Valve Springs
05-16-2008, 03:11 PM
#1
Valve Springs Of someone needs a set of valve soirngs let me know, I'm stocking PAC 1218's and 1518's.
PAC use to make Comp 918's (comp switched and has had trouble since)
1218 is gor for .600 and the 1518 is good to .650 lift and does not require a seal or seat change. True drop in beehive with less weight than the doubles, nitrided surface. Premium spring for $265 delivered.
PAC use to make Comp 918's (comp switched and has had trouble since)
1218 is gor for .600 and the 1518 is good to .650 lift and does not require a seal or seat change. True drop in beehive with less weight than the doubles, nitrided surface. Premium spring for $265 delivered.
05-22-2008, 04:24 AM
#2
Here is some more info to digest:
62 gram spring
I stock them both now, ... lighter weight, better valve control
:
The beehive design has a few advantages over a standard style spring. The smaller coils at the top allow for a very light retainer. The steel retainer for a beehive spring is about half the weight of a standard steel retainer. The beehive springs are resistant to harmonics due to the fact that the coils have different outside diameters and the wire is oval and not round.
The smaller coils at the top also allow the valve train to start moving easier and gain lbs per inch of lift at a much greater rate. This allows for greater control of the valve train.
The beehive design has a few advantages over a standard style spring. The smaller coils at the top allow for a very light retainer. The steel retainer for a beehive spring is about half the weight of a standard steel retainer. The beehive springs are resistant to harmonics due to the fact that the coils have different outside diameters and the wire is oval and not round.
The smaller coils at the top also allow the valve train to start moving easier and gain lbs per inch of lift at a much greater rate. This allows for greater control of the valve train.
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less valvetrain weight (which should result in slightly less parasitic losses and better hydraulic lifter operation) and improved valve spring harmonic control.
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less valvetrain weight (which should result in slightly less parasitic losses and better hydraulic lifter operation) and improved valve spring harmonic control.
:
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WIth a beehive spring it's like having 3 different springs in one. At the bottom is your damping coils that help control spring surge. THose close out first and then the rate will jump up and be sorta linear with the center coils. As those close out, you get to the top where the rate becomes very progressive. This allows you to have lower seat loads, but still keeps a good amount of load over the nose.
Then there's the weight difference. A PAC-1218 with steel retainer is 20 grams lighter then a patriot/prc with a Ti. retainer.
Less mass generally means you can turn more RPM. And anytime you can take seat load off and keep you valvetrain under control you will make more power. Which is what that progressive rate allows you to do.
:
WIth a beehive spring it's like having 3 different springs in one. At the bottom is your damping coils that help control spring surge. THose close out first and then the rate will jump up and be sorta linear with the center coils. As those close out, you get to the top where the rate becomes very progressive. This allows you to have lower seat loads, but still keeps a good amount of load over the nose.
Then there's the weight difference. A PAC-1218 with steel retainer is 20 grams lighter then a patriot/prc with a Ti. retainer.
Less mass generally means you can turn more RPM. And anytime you can take seat load off and keep you valvetrain under control you will make more power. Which is what that progressive rate allows you to do.
:
Yeah the small beehives are great for the .600 lift stuff that's not super agressive and work very well and a lot is the fact that they are so much lighter as well. For really agressive and high lift .650+ stuff I use even bigger PAC beehives like the 1220 and 1520 or doubles but the PAC small drop in beehive springs 1218 and 1518 are very high quality and they have a great reputation as well. Their 1518 is the higher stress duty version that is nitrided and it costs more money but I know a ton of these LS1 places sell them and use them on here.
Yeah the small beehives are great for the .600 lift stuff that's not super agressive and work very well and a lot is the fact that they are so much lighter as well. For really agressive and high lift .650+ stuff I use even bigger PAC beehives like the 1220 and 1520 or doubles but the PAC small drop in beehive springs 1218 and 1518 are very high quality and they have a great reputation as well. Their 1518 is the higher stress duty version that is nitrided and it costs more money but I know a ton of these LS1 places sell them and use them on here.
I stock them both now, ... lighter weight, better valve control
