Pictures and info about securing the cam and crank sprockets.
Pictures and info about securing the cam and crank sprockets.
I was digging around and it seems that the harmonics are transmitted up into the camshafts especially on timing chain engines and this could be a cause for the camshaft issue. Seems like this is something that needs to be dealt with. Custom damper prices are not to bad so I think this is the way to go.
Doing some more digging and found some really in detail stuff about this. Found that large hubs only making dampening harder and was looking at the N/A hub and realized it was different. It has the bolt together setup and the damper ring is much larger while the hub is much smaller. The later one piece has a much larger hub assembly and smaller damper ring on the outside. The earlier unit may be a much better assembly for these applications. It is also similar to what the m104 uses and I run a 5-600hp at over 7k through a stock pulley for years with no problems but crank harmonics are probably really different even though it is the same architecture.
Thats correct, i also got the Advice from muuris to change my Damper to the om602 2-Piece Damper to avoid that Failure.
The only thing that concerns me is the different flywheel and that the balancer may be tuned different for the cast iron flywheel vs the flexplate one in the newer engines. I have a growing list of questions.
So some interesting news. I talked to a company about getting a damper done. I am going to send both versions out to them to take a look at and get one done. Not to bad overall costs.
The really interesting thing is that he specifically mentioned that around 6k inline engines have terrible harmonics. Blowing through this rpm is ok but staying there for any length of time is really bad. Some people will shift at 5800 rpm to stay out of this harmonic and or just blow through to higher rpms quickly.
Baldur, the 2 stroke mafia would have me killed for getting the TZ crank in my RD350 engine welded. Reducing inertia at the tapered crank snout tend to be enough on the 2 strokes I work onl
Whipplem104, this is an interesting topic. I've enjoyed reading about it. From what I've read, there are 2 different problems at the front of the crank. 1 is the torsional harmonics that can affect the cam, another is bending, which may be what broke your crank.
Diesels are mentioned in particular on the bending issue:
"This bending is driven mostly by the firing force of the first cylinder(s) behind the first main. The force tends to drive the crankpin down and the webs bend sideways like the legs of a bridge. As the force stops, the legs spring back. As a result, there is a rocking motion through the front main that makes the nose of the crank move in the opposite direction to the springing of the first pin. This leads to a vibration caused by the nose of the crank bouncing up, down and sideways. I have seen this get so severe in diesels that the viscous dampers have the internal inertia ring friction-welded to the case making the damper totally lock up. In modified racing engines, it is generally a broken crank nose. In general, heavy pulley or damper packages just aggravate the motion and do nothing to control it."
This page is centered on Porsche flat 6 engines, but I understand a flat 6 crank can have some of the same vibration problems an inline 6 has
http://performancedevelopments.com/porsc...nefailure/
It is a super cool topic. The inherent rpm frequencies is interesting. It seems the inline 6 can have two different frequency ranges that are exceptionally bad. Either low to mid 5k range and the low to mid range 6k range.
We did not break the crank, Just the pulley spun about 12 degrees. Minor chip at the key. No need to remove the crank. Sending the stock dampers out to be evaluated and develop a solution. Then pin it and it seems like pinning the cam gear is a good idea as this is probably the root cause of cam gear rotation. I read that F1 engines this is the major factor in cam timing and that they used dampers on the cam to deal with this. Porsche GT3 and turbo engines have this problem as well etc etc.
(04-01-2016, 10:03 AM)raysorenson Baldur, the 2 stroke mafia would have me killed for getting the TZ crank in my RD350 engine welded. Reducing inertia at the tapered crank snout tend to be enough on the 2 strokes I work onl
Whipplem104, this is an interesting topic. I've enjoyed reading about it. From what I've read, there are 2 different problems at the front of the crank. 1 is the torsional harmonics that can affect the cam, another is bending, which may be what broke your crank.
