Valve springs

[rtee007]

MP #5249848 are listed at Max lift .540" list with spring 1.86" height.
Eddie RPM heads come with a spring rated at Max .580" lift and 1.46" height.

Have you found these Edelbrock springs to be sufficient?

 

[khryslerkid]

There are so many things to consider when selecting the right valve springs.
The things you have to consider is open pressure and closed pressure for the height of your cams lift. Coil bind is very important. Retainer to valve seal clearance. Flat tappet, or roller lifter. Then the inside and outside diameter of the spring has to be considered. Then the rocker ratios. Too much spring pressure might tend to wipe out the lobes or bend push rods ect.

I went through this when I bought a Sum6401 cam. The recommended spring was a comp cam spring and doing the math it was way too heavy of a spring. I asked a lot of questions and did a lot of research. You need to fully understand what is needed to make the right selection. I never thought it would be so involved.

Ideally, if you found someone that had the same application that you are useing and would have their parts list, you would be "good to go". I found a lot of wrong set ups in my researching.
I also read that the pre-assembled heads generally come with the same springs and may not be correct for what you really need. All I'm saying is take the time to do the research yourself, so you know you have the right spring for the job.
Hope this isn't too much info all at once, just sharing my experience.

http://www.lunatipower.com/Tech/Valvetrain/ValveSpringTech.aspx

 

[IQ52]

Sufficient for what?

 

[lewtot184]

Sufficient for what?

this! springs are dependent on the lobe profile.

 

[rtee007]

Max lift on the two camshafts will be between .550 & .560
I can't select the cam I am told until I know what compression ratio the engine will be. That is what Lunati told me on the phone.
Somewhere between 9.5 to 10.5 is projected CR.
It's hyd roller cam set up. Magnum engine.

 

[khryslerkid]

You definitely have to have all of your numbers. Either a proven combination or do the math on what you are trying to use.

I bought an assembled short block and had to do everything in reverse from what I had. Mind blowing to say the least. There are so many options. Start with what you want to end up with when it's all done. The guys on here that do it for a living, will help you the most...

 

[rtee007]

You definitely have to have all of your numbers. Either a proven combination or do the math on what you are trying to use.

I bought an assembled short block and had to do everything in reverse from what I had. Mind blowing to say the least. There are so many options. Start with what you want to end up with when it's all done. The guys on here that do it for a living, will help you the most...

"All the numbers"........educate me, I am here to learn!

 

[lewtot184]

i don't think i'd use either of those two springs with a roller. good chance the lift at the valve will be greater than the cams advertised lift numbers due to rocker ratio. i'd run the spring lunati recommends.

 

[rtee007]

I sent them a request earlier but have received no answer yet.

 

[khryslerkid]

"All the numbers"........educate me, I am here to learn!

I'll leave that up to the experts!

All I can say is ask lots of questions, like you are and do a lot of reading.

 

[lewtot184]

because a spring may coil bind at a higher lift doesn't always make it suitable for higher lift cams.

 

[IQ52]

So the plan is to use a retro-fit hydraulic roller combination in a roller block with 61775 magnum heads, is that correct?

 

[rtee007]

Yes. As you read in the A Bodies forum. And Lunatis's contact us message system isnt working. Guess it will warrant a call.

So the plan is to use a retro-fit hydraulic roller combination in a roller block with 61775 magnum heads, is that correct?

 

[IQ52]

So then, like I said over on ABodies, if those heads have the original 5845 Edelbrock springs, then you are good to go with either the '12 or '13 camshaft.

 

[rtee007]

So then, like I said over on ABodies, if those heads have the original 5845 Edelbrock springs, then you are good to go with either the '12 or '13 camshaft.

I am still letting the machine shop go over Edelbrocks work. Cheaper now that to have a problem later.