www.CVOHARLEY.com
CVO Technical => Twin Cam => Topic started by: johnsachs on December 20, 2017, 06:45:52 PM
-
Another one bites the dust.
More and more I'm gaining a major dislike for beehive springs. "I know a few things because I've seen a few things."
This one is from a 124 S&S HC crate motor. Owner is NOT a hammer. 5500 miles, and boom. Don't want to hear that GM, etc., etc, uses thousands of them(they use thousands of valve lifters also) and don't have the problems that the Harley world has with them.
Checked the assembly of the opposing head, and that was spot on. .650" lift spring, installed height 1.870", 160 lbs. on the seat.
John
-
John, what do you think is causing it? I'm the guy who mentioned the GM thing because I'm a GM tech and just don't see a high rate of failures. I'm not trying to slam anyone just trying to figure it out. Is it spring rate, metallurgy, or just plain poor QC. The same goes for the lifter issue.
James
-
Could the part just be sourced from a low quality Chinese Mfg?
-
Just a couple questions.
Is it true that on our "stock" 110", '09 version, has too much valve spring pressure? Is it possible that this "may" be part of the lifter failures?
Now over the years in auto industry, the Bee Hive springs have had great success as John has stated.
So for STOCK 110" motors, would bee hive along with new lifters be a good and safe combination?
I see failures of the bee hive in high lift situations and just thinking that in normal stock lifts, they may be a help.
Thanks in advance for the thoughts.
-
Just a couple questions.
Is it true that on our "stock" 110", '09 version, has too much valve spring pressure? Is it possible that this "may" be part of the lifter failures?
Now over the years in auto industry, the Bee Hive springs have had great success as John has stated.
So for STOCK 110" motors, would bee hive along with new lifters be a good and safe combination?
I see failures of the bee hive in high lift situations and just thinking that in normal stock lifts, they may be a help.
Thanks in advance for the thoughts.
Dan, I am definitely not a wrench myself but I've had four 110 failures and talked to numerous techs whose input I value and respect. The consensus is that there is indeed very high valve spring pressure that may lead to failures. Seems plausible to me since similar lifters don't seem to fail nearly as often or as quickly in other applications. Others of course may well have diffing opinions but no one has conclusively been able to point to the root cause of the 110 problematic failure rate. It may very well be a 'perfect storm' of several things that in and of themselves might not be troublesome but in combination they are.
-
.650" lift is a lot for any valve spring.
-
so it seems to me, from my non-mechanic pov, that the high lift of the 255 cam is the underlying cause of a lot of these failures. if thats the case, what would be a good cam to use for someone who is perfectly happy with the 'stock' performance of their bike?
i'm only 'half-worried' about it right now, being under esp. but when the esp expires, would definitely take a look at making this motor as reliable as possible.
-
so it seems to me, from my non-mechanic pov, that the high lift of the 255 cam is the underlying cause of a lot of these failures.
255 Is Not High Lift In Modern 110 Head. .555 Lift.
-
Not only lift but ramp profile needs to be considered, among other things (i.e. spring preload, seated force).
IMHO anything above .550" is "big" for a roller lifter + pushrod engine.
-
i had the B hives working with a 625 lift cam and never an issue in 38k miles... or with the S&S lifters w/limiters, i must have some dumb luck or what. or is the set up work have a lot to do with longevity,
-
.650" lift is a lot for any valve spring.
The spring that failed is rated for up to .650" lift. Not necessarily the lift of the cam.
-
Understood
-
I can't help but wonder if these failures are related to a common manufacturing source with a less than stellar quality record. The photo's I've seen of failed parts all look the same, with the break in the same place. :nixweiss:
Jerry
-
I don't know how many manufacturers are involved in producing beehive springs. I know that I've seen 3 different brands break including factory production 88" - 103"
IMO, I don't feel that the Screamin Eagle dual springs have too much pressure on the seat or at max lift if set up properly. They seem to be set up properly when used by the MoCo on production bikes. Some of the MoCo optional (catalog) beehive springs DO have too much tension. They don't find their way on production bikes. I have checked their stage 4 beehives ( with 40,000 miles), and find them to be edgy like 210 on the seat on a1.875" intake valve, and a 1.570" exhaust valve.
As to why they fail, IDK :nixweiss:. I see some beehive springs lean when removed, and the spring seat is shiny about a third of the way around.
Lifters, I must be lucky, haven't had many failures come in, and I have some customers that are real hammers.
CVOSTU, big man ,cruises at 90 mph, likes to play, and a high mileage rider. 2 bikes NO lifter issues, CVO dual valve springs, high mileage.
John
-
I can't help but wonder if these failures are related to a common manufacturing source with a less than stellar quality record. The photo's I've seen of failed parts all look the same, with the break in the same place. :nixweiss:
Jerry
I thought the same thing as soon as I saw the photo.