Diesels are mentioned in particular on the bending issue:
"This bending is driven mostly by the firing force of the first cylinder(s) behind the first main. The force tends to drive the crankpin down and the webs bend sideways like the legs of a bridge. As the force stops, the legs spring back. As a result, there is a rocking motion through the front main that makes the nose of the crank move in the opposite direction to the springing of the first pin. This leads to a vibration caused by the nose of the crank bouncing up, down and sideways. I have seen this get so severe in diesels that the viscous dampers have the internal inertia ring friction-welded to the case making the damper totally lock up. In modified racing engines, it is generally a broken crank nose. In general, heavy pulley or damper packages just aggravate the motion and do nothing to control it."
This page is centered on Porsche flat 6 engines, but I understand a flat 6 crank can have some of the same vibration problems an inline 6 has
http://performancedevelopments.com/porsc...nefailure/
(04-01-2016, 10:03 AM)raysorenson Baldur, the 2 stroke mafia would have me killed for getting the TZ crank in my RD350 engine welded. Reducing inertia at the tapered crank snout tend to be enough on the 2 strokes I work onl
Whipplem104, this is an interesting topic. I've enjoyed reading about it. From what I've read, there are 2 different problems at the front of the crank. 1 is the torsional harmonics that can affect the cam, another is bending, which may be what broke your crank.
Diesels are mentioned in particular on the bending issue:
"This bending is driven mostly by the firing force of the first cylinder(s) behind the first main. The force tends to drive the crankpin down and the webs bend sideways like the legs of a bridge. As the force stops, the legs spring back. As a result, there is a rocking motion through the front main that makes the nose of the crank move in the opposite direction to the springing of the first pin. This leads to a vibration caused by the nose of the crank bouncing up, down and sideways. I have seen this get so severe in diesels that the viscous dampers have the internal inertia ring friction-welded to the case making the damper totally lock up. In modified racing engines, it is generally a broken crank nose. In general, heavy pulley or damper packages just aggravate the motion and do nothing to control it."
This page is centered on Porsche flat 6 engines, but I understand a flat 6 crank can have some of the same vibration problems an inline 6 has
http://performancedevelopments.com/porsc...nefailure/
hy fine people....
recently i have been tighgtening one this harmonic balancer in a engine i´m building... i did the extra securing just in case...
To my understanding this key wich holds the harmonic damper and the chain sprocket is not suposed to hold the twist , it seems to me that it is secured only by the bolt and the tight strenght.... i´ve observed that most vibes in this MB engines tend to twist the bolts in the right hand motion... despite i never seen one slipedd , most engines i know are 5 cylinder as mine.
nevertheless i found that there are 2 types of bolt (strenght force) 8.8 and 10.9 and the tightening recomended for both difers being one 200N and 90º and the other one 320N , what i belive some have experienced is caused by deficiency in the tightening procedure...
i have seen some cranks with the snout broken, and some with bolts apart but slipped after being subjected to 200N and 90º in a 22mm 1.50 treads ...
well like every one else i would like to be sure if this is really a problem that afects all engines 5 and 6 cyl, or it is just reported in the 606? and the other thing is that it may be corrected by changing the weight and therefore the resonance vibration, or even with a diff set up for tightening
By the way , i expect to balance my engine with a special balancing device, wich can read vibes in many ways then i´ll post the readings and from that we can understand if there is resonant vibes , unfortunatly it will take time.
Thanks
Harmonics are different that just internal balancing though. This is a crank twist issue from each cylinder firing and the resulting harmonic in the crank shaft from this at different RPMs. There is a method of measuring this in the crank to some degree. I was quoted 2500.00 for that and then there is actually measuring it on a running engine which was around 25k.
i can do that for free, weather engine running or stopped in charge or without... is just vibes... it just takes time and bother a friend...
eventhough they are just harmonics they must travel through some kind ressonance, what intrigues me is the fact that the hub spins and does not break , it should break instead, just cause it should be tight enough to prevent sliping and the release of energy would be rupture...
just that ;(
Ha. Well, absence of evidence is not evidence of the absence, so they say. Or, just because you are not paranoid doesn't mean they aren't out to get you :-)
Feeling smug in my low rpm, high torque plan, but only because I haven't put it together and found something else to break yet. And more torque could make it happen at a different rpm.
tunning is all about that
U tune till it brakes, one step aft , solution , tune again , it brakes, another step aft , tune again , u´ll never happy ....
