mpcv2000

iTrader: (1)

Before you read ( updated Dec 3rd 2012 ) .
According to PAC Racing ( because they have inspected my springs ) told me the springs specifications are the exact same as a CompCams # 26918 .
They didn't say it was a CompCams but the specs. are the same .

So it is not a PAC1218 faillure because this spring is not a PAC , it is a BeeHive spring faillure , yes.

So this said here's the story .

Earlier summer 2012 I broke a Bee Hive ( edited ) spring for no particular reason just cruising around .
Lucky enough I didn't do any damage so I've replaced the broken spring and keep driving it all summer.

( pics. from earlier this summer ) :



















Today ( this morning on Nov. 15 2012 ) I broke another one but this time I was not that lucky.
















































The valve is stuck there ( probably bent ) .
I don't know how bad it will be when I'll lift the head but we'll see pretty soon.

Sad way to end my 2012 season.


Anyone else breaks BeeHive springs like that ?

They are rated .600 of lift and 1st time I broke a spring my cam specs. were : 223/230 .565/.565 112 LSA and 1 month ago I replaced the camshaft by another with the following specs. 228/236 .576/.572 110 LSA .

I don't think the cam has anything to do with breaking the springs with the specs. I have even with the new camshaft don't you think ?

fex77k

iTrader: (2)

I'm running 1218's on my current 396. I have a cam that is very close to your first one. I have around 4500 miles on them, and 11 or so 9 second runs on them. I turn it to 6800 on the track since the cam and heads fall on their face after that.

guppymech

iTrader: (7)

What installed height did you set the springs to? PAC lists coil bind at 1.140. Also are your cam lift specs with the 1.6 rockers you're using or 1.5s. I've read that LT1 heads need +.050 locks to set beehives up at 1.800. From looking at your pics it looks like you have alot of valve stem showing above the locks. Did you use standard locks, which would give you a installed height closer to 1.750. 1.750-1.140=.610-.576=.034 to coil bind. I'm just speculating on the 1.750 installed height.

mpcv2000

iTrader: (1)

I cannot answer that question , too technical for me but I have bought the heads from Lloyd Elliot as a LE2 package back in June 2010 but it got installed only in November the same year as a winter project .

Here's a "copy and paste" of my actual motor setup :


Lloyd Elliot LE2 package. www.Elliottsportworks.com
-Fully Ported heads milled 0.030" with 0.56cc chamber, casting 10128374.
Manley 2.00/1.56 6000 series valves.
PAC 1218 bee hive springs (145 lbs seat and 340 lbs open)
Steel retainers and locks.
205 cc intake port flow about 275/190 CFM.
-12.05:1 Comp. Ratio , 240PSI Compression.
-CompCams Pro-Magnum Roller rocker 1.6:1 7/16" studs "NSF" (None Self Aligned).
-850-16 CompCams Hi-energy hydrolic roller lifter.
-7937-16 CompCams Hi-Tech Pushrods 5/16"X7.050".
-300-8245 ARP Perma-Lock 7/16" 12pt Rocker arm nut.
-MR-1896 Sealed Power 5/16" Guide Plate.
-Fully ported Intake manifold casting 12552138.
-AS&M 58mm Throttle body.
-Ford Racing SVO 30 Lbs. Injectors.
-Camshaft:223/230 .565/.565 112 LSA( old setup Sept 2012 )
-New camshaft:228/236 .576/.572 110 LSA( Oct. 2012 )
-Fel Pro 1074 head gaskets .039".
-Fel Pro 1284 intake gaskets.
-Autolite #104 0.030".
-Hypertech 160 degree thermostat.
-MSD 83811 Pro-Billet Distributor.
-MSD 8226 Blaster coil.
-MSD 32149 8.5mm Spark plug wires.
-TPIS High flow mass air sensor housing.
-Meziere WP118HD Electric Water Pump.

-Shortblock :
-385CI ( 6.3L ) LT1 4 Bolt main Corvette shortblock.
-Scat 9000 stroked lightweight forged crank.
-Scat forged rods.
-Bored .040" over.
-Forged Pistons -5cc dish.
-4045MS-15 .040" + .005" Mahle rings file to fit.
-Rings gap : 1st .018" , 2nd .020".
-ARP main studs.
-Melling 10555 High Volume Oil pump.
-Clevite 77 MS-909H STD bearings crank Bearings.
-Clevite 77 CB-663H STD Connecting rods bearings.
-12370835 GM single roller extreme duty timing chain set.
-Fluidampr Harmonic balancer # 740101.
-Balanced and Blueprinted.