In all my wrenching days ( not on bikes) any broken springs I've come across have been middle top or bottom, more middle and top then bottom though.
I can't help but wonder that maybe riding style could be part at play, ( not meaning to knock any ones riding) such as more spring failures on a bike that is being shifted at higher rpm them one being shifted at lower rpm. Perhaps the springs can't handle being pushed on high rpm.
The fault doesn't seem to be happening across the board on the 110s and the milage doesn't appear to be a factor either.
I've been around motors in the 100 of thousand hours on them with no spring issues but haven't been subjected to high rpm.
I could be totally wrong but I think springs break due to higher rpm there not designed for. I would put in springs that are designed for higher rpm if I had to do a replacement.
-
Did the spring pads get checked to see if they are perpendicular to guides?
-
Dual springs work. Beehives not all the time. I won't be using any beehives in the big builds any longer. I too had similar failures with springs rated at .600 and .650 from name brand companies. Others I had come back for freshening up dropped serious pressure. The factory springs are not that bad but the noise the stockers make in the mid 2K rpm range is harmonics and that hammers lifters. So my point is there are dual and then there are better dual springs. Using a TI retainer becomes smart to keep the spring weight down. When working with a top quality spring such as PAC there are enough options to dial in what the build will need for pressure and the gain the ability to control the harmonics.
On a side note I have also seen two versions of the factory OEM springs used in the CVO 110, one with dual springs and dampener and one version without. I prefer no flat dampener and the interference fit . We need to keep in mind the valve train in this motor is heavy and even though the cams may not have high lift or long duration they have very high lift rates and need a proper spring with enough pressure, spring rate and seat pressure, or the valve train will loft and/or float.
I will still use the OEM beehive on the 7mm valve stuff under .600 lift except if someone is using one of the jack hammer type cams.
-
Did the spring pads get checked to see if they are perpendicular to guides?
Good thing to check. Have seen some that were way off after a guide change.
As to why they fail, IDK :nixweiss:. I see some beehive springs lean when removed, and the spring seat is shiny about a third of the way around.
Talked to the PAC guys at PRI. If the springs tilt/lean I was told to send them back. This was common when they first came out but has been corrected. They should sit flat/square.
-
Another one bites the dust.
More and more I'm gaining a major dislike for beehive springs. "I know a few things because I've seen a few things."
This one is from a 124 S&S HC crate motor. Owner is NOT a hammer. 5500 miles, and boom. Don't want to hear that GM, etc., etc, uses thousands of them(they use thousands of valve lifters also) and don't have the problems that the Harley world has with them.
Checked the assembly of the opposing head, and that was spot on. .650" lift spring, installed height 1.870", 160 lbs. on the seat.
John
I took this photograph.
-
Did the spring pads get checked to see if they are perpendicular to guides?
First thing I checked, because I couldn't tell if the broken spring was a leaner.
Used my snap gauge along with a retainer and keepers. Never more than .004" out around the retainer and base area. Valve to guide clearance within S&S specs.
My biggest problem with the beehives is if a spring breaks, 99.9 % of the time the valve drops, causing major damage. Dual spring breaks one of them 99.9% of the time usually prevents the valve from dropping. ;)
John
1 thing to note: When using valve spring shims on late 103" heads, be SURE the hole in the center of the shim has a large enough diameter to clear the guide retaining ring. :o
-
I shim on top of the spring seat/seal holder.
I have found similar in spring seat measurements and felt it was not enough to fix it or hurt the reliability of the spring.
-
Shimming on top of the seal's holder is always a good idea. That way you minimize the risk of the
retainer crushing the seal.
High rpm (and heat) shorten a spring's life. Choosing a bee-hive vs. dual is a trade off, like most everything.
The springs are oil cooled on these engines and they tend to run hotter than say, a water cooled V8 spring.
So we have that working against us. If you want ultimate protection from a broken spring taking your
motor out, run a dual spring. The downside is, the spring and retainer are heavier, so more pressure may be
necessary to control the valve train.
Tradeoffs are a way of life... food for thought is all....
Added:
Springs have a natural resonant frequency. Beehives mitigate this by having many resonant points,
each of which are less than one single (major) frequency. Dual springs will have a major resonant frequency
for the inner and one (major) for the outer. (hopefully those are nowhere close to one another)
Keeping the spring out of the resonant range also makes them live longer. What's the resonant frequency
you may ask. Good question, that needs to be answered by the spring manufacturer or spintron testing.
Running at an RPM where the spring resonates (rings) will kill them too.
-
This is an example of what resonance can do to a structure.
http://www.youtube.com/watch?v=XggxeuFDaDU
-
This is an example of what resonance can do to a structure.
