408 cam selection - New Information Please come inside!!

[1slow01z71]

I seriously doubt that

[RedHeartbeat]

He said my engine needed about another .060" lift and another 20 degrees of duration plus it should be indexed 4* positive. Right now it's only +1. He says I'm easily leaving 50 HP on the table using this current cam.

[carfreak07]

918's are on the WCCH already.

I hope your not gonna run the 918 on that cam you just described.....did I read that wrong.

I wouldnt consider going over 590 lift with those, they are only good for 600 and you have things expanding and contracting in there.....might check that out. I could be wrong to! I did have a comp represenitive tell me not to run the 918's on a 581/588 cam.....so n e way I hope this helped you or keeps you from breaking something.

jarrod

[SCIV]

So you are saying that Comp 918's which are claimed to be good to .600 lift, are NOT good to .600 lift???

What kind of am I getting sold here?

What should I use, the 921's? If that is the case, then I will probably go with TSP's 1st cam recommendation...

233/239 .595/.603 114 LSA

EDIT - Forget the 921's...I just saw their price!! What should I use?

[RedHeartbeat]

I ran my old cam with the 918s and it was not an issue at almost .610 lift.

[farmtruc]

Just an fyi, we've used the 918's on big cams before, they work fine. Actually, I would rather use the 918's over any dual springs anyday for a semi daily driver, we don't experience any valve float, we have had one break, yet, and the combination seems to make the valve train quiet.

SC, we put a 240 cam in a daily driver GTO, 408, it runs great.

[SCIV]

Then how about that cam? 233/239 .595/.603 114

I don't want to ruin a $5,000 setup over a $100 part; you know what I mean?

[RedHeartbeat]

FWIW, Erik at HKE says to run the springs shimmed close to coil bind. He expressed concerns about my Patriot springs and is shimming the springs up .060" to the way he prefers them. He told me that if I were to ever replace the heads, contact the manufacturer of the head and tell them how much lift I planned on running so that the springs could be setup to their specs. He recommended not buying off the shelf heads unless you're going to have them shimmed properly. I think he said that he likes them shimmed within .050" of coil bind.

[SCIV]

FWIW, Erik at HKE says to run the springs shimmed close to coil bind. He expressed concerns about my Patriot springs and is shimming the springs up .060" to the way he prefers them. He told me that if I were to ever replace the heads, contact the manufacturer of the head and tell them how much lift I planned on running so that the springs could be setup to their specs. He recommended not buying off the shelf heads unless you're going to have them shimmed properly. I think he said that he likes them shimmed within .050" of coil bind.

Hmmm...
I really don't understand how running them closer to bind is better?

[RedHeartbeat]

Yeah, I don't quite understand it either but he's the one building 408s turning 9000+ rpm so I'll let his opinion stand on this small issue.
It's supposed to prevent valve float.