha, I'm really not much of a fighter. You only boiled my blood cause I knew you were dead wrong, too bad we were talking about different pulley designs.

at least it helps out the 1.6 guys, its cheap way to loose a little rotating mass, I should weigh it sometime

i cant spell, damn public schools fault!!
 

there was a guy on feoa.net i think he was running a set of festiva single V belt pullies. i have the V belt set up on my b6t in the festiva but i havent had a chance to see if it will also fit on the bp. i wanted to use a ATI balancer but i just dont have the room for the two pullies i dont know what to do....

unfortunately the B6T is a short nose 1.6L. An SNC crank pulley does not fit on an LNC 1.6L. However an LNC 1.6L Crank pulley does fit on the 94+ 1.8L BP. So close but no cigar. If the B6T was an LNC then we may have almost stumbled upon an oem PS/AC elimination pulley.

Also with that being said. I do have a 1.6L LNC crank pulley that I may modify if it is agreed that will not mess up the Harmonic balancer. All i would have to do then is run a VBelt pulley for the W/P and ALT. which i have as well. I wasn't really looking for a huge weight saving. It was more that i hated looking down in the engine bay and seeing the crank pulley with a missing belt. The weight saving aspect is a definite plus though...

yup its agreed, no damage to the harmonic balancer if you don't touch the rubber, and a little less than a 1/2lb of weight savings, whoopie.

This is like a thread where you debate the weights of different fire extinguishers. I mean come on. Some things are better left alone. You know that's a really important part that was designed around the 1.8L engine it's bolted too. How do you know a different one from a different engine retrofitted to it will work? What if a balancer from some honda weighed 5 lbs less and bolted right up? Would it protect the engine?

Lord help us all you better be running a 1.6 aluminum flywheel and the lightest clutch available for it if you're worrying about loosing 1/2 a pound with a low moment of inertia on a highly critical part.

Curly- I still don't think you get it. The ruber is not the balancer. The unit is the balancer. Big hunk of metal bolts to crank. Big steel ring goes around it and is mounted by a rubber ring. You mess with the big metal ring, you're messing with the dampner. It's NOT just the rubber ring.

Nother thought: You could try running only 4 flywheel bolts instead of 6. Or maybe 3 oddly spaced. Or maybe ditch the lock washers and use a spec of locktite instead. Maybe drill the centers of the bolts out to. And grind the heads down some after torquing them. Why not?

Jesus tits...

Attachment 210530

Not quite true. You can't touch the rubber, or anything suspended by the rubber. Technically changing the weight of anything in the entire rotating assembly will have an effect on the efficiency of the damper, but it is not nearly as pronounced.

If the material you want to remove is attached to the inner ring in the uber-ghetto picture attached, you can safely remove it (from a vibrational standpoint at least). If it is attached to the outer ring, then it is a functional part of the damper and removing it will effect the dampening. Removing this material won't destroy the damper completely, it will just change it's natural frequency (increase it if you remove material), and this will change the effectiveness of the damper over different RPM ranges. For example, you could change where the damper is effective, and make it not effective in a range that you regularly operate your engine at.

Does anyone happen to have a link or something to some decent damper design info by any chance? They're pretty simple torsional vibration systems and the math behind them shouldn't be all that tricky, I'm surprised they still seem like such a dark art.

uber ghetto is right. Can you say wobble?

What's funny is Mike is a local to me and he posed this question a day or 2 within our local club. I answered him with a resounding NO and he said OK, he won't touch it. Then he goes and posts it on here. But then again this is the kid would wants to go through all the effort of putting back together and installing a block with rusted cylinder walls with the only R&R on the engine being going around each cylinder with a rubber squeegy to rub the rust off while the pistons are still in the block! I get no respect.

Psh, what do you know about turbocharging a miata or harmonic balancers????

Mike, you don't know me or curly. You can't trust some guy on a forum. How do you know I'm right? You don't. I could be pulling all this out of my ass. Either "play it safe" and leave good enough alone (assuming stock is good enough), find someone more knowledgeable you trust whos experienced and take their advice, or do your own research on the matter and draw your own conclusions.

