Engine rebuild Vibration issues.
10-18-12, 05:10 AM
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Engine rebuild Vibration issues.
Hello all, I have a question. I been looking at websites and googling and doodling trying to find an answer. I thought i would just drop in and ask here.
I Rebuilt my engine about a month ago. I think i put the wrong front counter Weight on as i had a few floating around.
So my engine runs great. I cant feel any vibration Unless its over 4k then i can feel it and i can hear it in the frame of the car. Its Not Horrible. And im not to worried. However Before i tear the front cover off and try the other weight back on, Is there a way i can ad a weight to the pulley area? And if i were to pull the engine out Can it be Balanced without taking the Insides of the engine back apart?
Because im sure its just the front counter weight. But i used two different rotors, One was 2mm apex seals the other 3mm apex seals. The 3mm apex seal rotor was the Lighter one. So i figured the weight of the 2mm seals vs 3mm seals would be ok.. Can anyone verify that for me? The two rotors were off by 30 grams and that i am told is Fine for street cars and from factory as the limit is 50 gram weight difference. So since the 3mm apex seal rotor was Lighter I felt that i should be ok weight wise from 2mm apex seals vs 3mm.
Agian the engine isn't way off. its just enough i can notice it. So i figured i could do a temp weight fix externaly on the engine? Any ideas? Thanks
I Rebuilt my engine about a month ago. I think i put the wrong front counter Weight on as i had a few floating around.
So my engine runs great. I cant feel any vibration Unless its over 4k then i can feel it and i can hear it in the frame of the car. Its Not Horrible. And im not to worried. However Before i tear the front cover off and try the other weight back on, Is there a way i can ad a weight to the pulley area? And if i were to pull the engine out Can it be Balanced without taking the Insides of the engine back apart?
Because im sure its just the front counter weight. But i used two different rotors, One was 2mm apex seals the other 3mm apex seals. The 3mm apex seal rotor was the Lighter one. So i figured the weight of the 2mm seals vs 3mm seals would be ok.. Can anyone verify that for me? The two rotors were off by 30 grams and that i am told is Fine for street cars and from factory as the limit is 50 gram weight difference. So since the 3mm apex seal rotor was Lighter I felt that i should be ok weight wise from 2mm apex seals vs 3mm.
Agian the engine isn't way off. its just enough i can notice it. So i figured i could do a temp weight fix externaly on the engine? Any ideas? Thanks
10-20-12, 10:11 AM
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Did you just say you have one rotor installed with 3MM seals, and one with 2MM seals?! That's just wrong. 3MM seals are quite a bit heavier than 2MM, slower to respond to movement, and generally don't seal as well. So the engine will always be out of balance in several ways.
No, you can't externally balance. If you have the wrong counterweight, it must be replaced with a KNOWN counterweight matched to rotor weight and flywheel. If you don't have your counterweights marked and sorted, then you may just have to buy one from Mazda.
No, you can't externally balance. If you have the wrong counterweight, it must be replaced with a KNOWN counterweight matched to rotor weight and flywheel. If you don't have your counterweights marked and sorted, then you may just have to buy one from Mazda.
10-21-12, 10:39 PM
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Did you just say you have one rotor installed with 3MM seals, and one with 2MM seals?! That's just wrong. 3MM seals are quite a bit heavier than 2MM, slower to respond to movement, and generally don't seal as well. So the engine will always be out of balance in several ways. Ift could be the other way around.. almost the same surface is touching the rotor housing
No, you can't externally balance. If you have the wrong counterweight, it must be replaced with a KNOWN counterweight matched to rotor weight and flywheel. If you don't have your counterweights marked and sorted, then you may just have to buy one from Mazda.
No, you can't externally balance. If you have the wrong counterweight, it must be replaced with a KNOWN counterweight matched to rotor weight and flywheel. If you don't have your counterweights marked and sorted, then you may just have to buy one from Mazda.
Last edited by rx7_FREAKKK; 10-21-12 at 10:57 PM.
10-21-12, 11:41 PM
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He said 3mm don't seal as well. He also meant that the 3mm seals don't have as high compression.
This is fairly common consensus, however I don't know enough to give an educated response. But it was Aaron Cake that said that, and whatever you says you listen. I don't think I've seen anyone who knows more than he does about these engines.
This is fairly common consensus, however I don't know enough to give an educated response. But it was Aaron Cake that said that, and whatever you says you listen. I don't think I've seen anyone who knows more than he does about these engines.
10-22-12, 03:04 AM
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I agree its always best to put the same MM seals in the same Engine. Im just trying to say it should not be an Issue if done right. Never heard bad stories of people that have.