My motor built thread back in 2010 ..here.. .

95mysticta

iTrader: (4)

WOW... i ran the 1518s (.650 lift version) with that 223/230 cam and had major float issues above 6,000rpm. Did you run into that issue or did you not spin it that high? I couldnt imagine with the bigger more aggressive cam it would even take it. Never broke a spring in the 10,000kms i put on it before i changed the springs out for a set of Crane double springs rated for 150lb seat pressure opposed to the 120-130 it was originally setup at with the 1518s.

speed_demon24

iTrader: (6)

Glad I switched away from pac after I broke a 1220. First set of springs were changed out at 20k, and this happened with 6k on the 2nd set so I'm guessing it was a spring issue.

mpcv2000

iTrader: (1)

I think my cut off is set at 6300RPM but I have the shift light set at 5800RPM so I may have a few times hit the rev limiter but nothing that will hurt the motor.

To be honest I don't know if the valves floats or not at high RPM.

fex77k

iTrader: (2)

This is the cam I'm running to 65-6800 on the strip, I run impala head gaskets with 1.6 rockers.

I've beat the hell out of my 1218's, I got them early 2009.

mpcv2000

iTrader: (1)

Maybe I should start beating my car so it won't break.







I guess I'm not lucky .

fex77k

iTrader: (2)

It would look at your valvetrain geometry. Pull some of the others and test them. See if you can find your installed height.

mpcv2000

iTrader: (1)

I'm sending the heads back to ( Edit Feb 16 2013 ) Mr. No name for inspection ( repair ) and probably double springs so it will never happen again.

Still don't know what will be the damage under the head ( piston , etc. )

I should find out later this month.

mpcv2000

iTrader: (1)

Since I have this picture handy here's the exact specs of the new camshaft I'm running since Oct. 2012 :

guppymech

iTrader: (7)

That's really a nicely built engine you've got there, hopefully you didn't hurt the shortblock too bad. Maybe send one of the broken springs back to PAC for analysis, they and their parent company (Peterson Spring) make springs for alot of companies. They'll be able to tell if the wire had a manufacturing flaw or surface defect causing a stress crack.

mpcv2000

iTrader: (1)

I'm already talking to Matt at PAC , I'll give him some close up view of the springs and I'll post the pics. here too.

fex77k

iTrader: (2)

I have some composite covers if you need a replacement.

mpcv2000

iTrader: (1)

I need a left side for sure.

PM me price etc.
I'm a buyer ( obviously )

96capricemgr

iTrader: (1)

I have seen some other's have increasing issues with the PAC springs and similar to speed_demon24 the second set same spring this time nitrided broke at half the mileage of the first.

They seem to have some sort of major QC issue building IN RECENT YEARS.

In this other case I know of the nitriding alone should have extended spring life. If you repeatedly get similar life out of springs you know that it is just the limit of that valvetrain combination, when you buy the "same" part or an upgraded nitrided version of that same part and life drops dramatically this is a QC problem.

Wicked94Z

iTrader: (26)

I would say alot of the beehive failures are from harmonics in the spring from not setting installed height correctly, the surge heats and fatigues the spring. Also this will leave you with less pressure, hence the float issues.

mpcv2000

iTrader: (1)

Not that I have anything informative to add for now except today I took closeup pictures of both springs.



Here's the spring that broke earlier this summer on the right side bank ( no internal damage ) .







( It's in 3 pieces because I had to cut it with a die grinder since I was unable to grab it with a spring compressor tool ).









This is a closeup view of the one that broke on Nov. 15 2012 on left side bank .















Funny thing is they both broke about the same place and this with 2 different camshafts specs. 6 month apart.


Left spring in from earlier this summer and the right one broke this Nov.









I have no choice but to pull the motor and transmission out.


This is not what I had in mind for this winter as far as car project .

IllusionalTA

iTrader: (9)

X2.2million