In god we trust... Says it on the dollar bill. Oh and Flyin' Miata told me i can use the 1.6L pulley on a 1.8L

PS pulley is not suspended by the rubber on the 1.6 pulley. which is why I removed it, but did not go further by removing the 'nose' labeled in my previous pictures. And as I said in the beginning, you could face off that nose to save some more weight, while still maintaining a harmonic balancer. whether or not that harmonic balancer with the lightened load would still work, I have no idea.

To add more fuel to this fire, if the damper was so sensitive, wouldn't removing the tension of the p/s belt or a/c belt affect the properties of the damper?

I should clarify, my MS Paint drawing on the first page is incorrect, the green line representing the rubber should be to the right of where the PS pulley is secured, which means the PS pulley (again, on a 1.6 only) is not part of the weight for the harmonic damper

I also wanted to say Patsmx5 makes a good point, the weight reduction is very minimal and is probably not worth the effort, much less does it make any difference. my car is street legal, yet only really used for racing (<1000 street miles per year) so any weight reduction is good by my book. I also work in a machine shop, so I didn't spend any money, I didn't even take time out of my day to drive to a friend's machine shop, I simply brought the pulley to work and spent 1/2 of my 10 minute break on the lathe.

Sure would, but I don't think by a noticeable amount. The stiffness of the crank and damper are much much higher than that of the belts, and the vibrations that the damper is made to dissipate are at fairly high frequency (and very low amplitude). The belts are on the damper and would have some effect on it, but I am fairly sure the frequency's are so high and the stiffness of the belts so low that it would not really change anything.

I wanted to remove the PS Pulley purely for aesthetics. The slight weight reduction is an unintentional added bonus.

What's also is funny is that you didn't mention our local club is a SMS based Text messaging service. You could only reply with a "No" because there is not much room for elaboration. Perfectly valid to post here for the full story.

Aesthetics? You mean assthetics. Your cara was painted by a crackhead who offered to give you head for an additional $5. How concerned were you with the cars looks then? And then you drilled a hole through the hood when installing hood lifts. And I'm sure a few of us remember how you "rolled" you fenders in my driveway.... HAHAHAHAHAHAHA

No is no. Is it not?


I love Mike's threads.

I feel like I'm just wasting my time replying to all his threads. Seems like he's looking for us to say what he wants to hear.

seriously. 1 engine = 4 failed threads

thread 1 was of the original pics of the shitty engine
thread 2 was of the "reconditioned" with rubber squeegy engine
thread 3 was destroying the harmonic balance to give shitty engine even more reason to fail
thread 4 was trying to sell 100% perfect pistons/rods from shitty engine

did i miss any?

Hey now, never underestimate the power of rubber squeegies...

Now the truth comes out He said he "honed it 3 spins" in his thread. I...... doubted that.

First of all, 3 spins with a hone wouldn't do anything. It takes a clean cylinder and a hone on a drill a while. Easy to spend 10 minutes just honing one cylinder to get the final clearance right. Hell they make threads where you manually crank down the tension to speed the process up.

Second it had he honed it, it would be pretty obvious. Clean scratches intersecting one another. From his pics, it looked like he too steel wool to them or something.

I had an OBX crank pulley on my short nose. My uncle machined the a/c and ps groves out and it worked fine. This was done in 3 different STS2 miatas and none of them ever had a problem. The pulley cost $60. We also had to drill new holes on it because the original ones were a little off. But compare $60 to $100+ from other brands an you have a good deal

and how much power were these miatas in sts2 making?

At a dynojet here in Indianapolis, one (lets say A)was low in power @ 110hp at the wheels @ 16 degrees of timing. That was before a rebuilt, the leak down test for A showed some substantial leakage.
Specimen B pulled 120 hp with only 10 degrees of timing. But the head was rebuilt by Steward Engines and we havent dynoed it yet.
Specimen C (used to be my car) was never dynoed, leakeage tests were excellent after using the pulley for an year and 3 months on a gt2554 pulling around 200hp (I estimate).
(ALL THESE SPECIMENS WERE SHORT NOSE)
I think as long as you do a professional job (not cutting the pulley with a hack saw) you will be fine. This is just my opinion

Yeah. Good luck convincing paul though. He broke a motor from not running one. And he wasn't the first.

1. those are all low power if you ask me
2. a year and 3 mos don't mean shit, you might drive 4000 miles in that time while I drive 50k. how many miles on the 200hp car with butchered pulley?
3. why are we talking leak down tests? the oil pump gear shatters