You'll have to ask them. I don't run a chain.
Dump the gear and go timing chain?
- Thread starter 2GNS4ME
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Cheeseburger
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- Jan 25, 2004
Who is "them"? I have a feeling that you well find a high percentage of broken chains were with aluminium blocks.
A V8 cover. You need to remember that we're specifically talking about a V6 application here. A chain drive goes through some different motions with the V6.
So you're insinuating that engine builders are using the chain to absorb some of the wide range of harmonics? Much the same way the harmonic damper does? It would seem to me that would concentrate a lot of stresses at the chain itself. These stresses don't just disappear. Some component(s) are going to have to deal with them.
If the harmonics that the chain had to deal with happened to be just right, I could see the chain dismantling itself. Much the same way a driveshaft does at critical speed.
I seem to recall Nick posting some stories on chains?
What is being lost here is the fact that no one is performing high end development of a chain drive system for the ol' BUICK V6. What you are still getting today is the same sort of chain drive systems that were available long ago, before 1989.
Harmonics. Now this is an interesting thought. If an engine builder is trying to isolate the chain drive from crankshaft harmonics by setting a damper between the two, then what does that say of a system where no harmonic damper is being used? Sound familiar? The TR crank hub?
With no crankshaft harmonics being dealt with by a true blue harmonic damper, does that mean that a chain drive would have to deal with that much more harmonics? And the harmonics on a Buick V6 is nothing to sneeze at.
Remember. Those forces don't just disappear into thin air. Some component(s) are going to have to deal with it, in part, or in whole.
Some of that force is translated into chain or belt slap. If things are done in an effort to reduce the slap, does that mean that these harmonic and tortional forces have to move, in part, to other components? Remember, these forces don't just disappear.
With no crankshaft harmonics being dealt with by a true blue harmonic damper, does that mean that a chain drive would have to deal with that much more harmonics? And the harmonics on a Buick V6 is nothing to sneeze at.
Remember. Those forces don't just disappear into thin air. Some component(s) are going to have to deal with it, in part, or in whole.
Some of that force is translated into chain or belt slap. If things are done in an effort to reduce the slap, does that mean that these harmonic and tortional forces have to move, in part, to other components? Remember, these forces don't just disappear.
HouseofSpeed
Hangin' and Bangin'
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- May 27, 2001
That cover pic was just to illustrate what has been done by serious builders that run chains and make a lot of power at high RPM. I was not comparing a V6 to a V8 in terms of components or harmonics...just giving an example of how it is dealt with in that example and showing that chains must not be that bad if Roush-Yates is making components for them.
I am also saying that a gear drive generates more power depleting harmonics in dyno testing than similar chain and belt setups....and that is a proven fact.
Understand that no one is doing R&D on a Stage V6 because the engine is not relevant to the performance community at large. I believe there is one sprint car class in the midwest that uses them...but outside of that, the last time they were a preferred powertrain was over 20 years ago. What I am trying to outline is that an air pump is an air pump....and cam timing is not limited to gears and chains. I realize that everyone has their own take on what works and what doesn't.....all I can share with you is what I know from 20+ years as a competition engine builder / tuner / instructor.
HouseofSpeed
Hangin' and Bangin'
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- May 27, 2001
In reality, you are assuming that the chain or belt generates the same level of harmonics as the gear drive....and that's not the case. So, while each will create its own stresses {belt is negligible because of construction and they don't slap like a blower belt does...they are tight....typically using more than one type of tensioner....hydraulic and mechanical in some OE examples....if they slapped around as you are suggesting, an interference fit engine (2.0 DOHC Mitsubishi, 4.0 DOHC Toyota V8, etc.) would not be able to live at all.} you really can't compare gear to gear contact (even helical cut) with a chain or a belt.
If a belt did not slap, there would be no need for idlers and tensioners.
I'm not assuming that a chain or belt generates harmonics, and I'm certainly not comparing that to what harmonics a gear drive might generate. What I'm saying is, an engine creates harmonics that travel through the crankshaft, and whatever cam drive is being used will have to deal with those harmonics. The harmonics may travel through the different forms of cam drive, or the cam drive method may absorb some of those harmonics. Either way, the cam drive method has to deal with those harmonics. The harmonics do not just disappear because you put a belt on.
What people who are reading this thread would really appreciate is any news of any new developments that you've heard of with timing chain development that is being directly applied to the Stage II Buick V6. That's kinda how we V6 guys are. V8 stuff is fine, but what's being done for our V6s? Are we stuck with old timing chain technology?