But let me say one thing, if u are twisting cranks already u´re closer to heaven than i am, and most here
As said before, i found strange people report the harmonic damper slip, and nothing happen to time chain drive sprocket, wich is my worst fear, i´m i missing something ?
If u want to try a lighter damper made by the star , search for 602.982 it uses a very light version of it, and is a DI engine wich usually have a lot more vibes and sharper response.
regards
(03-31-2016, 11:08 AM)Max Thats correct, i also got the Advice from muuris to change my Damper to the om602 2-Piece Damper to avoid that Failure.
(03-31-2016, 11:08 AM)Max Thats correct, i also got the Advice from muuris to change my Damper to the om602 2-Piece Damper to avoid that Failure.
I plan to secure these sprockets also and when I look previous pictures I want to add one thing. Thread and bolt is nice way to secure cam sprocket but it does not seem to be the best way for crank damper. If crank damper is secured with threaded bolts then damper may not be able to tighten chain sprocket between crank and damper because damper position is locked with securing screws. It may be problem especially when damper was removed and not pressed on tightly. Then damper main bolt is just pressing against damper and not chain sprocket. That's why spring pin seems to be better option, there are different pins.
Bolted
New SFI rated balancer will be shipping out this week. I will post up pictures when it gets here.
We will pin this one as well. But you also need to address the increased crank harmonics or it will wipe out the bearings and maybe break the crank shaft.
(08-17-2016, 11:53 AM)whipplem104 New SFI rated balancer will be shipping out this week. I will post up pictures when it gets here.
(08-17-2016, 11:53 AM)whipplem104 New SFI rated balancer will be shipping out this week. I will post up pictures when it gets here.
New balancer came in today. I posted up the 2 stock variations as well.
After discussing pinning the crank with the company it was not recommended. What we are going to do instead is to install a stud and it will be longer and nut down. This will create pull from the rear of the snout.
I read through this thread, and my interest in the failing woodruff key etc.
I decided to look in ASRA/WIS for damage info or superceded parts.
I could only come up with ONE document relating to anything in the top-end of the engine....
Had to go out and do stuff today, so didn't finish my previous post.
OM602 -
(08-27-2016, 06:11 AM)hooblah This has been going on for sometime now yet I still don't see any conclusive evidence of failure, just pure speculation and scaremongering.
(08-27-2016, 06:11 AM)hooblah This has been going on for sometime now yet I still don't see any conclusive evidence of failure, just pure speculation and scaremongering.
(08-28-2016, 04:05 PM)whipplem104 What I learned looking into it is that is a crank harmonic issue. Thus the new harmonic dampener.
(08-28-2016, 04:05 PM)whipplem104 What I learned looking into it is that is a crank harmonic issue. Thus the new harmonic dampener.
We have not installed it yet. I am searching for a stud to replace the bolt with right now. It will have a stud and a nut instead of the bolt.
I just got it last week. So it will be installed soon and we will see. But it is a bit of a guessing game without spending a whole lot more money on the design. The engineers make some assumptions based on the additional power and rpm and the frequency that the original was tuned for. And experience of course.
(08-28-2016, 04:05 PM)whipplem104(08-27-2016, 06:11 AM)hooblah This has been going on for sometime now yet I still don't see any conclusive evidence of failure, just pure speculation and scaremongering.
We spun the crank pulley in a matter of 1 day. We were on the dyno and at the racetrack so a total of around 10 minutes of run time and it sheared the key and moved about 15 degrees. What I learned looking into it is that is a crank harmonic issue. Thus the new harmonic dampener. The harmonics are most likely causing the camshaft spin issue as well. As well as failed bearings and broken crankshafts etc.
It is about sitting in a bad harmonic frequency. So say running the engine at 6200 rpm for an extended period of time. Like more than a couple of seconds. A dampener that was designed for 200hp and a peak rpm of 52=5500 will not dampen the harmonics of the engine at 6000rpm at 500hp. All numbers are just examples as we obviously did not go with the run the engine on the dyno and measure harmonics version of this design with the company because it costs more money than the whole car project. But that is the jist of it.
