Broken valvspring.

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pdq67
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Re: Broken valvspring.

Post by pdq67 » Tue Jan 16, 2018 2:11 am

swampbuggy wrote:
Mon Jan 15, 2018 9:10 pm
Yep PDQ67 this is why you sometimes see engine builders wearing thin rubber gloves don't you reckon ? Warp ----do you guys wear them ???? Mark H. :D
swampbuggy,

Years ago AP Greens F-600 Ford 6-wheeler Gunning Truck lost a wrist pin keeper and scored a cylinder so we had the Mexico, MO Ford dealership R&R it's 361 FE engine.

I noticed that they had stood its pair of heads over right next to the shop's drinking fountain.

Well, we convoyed out of Mexico, MO with me 1st driving it. I got up the east bluff of the Miss River on Hwy 54 when a spring broke, thus dropping a valve! I pulled a valve cover and saw that the spring had a very small rust spot on it at the break.

We called the shop and told them what happened and they said to get hold of the big Ford Dealer at Hannibal and rebuild it again!

The 2nd time was going to take a complete head, piston and rod, plus a reground crank. We ended up getting a new re-manufactured 391 for it!

The story doesn't end here because we found out that the 391 leaked antifreeze under the bell housing in the back. I looked the rebuild tag over and it said, stock bore, crank .010 and rods .020. Now I know why it had a stock bore! it had been pulled due to the leak and rebuilt and sent out the door again. The block had a real small sand hole between the blocks webbing is why it leaked a bit!

Needless to say, the 391 turned the smaller F-600 right on!! it ran like our F-750 with a 391 did.

I had to fly out of South Bend, IN to the Quincy, IL airport and then take a cab to the Hannibal, MO Ford Dealer on Hwy 61 and then drive the truck back to South Bend! Not fun at all..

pdq67

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Re: Broken valvspring.

Post by englertracing » Tue Jan 16, 2018 3:16 am

Newold1 wrote:
Mon Jan 15, 2018 3:56 pm
I am not going to spend anytime defending my reading or questions, no need the OP has answered 4 of the 5 quite well in his second post.

Iam also very glad to hear from the OP that a bent valve was the only real significant damage. With the intake side this is more prevalant because the intake side tends to let go and drop the valve with the piston near the top of the cylinder piston travel and hence tends to bend the valve , drive it up and leave it stuck in the guide ABOVE a point where it drives into the piston and causes catastrophic engine damage. If the exhaust spring breaks it drops the exhaust valve into the cylinder generally close to the bottom of piston travel in the cylinder leaving the entire valve out of the guide fully into the cylinder with the piston traveling up and you can imagine what happens from there!

I was pretty sure when he posted the pics, I knew the spring and the approximate age. I knew this because this was the exact spring I and many others in the aftermarket started having serious problems with back starting about 2008 right after it was introduced and I was having my own issues with this spring on LS builds. I also saw the same type of problems from an early aftermarket same basic spring from a large industry valve spring manufacturer.

I would like to say at this point Comp realized the failures and problems and changed the manufacture and design of this spring and since then the scope , reason and magnitude of this past problem has been eliminated in that part number to my understanding.

The real reason for this problem in this beehive spring as well as some others in the industry stems pretty much from how the spring wire was wound during manufacture. If you take one of this period years particular beehive spring and stand it up and look down the top opening of the spring you will see that the center of the top opening in the spring at the retainer opening you will see that the center of the bottom opening in the spring is not directly under the top opening center. You might ask, why does this matter! It matters because as the spring is compressed the top of the spring is off center with the bottom of the spring and as the compression distance increase the wire of the spring section at the break points is being bent back and forth horizontally as the valve stem going down in the guide tries to align the two openings. Obviously valve spring wire tends to end and twist as it compresses but not in this fashion. That type of unintended bending moment at that point heats the wire and weakens it. Just like bending a paperclip wire back and forth until it breaks. I as well as hundreds of other LS aftermarket beehive spring head users and other beehive valve spring users had this breakage show up and had lots of damage and grief. Why does it not happen on all beehive springs is because not all beehive springs are made with this defect. This is backed up by the millions of beehives that are in use today in millions of vehicles. I don't think you will see this issue with any of Comps beehives today and other major spring manufacturers also eliminated this condition and beehive spring usage in the aftermarket in general is much better today than back then.

If you are using beehives today in your builds and performance uses, just take the springs and do this top down look. If you see this top to bottom misalignment-STOP-send them back if you can or can them and get another good set of beehives. I won't go into the long detail of how this problem was identified just let me say a few good valve spring experts and some good spintron testing found and proved the problem.