That's definitely what's going on inside a Harley valve train (or compensator)!
-
So Matt
What are you recommending for the CVO head motors?
-
dual spring
-
These posts on different forums have got me also thinking twice about beehives,have too many heads out there we've done with no failures reported back to us,but hearing from others is a eye opener
-
These posts on different forums have got me also thinking twice about beehives,have too many heads out there we've done with no failures reported back to us,but hearing from others is a eye opener
Don't give up yet. ;D
I've seen more dual spring failures in the past year than I have beehive. Most failures can be traced back to something other than the spring.
-
Larry,
How many of the dual spring were catastrophic failures vs beehive failures that you saw?
Also to put the failures in perspective how many have you seen the (past year) of each to understand the comparison?
-
We are close to having shelf springs that won't have any compromise, a dual conical with appropriate spring rates and installed heights for what we are doing in these roller cam applications.
-
Don't give up yet. ;D
I've seen more dual spring failures in the past year than I have beehive. Most failures can be traced back to something other than the spring.
I'll go along with that. Beehive failures are not as common, but almost always catastrophic.
Dual spring failures OTOH, don't destroy the motor in most cases. A bent valve is usually the
worst case but that can go either way too.
-
The stock beehives would break the retainer.
All of the beehive broken springs I have seen never lost a valve. Some were bent. Some weren't. None of them destroyed a motor.
The worst dual spring IMO are the ones that use a flat wire damper. Dual springs with an interference fit are better.
Some broken springs. Broken spring seats. No disasters.
And as John mentioned before a lot of them had the wrong shims. Springs dancing around like strippers at the tittie bar.
-
I've seen Two beehive failures. One was a disaster, one was a minor disaster. lol
Tittie bars rule.
-
Tittie bars rule.
And Dallas has them, with some absolutely gorgeous women. (picking jaw off floor and wiping up drool)
-
And Dallas has them, with some absolutely gorgeous women. (picking jaw off floor and wiping up drool)
We have some of the finest babes in the country, allot of them!
Before the age of "PC" (when I was a manager) I used to hold my monthly staff meetings at BabyDolls.
Allot of the engineers in other departments wanted to work in my group. lol (I knew how to "motivate"
employees)
-
https://speedtalk.com/forum/viewtopic.php?f=1&t=52071
Another one bites the dust
-
Beehive springs are great, until one fails. Then they're not so great. Everything is a tradeoff. The factory Harley springs
seem to hold up pretty well. Don't know why though.
-
They break too. I have had a few retainers split too. Fortunately the damage was minimal and at low speed.
-
They break too. I have had a few retainers split too. Fortunately the damage was minimal and at low speed.
yep. nothing is fool proof. The Harley springs are pretty good though.
-
They break too. I have had a few retainers split too. Fortunately the damage was minimal and at low speed.
I did have a customer report back that a stock retainer broke on a set of street port heads,2.5 years after we did the heads.wanted me to cover it.sorry,not gunna happen
-
I did have a customer report back that a stock retainer broke on a set of street port heads,2.5 years after we did the heads.wanted me to cover it.sorry,not gunna happen
dang .... nobody will warranty them HD parts :nixweiss:
-
Ferrea valves has a very informative video of Spintron fixture generated images of spring surge, rocker arm, and pushrod failures, and is totally recommended viewing for engine builders! My favorites are: spring surge so violent that the spring actually lifts from its seat, and that is while the spring is at max lift! Early attempts at manufacturing carbon fiber pushrods that will function flawlessly at 9300 RPM, but fail catastrophically at about 6800 rpm, (used in NASCAR engines, they failed during caution laps, not racing!), they refer to that resonance phenomina as a "fuss point". That video starts out at 9200 rpm and slowing down the rpm. The carbon fiber pushrod explodes into dust and filament at about 6800! Fuss point, I guess! That's why I always inspect used springs upon removal. I have seen springs with shiny marks on the coils from touching, but the installed height allows for higher lifts by more than .100". We are all still learning. The video may be available from the sales staff. My copy is on VHS!!! It is required viewing for my staff. TIMINATOR
-
You also need to inspect the valve stem above the keeper groove. The 5:00 0'clock and 11:00 o'clock positions for keeper movement. ;)
John
-
I brought up the beehive issues a couple years ago.....and was told I was FOS🤔
The s&s springs even look like offshore units
Comp seems to fixed all the broken spring issues
I'll stick with the small rev wound duals
-
I brought up the beehive issues a couple years ago.....and was told I was FOS🤔
The s&s springs even look like offshore units
Comp seems to fixed all the broken spring issues
I'll stick with the small rev wound duals
Most of the S&S beehives come from AV&V.
I'm a dual spring guy when it becomes my choice. :huepfenlol2:
John