SStrokerAce

Why would you want to use the 26986-16 springs when you have the 26918-16 springs?

The Engineer, on your cam you could grind the cam with a small base circle... the real question is have to assembled the bottom end yet? It's the best thing to clearance the rods rather than reduce the stiffness of the camshaft to have it fit. Some lobes cause the cam to have a small enough base circle that the cam doesn't need to be ground with a even smaller base circle.

As I said before lift it super critial in your setup, professionally I don't think the XFI lobes will give you enough lift to get you where you want to go with a 2.02 valve in those AFR heads. Do a google search about curtain area.

Bret

shannons86

Brett, Brett, Brett, the only way a camshaft stiffness is reduced is when the lobe is undercut (into the barrell) Most samll base circles dont get into the barrell so how does that reduce stiffness when the barrell is the smallest portion anyhow????

White_96_SS

Ive got a 396 stroker and i ordered the XFI 579 584 from Comp Cams through summit...IT DID NOT CLEAR the rod bolts..then ordered the SAME cam but small base circle (1.050) and STILL DID NOT CLEAR.. now they are grinding me the exact same came however the new specs are..
New Grind # Directly from Comp: 3018-S/3039-S HR113+4 (Base Circle: .900)
...................... INT EXH
Gross Valve Lift: 584" 579"
Duration @.050: 242 248
Lobe Seperation: 113.0

SStrokerAce

How do you think you get a .900 base circle cam unless they reduce the size of it that much? The lobes he is looking at will easily be 1.200" or larger on the base circle, it's not the same core that they will cut the cam on going from the 1.200" base down to a .900" base circle... you couldn't do that on the same core because you would break thru the case hardening. I've had plenty of cams with 1.100" base circles that push the limits of that core... and you can't go much farther if at all on it.

White_96_SS, what rods did you put in that stroker that didn't clear?

Bret

Bodenham

While spec'ing any stroker motor, one should look at rods that use capscrews and not headed bolts for the reasons listed above. The head of the rod bolt is what will hit, so better off not having one. Look for a lighter weight, high quality rod to do the job. Manly has some nice choices.

shannons86

Thats because there are diffrent cores for the small base circle cams... any standard cam can most of the time go to a 1.050" bc

SStrokerAce

Isin't that what I said captian obivous?

shannons86

Well why the hell would anybody want to grind on there rods when a camshaft can be made to clear without disturbing stiffness?

SStrokerAce

Because you WILL disturb the stiffness.

shannons86

you forgot to put the "not" after the WILL

SStrokerAce

You ever hear of a torsion bar? Maybe you need to look that up and figure out how they figure out the stiffness of that.

Bret

shannons86

Why dont you tell us all knowing one. What does that have to do with a camshaft?

SStrokerAce

You wanna pick a fight too? If you can't figure out what a cam and a torsion bar have in common then maybe you shouldn't be arguing with me about it.

Bret

shannons86

Typical answer for someone who dosent know what in the heck they are talking about. thats like saying a leaf spring and a fender have something in common.

The Engineer

What type crank, rods and rod bolts do you have in your 396? I guess the rods with 12 point cap screws have additional clearance over the traditional rod bolt w/ nut.

I really like the numbers on the XFI cam. Although, I haven't bought the cam yet and I'm several weeks away from the final assembly. So, you should have yours running before me. PM me and let me know what you think about the XFI when you get it running. Hopefully, Comp has figured out the small base circle now for you. I like high-torque, low-RPM stroker engines and plan to only turn around 6300 with mine. Also, a lot of people over-cam their engines these days. Good luck with your new 396 and let me know how it runs!

http://www.cardomain.com/ride/2189634