I heard talk about apex seals for ages. Now for the first time i hear that 2mm seals have more compression than 3mm seals? Just nuts. I been watching threads for a long time. If the Weight is the same then all ya got is a compression issue. cant be a issue at all if its within the Compression range for it to Ignite
I heard talk about apex seals for ages. Now for the first time i hear that 2mm seals have more compression than 3mm seals? Just nuts. I been watching threads for a long time. If the Weight is the same then all ya got is a compression issue. cant be a issue at all if its within the Compression range for it to Ignite
10-22-12, 05:36 AM
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I heard talk about apex seals for ages. Now for the first time i hear that 2mm seals have more compression than 3mm seals? Just nuts
and there is those that take the time to study the factory bulletins and SAE papers
sounds to me like you may have s5 and s4 rotors or even an rx4/GSL-SE 3mm rotor mixed together
and or at least one mismatched CW
any and all of which will equal a destroyed stat bearing before long , all well understood for eons ,, and doesnt take much of a imagination to see why
if you search.. i have posted the pics you need to ID the various front and rear masses.. and if you search,, there is also umpteen posts on how to ID turbo and NA s4 rotors,, and s5 rotors
written by people who have been there and done that and not listened to the street hype
Last edited by bumpstart; 10-22-12 at 05:38 AM.
10-22-12, 11:55 AM
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nah im going to put the other front weight on. I think it got mixed up. Before i take the engine Apart agian.
I may not be the smartest man on this planet. But for god sakes I can tell a compression loss Vs a weight issue when an engine is running. I have had a DEAD rotor and one working rotor and didnt have a vibration sharp as that
And yes im aware of the front friggin thrust bearing.
I may not be the smartest man on this planet. But for god sakes I can tell a compression loss Vs a weight issue when an engine is running. I have had a DEAD rotor and one working rotor and didnt have a vibration sharp as that
And yes im aware of the front friggin thrust bearing.
Last edited by rx7_FREAKKK; 10-22-12 at 11:58 AM.
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10-22-12, 12:41 PM
#8
if you know everything, then why would you ask these questions?
1. swapping the counterweight is pretty involved and probably would not be successful with the engine left in the car. ever see the results of a thrust washer get smashed by the hub bolt?
2. coolant seals are cheaper than a whole new engine. i am suggesting you take the time to open the engine up and put a matching rotating assembly together. cheap now means expensive later.
3. 2mm seals do seal better. mazda paid engineers millions upon millions of dollars to go from the original 6mm apex seals down to the 2mm seals. you think a few of your backyard mechanic buddies know better than the people that designed the engines?
of course you will ignore all this and do what youd like anyway but when this engine prematurely fails, dont blame it on the design of the engine.
1. swapping the counterweight is pretty involved and probably would not be successful with the engine left in the car. ever see the results of a thrust washer get smashed by the hub bolt?
2. coolant seals are cheaper than a whole new engine. i am suggesting you take the time to open the engine up and put a matching rotating assembly together. cheap now means expensive later.
3. 2mm seals do seal better. mazda paid engineers millions upon millions of dollars to go from the original 6mm apex seals down to the 2mm seals. you think a few of your backyard mechanic buddies know better than the people that designed the engines?
of course you will ignore all this and do what youd like anyway but when this engine prematurely fails, dont blame it on the design of the engine.
10-22-12, 12:43 PM
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if you know everything, then why would you ask these questions?
1. swapping the counterweight is pretty involved and probably would not be successful with the engine left in the car. ever see the results of a thrust washer get smashed by the hub bolt?
2. coolant seals are cheaper than a whole new engine. i am suggesting you take the time to open the engine up and put a matching rotating assembly together. cheap now means expensive later.
3. 2mm seals do seal better. mazda paid engineers millions upon millions of dollars to go from the original 6mm apex seals down to the 2mm seals. you think a few of your backyard mechanic buddies know better than the people that designed the engines?
of course you will ignore all this and do what youd like anyway but when this engine prematurely fails, dont blame it on the design of the engine.
1. swapping the counterweight is pretty involved and probably would not be successful with the engine left in the car. ever see the results of a thrust washer get smashed by the hub bolt?
2. coolant seals are cheaper than a whole new engine. i am suggesting you take the time to open the engine up and put a matching rotating assembly together. cheap now means expensive later.
3. 2mm seals do seal better. mazda paid engineers millions upon millions of dollars to go from the original 6mm apex seals down to the 2mm seals. you think a few of your backyard mechanic buddies know better than the people that designed the engines?
of course you will ignore all this and do what youd like anyway but when this engine prematurely fails, dont blame it on the design of the engine.