(08-28-2016, 04:05 PM)whipplem104(08-27-2016, 06:11 AM)hooblah This has been going on for sometime now yet I still don't see any conclusive evidence of failure, just pure speculation and scaremongering.
We spun the crank pulley in a matter of 1 day. We were on the dyno and at the racetrack so a total of around 10 minutes of run time and it sheared the key and moved about 15 degrees. What I learned looking into it is that is a crank harmonic issue. Thus the new harmonic dampener. The harmonics are most likely causing the camshaft spin issue as well. As well as failed bearings and broken crankshafts etc.
It is about sitting in a bad harmonic frequency. So say running the engine at 6200 rpm for an extended period of time. Like more than a couple of seconds. A dampener that was designed for 200hp and a peak rpm of 52=5500 will not dampen the harmonics of the engine at 6000rpm at 500hp. All numbers are just examples as we obviously did not go with the run the engine on the dyno and measure harmonics version of this design with the company because it costs more money than the whole car project. But that is the jist of it.
Well I did not start the thread on the subject and was skeptical myself until I did it. I can easily come up with reasons why it is a problem for some and not others. Mostly power level and rpms. Also sitting in certain rpms for extended periods of time vs pushing right past them. The company that I am working with on the balancer said that inline 6 engines are prone to really bad harmonics at around 6000rpm. This can shift due to variables a bit but they avoid sitting in the range of 5800-6200 rpm. Revving through the rpm range quickly is ok because the harmonics do not have a chance to build up. So say in 1st gear or 2nd gear you may only be in that rpm range for a second or less. In 3rd and 4th you could be there for a long time. Especially 4th gear. So even driving type can dictate if it is a problem. But mostly it is an increased power level issue at a certain rpm range.
MR 04 ,
Are u guys running the 606 crank as it was original build, or did made it lighter? run stock rods and pistons , or were for lighter custom pistons and rods?
I have helped tune some 605/6´s and we never found out interesting to drive at those rpm u mention, actually we found the engine behaves better in the 3.5 k to 5.5, thats were we point the 100hp cylinder to be , between 3.5 and 5.5k.
We still make decent power in the upper range but it stops climbing. The engine is bone stock. I wanted the revs to make hp without so much torque but that seems unrealistic. So we are going to shift the rpm down a bit as well. But I will probably still rev out to 6k in 1st and 2nd gear and short it in 3rd and 4th. Keep it at or below 5700rpm. Depending on what dyno you are on, etc. etc. We are already making more than 100hp per cylinder at the crank. Looking for more.
What do you think it would take to keep it climbing for another 1000rpm?
I've heard it slows down because diesel doesn't burn as fast as petrol. However, as far as I'm aware nobody has tried a set of high lift cams. Perhaps this can shift the power band and help to produce more power higher up?
i see ,
i never tryed to lighten a diesel internals to the bone as the gasser´s are or use to be , first cause they will exibit idle problems and the second i never prepared race engines.... good (cheap )replacement parts too played a role on that......
but this days and taking acount the availability of VNT type turbos , i wonder if that is not the way to go ....
is a bit of topic but , a 606 crank weighs about 20kilos , the piston 350grams and a rod 750g so complete set 25 to 30 kilos add some kilos to bearing drag and in the end we end up having a rotating mass of more than 30kg at 6k it will use some kW, plus the 2kilo harmonic damper and the 30 kg stock clutch pack, how many i dont know those calculations are far from what i plan for my amusement.....
i vote that this vibes mentined , and some other dificulties in rotating high , are most related to internal drag than they are to flame burning speed or what ever people think about diesels ....cams, valves, springs dadada...
another plan to consider is the IDI type engine , wich can easyly be converted to a low press DI , even using the IDI pistons...
for the sake of the thread , i never saw this problema with sliping harmonic damper, i seen crank snout colapse but that is mostly due to umbalanced parts. and its very hard to belive in crank power twist, expecialy This cranks.
