CAM PERFORMANCE QUESTION

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clementine said:
Agreed, after reading many 'cam choice' threads on here, I have not seen many 'square' ish cam choices. I still am wrapping my head around cam science, especially overlap and centerline.

…..does this come apart and go back together easily and quickly?'
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Yes, take your time pulling everything apart. It is easy.

On the cam “science” stuff.. make it easy on yourself by understanding that basics and work in from there. Duration is operating RPM
Overlap is how rowdy a cam can sound. It is the time when both valves are open.
Centerline is where the top of the cams lobe is lifting the valve at its highest in relation in degrees.

“Square” cams, are just fine if the head flow has a good balance or ratio between the intake and exhaust ports. split duration cams helped the weaker exhaust port breath out the bad. A longer exhaust duration also extends the RPM range of the cam. It can also dampen the effectiveness of the low rpm range of the cam. This can also be just a small part of that issue as the head, intake & carb could also play a roll.

If you have a good flowing head as far as the valve is being lifted on both sides, a single pattern cam is just fine. Do a search on cam testing dyno runs.

IIRC, MoPar Muscle mag did one with around 8 or 9 different cams using the MP Purple line as there base to test from.
 
Non OD...... thanks for the clarification.

Still going to be on the big side for the cubes, CR, and EFI.
 
The idea with alot of overlap, both valves open at the same time is to help pull in a fresh charge of air and fuel in stock heads and/or heads that don’t flow well out the exhaust side. That’s why some cams have more lift and duration on the exhaust side as well. This all gives you a rough and lopey idle as some exhaust is pulled back into the intake manifold at low rpm. It will also raise the power band of the motor limited by how well the heads flow. Passenger car heads just are not racing heads, kind of a band aid to get more go.
 
Just too bad you can’t bump up the compression ratio some just short of detonation cause a cam with a lot of overlap will bleed off compression.
 
ch1ll said:
The idea with alot of overlap, both valves open at the same time is to help pull in a fresh charge of air and fuel in stock heads and/or heads that don’t flow well out the exhaust side. That’s why some cams have more lift and duration on the exhaust side as well. This all gives you a rough and lopey idle as some exhaust is pulled back into the intake manifold at low rpm. It will also raise the power band of the motor limited by how well the heads flow. Passenger car heads just are not racing heads, kind of a band aid to get more go.
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will be thinking about this....
 
That cam is really not as huge as people think. It will have more torque than the .509" hydraulic Purple Shaft and a better idle, yet people recommend that for almost everything..lol. The 110LSA might help with bottom end over a .528" "magic" Purple Shaft solid, although the duration is higher. Try it with the lash set at .026/.030" first and see how it does. The Magnum solid lobes can be set from .015-.030" according to Comp Cams, and I have tried a 270s from .016" to .028" myself and it does help with tuning somewhat on a short stroke engine (318 in my case).
 
Bighead440 said:
That cam is really not as huge as people think. It will have more torque than the .509" hydraulic Purple Shaft and a better idle, yet people recommend that for almost everything..lol. The 110LSA might help with bottom end over a .528" "magic" Purple Shaft solid, although the duration is higher. Try it with the lash set at .026/.030" first and see how it does. The Magnum solid lobes can be set from .015-.030" according to Comp Cams, and I have tried a 270s from .016" to .028" myself and it does help with tuning somewhat on a short stroke engine (318 in my case).
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It's a baby. The 557 purple shaft is 296 /557, 248 @ 50 on a 110. For example.
 
RustyRatRod said:
I believe you can tune it to run very well. Millions of "overcammed" engines have performed extremely well. Yours will too.
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And here's 1 example that did, my 440-6 motor with bv 906's@under 10:1, comp sft, .650"/.650"-290@.050, single 850DP, Team G, made 530fwhp according to weight/mph.
 
Hot Metal said:
And here's 1 example that did, my 440-6 motor with bv 906's@under 10:1, comp sft, .650"/.650"-290@.050, single 850DP, Team G, made 530fwhp according to weight/mph.
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Hell yeah. Although not truly comparable, I remember some of the motors we modded and built as kids in school. I had a Chevy 350....mid 70s so what.......9:1 at the most? I put an Alliance cam in it. Remember those? .480/292 on like a 107....109......I don't remember. It was an odd LSA and tight. I think it was either 230 or 232@.050. But it sounded good enough to fend off most red light battles. LOL It did run fairly well, too. Because of how well it SOUNDED, that motor actually got us some engine jobs going through school. Everybody wanted their chit to sound like Rob's Nova. LMAO
 
RustyRatRod said:
Hell yeah. Although not truly comparable, I remember some of the motors we modded and built as kids in school. I had a Chevy 350....mid 70s so what.......9:1 at the most? I put an Alliance cam in it. Remember those? .480/292 on like a 107....109......I don't remember. It was an odd LSA and tight. I think it was either 230 or 232@.050. But it sounded good enough to fend off most red light battles. LOL It did run fairly well, too. Because of how well it SOUNDED, that motor actually got us some engine jobs going through school. Everybody wanted their chit to sound like Rob's Nova. LMAO
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Yeah Rob, that's like the Alliance BBM hydraulic with 242*@.050". .476" lift and 112LSA, perfect for single springs and stock heads with a choppy idle in a 440!
 
Bighead440 said:
Yeah Rob, that's like the Alliance BBM hydraulic with 242*@.050". .476" lift and 112LSA, perfect for single springs and stock heads with a choppy idle in a 440!
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That's what that motor was, too. Stone stock, valve sprAngs and all. lol I even broke all the rules and slapped an Edelbrock Scorpion SINGLE PLANE intake on it. lol It had a 6210 double pumper on it. lol That car really ran pretty well.
 
LMAO!!! Bringing back the memories of an old mill I had. I would get challenged until I rolled up to the light. I had the “idle like a lumberjack on crack” Purple cam in a high compression 360 w/a small AVS which was not working correctly with the stock step up springs. The idle was all over the place. It would scare off the lesser informed.
ROTFLMAO!!!

It was a 4spd car w/4.10’s, so it jumped rather well!
 
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