Don't be assuming anything
10-22-12, 12:46 PM
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if you know everything, then why would you ask these questions?
1. swapping the counterweight is pretty involved and probably would not be successful with the engine left in the car. ever see the results of a thrust washer get smashed by the hub bolt?
2. coolant seals are cheaper than a whole new engine. i am suggesting you take the time to open the engine up and put a matching rotating assembly together. cheap now means expensive later.
3. 2mm seals do seal better. mazda paid engineers millions upon millions of dollars to go from the original 6mm apex seals down to the 2mm seals. you think a few of your backyard mechanic buddies know better than the people that designed the engines?
of course you will ignore all this and do what youd like anyway but when this engine prematurely fails, dont blame it on the design of the engine.
1. swapping the counterweight is pretty involved and probably would not be successful with the engine left in the car. ever see the results of a thrust washer get smashed by the hub bolt?
2. coolant seals are cheaper than a whole new engine. i am suggesting you take the time to open the engine up and put a matching rotating assembly together. cheap now means expensive later.
3. 2mm seals do seal better. mazda paid engineers millions upon millions of dollars to go from the original 6mm apex seals down to the 2mm seals. you think a few of your backyard mechanic buddies know better than the people that designed the engines?
of course you will ignore all this and do what youd like anyway but when this engine prematurely fails, dont blame it on the design of the engine.
Don't be assuming anything, "of course you will ignore all this and do what youd like anyway but when this engine prematurely fails, dont blame it on the design of the engine"
That's enough of the bullshit.
10-22-12, 12:49 PM
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if you know everything, then why would you ask these questions?
1. swapping the counterweight is pretty involved and probably would not be successful with the engine left in the car. ever see the results of a thrust washer get smashed by the hub bolt?
2. coolant seals are cheaper than a whole new engine. i am suggesting you take the time to open the engine up and put a matching rotating assembly together. cheap now means expensive later.
3. 2mm seals do seal better. mazda paid engineers millions upon millions of dollars to go from the original 6mm apex seals down to the 2mm seals. you think a few of your backyard mechanic buddies know better than the people that designed the engines?
of course you will ignore all this and do what youd like anyway but when this engine prematurely fails, dont blame it on the design of the engine.
1. swapping the counterweight is pretty involved and probably would not be successful with the engine left in the car. ever see the results of a thrust washer get smashed by the hub bolt?
2. coolant seals are cheaper than a whole new engine. i am suggesting you take the time to open the engine up and put a matching rotating assembly together. cheap now means expensive later.
3. 2mm seals do seal better. mazda paid engineers millions upon millions of dollars to go from the original 6mm apex seals down to the 2mm seals. you think a few of your backyard mechanic buddies know better than the people that designed the engines?
of course you will ignore all this and do what youd like anyway but when this engine prematurely fails, dont blame it on the design of the engine.
I told you above. I am aware of the thrust washer. Did i not make that clear
10-22-12, 02:56 PM
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if you know everything, then why would you ask these questions?
1. swapping the counterweight is pretty involved and probably would not be successful with the engine left in the car. ever see the results of a thrust washer get smashed by the hub bolt?
2. coolant seals are cheaper than a whole new engine. i am suggesting you take the time to open the engine up and put a matching rotating assembly together. cheap now means expensive later.
3. 2mm seals do seal better. mazda paid engineers millions upon millions of dollars to go from the original 6mm apex seals down to the 2mm seals. you think a few of your backyard mechanic buddies know better than the people that designed the engines?
of course you will ignore all this and do what youd like anyway but when this engine prematurely fails, dont blame it on the design of the engine.
1. swapping the counterweight is pretty involved and probably would not be successful with the engine left in the car. ever see the results of a thrust washer get smashed by the hub bolt?
2. coolant seals are cheaper than a whole new engine. i am suggesting you take the time to open the engine up and put a matching rotating assembly together. cheap now means expensive later.
3. 2mm seals do seal better. mazda paid engineers millions upon millions of dollars to go from the original 6mm apex seals down to the 2mm seals. you think a few of your backyard mechanic buddies know better than the people that designed the engines?
of course you will ignore all this and do what youd like anyway but when this engine prematurely fails, dont blame it on the design of the engine.
To Balance a rotating assembly cost 350 bucks EASY.
Besides I Worked on trying to find 2 s4 2mm Rotors that are the same weight. And its not easy Unless I spend 75 plus dollars each.
Last edited by rx7_FREAKKK; 10-22-12 at 02:58 PM.
