Upgrading my valve springs, can someone take a look?
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Supreme Member
Joined: Jan 2000
Posts: 1,180
Likes: 82
From: Mississauga, Ontario Canada
Car: 1987 GTA
Engine: 5.7
Transmission: T5WC
Axle/Gears: 3:27
Upgrading my valve springs, can someone take a look?
Wondering if someone would mind taking a look at this potential setup to go to a Beehive spring. I have Flotek 180 aluminum heads. Max lift is .550 with their springs. Spring pocket is 1.560. I'm running a .562 Lift with the LP74211 cam. I checked it and I'm of course flirting with coil bind. Have about .030 clearance. I'd like to go with the following:
PAC-1219-16 SPRINGS
PAC-S111-26 LOCATOR (Guide Boss is .560 Brass)
COMP 787-16 RETAINER
COMP 611-16 LOCKS
FELPRO SS72861 SEALS.
That will stack up in a 1.750 Installed height. So my seat and open pressure will be a touch higher but my coil bind clearance will be safe at just shy of .090
PAC-1219-16 SPRINGS
PAC-S111-26 LOCATOR (Guide Boss is .560 Brass)
COMP 787-16 RETAINER
COMP 611-16 LOCKS
FELPRO SS72861 SEALS.
That will stack up in a 1.750 Installed height. So my seat and open pressure will be a touch higher but my coil bind clearance will be safe at just shy of .090
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From: 51°N 114°W, 3500'
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: Upgrading my valve springs, can someone take a look?
There are so many measurements other than just coil bind.
Other things to check:
Piston to valve clearance. Depending on the cam timing, there is always a chance that the piston may contact the valve. This happens as the piston is moving towards or away from the valve while it is opening or closing. Modeling clay on top of the piston is the best way to do it but if properly building an engine, parts will need to be removed and installed many times before its assembled correctly. Don't skip steps.
Coil bind. You can use the springs info card to see where coil bind occurs. From your install height to max lift should be less than whats stated on the card.
Spring retainer to valve seal clearance. With too much lift, the bottom of the spring retainer may make contact with the top of the valve seal. Worst case is when it forces the retainer off the spring and the possibility of the keepers coming off which will result in a dropped valve.
The main reason for a spring swap is for a higher spring rate. The cam, pushrods and rockers open the valve. Pure mechanical force that could be damaged if there is any sort of resistance. The springs however close the valve. Heavier springs keep the lifter firmly on the cam however cam grind determines how fast they can close. Valve float isn't the valve staying open as the lifter goes over the cam lobe but when the valve comes crashing down onto the seat. If spring pressure is too weak, the valve will bounce and cylinder pressure is prematurely released.
Other things to check:
Piston to valve clearance. Depending on the cam timing, there is always a chance that the piston may contact the valve. This happens as the piston is moving towards or away from the valve while it is opening or closing. Modeling clay on top of the piston is the best way to do it but if properly building an engine, parts will need to be removed and installed many times before its assembled correctly. Don't skip steps.
Coil bind. You can use the springs info card to see where coil bind occurs. From your install height to max lift should be less than whats stated on the card.
Spring retainer to valve seal clearance. With too much lift, the bottom of the spring retainer may make contact with the top of the valve seal. Worst case is when it forces the retainer off the spring and the possibility of the keepers coming off which will result in a dropped valve.
The main reason for a spring swap is for a higher spring rate. The cam, pushrods and rockers open the valve. Pure mechanical force that could be damaged if there is any sort of resistance. The springs however close the valve. Heavier springs keep the lifter firmly on the cam however cam grind determines how fast they can close. Valve float isn't the valve staying open as the lifter goes over the cam lobe but when the valve comes crashing down onto the seat. If spring pressure is too weak, the valve will bounce and cylinder pressure is prematurely released.
Thread Starter
Supreme Member
Joined: Jan 2000
Posts: 1,180
Likes: 82
From: Mississauga, Ontario Canada
Car: 1987 GTA
Engine: 5.7
Transmission: T5WC
Axle/Gears: 3:27
Re: Upgrading my valve springs, can someone take a look?
There are so many measurements other than just coil bind.
Other things to check:
Piston to valve clearance. Depending on the cam timing, there is always a chance that the piston may contact the valve. This happens as the piston is moving towards or away from the valve while it is opening or closing. Modeling clay on top of the piston is the best way to do it but if properly building an engine, parts will need to be removed and installed many times before its assembled correctly. Don't skip steps.
Coil bind. You can use the springs info card to see where coil bind occurs. From your install height to max lift should be less than whats stated on the card.
Spring retainer to valve seal clearance. With too much lift, the bottom of the spring retainer may make contact with the top of the valve seal. Worst case is when it forces the retainer off the spring and the possibility of the keepers coming off which will result in a dropped valve.
The main reason for a spring swap is for a higher spring rate. The cam, pushrods and rockers open the valve. Pure mechanical force that could be damaged if there is any sort of resistance. The springs however close the valve. Heavier springs keep the lifter firmly on the cam however cam grind determines how fast they can close. Valve float isn't the valve staying open as the lifter goes over the cam lobe but when the valve comes crashing down onto the seat. If spring pressure is too weak, the valve will bounce and cylinder pressure is prematurely released.
Other things to check:
Piston to valve clearance. Depending on the cam timing, there is always a chance that the piston may contact the valve. This happens as the piston is moving towards or away from the valve while it is opening or closing. Modeling clay on top of the piston is the best way to do it but if properly building an engine, parts will need to be removed and installed many times before its assembled correctly. Don't skip steps.
Coil bind. You can use the springs info card to see where coil bind occurs. From your install height to max lift should be less than whats stated on the card.
Spring retainer to valve seal clearance. With too much lift, the bottom of the spring retainer may make contact with the top of the valve seal. Worst case is when it forces the retainer off the spring and the possibility of the keepers coming off which will result in a dropped valve.
The main reason for a spring swap is for a higher spring rate. The cam, pushrods and rockers open the valve. Pure mechanical force that could be damaged if there is any sort of resistance. The springs however close the valve. Heavier springs keep the lifter firmly on the cam however cam grind determines how fast they can close. Valve float isn't the valve staying open as the lifter goes over the cam lobe but when the valve comes crashing down onto the seat. If spring pressure is too weak, the valve will bounce and cylinder pressure is prematurely released.
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