Valve springs

89cumminstd

89cumminstd

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Dec 3, 2014
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There may be a thread on this already but I am thinking about getting 3500 governer springs in my p-pump, what pound valve spring should be ran with this?
 
And to clarify... When they are saying 60lb springs they are actually the factory weight + 60lb, so they are allegedly 150lb springs. But there were tests done on PacBrakes 60lb springs, (the most commonly used ones because they're cheap) and at peak lift they were the same pressure as stock springs so there was realistically no benefit to having them. I believe hamilton has the info on his page under his aftermarket springs. I'd read up on it before you spend the money on them... Better to spend a little more to get a quality product.
 
stubz616 said:
And to clarify... When they are saying 60lb springs they are actually the factory weight + 60lb, so they are allegedly 150lb springs. But there were tests done on PacBrakes 60lb springs, (the most commonly used ones because they're cheap) and at peak lift they were the same pressure as stock springs so there was realistically no benefit to having them. I believe hamilton has the info on his page under his aftermarket springs. I'd read up on it before you spend the money on them... Better to spend a little more to get a quality product.
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That's good to know it's very confusing. If Your saying they have the same performance and theGoose said they have 90 pounders from the factory I should be alright with stock springs right?
 
89cumminstd said:
That's good to know it's very confusing. If Your saying they have the same performance and theGoose said they have 90 pounders from the factory I should be alright with stock springs right?
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Stock springs are okay to about 3500 but if you plan on revving it that high frequently I would go with the cheap insurance and get a set of springs. I have Hamiltons springs, retainers, and locks because he shows the actual pressures the springs put out at different lift heights right on his site.
 
lift Stock 60lb (150*)
1.940” 88 150
1.900“ 98 156
1.800“ 125 170
1.700“ 150 187
1.600“ 182 210
1.500” 210 225
1.400“ 245 245

Stock cam guys fall in the ~1.547" In. and ~1.504" EX range at max lift.
 
Been running pacbreak springs for 40000 miles now sees over 4k quite a bit. No problems yet.
 
I don't think that just because a spring has the same open pressure as another it can be said there is realistically no benefit to them. Lot's of people getting by with 6691 springs and the increase in seat pressure is there for a reason. For a truck revving to 3300-3500rpm and not seeing much over 55lbs of boost I think the Cummins 6691 [60lb] springs would work fine. Especially on a factory cam.

Now the keepers pulling through the retainers, that's another issue...
 
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You mean shim them or do you have threaded locks and valve stems like the pulling trucks have? I wouldn't go around "tightening" valve springs to get the right "pound" valve spring unless you fully know what you're doing.
 
Why do so many people try to get around buying the correct parts by rigging chit? Just buy the correct valve springs and be done. There is no secret voodoo magic. If you want to play be ready to pay. Whether that means now on the correct parts or paying later when it is too late. It is cheaper now.

Edit: don't mean to come off as a complete azz hat just trying to get people out of the ricer rigging mindset
 
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Shimming up stock springs could cause them to coil bind. I doubt that would be an issue with a stock cam. Get the correct springs with good retainers and keepers. You will sleep better at night.
 
zfaylor said:
Why do so many people try to get around buying the correct parts by rigging chit? Just buy the correct valve springs and be done. There is no secret voodoo magic. If you want to play be ready to pay. Whether that means now on the correct parts or paying later when it is too late. It is cheaper now.

Edit: don't mean to come off as a complete azz hat just trying to get people out of the ricer rigging mindset
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I'm not in the ricer mind set nor am i trying to get around buying anything or trying to rig. This forum is to answer questions and help people right? Go on youtube if you want to leave negative comments all day.
 
pac brake springs have SOME benefit over stockers. they can handle higher drive and boost pressures without floating the valve off the seat. But off the nose of the cam, they have the same pressure. To say they have no benefit is a misnomer. When valves float and smack piston, it doesn't happen at max lift, it happens closer to the seat. when they should be closed but aren't yet. Running too high a spring pressure can/will wipe out cams/lobes wear out valve train components etc. Hamilton expresses his opinion, and his springs are suitable for max effort builds. Not necessarily ideal for a daily driver thats warmed up a bit. Call a spring manufacture not a reseller, most of them will be glad to explain it if you can get in touch with someone who's not a front line ass clown.

Shimming a valve spring doesn't increase its Rate. It increases its seat pressure. You need a spring wound with a higher rate. The pressure at the nose of the cam doesn't need to be super crazy high. You just need enough pressure to keep the follower in contact with the cam. Every pound of boost and or drive pressure acts against the valve to make it heavier. The higher the boost, the higher the seat pressure needed to keep it shut.
 
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