More street torque: Part 2 cam and head selection

1541 Views 3 Replies 4 Participants Last post by scrnic1, Apr 13, 2012

mjranchero

Discussion Starter · Apr 12, 2012

As my last thread ended; I accepted delivery of Scat 408 stroker kit for 79 Ranchero (4000 lb) with FMX auto. I am looking for a fun, torquey ride that I may drag race on occasion. Car is used at higher altitude ( @ 6000 ft above sea level) and will not see alot of high RPM stuff. I was planning to use stock torque converter but since i have the engine out I could change if needed.

I am about to select heads and cam. I spoke with Comp Cams tech support today. The rep I spoke with suggested their .519/.523 lift 274/286 duration hydraulic flat tappet cam. I am looking to keep CR down a little bit so was looking at RHS 64cc aluminum head. I have seen a few threads that suggest a 408 should have min of 210cc intake runners. Comp's tech rep suggested that I'd like their 180cc int head better for my application, since I'm interested in a torquey medium RPM engine. I'd like to hear some of your thoughts.

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punkur67

· #2 · Apr 12, 2012

If you want the best setup, get the flow numbers on the heads and match a cam to those. People always put a big cam in and it doesnt work good. If your heads max the flow out at .550 lift then why put a cam in that lifts to .700.

Then when you have selected a cam, have a converter made to match the cam. Smaller ports are beter for torque as well as a dual plane intake. I used trickflow track heat 170cc heads and had them ported. The smaller runners will increase the velocity but can still get good flow numbers. I have smaller ports but flow more than the 190cc heads at a higher velocity. Paired with a good dual plane and torque you will have.

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n2omike

· #3 · Apr 13, 2012

With a 408, between those two heads, I'd go with the 210cc runners. You're feeding 'big block' cubic inches through small block heads... so it's hard to go too big.

Plus, the bigger/better the heads, the less cam duration you need to adequately feed it.

I'd go with the Performer RPM or the Performer RPM Air-Gap on that engine. Add headers and at least a 2-1/2" exhaust with nice 'see through' mufflers and mandrel bent tail pipes... and you're off to a great start!

Good Luck!

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scrnic1

· #4 · Apr 13, 2012

+1 Except that id got a little more on the cam lift, and have been told that adding cubes tends to "tame" durations a bit. It doesnt sound right, but wiser minds told me so. I personally wouldnt look at a cam smaller the .540 lift, my .02

n2omike said:
With a 408, between those two heads, I'd go with the 210cc runners. You're feeding 'big block' cubic inches through small block heads... so it's hard to go too big.

Plus, the bigger/better the heads, the less cam duration you need to adequately feed it.

I'd go with the Performer RPM or the Performer RPM Air-Gap on that engine. Add headers and at least a 2-1/2" exhaust with nice 'see through' mufflers and mandrel bent tail pipes... and you're off to a great start!

Good Luck!

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