10-22-12, 03:03 PM
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You want to play word Games. lets play what is that part called. I ******* put the ****** ****** together. I know what each part DOES and how it WORKS. Im not going to sit here and Play Part name game.
10-22-12, 03:05 PM
#16
engine out of balance will result in a vibration at 4k and at about 6500, sounds like you have the wrong counterweight.
as for seals, no. having one rotor with 2mm seals and one with 3mm seals will not throw the engine out of balance. consider the seals separate from the rotors, the only drag they incur is from the springs which 2mm and 3mm will have similar pressures applied.
compression difference between 2mm and 3mm is negligible, regardless of opinion i haven't seen many 3mm engines give crappy compression results UNLESS the engine has very high mileage and the housings are starting to show wear internally.
measure the width of a series 4 front CW and and a series 5/6 and you will see if there was an error or not. the S4 front CW is noticably thicker/heavier. if running a light flywheel and the wrong rear CW is used, that is a little trickier to diagnose, i have a hard time telling a series 4 auto CW from a series 5/6.
almost any resonant vibration in neutral is internal. i just had a customer ask about balancing a rotating assembly due to a vibration. i said no, you should not feel any vibration while not moving and unless pushing over 9500RPMs the assembly does not need to be balanced beyond factory spec. if you want to be sure, remove all your accessory drive belts and run the engine again. if the vibration is still present then you need to take the engine apart, at least somewhat.
as for seals, no. having one rotor with 2mm seals and one with 3mm seals will not throw the engine out of balance. consider the seals separate from the rotors, the only drag they incur is from the springs which 2mm and 3mm will have similar pressures applied.
compression difference between 2mm and 3mm is negligible, regardless of opinion i haven't seen many 3mm engines give crappy compression results UNLESS the engine has very high mileage and the housings are starting to show wear internally.
measure the width of a series 4 front CW and and a series 5/6 and you will see if there was an error or not. the S4 front CW is noticably thicker/heavier. if running a light flywheel and the wrong rear CW is used, that is a little trickier to diagnose, i have a hard time telling a series 4 auto CW from a series 5/6.
almost any resonant vibration in neutral is internal. i just had a customer ask about balancing a rotating assembly due to a vibration. i said no, you should not feel any vibration while not moving and unless pushing over 9500RPMs the assembly does not need to be balanced beyond factory spec. if you want to be sure, remove all your accessory drive belts and run the engine again. if the vibration is still present then you need to take the engine apart, at least somewhat.
Last edited by RotaryEvolution; 10-22-12 at 03:11 PM.
10-22-12, 03:13 PM
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Your complaining about $75 each for a rotor? That is pretty cheap for any used rotors. You should have done that in the first place now look what you have gotten yourself into. How are you going to ask for help to fix YOUR mistakes and then tell some of the most knowledgeable people on this forum that they dont know what they are talking about?
Last edited by TheGoldenSB; 10-22-12 at 03:19 PM.
10-22-12, 03:21 PM
#18
is this your personal rule Karack?
Honestly, if the engine is N/a and seeing over 8500 rpm, i would probably build them with s5 n/a or rx8 rotors. one having a factory 8k redline, the latter being around 9200. 9500 seems a fair "new age" assessment.
10-22-12, 03:21 PM
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engine out of balance will result in a vibration at 4k and at about 6500, sounds like you have the wrong counterweight.
as for seals, no. having one rotor with 2mm seals and one with 3mm seals will not throw the engine out of balance. consider the seals separate from the rotors, the only drag they incur is from the springs which 2mm and 3mm will have similar pressures applied.
compression difference between 2mm and 3mm is negligible, regardless of opinion i haven't seen many 3mm engines give crappy compression results UNLESS the engine has very high mileage and the housings are starting to show wear internally.
measure the width of a series 4 front CW and and a series 5/6 and you will see if there was an error or not. the S4 front CW is noticably thicker/heavier. if running a light flywheel and the wrong rear CW is used, that is a little trickier to diagnose, i have a hard time telling a series 4 auto CW from a series 5/6.
almost any resonant vibration in neutral is internal. i just had a customer ask about balancing a rotating assembly due to a vibration. i said no, you should not feel any vibration while not moving and unless pushing over 9500RPMs the assembly does not need to be balanced beyond factory spec. if you want to be sure, remove all your accessory drive belts and run the engine again. if the vibration is still present then you need to take the engine apart, at least somewhat.
as for seals, no. having one rotor with 2mm seals and one with 3mm seals will not throw the engine out of balance. consider the seals separate from the rotors, the only drag they incur is from the springs which 2mm and 3mm will have similar pressures applied.