I do not think another 1000 rpm is going to happen. I believe that it is simply an rpm burn time issue. We did not gain any significant power above 5k rpm from increasing boost from around 35 psi to 50 psi. I would say next to nothing really. If it was an air flow issue I would think that I could not get the extra boost or my exh back pressure would be to high which neither seems to be the case. We are trying the n/a intake cam to see if it shifts at all and going to play with timing. But I do not expect much more than a few hundred rpm shift to the right. We are also just going to open a bottle of nitrous in the intake to see if it does anything up top as well. I do not expect much. I could build more hp with torque down low but to be honest I am afraid of pushing more than around 600lb/ft wheel torque through the bottom end. We are going to drop the A/R down to a .91 to get the spool on the turbo up a bit and then match the converter to stall at the point boost starts to come in.
(09-01-2016, 08:10 AM)barrote how did u went from 35 to 50psi, at the cost of back pressure?
(09-01-2016, 08:10 AM)barrote how did u went from 35 to 50psi, at the cost of back pressure?
yes that was the question.
i usually build the power around the pump , unless the engine is too week to sustain the pump output, then is time to blueprint here and there, driveability and tq curve.
sometimes the backpressure steals the power increase given by boost, a exemple is a 120cc pump for a 606 is fine with 1.5 bar , trying to run 2 bar wont lead u nowhere, fuel is needed , and once we force the turbo to 2 bar the EGP raises and steals the power out of the system .....
dadad, hope u understand my point....
The pump we have can easily put out way more fuel than we can burn. The only way to burn that much fuel would be to make over 1200lb/ft of torque based on what we are using now.
It is a dieselmeiken 230cc pump. We have it near the stock settings. which are supposed to be around 140cc if I remember. So it might be 160-180cc. We are not using all of it though. PLenty of smoke in the low rpm high torque area. It is fed with a bosch 044 set with a pressure reg. at 15psi.
We turned it all the way up on the dyno and all it did was overheat and cause a black out. No more hp up top.
i see,
Drill the precups to 3mm , botle neck to 8mm, pop pressure to 150, give it intake pressure and advance , sure it wont black out anything after 1.5bar boost,
basically if u can have 2 bar intake at 3k , u have 2k margin to twist gear boxes and clutches hehhehe. in the dyno u wont see much diference , but the rocket efect will show when driving hehehe.
Regards
In my opinion i think its the mechanical pump that is the limt after 5500rpm. Thats why im going over to EDC pump now with DSL1 controller.
Look at the dyno on this: http://www.superturbodiesel.com/std/show...p?tid=7355
It have been talk about that the govenor is not up for the task and starts cutting fuel way before the rpm limit kicks in.
When drifting with my car it wont go over 5800rpm. But if i turn out the alda i get more smoke but rpm limits at 6000. But the guvenor rpm limit is at 7000rpm. Its the same with both Dieselmeken and Pekka Herlevi pumps.
I can pull the car on the straights way over 6000rpm but it feels flat.
I appreciate the input here. We have the injectors at 150. And we have plenty of fuel. We are on a 3d boost stategy and it will rev free past 6k no problem. Our hp just goes flat though at around 4500-4700 rpm. Torque falls off at the same rate rpm increases. Thus no hp increase. The car is plenty fast. I am talking about actual data though. It just will not maintain torque above 4400-4700 rpm. I would love to get to 5800 rpm with a flat tq curve but it just is not happening.
Also I have seen absolutely no evidence that drilling the prechambers makes any hp. If there is some I will go through the trouble but no one that I have ever found did this and put it on a dyno for a before and after. I am on the fence a bit on this subject. I can argue that the more open holes would cause a faster flame front into the cylinder but I also can argue that what is the restriction. As the flame front moves into the cylinder then raw fuel vapor is following it and burning in there. So I would think that all we would do is have a quicker initial flame but that could just be adjusted by timing. We need a faster burn rate of the fuel. Or it also could be an ignition delay issue.
One guy dynoed and said it gave 3hp and 16lb or whats it called in torque.
3hp is hardly worth removing the prechambers for. And well withing the error from run to run on a dyno. And certainly not something that could be felt. That would be a .006% increase in power. I am looking for things that yield a 50-100 hp increase.