Valve Spring Coil Bind.
Racer
Joined: Jul 2007
Posts: 444
Likes: 0
From: Roselle IL
be carefull when these guys say it will meet specs.
The keys to valve springs are seat pressure and nose or open pressure. You need to go to someone at Crane and get a recommendation for these two elements. Ask for the optimum pressures and be sure to get them from someone who knows what they mean.
In order to achieve the pressures that you specify, the person building your valves will play with several factors to meet these specs, including installed height, spring rate, spring length, shims, etc. Each unique combination will also have a unique travel limit. The valve assembler must know your net lift (advertised lift minus the lash) in order to insure it works with the configuration.
DO NOT just accept a .600 lift head. You are potentially asking for trouble. I went through this with my heads. I was ready to buy an AFR head. I gave them my specs and they said don't worry about it we will give you are standard .600 configuration and it will work becuase WE know better than the cam company. Well, I worked with the actual guy who designed the cam and he recommended a 350 lb nose pressure. He had decades of experience backing that up. AFR was going to give me 400 lbs. This was extra pressure not necessary to avoid float and served no purpuse other than add wear and risk of wiping a lobe. We fought, they wouldn't change, so I bought from Brodix who were happy to build a set of heads that matched my specs.
Good luck
The keys to valve springs are seat pressure and nose or open pressure. You need to go to someone at Crane and get a recommendation for these two elements. Ask for the optimum pressures and be sure to get them from someone who knows what they mean.
In order to achieve the pressures that you specify, the person building your valves will play with several factors to meet these specs, including installed height, spring rate, spring length, shims, etc. Each unique combination will also have a unique travel limit. The valve assembler must know your net lift (advertised lift minus the lash) in order to insure it works with the configuration.
DO NOT just accept a .600 lift head. You are potentially asking for trouble. I went through this with my heads. I was ready to buy an AFR head. I gave them my specs and they said don't worry about it we will give you are standard .600 configuration and it will work becuase WE know better than the cam company. Well, I worked with the actual guy who designed the cam and he recommended a 350 lb nose pressure. He had decades of experience backing that up. AFR was going to give me 400 lbs. This was extra pressure not necessary to avoid float and served no purpuse other than add wear and risk of wiping a lobe. We fought, they wouldn't change, so I bought from Brodix who were happy to build a set of heads that matched my specs.
Good luck
Thread Starter
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
be carefull when these guys say it will meet specs.
The keys to valve springs are seat pressure and nose or open pressure. You need to go to someone at Crane and get a recommendation for these two elements. Ask for the optimum pressures and be sure to get them from someone who knows what they mean.
In order to achieve the pressures that you specify, the person building your valves will play with several factors to meet these specs, including installed height, spring rate, spring length, shims, etc. Each unique combination will also have a unique travel limit. The valve assembler must know your net lift (advertised lift minus the lash) in order to insure it works with the configuration.
DO NOT just accept a .600 lift head. You are potentially asking for trouble. I went through this with my heads. I was ready to buy an AFR head. I gave them my specs and they said don't worry about it we will give you are standard .600 configuration and it will work becuase WE know better than the cam company. Well, I worked with the actual guy who designed the cam and he recommended a 350 lb nose pressure. He had decades of experience backing that up. AFR was going to give me 400 lbs. This was extra pressure not necessary to avoid float and served no purpuse other than add wear and risk of wiping a lobe. We fought, they wouldn't change, so I bought from Brodix who were happy to build a set of heads that matched my specs.
Good luck
The keys to valve springs are seat pressure and nose or open pressure. You need to go to someone at Crane and get a recommendation for these two elements. Ask for the optimum pressures and be sure to get them from someone who knows what they mean.
In order to achieve the pressures that you specify, the person building your valves will play with several factors to meet these specs, including installed height, spring rate, spring length, shims, etc. Each unique combination will also have a unique travel limit. The valve assembler must know your net lift (advertised lift minus the lash) in order to insure it works with the configuration.
DO NOT just accept a .600 lift head. You are potentially asking for trouble. I went through this with my heads. I was ready to buy an AFR head. I gave them my specs and they said don't worry about it we will give you are standard .600 configuration and it will work becuase WE know better than the cam company. Well, I worked with the actual guy who designed the cam and he recommended a 350 lb nose pressure. He had decades of experience backing that up. AFR was going to give me 400 lbs. This was extra pressure not necessary to avoid float and served no purpuse other than add wear and risk of wiping a lobe. We fought, they wouldn't change, so I bought from Brodix who were happy to build a set of heads that matched my specs.
Good luck
Thank you for the advice but I was already on your track. I placed the order for the heads, and sent them the info on what cam I have. Their shop builds Nascar engines, and ironically one of the guys knew the tech I spoke with at Crane. The tech building my heads is going to use my cam specs to make sure they are set up properly for me.
I think I'll be all set.