compression difference between 2mm and 3mm is negligible, regardless of opinion i haven't seen many 3mm engines give crappy compression results UNLESS the engine has very high mileage and the housings are starting to show wear internally.
measure the width of a series 4 front CW and and a series 5/6 and you will see if there was an error or not. the S4 front CW is noticably thicker/heavier. if running a light flywheel and the wrong rear CW is used, that is a little trickier to diagnose, i have a hard time telling a series 4 auto CW from a series 5/6.
almost any resonant vibration in neutral is internal. i just had a customer ask about balancing a rotating assembly due to a vibration. i said no, you should not feel any vibration while not moving and unless pushing over 9500RPMs the assembly does not need to be balanced beyond factory spec. if you want to be sure, remove all your accessory drive belts and run the engine again. if the vibration is still present then you need to take the engine apart, at least somewhat.
10-22-12, 03:24 PM
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Your complaining about $75 each for a rotor? That is pretty cheap for any used rotors. You should have done that in the first place now look what you have gotten yourself into. How are you going to ask for help to fix YOUR mistakes and then tell some of the most knowledgeable people on this forum that they dont know what they are talking about?
Last edited by rx7_FREAKKK; 10-22-12 at 03:28 PM.
10-22-12, 03:30 PM
#21
You see there... When i was learning(before i was doing and coming up with my own rules for building) the limit was 8500 rpm max on a factory balance.
is this your personal rule Karack?
Honestly, if the engine is N/a and seeing over 8500 rpm, i would probably build them with s5 n/a or rx8 rotors. one having a factory 8k redline, the latter being around 9200. 9500 seems a fair "new age" assessment.
is this your personal rule Karack?
Honestly, if the engine is N/a and seeing over 8500 rpm, i would probably build them with s5 n/a or rx8 rotors. one having a factory 8k redline, the latter being around 9200. 9500 seems a fair "new age" assessment.
but i'm hesistant to ever recommend balancing a rotary rotating assembly because i feel most shops do not do it properly and they all take material off in a certain position which may or may not be the proper location. the rotor has 2 planes to balance versus a single plane in piston engines. the rotors have 6 tips per rotor which all need to be balanced simultaneously. do most shops capable of balancing the assemblies have the proper equipment to balance all 6 tips per rotor? i doubt it. lightening the rotors would actually be as beneficial or more than an improper balance job. apex seals also are a very large contributor to the wear caused by high revs, soft and/or light seals are needed to save the housings from chatter and gouging. clearance the sides of the rotors and the only thing you have to then worry about is bearing wear.
i would wager most endurance rotaries have lightened, side clearance rotors running factory balance running either carbon or ceramic apex seals. that is what i would do.
most of the damage i see from stock-ish high RPM tracked engines is actually apex seal gouging into the rotor housings. not even a mark from the rotors on the irons or excessive wear on the bearings that would cause premature failure even after seasons of abuse. ceramics or carbon seals would have saved the housings in that event, ceramics being proven for long term use where carbons are sacrificial.
most of the imbalance issues i see are from hard cuts at high RPMs, this is no fault of the engine but the system that is powering it. rotary engines and hard cuts do not mix, perhaps this is why mazda incorporated very soft cuts at high RPMs and moderate boost cuts for boosted engines that only affected half the engine so that the engine would still be driven but under limited power, moving everything forward still reducing slack in the rotating assembly which causes the imbalances that cause the engines to fail, shearing gears and bouncing rotors off housings/irons.
regardless of how thick the e-shaft is, it is the focal point of where imbalances start and those reasons mentioned are what cause the e-shaft to begin deflecting right in the center of the engine(there is no support between the rotors). some high RPM builds include 2 piece shafts with a center bearing to prevent that deflection from occurring. IMO it's cheaper to use ceramic seals, eliminate any cuts and run a scatter shield than even paying for a split shaft engine build(by a wide margin i might add).
to sum it up i just rarely see factory imbalance issues in any engine i tear apart, including engines i have dynoed to 9k pushing over 500whp. this includes my talks with Jonathan at Goopy who has cranked out over 1100 2 rotor wheel horsepower on a factory balanced engine.
Last edited by RotaryEvolution; 10-22-12 at 03:53 PM.
10-22-12, 09:05 PM
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Thanks. yes its no race engine. i hear they are very tight on Specs at that Rpm. But my Vibration isnt bad. hardly Notice at idle. I hit 4k 6k then i feel it. Just dont feel like out of weight rotors to me. I will be taking it apart tonight or tomorrow. Ill change counterweights . Then repost my findings