Cc305 vs cc503
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Cc305 vs cc503 eventually I will be building a 383, local guy will build the entire engine including ported heads etc I’m consider one of the 2 cams listed, they seem very similar on paper with the obvious differences, lsa and a few degrees etc. I’m just curious if anyone has used both and what the power differences are... which makes better power, more peak etc.
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I have a smaller cam than the 503 in my 383 and have passed Calif. smog for years now
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The engine builder/tuner said the 305 was a great cam for what I wanted emissions wise. He said the 306 won’t pass up here. I then saw the 503 and see it’s very popular even in 383s. I was looking for a bit more chop than the 305 but he also mentioned a custom grind based off the 305 that has a few more degrees. I was really just curious if there were any major differences between the 305 and 503 power wise. Is one better in the low end than the other? Similar mid range? Which one has better top end etc. Probably just best to go with the engine builders choice.
Last edited by PARMY; Jun 13, 2018 at 02:18 PM. Reason: error
I had a CC305 in a supercharged 383 with stock heads. It passed Ont. emissions back in 2001 or 2002. It is a small cam for that size engine NA no doubt but has great manners and passed the roller test at the time.
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FWIW I have a smaller cam in my 383 (214/224, 555/568, lsa 115) and I have to say, it must make at least 400tq to the wheels and probably around 380hp through a 6 speed. super fun to drive on the street, tons of low end torque and pulls hard up top for what it is. not the ideal cam for the setup but I am happy with it.....for now. wish it had more lope at idle though, can really only hear it on cold starts under 30* when the idle is really low in closed loop.
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I was just about to rag on the cc305 a bit for being an old technology cam ground on some ancient lobes that came out before most of today's LT1 owners were even conceived but then recalled that it is now ground on Xtreme Energy lobes (same with the cc306). The Xtreme Energy lobes are still technically older tech but are much improved over the ancient Magnum lobes IMO. Honestly, both the cc305 and cc503 are decent cams. The cc305 on a 114 lsa was a very popular blower grind back in the day. I personally like the valve events of the cc503 more and think it's one of the best LT1 shelf grinds BUT there is more overlap in it (bad for sniffer test) versus the cc305. As said, tuning plays a big part in it however. Anyways, if it were me I would pass on both the cc305 and cc503 cams and call up Lloyd Elliott for a custom grind. The cam is arguably the brain of the motor and with a 383 setup like yours I would opt for custom (from a reputable LT1 individual) because there is value in having a cam with the right valve events to not only deliver optimal performance but to meet the goals, constraints, etc. of the end user more, just my .02.
Last edited by StealthFormula; Jun 14, 2018 at 12:53 PM.
I'd choose the CC503 for a NA application.
The CC503 has less-ancient XE lobes and gives more area under the lift curve, better average horsepower, than the older Magnum lobes of the CC305.
Edit: just saw the post above mine. Never heard that there are now two different versions of CC305 cams out there .. ??
The CC503 has less-ancient XE lobes and gives more area under the lift curve, better average horsepower, than the older Magnum lobes of the CC305.
Edit: just saw the post above mine. Never heard that there are now two different versions of CC305 cams out there .. ??
Have a look at the valve events and LSA (overlap)
Comp 305
http://www.compcams.com/Company/CC/c...csid=1102&sb=2
Comp 503
http://www.compcams.com/Company/CC/c...csid=1111&sb=2
Comp XFI 467 (far better choice than either of the other 2)
http://www.compcams.com/Company/CC/c...csid=1107&sb=2
All are similar in valve events in terms of degrees. The 305 is old lobe technology. The 503 is a great cam for stock cubes where emissions may or may not matter, capable tuning helps. These 2 cams are very similar but the 305 has another degree of LSA to assist in staving off cylinder pressure bleed off during filling on the intake stroke. The intake valve closing event and ICL/LSA have primary effects on overlap, which will be your biggest enemy for emissions, as some of the air and fuel charge is leaving the exhaust port unburnt (= high NOX/HC). 3rd choice and others like it- the 467. Longer duration, higher lift, very similar valve events but very different lobes. And another degree of ICL/LSA vs. overlap. More power potential with no worse or slightly better emissions challenges for your tuner. Look at the lift it makes in the almost same number of degrees as either of the other 2. Cylinders will fill a lot quicker and more efficiently and atomize the fuel charge in the intake port a lot better.
Nobody asked what heads you're running on your 383. Care to share? If it's stock LT1 170cc heads then stop me, lol. The other 2 would be about your maximum choices for stock untouched heads.
Comp 305
http://www.compcams.com/Company/CC/c...csid=1102&sb=2
Comp 503
http://www.compcams.com/Company/CC/c...csid=1111&sb=2
Comp XFI 467 (far better choice than either of the other 2)
http://www.compcams.com/Company/CC/c...csid=1107&sb=2
All are similar in valve events in terms of degrees. The 305 is old lobe technology. The 503 is a great cam for stock cubes where emissions may or may not matter, capable tuning helps. These 2 cams are very similar but the 305 has another degree of LSA to assist in staving off cylinder pressure bleed off during filling on the intake stroke. The intake valve closing event and ICL/LSA have primary effects on overlap, which will be your biggest enemy for emissions, as some of the air and fuel charge is leaving the exhaust port unburnt (= high NOX/HC). 3rd choice and others like it- the 467. Longer duration, higher lift, very similar valve events but very different lobes. And another degree of ICL/LSA vs. overlap. More power potential with no worse or slightly better emissions challenges for your tuner. Look at the lift it makes in the almost same number of degrees as either of the other 2. Cylinders will fill a lot quicker and more efficiently and atomize the fuel charge in the intake port a lot better.