In the world of the BUICK V6, particularly the turbocharged BUICK V6, the cam drive method has to be durable. It's not enough to say that you will make more power with a chain. It also has to last for a reasonable amount of time. This is why timing chains are generally not recommended for serious BUICK V6 racing engines by well known BUICK V6 racing engine builders. Again, I give Jim Ruggles as an example, and if anyone is truly interested, I can present a quote on how he feels about chains vs. gear drive for the BUICK V6.
HouseofSpeed
Hangin' and Bangin'
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- May 27, 2001
Well...there is no R&D on Stage 2 V6 stuff to my knowledge. Small market, no real source of new components. Were originally designed as a competition specific piece that currently has no platform to compete in...I love the Buick stuff too, but just no home for it.
I wouldn't say that you are stuck with old tech....step up to a dry cover and a belt drive, almost infinite cam timing adjustment without stripping the front of the engine and the durability and reliability of a kevlar reinforced belt ....also will eliminate the greater level of harmonics found in your current gear drive.
I wouldn't say that you are stuck with old tech....step up to a dry cover and a belt drive, almost infinite cam timing adjustment without stripping the front of the engine and the durability and reliability of a kevlar reinforced belt ....also will eliminate the greater level of harmonics found in your current gear drive.
I'm going out on a limb here and am going to assume that most people really don't want to go through the process of going to a belt drive. The question here is chain or gear drive.
Do you have any information on what sort of level of harmonics we're talking about here? Particularly with the Buick V6?
I have to add that I've been running a gear drive, the same gear drive since around 2005 and can't say that I've been able to identify any unexplainable wear that I can associate to using the gear drive. If anything, I notice less wear to the front cam journal bushing, which ends up giving better oiling system control.
HouseofSpeed
Hangin' and Bangin'
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- May 27, 2001
Donnie...you have to look at it from a broader perspective.....do you think the cam drive method on any of the endurance applications I mentioned above....from NASCAR to Baja / SCORE / KoTH....can afford to not be durable? Understand that for sheer abuse...nothing sees more than the loading and unloading of the prop drive / crank in an off-shore racing boat as it leaves and enters the water during the race...and they don't use gear drives brother. I have never heard anyone say to not use a chain on a Stage engine....why would they have been used in Busch applications if that were the case? You have to put these quotes in context.....how old is the quote from Ruggles? If its from 1984....chances are with the tech available now his thoughts would be a little different. Jim certainly knows his stuff....but is not the only source for quality info.
Cheeseburger
Active Member
- Joined
- Jan 25, 2004
I think the belt drive issue is availability and cost as the main issue which is why more people are not using it.
The point here is, the only chain technology available today for the Buick V6 is the same that was available when Jim came up with his opinion on them. Why would his opinion now change?
You keep mentioning these other racing venues. Are they using the Buick V6?
HouseofSpeed
Hangin' and Bangin'
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- May 27, 2001
You asked for technology and I offered a suggestion....I will dig through some of my notes and see what I can come up with on harmonics. At the end of the discussion...gears are gears, chains are chains...innovation with regard to those components is like designing a wheel that isn't round....no need for it and it doesn't make sense.
Also remember that you are talking about a drag racing application....a long way from an endurance application from front to back. Which is not to say that it hasn't worked for you...just saying its apples to oranges if you are talking about what Ruggles built engines for as compared to your application.
The opinion of chain life in the BUICK V6 by Jim Ruggles. (naturally aspirated applications)
"Engine builders will argue ad nauseum about the relative superiority of chain and gear drives. With regard to a V-6 engine, such arguments are irrelevant. Due to reverse acceleration of the valvetrain, chain drives will have a very short life."
More of his opinion coming up.
"Engine builders will argue ad nauseum about the relative superiority of chain and gear drives. With regard to a V-6 engine, such arguments are irrelevant. Due to reverse acceleration of the valvetrain, chain drives will have a very short life."
More of his opinion coming up.
HouseofSpeed
Hangin' and Bangin'
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- May 27, 2001
Example is that chain tensioner design in that picture I supplied....takes care of a lot of the problems Jim saw with chains back in the day. That is a fabricated cover and mechanical chain tensioner that could be built for a Stage engine as well.
Again, I am giving you examples of engines that see far more abuse than a Buick V6 and in some cases are of a more fragile construction....I know you have tunnel vision on this topic...but there is no inherent frailty to the Stage 2 which would cause me to say that what works on a NASCAR V8 from a design and tech standpoint would not work on a Buick V6.
I asked about chain technology specifically, but thanks for your suggestions. I also want to say, I do appreciate your responces. Thank you.