To the original poster if you choose to stay with a beehive spring for your application then check the new ones and make sure they don't suffer out of the box with this problem. If it were my call I would switch to a good conical spring or a nice set of straight doubles. JMO

Sweet reply, I've got another simpler reason they can fail.
If installed with a goodson valve spring mic, the small retainers go inside the mic"s counterbore. The valve spring mic is designed to have the retainer on top of the mic not down in it, this ends up giving you a 1.6xx" installed height instead of a 1.8" installed height, the larger softer coils move first and coil bind, leaving the smaller coils to compress and creating torsion at the beginning of the first small coil,
Ask me how I know..... it still makes me sick, broken rod, piston was an aluminum ball found upside down in the broken cylinder/block, broken head(chamber and cam tower) broken camshaft, broken rocker arm, valve stem even broke the cast Alu valve cover.... this was on a little Ford 2.3 ministock race motor,
I was young and I though I lost a plug wire, as I had once before, kept running it, it quit like the ignition was turned off , I was coasting to the infield clutch in, decided to let the clutch out to try and get it to start, and it made terrible clattering noise,
Pulled the valve cover at the track, found a mess,
Pulled the head at home at around midnight to find the cylinder entirely broken out and the piston upside down and the chamber with a hole the size of a quarter.

So, make sure they actually get installed at the recommended height.
I think I used the 29615 springs, then I went to 29618 and never had a problem with them at the correct installed height.

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Re: Broken valvspring.

Post by Geoff2 » Tue Jan 16, 2018 4:12 am

There were a batch of faulty Comp BH springs, I believe around 2007-8. Could they have been from this batch?

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Re: Broken valvspring.

Post by digger » Tue Jan 16, 2018 4:15 am

doesnt look like fatigue to me

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Re: Broken valvspring.

Post by modok » Tue Jan 16, 2018 4:27 am

Newold1 wrote:
Mon Jan 15, 2018 3:56 pm

The real reason for this problem in this beehive spring as well as some others in the industry stems pretty much from how the spring wire was wound during manufacture. If you take one of this period years particular beehive spring and stand it up and look down the top opening of the spring you will see that the center of the top opening in the spring at the retainer opening you will see that the center of the bottom opening in the spring is not directly under the top opening center. You might ask, why does this matter!
Am I understanding correctly... you say the springs had too much inclination?
And this causes failure?
Glen Urban

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Re: Broken valvspring.

Post by Robban 54 » Tue Jan 16, 2018 6:11 am

Hello again
The batch nr of the old ones is C0-11-027 and they are from 04-11-11

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Re: Broken valvspring.

Post by Newold1 » Tue Jan 16, 2018 7:21 am

I would try the Comp Cams 7228-16 Conicals for your application. I think your retainers might even match up but I would use new machined valve locks.

Best of luck for the future.

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Re: Broken valvspring.

Post by jsachs1 » Wed Jan 17, 2018 5:27 pm

Another area to watch when using beehive springs is to match the spring to the cam. In other words DON"T use a .650 " lift beehive spring on a cam that only lifts .600". :wink:
John

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Re: Broken valvspring.

Post by Robban 54 » Thu Jan 18, 2018 7:43 am

Ok? It was new to me.
My lift is at the valve intake 0.575 "exhaust 0.555"
:shock:

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Re: Broken valvspring.

Post by Newold1 » Thu Jan 18, 2018 8:02 am

That is for the most part an issue depending on what your installed height versus coil bind on the spring is. You can always install a spring in this range such that the installed height minus valve lift will stay about .050" to .060" away from coil bind as a preferred range. OP can you determine what your installed height is and whether your open height is by subtracting it from that installed height. If this dimension is wide by lets say +.100" or more at some rpms some springs can develop a harmonic or oscillation that can damage and sometimes break valve springs. totally depends on the spring and the uses.

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Re: Broken valvspring.

Post by DaveMcLain » Thu Jan 18, 2018 10:08 am

Newold1 wrote:
Thu Jan 18, 2018 8:02 am
That is for the most part an issue depending on what your installed height versus coil bind on the spring is. You can always install a spring in this range such that the installed height minus valve lift will stay about .050" to .060" away from coil bind as a preferred range. OP can you determine what your installed height is and whether your open height is by subtracting it from that installed height. If this dimension is wide by lets say +.100" or more at some rpms some springs can develop a harmonic or oscillation that can damage and sometimes break valve springs. totally depends on the spring and the uses.
One of the problems that you find if you pull all of the springs to coil bind and measure them is how much variation there will be when it comes to coil bind height. It can vary .040-.060 or so pretty easily.

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Re: Broken valvspring.

Post by Robban 54 » Thu Jan 18, 2018 2:00 pm

Hello
Coil bind spring 26918 is 1,100 "
Installed height about 1,750 "
Diff 0.650 "
In lift 0.575 "from coil bind 0.075"
Ex lift 0.555 "from coil bind 0.095"
Is it too much.
Max rpm 6500
RR

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Re: Broken valvspring.

Post by Newold1 » Thu Jan 18, 2018 7:51 pm

If you are going to use the 26918 spring I would shim the spring to a 1.725" installed height and with your valve lifts you will be at between ..050" and .070" before coil bind and that should be a better place to run those springs. You should be as exact as you can with installed height measurements so as to not lessen those distances between max lift and coil bind by to much.

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Re: Broken valvspring.

Post by Robban 54 » Fri Jan 19, 2018 2:51 am

Hello again.
Thank you Newold1 for your good answers.
I will look at both springs.
And the spring pressure can not be too high?
Original Edelbrock is 90lbs seat pressure.
RR

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Re: Broken valvspring.

Post by Newold1 » Fri Jan 19, 2018 7:57 am

Even with that small change in installed height your closed pressure should be in the 140-150lb range and that will not be a problem with your camshaft and lifters.

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