pac1218 failure
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Joined: Jan 2007
Posts: 275
pac1218 failure
*UPDATE*
I have been in contact with PAC about this and it appears that they really stand behind their product and right now I have another set of springs on the way to me, and my broken one is on the way to their lab for analysis. I am very pleased with them.
So I was on the highway cruising today @ 2000 rpms on my way to the parts store to get some new header gaskets and I suddenly hear a loud knocking noise and my first thougt was rod bearing (second thought: 383 h/c build
) but the oil pressure seemed fine so I took the next exit and had the car towed home. Popped the passenger side valve cover and found this:
I have never heard of PAC springs break, just the 918's (Untill now
)
Springs installed at 1.750" as recommended, pushrod length checked etc.
So what are the chances I have a bent valve? As you can see in the pic the valve is still being hold by the locks and retainer, but then what would the knocking noise be? hmm. Had no time to check further today.
I have only put 40-60 miles on this setup and the car ran REALLY good under this time.
Im gonna contact PAC to see what they have to say about this and if they are going to replace the springs, but I am not sure I want to run the 1218s after this. I Will update what they tell me.
I have been in contact with PAC about this and it appears that they really stand behind their product and right now I have another set of springs on the way to me, and my broken one is on the way to their lab for analysis. I am very pleased with them.
So I was on the highway cruising today @ 2000 rpms on my way to the parts store to get some new header gaskets and I suddenly hear a loud knocking noise and my first thougt was rod bearing (second thought: 383 h/c build
) but the oil pressure seemed fine so I took the next exit and had the car towed home. Popped the passenger side valve cover and found this:I have never heard of PAC springs break, just the 918's (Untill now
)Springs installed at 1.750" as recommended, pushrod length checked etc.
So what are the chances I have a bent valve? As you can see in the pic the valve is still being hold by the locks and retainer, but then what would the knocking noise be? hmm. Had no time to check further today.
I have only put 40-60 miles on this setup and the car ran REALLY good under this time.
Im gonna contact PAC to see what they have to say about this and if they are going to replace the springs, but I am not sure I want to run the 1218s after this. I Will update what they tell me.
Last edited by krillformula; Apr 2, 2008 at 02:17 PM.
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Joined: Aug 2005
Posts: 4,405
From: Kantuckee Yo'
Here we go with the beehives again.
Put the piston at TDC. Pull the spring and move the valve up and down by hand. If no binding occurs I would say your chances are good that you dont have a bent valve.
Put the piston at TDC. Pull the spring and move the valve up and down by hand. If no binding occurs I would say your chances are good that you dont have a bent valve.
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Joined: Jun 2005
Posts: 147
From: Central, KY
And you people are saying Dougs problem is pushrod length.... hahaha. Looks like you all need to switch springs. Must be a bad batch or something.... or maybe just way to aggressive cam lobes for those little springs.
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wrd1972: Im gonna try that tomorrow.. And I am thinking about doing the same thing as you and go with double springs, have to do some research.
And yepp thats why I went with the PAC over the COMP.. Hmm what brand next?
And yepp thats why I went with the PAC over the COMP.. Hmm what brand next?
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Joined: Jun 2006
Posts: 2,092
From: lakeville, pa
the ticking you heard was most likely due to the play between the rocker and valve tip, way too much lash.
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Joined: Jun 2005
Posts: 147
From: Central, KY
[QUOTE=dangalla;5284378]no, like i said a bunch of times his problem is his builderQUOTE]
Do you have ANY idea what a .300 longer pushrod would do to an engine, how it would react or anything? I said it once and i'll say it again, if it were that much longer than needed first off its very possible it'd totally roll off the valve tip, secondly if it was that far off and then had to much preload it'd hold the valve open and the whole power curve would be totally screwed it wouldn't full like a train to 5700 and then take a giant ****. I dont' see how you can possibly diagnose a pushrod being to long when in another post you can't even understand how a lobe being to aggressive can cause float.
Do you have ANY idea what a .300 longer pushrod would do to an engine, how it would react or anything? I said it once and i'll say it again, if it were that much longer than needed first off its very possible it'd totally roll off the valve tip, secondly if it was that far off and then had to much preload it'd hold the valve open and the whole power curve would be totally screwed it wouldn't full like a train to 5700 and then take a giant ****. I dont' see how you can possibly diagnose a pushrod being to long when in another post you can't even understand how a lobe being to aggressive can cause float.
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Joined: Mar 2002
Posts: 3,245
From: Ocala, Florida
[QUOTE=;5284572]
Be careful man, these self proclaimed internet experts have it out for us. 
no, like i said a bunch of times his problem is his builderQUOTE]
Do you have ANY idea what a .300 longer pushrod would do to an engine, how it would react or anything? I said it once and i'll say it again, if it were that much longer than needed first off its very possible it'd totally roll off the valve tip, secondly if it was that far off and then had to much preload it'd hold the valve open and the whole power curve would be totally screwed it wouldn't full like a train to 5700 and then take a giant ****. I dont' see how you can possibly diagnose a pushrod being to long when in another post you can't even understand how a lobe being to aggressive can cause float.
Do you have ANY idea what a .300 longer pushrod would do to an engine, how it would react or anything? I said it once and i'll say it again, if it were that much longer than needed first off its very possible it'd totally roll off the valve tip, secondly if it was that far off and then had to much preload it'd hold the valve open and the whole power curve would be totally screwed it wouldn't full like a train to 5700 and then take a giant ****. I dont' see how you can possibly diagnose a pushrod being to long when in another post you can't even understand how a lobe being to aggressive can cause float.
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Joined: Jun 2006
Posts: 2,092
From: lakeville, pa
krill i would contact pac, and PM yeahdoug on here, i know he works at pac
git_some, i will shoot you a pm when i get a chance, dont want to rob his thread
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Joined: Jun 2005
Posts: 147
From: Central, KY
I mean does anybody else see a pattern here? We've got 2 other guys who are having valve float problems using these springs that have the exact same cam. And then this guy breaks the same spring those other 2 guys are using with only like 40-50 miles on them....