Nobody asked what heads you're running on your 383. Care to share? If it's stock LT1 170cc heads then stop me, lol. The other 2 would be about your maximum choices for stock untouched heads.
Have a look at the valve events and LSA (overlap)
Comp 305
www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1102&sb=2
Comp 503
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1111&sb=2
Comp XFI 467 (far better choice than either of the other 2)
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1107&sb=2
All are similar in valve events in terms of degrees. The 305 is old lobe technology. The 503 is a great cam for stock cubes where emissions may or may not matter, capable tuning helps. These 2 cams are very similar but the 305 has another degree of LSA to assist in staving off cylinder pressure bleed off during filling on the intake stroke. The intake valve closing event and ICL/LSA have primary effects on overlap, which will be your biggest enemy for emissions, as some of the air and fuel charge is leaving the exhaust port unburnt (= high NOX/HC). 3rd choice and others like it- the 467. Longer duration, higher lift, very similar valve events but very different lobes. And another degree of ICL/LSA vs. overlap. More power potential with no worse or slightly better emissions challenges for your tuner. Look at the lift it makes in the almost same number of degrees as either of the other 2. Cylinders will fill a lot quicker and more efficiently and atomize the fuel charge in the intake port a lot better.
Nobody asked what heads you're running on your 383. Care to share? If it's stock LT1 170cc heads then stop me, lol. The other 2 would be about your maximum choices for stock untouched heads.
Comp 305
www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1102&sb=2
Comp 503
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1111&sb=2
Comp XFI 467 (far better choice than either of the other 2)
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1107&sb=2
All are similar in valve events in terms of degrees. The 305 is old lobe technology. The 503 is a great cam for stock cubes where emissions may or may not matter, capable tuning helps. These 2 cams are very similar but the 305 has another degree of LSA to assist in staving off cylinder pressure bleed off during filling on the intake stroke. The intake valve closing event and ICL/LSA have primary effects on overlap, which will be your biggest enemy for emissions, as some of the air and fuel charge is leaving the exhaust port unburnt (= high NOX/HC). 3rd choice and others like it- the 467. Longer duration, higher lift, very similar valve events but very different lobes. And another degree of ICL/LSA vs. overlap. More power potential with no worse or slightly better emissions challenges for your tuner. Look at the lift it makes in the almost same number of degrees as either of the other 2. Cylinders will fill a lot quicker and more efficiently and atomize the fuel charge in the intake port a lot better.
Nobody asked what heads you're running on your 383. Care to share? If it's stock LT1 170cc heads then stop me, lol. The other 2 would be about your maximum choices for stock untouched heads.
cc305 lift w/ 1.6RRs = .544/.544
cc503 lift w/ 1.6RRs = .537/.544
XFI 467 w/ 1.6RRs = .576/.570
I dig the XFI 467 cam mentioned, nice specs on it and it's on more modern, more aggressive XFI lobes. I personally favor the XFI stuff and have been running a custom XFI lobed cam for the past 10-11 years now.
I'd choose the CC503 for a NA application.
The CC503 has less-ancient XE lobes and gives more area under the lift curve, better average horsepower, than the older Magnum lobes of the CC305.
Edit: just saw the post above mine. Never heard that there are now two different versions of CC305 cams out there .. ??
The CC503 has less-ancient XE lobes and gives more area under the lift curve, better average horsepower, than the older Magnum lobes of the CC305.
Edit: just saw the post above mine. Never heard that there are now two different versions of CC305 cams out there .. ??
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The XFI grinds in terms of published lift spec is with 1:6 RR vs the 1:5 on other cams.....if you are comparing "lift" #'s
FWIW I run the XFI in my 383. You need a good spring for the ramps of this grind. Lunati is what Lloyd advised for me
FWIW I run the XFI in my 383. You need a good spring for the ramps of this grind. Lunati is what Lloyd advised for me
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FWIW the XFI grinds published "lift" specs are with 1:6 RR vs the 1:5 of the other two cams mentioned so do the math for the other cams to get comparable lift #'s as Stealth did
I have the XFI in my 383. You need a good spring for the ramps of the XFI. Lloyd advised, and sold me, Lunati springs
EDIT: apologies for double post...hotel internet is slowwwww
I have the XFI in my 383. You need a good spring for the ramps of the XFI. Lloyd advised, and sold me, Lunati springs
EDIT: apologies for double post...hotel internet is slowwwww
Last edited by BALLSS; Jun 14, 2018 at 02:02 PM.
Thread Starter
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Have a look at the valve events and LSA (overlap)
Comp 305
http://www.compcams.com/Company/CC/c...csid=1102&sb=2
Comp 503
http://www.compcams.com/Company/CC/c...csid=1111&sb=2
Comp XFI 467 (far better choice than either of the other 2)
http://www.compcams.com/Company/CC/c...csid=1107&sb=2
All are similar in valve events in terms of degrees. The 305 is old lobe technology. The 503 is a great cam for stock cubes where emissions may or may not matter, capable tuning helps. These 2 cams are very similar but the 305 has another degree of LSA to assist in staving off cylinder pressure bleed off during filling on the intake stroke. The intake valve closing event and ICL/LSA have primary effects on overlap, which will be your biggest enemy for emissions, as some of the air and fuel charge is leaving the exhaust port unburnt (= high NOX/HC). 3rd choice and others like it- the 467. Longer duration, higher lift, very similar valve events but very different lobes. And another degree of ICL/LSA vs. overlap. More power potential with no worse or slightly better emissions challenges for your tuner. Look at the lift it makes in the almost same number of degrees as either of the other 2. Cylinders will fill a lot quicker and more efficiently and atomize the fuel charge in the intake port a lot better.
Nobody asked what heads you're running on your 383. Care to share? If it's stock LT1 170cc heads then stop me, lol. The other 2 would be about your maximum choices for stock untouched heads.
Comp 305
http://www.compcams.com/Company/CC/c...csid=1102&sb=2
Comp 503
http://www.compcams.com/Company/CC/c...csid=1111&sb=2
Comp XFI 467 (far better choice than either of the other 2)
http://www.compcams.com/Company/CC/c...csid=1107&sb=2
All are similar in valve events in terms of degrees. The 305 is old lobe technology. The 503 is a great cam for stock cubes where emissions may or may not matter, capable tuning helps. These 2 cams are very similar but the 305 has another degree of LSA to assist in staving off cylinder pressure bleed off during filling on the intake stroke. The intake valve closing event and ICL/LSA have primary effects on overlap, which will be your biggest enemy for emissions, as some of the air and fuel charge is leaving the exhaust port unburnt (= high NOX/HC). 3rd choice and others like it- the 467. Longer duration, higher lift, very similar valve events but very different lobes. And another degree of ICL/LSA vs. overlap. More power potential with no worse or slightly better emissions challenges for your tuner. Look at the lift it makes in the almost same number of degrees as either of the other 2. Cylinders will fill a lot quicker and more efficiently and atomize the fuel charge in the intake port a lot better.
Nobody asked what heads you're running on your 383. Care to share? If it's stock LT1 170cc heads then stop me, lol. The other 2 would be about your maximum choices for stock untouched heads.
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To build off the above...I know many of us know this already but just as an FYI for any readers that may not...Comp Cams for whatever reason quotes the lift of the XFI lobed cams assuming a 1.6 ratio rocker and quotes the Magnum and Xtreme Energy lobed cams assuming a 1.5 ratio roller rocker. To directly compare the lift between cams a little math is necessary, here's the results:
cc305 lift w/ 1.6RRs = .544/.544
cc503 lift w/ 1.6RRs = .537/.544
XFI 467 w/ 1.6RRs = .576/.570
I dig the XFI 467 cam mentioned, nice specs on it and it's on more modern, more aggressive XFI lobes. I personally favor the XFI stuff and have been running a custom XFI lobed cam for the past 10-11 years now.
cc305 lift w/ 1.6RRs = .544/.544
cc503 lift w/ 1.6RRs = .537/.544
XFI 467 w/ 1.6RRs = .576/.570
I dig the XFI 467 cam mentioned, nice specs on it and it's on more modern, more aggressive XFI lobes. I personally favor the XFI stuff and have been running a custom XFI lobed cam for the past 10-11 years now.
I'm running the cc305 with ported stock heads, 2.00/1.56 valves and 1.6 rockers. Big flat torque curve and nearly stock sounding and very smooth. The engine was built about 8 years ago though and I'd likely do things differently today. Long story short, talk to the tuner and do the research. Asking here doesn't hurt but everyone is going to have different opinions. Valve size, porting and other factors apply here as well.
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I actually just spoke with him this morning and decided to go with the cc305. Reason being that it’s easier for emissions and for what I want from the car, it works out great. My builder has a ton of experience with LT1s and has used this cam a lot. Like you mentioned, great flat torque curve and no need to rev the crap out of the motor. Heads will be stock ported with larger valves, port matched intake, 58mm TB and I already have new pace setter 1 3/4 headers and ORY. I’m not looking for big HP.....somewhere between 350-400 would be great and said most likely it will make in the 360-380hp range at the wheels.
I actually just spoke with him this morning and decided to go with the cc305. Reason being that it’s easier for emissions and for what I want from the car, it works out great. My builder has a ton of experience with LT1s and has used this cam a lot. Like you mentioned, great flat torque curve and no need to rev the crap out of the motor. Heads will be stock ported with larger valves, port matched intake, 58mm TB and I already have new pace setter 1 3/4 headers and ORY. I’m not looking for big HP.....somewhere between 350-400 would be great and said most likely it will make in the 360-380hp range at the wheels.