Lobe Separation angle. Or, valve overlap.

Wider the angle, smoother the idle, and higher vacuum at idle.

Narrower angle gives ya better top end power.

 

Hence the 248/252 @ .050" .576"/.584" 108 LSA+4 in my Dakota. I have all of 3" of vac at idle.

I'll just go with the 1.7s on the Ram, if I ever get em put on

 

i was looking at this cam, or this cam

im also going to be getting the eq monsters from odessa, the air gap from hughes, and headers. hopefully some 1.6 roller rockers too. anything else i should be adding? i already addressed the y pipe, so thats taking care of. will also be contacting sean from hemifever about some custom tunes.

also, this is all going on a 360 block that im going to be picking up. so i can swap out my 318.

 

What about computer friendly cams? I know they make some, but I dont know how the are friendly to the computer. I had thought of building a motor till mine went sky high and had to swap in my spare.

 

i dont want a comp friendly cam. im building up the motor for a reason.... towing. next year it will be gears. want the HP, and TQ first.

 

with the heads shaved .040 will the stock push rods be fine and the springs that were reccomended will still work good?
I'm only doing the heads right now on the 318,I am going to find a 360 magnum block and start building that up with the parts you guys recommended.(you guys seem like you really know what your talking about) also on those springs whats the max valve lift?

 

The push rods will not be OK. Stock rockers are not adjustable, so the PR length has to be dead nuts on. Cutting the heads won't affect the springs, but I sure wouldn't spend any money on stock Magnum heads, they're either cracked now, or will crack.

But...Have you figured out what cutting the stock heads .040 is going to put you compression at, your quench? Don't forget to mill the intake side othe intake manifold will never seal.

My Eddy heads were cut .030, supposedly good for 1 point in compression on a stock 360, guessing the Magnum heads would be close to that, all depends on the cc of a Magnum combustion chamber compared to Eddy Heads which are more like 63cc, not the advertised 58cc.

 

It's not a good idea to run stock springs with a cam upgrade. Springs get weaker with age and use, and they should probably be replaced on a high mileage stock engine if it is being rebuilt, let alone for use with a performance cam. (An RV cam is stil a performance upgrade.) Comp Cams has a number of tech guys that don't always agree with certain things. While most insist on new springs with a cam swap, one tech guy told me he wouldn't go any higher than something like a 195/200 @ .050 with the stock springs.

 

Quote:

for springs i can go to summit and they start at 35 for a set of springs(just dont know what to look for in size).I was looking at a tfs kit with the springs,locks and retainers for 125.
that cam u said will it give me good tire smoking low end with my 3.55 gears?and would it have a noticable idle(I like the old muscle car sound)

There are only a few springs that can be used with stock heads without machining and/or using longer valves: either the Mopar spirngs or Hughes.

 

A wide LSA, like a 114, among other things, is more computer friendly (unless the duration gets too large), produces better vacuum at idle...and produces a wider power range, with the peak power being higher in the rpm range.

A narrower LSA such as a 110, increases the overlap, produces a rougher idle, less vacuum...and a narrower power range, with peak power at a lower rpm, which is good for a heavier vehicle.

In general, around a 108 LSA produces the highest peak power as compared to a 114 LSA.