Edelbrock spring rate question

[scrappydoo]

I would like to know if the springs on the edelbrock head will be ok for this cam
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=650&sb=2

Comp cams recommend the 995 valve spring which has a spring rate of 441 (they also recommend the 26995 beehives which have a rate of 280) and installed seat pressure of 130 and the edelbrock spring rate is 350lb/in and seat pressure of 125.

RPM limit will be 5500, I feel that the springs that are installed on the eddy heads will be ok.

Let fly with your expert opinions.

 

[flyfish]

The 995 springs have a spring rate of 402 lbs/inch, and are listed with seat pressure of 115 lbs (at 1.70" installed height)….assuming this is the installed height of your springs, you would have 321 lbs open pressure. See link for specs:

http://www.summitracing.com/parts/CCA-995-16/Application/?prefilter=1

........I feel that the springs that are installed on the eddy heads will be ok..........

Are you asking if the springs that come with the heads (from the factory) would work? If so, (correct me if I'm wrong anyone) I believe those springs are made for flat tapped cams, not rollers. Roller cams (even mild ones like this) need more spring pressure to control the heavy roller lifters. I would go with more spring pressure if it were my car....lifter bounce can do hundreds of dollars in damage in the amount of time it takes you to read the word "BOUNCE".

 

[MRL Performance]

The Thumper line of cams are quite lazy on the lobe, not aggressive at all. So they dont need a lot of spring to control them. Plus your rpm level isnt going to be very high. If its not a race engine, and will live its life on the street, The RPM springs will work good. Plus the 995 spring wont work on the RPM head without shimming the living crap out of it to get the installed height right. Not a good thing.

 

[scrappydoo]

Thanks guys for the replies.

I spoke with my machinist about this and he agreed with you Mike, I'll just shim the stock edelbrock springs a little more if I can.

The other thing is Comp Cams spring specs are all over the shop, and I wonder if the 995 springs are correct for this camshaft anyway.

In the installed height chart listing it shows the 995 springs as having a spring rate of 441#/in but on the website it shows 402#/in.
Then for the 26995 beehive springs the website says it has a max. lift of .500"
This cam has a lift of over .500":scratch: