Browsing this Thread:
2 Anonymous Users
| |
|
Register To Post |
Matatk | Help me compare these two cams | ||
Webmaster
|
Trying to pinpoint my cam choice. Help me distinguish between these two cams:
http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=212&sb=2 08-302-8 RPM Range 1200-5200 Duration 264/274 Duration at .50 210/210 Valve lift (1/6 rr) .510/.510 LCA 112 Intake centerline 108 http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=207&sb=0 08-465-8 RPM Range 1200-5200 Duration 260/270 Duration at .50 210/218 Valve lift (1/6 rr) .56/.555 LCA 113 Intake centerline 109 It will be for my 355, edelbrock heads with mild port, ported plenum, big tube runners, long tube headers, chipped. Car is a DD in the summer, want a slightly lumpy cam but driveability is the #1 requirement. Good brake vacuum, etc. It will see some spirited driving, but mostly to and from work. Comments? Thanks. Matthew |
||
Posted on: 2009/9/24 2:54
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
BeachBum | Re: Help me compare these two cams | ||
Master Guru
|
In my opinion, that 2nd cam is a perfect match for your motor.... LPE used to offer the 211 cam for long tube 350-383 set-ups which was 211/219 - .533/.560 cam..... very close to that 2nd.
Its a torque cam.... Although in my opinion, I'd recommend getting rid of those long tube runners.... they made me slow. good luck ! |
||
Posted on: 2009/9/24 3:06
|
|||
Transfer |
anesthes | Re: Help me compare these two cams | ||
Master Guru
|
The second cam has a faster intake ramp, but they are both penuts.
-- Joe |
||
Posted on: 2009/9/24 10:38
|
|||
_________________
'79 Z28. 412 CID, NP 833 transmission, 3.73 10.5" rear end. |
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
Quote:
So how would that affect my driveability, gas mileage, etc? This car is not for drag racing, it's for a fun DD in the summer. |
||
Posted on: 2009/9/24 12:16
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
rklessdriver | Re: Help me compare these two cams | ||
Senior Guru
|
I don't think either of them will have any kind of a lick at idle, so power brakes and driveability will be good. If I had to pick between the (2) I would run the second cam.
The second cam has far more lift and slightly longer lobe centerlines so it SHOULD have a wider powerband by maybe 2-300RPM over the first cam. The first cam has a few degrees more seat timing but the ramp has a slower rate of lift and the lobe is not very big lift wise. It will make less peak HP/TQ on the order of 10-15 probally. It'll be down on power across the power band as well and you don't gain ANYTHING in driveabilty over the bigger second cam. Of these (2) there is no reason (unless you just want less power) to not run the second one. Will |
||
Posted on: 2009/9/24 13:51
|
|||
_________________
1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
|||
Transfer |
anesthes | Re: Help me compare these two cams | ||
Master Guru
|
Quote:
They're both near stock idle wise.. Even a 224 degree cam idles around 800rpm steady with plenty of vac. Usually cams with less lift have faster ramps, that second cam is kind of strange but should be ok. A 220-224 degree cam, HSR/miniram, and the right compression is easy 12 second daily driver with plenty of vac and a steady idle. Heck, even with a modified TPI (ported) the comp 503 is a 12 second combo. http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=196&sb=2 -- Joe |
||
Posted on: 2009/9/24 21:24
|
|||
Transfer |
rklessdriver | Re: Help me compare these two cams | ||
Senior Guru
|
Joe - I'm not following your comment about how a cam with less lift usually has the faster rate of lift.
You would have to break things down with a dial indicator and a degree wheel to map out every degree of lift/duration between 2 cams but I'm positive the cam with more lift will win on rate of lift every time - provided the duration of the 2 cams your comparing (such as in this case) are close to one another. I'm not trying to insult you with my (following) simplified explanation but I think it may help others understand what I'm talking about. The first cam has an Intake lobe with 264* (out of 360*) advertised duration. It has 210* (out of 360*) of duration remaining after the lifter has acheived .050 lift. In that 264* it is only capable of .318 lobe lift and back to 0 (well .020 or .006 or whatever they use for advertised duration). The second cam has less advertised duration to begin with at only 260*... It also has the same 210* of duration remaining after .050 lift. In only 260* of duration the second cam reaches .350 lobe lift and back to 0.... You were right the first time. The second cam has the faster rate of lift on the intake lobe. Not sure if you mispoke or what in your last post. For everyone else who may be lost: First thing you have to know is that cam lobes only have 360* of rotation to get everything done (valve closed, valve opening, valve max lift, valve closing, valve closed again). Timing events on a cam lobe are measured in "degrees of Duration". The total amount of time a lifter is off the heel of the cam or in positive lift (be aware that this point is measured differently by different cam grinders) is refered to as "Advertised Duration". Because .000000 lift and .0000001 lift is really hard to detect and repeat, cam grinders long ago started using .020 or .006 lift (it is a more repeatable measurement) as a place to start measuring for the Advertied Duration. It casues alot of confusion, but it's an important measurement and these days very overlooked and misunderstood. There are a host of other cam lobe timing measuerments for people to look at. Duration at .050, .100, .200 ect. They are smiply the remaining degrees of duration (remaining from your orginal 360*) at a given amount of lift. None of them mean anything unless you correlate them to the advertised duration. Then you can compare 2 differnt cam lobes by looking at and comparing all these timing numbers. Now I'm only talking about individual CAM LOBE timing events here. They are very simple to understand compared to... Actual entire camshaft and valve timing events, which are a product of the cam lobe timing events combined with the centerlines the cam lobes are ground on (in releation to the crankshaft)and rocker arm ratio. Valve timing events are measured by degrees in releation to the piston being at TDC or BDC of it's stroke. You almost always see the intake lobe centerline and lobe seperation on cam cards. Lobe seperation is nothing more than the intake & exhast centerline numbers added together and divided by 2. Some people put so much emphsis on it... I have no idea why. It really dosen't tell you that much useful. You sometimes you see the valve timing numbers on cam cards. These are very useful if can comprehend what is actually happening at those given points in a 4cyl engine. It's important to know how long the valve is actually off its seat when the piston is still on the up stroke and how long it continues to be open after the piston has gone past TDC and is approaching BDC. Same for the exhaust valve and for when the plug fires. OK thats enough of a camshaft clinic for tonight. If you want to burn more brain cells, get your info from 2 guys who really know whats going on... Not a 2nd rate hack like myself. First go read these gems. http://harveycrane.com/valuetiming.htm http://harveycrane.com/duration.htm http://harveycrane.com/cam_man.htm Then if your up for more, read these 40 pages of camshaft theroy. http://www.datsport.com/racer-brown.html Hey it's almost the weekend, I know you all really want to know this stuff and have nothing better to do. Will |
||
Posted on: 2009/9/25 1:35
|
|||
_________________
1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
Wow that's a lot of info! I just want a cam to drive my car on the street....lol. Thanks though!
Matthew |
||
Posted on: 2009/9/25 1:49
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
anesthes | Re: Help me compare these two cams | ||
Master Guru
|
Quote:
Depending on the type of cam (flat hyd, flat solid, roller hyd, roller solid) you can only make the ramp so steep. All cams have the same theoretical lift when cut on the same base circle. To create lift, they cut down the back side of the lobes. The more they cut, the more lift is into the cam. If you cut a lot and create a lot of lift, you have to make the ramp slower or the tappet won't follow or in some extreme conditions the side of the lifter body will crash into the lobe. So you end up with real gradual mountains. Obviously flat hydraulic cams are the worse (flat is worse, then the hyd plunger takes all the bite out of the cam). Solid rollers can have the steepest lobes. If you can grind a cam so the lift is not high but it gets there quickly, you can make up the lift with rocker ratio. Remember, the more lift a cam has, the farther the lifter is into the bore at seat. The closer to the cam centerline the lifter is, the harder it is to follow the lobe quickly without the lobe trying to push the lifter out of the block or the side of the lifter actually hitting the cam. Quote:
Actually you use a cam profile machine. It would take forever to try and do it with a degree wheel and a dial indicator. Since I don't have a $50k machine, nor the time to profile a cam by hand I just go by a simple comparison with some known data to select cams. It's almost impossible to compare cams from different manufacturers. Quote:
Yes, I said the second cam has a faster intake ramp. I then said that's odd, because normally the faster cams have less total lift. Quote:
Pretty good explanation for the new guys. Quote:
It gives a 'rough' idea what the purpose for the cam is.. If I'm looking for a blower cam, I start looking at cams with 113-115 degrees of lobe separation, then from my pool of cams I look at the rest of the specs and throw out the losers. Quote:
Can't live without 'em. |
||
Posted on: 2009/9/25 3:22
|
|||
Transfer |
dan0617 | Re: Help me compare these two cams | ||
Senior Guru
|
If you are staying with a long tube runner setup, run the 2nd cam you posted in the original post.
Better for you would be to put on a Superram or HSR intake, and run a LPE 219 cam. A CC503 (224/230 duration) cam WILL need serious fine tuning and a higher stall converter to end up with stocklike street manners, and a high stall converter is NOT stocklike street manners in itself. IF you want near stock street manners with the most HP and Torque you can get, again, run the 2nd cam you listed, or run the LPE 219 with a superram. Low 12 second combo for sure. Make SURE your heads are set up to accept the valve lift you are throwing at them. I didn't check, they may be able to in their out of the box configuration, or maybe not. Make sure before you buy the cam if you don't plan on doing any head/valve work. |
||
Posted on: 2009/9/25 16:27
|
|||
_________________
´89 Vert, 383, 230/236 cam, AFR 195's, LT Headers, HSR intake, 2800 stall, Zex 200 shot, ET Street Radials, tune by me. Runs were with D36 3.07's. On spray, 10.55 @ 132.78, 1.55 60 ft. On motor, 12.08 @ 113.15, 1.66 60 ft. |
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
Quote:
The heads I am running are the following with mild port work and decked .030: http://www.edelbrock.com/automotive_n ... chevy/sb_performer2.shtml http://www.summitracing.com/parts/EDL-60879/ Matthew |
||
Posted on: 2009/9/25 19:55
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
BeachBum | Re: Help me compare these two cams | ||
Master Guru
|
Matatk,
I like your rims.... can I ask where you got them ? Are those 16" or 17" ? Do you have other pictures I can see ? (Sorry, I do not mean to take your thread off-topic, feel free to PM if you wish) Back on the cams, I think with what you are trying to do with your TPI, either one will work, if I had to guess, I would say Cam # 1 would give you another 5-10 ftlbs of torque 4000 rpm and below, whereas cam # 2 would find you an extra 10 HP above 4000 rpm..... with 2 cams like that, there is almost always a crossover point.... the question is where in the rpm band it happens and then which torque curve helps your car accelerate to the speeds you desire. What is important as well is the converter/gearing information. Cam # 1 would probably work a little better with a stockish tight converter, whereas # 2 would benefit from a slightly looser converter and/or gearing. Although I personally think they would both be fine with a fairly tight converter. On the flipside cam # 2 might do better than we thing right off-idle because its a tad more agressive..... I would consider talking to compcams and getting their recommendation. As a matter of comparison, with a 120,000 mile 350 TPI motor with an Accell base, ported plenum and Accel runners, Dart heads and headers with a 3.07 gears and stock 85 converter I coerced 12.42 @ 108 mph out of it.....I think I was right around a 1.70 60 ft on that, but its been over 10 years since then and do not remember exactly. A converter a little more agressive and I probably could have gotten another tenth or two improvement. This was with the LPE 211 cam, which was 211/219 @ .050" - 112lsa - .533/.560 with 1.6's. This is just a matter of reference of the type of performance you could achieve out of a set-up like this. Just as a sidenote, the one thing that I have learned about this stuff, is that speed is addicting.... you'll build it as above, and then almost assuredly want more in a few short months... its not a bad idea to cam up for it now.... the 219 cam as others have mentioned would work well with this set-up too..... and if you ever decide you want more HP with a different intake, you'll already be cammed up for it. Good luck with whatever you choose ! |
||
Posted on: 2009/9/25 20:35
|
|||
Transfer |
dan0617 | Re: Help me compare these two cams | ||
Senior Guru
|
Quote:
Truer words have never been spoken. More addicting than tobacco. More addicting than beer. More addicting than liquor. Ranks right up there with sex, actually! |
||
Posted on: 2009/9/25 20:40
|
|||
_________________
´89 Vert, 383, 230/236 cam, AFR 195's, LT Headers, HSR intake, 2800 stall, Zex 200 shot, ET Street Radials, tune by me. Runs were with D36 3.07's. On spray, 10.55 @ 132.78, 1.55 60 ft. On motor, 12.08 @ 113.15, 1.66 60 ft. |
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
BB - thanks for your help. A guy has the second cam for sale brand new on CF for cheap. When edelbrock says the max lift on the springs already installed in the heads is .575, does that mean the cam can be up to .575 lift or .575-the recommended additional allowed clearance? Hmmmm...
As far as the rims, they are OE Reproductions from ebay. 17x9.5 on all 4. They weren't too expensive. I'm not sure if they have that style still, but they have others similar. I bought these early last summer. Thanks again, Matthew |
||
Posted on: 2009/9/26 2:44
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
BeachBum | Re: Help me compare these two cams | ||
Master Guru
|
Thanks for the pics, they look good. I have always liked the GS type black 5 spoke rims. I've never found a set that is affordable to me though.... I'll probably buy them if I ever do. I do not want to run any spacers though, prefer a bolt n go rim.
On the lift, your springs can handle a maximum .575 lift, which is what it simply means.... they're not designed to maintain pressures beyond that. Your two cams above are fine to run with .575 springs.... I always look at the lobe lift and then can easily figure out how much rocker arm I can from their. You have a very common .350 lobe on that second cam....multiple that by 1.6 and you have your .560 lift.... with room to spare. |
||
Posted on: 2009/9/26 16:53
|
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
Quote:
Excellent! Thanks again. Matthew |
||
Posted on: 2009/9/26 16:56
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
pr0zac | Re: Help me compare these two cams | ||
Elite Guru
|
i don't think that xfi cam will be ok without beehive springs although its a way better choice than the first.. even a cc304 is a very very small cam. i think that the second cam will give you more cause of all the lift that it has.. i don't really like the xfi cams. i think you should go custom. it will give you a better result by being able to tell them specifically what you want.
|
||
Posted on: 2009/9/27 0:40
|
|||
_________________
96 lt4. 357ci, 11:1, LE 226/232, LE2 LT4 heads, ported LT4 intake, EM Gladiator44, EM LT's, stock exhaust, NX kit. |
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
Quote:
Well I don't want a big cam, so if it's "small" that's ok. The stock cam is 207/213 .443/.459 (1.6) with 117 LSA. In my opinion, the two cams I listed are far better than stock. This is a daily driver. I'm not building a 421 inch cubic engine. I drive the car for pleasure. As far as going custom, I don't see the benefit for me personally. Besides, I'm on a budget, and if that xfi cam is still available I can get it for around $100 brand new from a guy dumping parts. Matthew |
||
Posted on: 2009/9/27 2:33
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
pr0zac | Re: Help me compare these two cams | ||
Elite Guru
|
as temping as the xfi cam may sound i am certain you are going to need to run beehive valve springs. and a 220ish cam isn't going to be a ton of cam for a 350. i had a 07-467-08 in my 355 and it wasn't all that bad. a cc304 cam is nice but i would say get something with more lift. maybe an lpe 74211.
|
||
Posted on: 2009/9/27 18:09
|
|||
_________________
96 lt4. 357ci, 11:1, LE 226/232, LE2 LT4 heads, ported LT4 intake, EM Gladiator44, EM LT's, stock exhaust, NX kit. |
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
I emailed comp cams regarding the lift/springs so I'll see what they say.
Matthew |
||
Posted on: 2009/9/28 1:37
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
89Vette | Re: Help me compare these two cams | ||
Senior Guru
|
FWIW, I asked Tony @ AFR about the XFI cams. He ended up building my heads with upgraded beehives (155psi) just to make sure valve-control was maintained.
With that in mind, I like Prozac's recommendation. |
||
Posted on: 2009/9/28 14:41
|
|||
_________________
383 stroker -- Semi-Siamesed SLP long-runner intake, AFR 195's, 4-2-1 headers, and a SR cam. ZF6 short-throw shifter. Custom body/interior. |
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
Finally got ahold of both edelbrock and comp cams. Spoke to the tech departments and was told by comp that the second cam would be fine with the spring pressure in the new heads. I pulled the trigger on the second cam today.
Matthew |
||
Posted on: 2009/10/3 23:27
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
PeteK | Re: Help me compare these two cams | ||
Moderator
|
#2
|
||
Posted on: 2009/10/3 23:39
|
|||
_________________
"It was really on a pass until it came apart." "Yeah. They always are." |
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
Quote:
Thanks, Pete....lol. |
||
Posted on: 2009/10/3 23:50
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
PeteK | Re: Help me compare these two cams | ||
Moderator
|
I would have bought #2 also. Even before you picked it.
|
||
Posted on: 2009/10/3 23:54
|
|||
_________________
"It was really on a pass until it came apart." "Yeah. They always are." |
|||
Transfer |
RedGut86 | Re: Help me compare these two cams | ||
Guru Newb
|
So the beehives aren't required right?
The beehives advantage is reduced mass which with a big lift, fast ramp cam like the XFIs is important. But I've also heard that the XFI cams just beat up valve springs and a dual spring when one fails, you still have another one, with beehives one goes and wave bye! I take it you are using the duals that come on the head right? |
||
Posted on: 2009/10/4 2:06
|
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
Quote:
I'm using what comes on the edelbrocks stock. All I know is it's a .575 lift with 120 seat/320 open pressure. This isn't gonna be a high revving race motor, it's pretty much for street fun. Matthew |
||
Posted on: 2009/10/4 4:02
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
pr0zac | Re: Help me compare these two cams | ||
Elite Guru
|
i am going to go ahead right now and say i told you so.. i have read numerous post about valve control issues with xfi lobes and motors being down on power because the xfi cams weren't matched with the lighter weight beehives springs. i don't think that the springs that come with the heads are going to be enough. the cams were specifically designed to be run using beehive springs and only those springs.
|
||
Posted on: 2009/10/4 21:37
|
|||
_________________
96 lt4. 357ci, 11:1, LE 226/232, LE2 LT4 heads, ported LT4 intake, EM Gladiator44, EM LT's, stock exhaust, NX kit. |
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
Quote:
I appreciate the input. I just got another email from comp from a different tech who stated to run beehives. So I emailed him back to get clarification. I will more than likely run beehives now. I wasn't planning on the extra $150 but oh well. |
||
Posted on: 2009/10/7 0:07
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
dan0617 | Re: Help me compare these two cams | ||
Senior Guru
|
Sell the heads and buy a set of 195 street ports from Jim. You will be glad you did. If you don't, mark my words, in less than a year you will be kicking yourself for not.
|
||
Posted on: 2009/10/7 1:09
|
|||
_________________
´89 Vert, 383, 230/236 cam, AFR 195's, LT Headers, HSR intake, 2800 stall, Zex 200 shot, ET Street Radials, tune by me. Runs were with D36 3.07's. On spray, 10.55 @ 132.78, 1.55 60 ft. On motor, 12.08 @ 113.15, 1.66 60 ft. |
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
This saga just continues.....
I emailed the second tech again and he told me he had the wrong specs for the edelbrock springs. He stated that with the .575 lift and 120/320 pressure those springs would be fine with the cam. I'll have to wait and see what I decide. Haven't made my final decision yet. |
||
Posted on: 2009/10/7 23:23
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
RedGut86 | Re: Help me compare these two cams | ||
Guru Newb
|
I'm interested where you go no matter what. I've heard a lot of internet chatter about the valve control issues and people proactively choosing to run stiffer springs, or claiming the Xfi lobes are tough on valve springs. However, I haven't seen any proof (or in person) the valve control issues. Make sure comp has your exact specs and if they say you should be fine, well, perhaps you are fine. What did you say max RPM is? If it is 5500 rpm or so, they might be thinking you won't see valve float.
I'd be curious to see how they work with your springs (which I wouldn't consider very high of pressures) however I don't want you to bust a spring either! |
||
Posted on: 2009/10/9 6:13
|
|||
Transfer |
Matatk | Re: Help me compare these two cams | ||
Webmaster
|
Thanks, Red, that's kind of what I'm thinking. I'm gonna run it and see how things work out. This isn't a high revving motor, I'm keeping the TPI. I gave comp the valve spring specs I got directly from edelbrock and they said it's fine.
Matthew |
||
Posted on: 2009/10/9 11:44
|
|||
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
Transfer |
You can view topic.
You cannot start a new topic.
You cannot reply to posts.
You cannot edit your posts.
You cannot delete your posts.
You cannot add new polls.
You cannot vote in polls.
You cannot attach files to posts.
You cannot post without approval.
|