split duration cam or not?
Thread Starter
Instructor
Joined: Sep 2006
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split duration cam or not?
With 1.75in LT headers/high flow cats and AFR 205 heads and stock muffler is a split duration cam not optimal? 224/224? 220/220? or would a 220/224 or 216/224 be better?
Seems most of the thunder racing custom cams are mostly split duration.
Seems most of the thunder racing custom cams are mostly split duration.
Last edited by mfoti; Dec 8, 2006 at 08:48 PM.
Tech Contributor
Joined: Mar 2003
Posts: 12,094
Likes: 197
From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Statistical inference is your best guidance here. Every H/C package from the top tuners all produce big numbers with a standard split. Other than FI applications by A&A, I have yet to see the same results with the same intake and exhaust lobes.
Stay with the findings of the best packages available. Reinventing the wheel rarely works.
Stay with the findings of the best packages available. Reinventing the wheel rarely works.
Thread Starter
Instructor
Joined: Sep 2006
Posts: 233
Likes: 1
Thanks Spin. You are 100% correct. The only problem i run into is that i don't see many head/cam packages with mild cams like 220/224. Most vendors team their heads up with much more aggressive cams.
Based on everythign i have read I am really focused on a 220/224 .561 114LSA cam. Is it bad to pick a cam and then find a suitable head? So assuming this is a good choice for me then would i be dissapointed if i went with a livermore stage 1 or 2 head over an AFR or lingenfelter? 5 or 10 extra hp isn't worth another $1000 to me. This is where i am struggling..matching a cam/head.
In the end although i will be doing the work myself, I will be going to a local tuner/vendor for advice. Vinci high performance and Next Level performance are just a few miles away. I am really trying to educate myself as much as i can in advance. I don't want to "assume" the tuner is going to pick the best cam for me.
As always thanks for the advice spin.
Based on everythign i have read I am really focused on a 220/224 .561 114LSA cam. Is it bad to pick a cam and then find a suitable head? So assuming this is a good choice for me then would i be dissapointed if i went with a livermore stage 1 or 2 head over an AFR or lingenfelter? 5 or 10 extra hp isn't worth another $1000 to me. This is where i am struggling..matching a cam/head.
In the end although i will be doing the work myself, I will be going to a local tuner/vendor for advice. Vinci high performance and Next Level performance are just a few miles away. I am really trying to educate myself as much as i can in advance. I don't want to "assume" the tuner is going to pick the best cam for me.
As always thanks for the advice spin.
Drifting
Joined: Jul 2003
Posts: 1,796
Likes: 1
From: Annandale VA
First, the AFR 205 heads are excellent, will work just fine with your relatively mild cam. Main drawback is their cost, so you might look at a set of tuner heads, which you can find much cheaper. With only .561" lift, you don't need heads with killer flow numbers; port velocity is much more important.
You might consider a cam on XE-R lobes, with lift a tad higher at .580" or so. This grind may actually idle better, at the expense of slightly more valvetrain noise and valvespring longevity. SInce you're considering a mild grind, you probably won't be buzzing the engine up to redline every day anyway.
I think you will like your cam. It's very similar to one that I ran in an LS1, a 218/224 w/ .550" lift. It idled exactly like stock, gave me plenty of power.
You might consider a cam on XE-R lobes, with lift a tad higher at .580" or so. This grind may actually idle better, at the expense of slightly more valvetrain noise and valvespring longevity. SInce you're considering a mild grind, you probably won't be buzzing the engine up to redline every day anyway.
I think you will like your cam. It's very similar to one that I ran in an LS1, a 218/224 w/ .550" lift. It idled exactly like stock, gave me plenty of power.
Melting Slicks
Joined: Feb 2006
Posts: 3,271
Likes: 182
From: Manassas VA
There are several excellent engine analysis programs available to evaluate various combinations.
My experience in using one of these on race motors is that they always indicate which is the best combination of heads/cam etc. You may or may not hit the actual HP/TQ numbers exactly on the nose but they do a great job of predicting relative performance between various combinations.
The programs which have a great amount of input detail are somewhat more expensive than the simpler ones but any of them is a small percentage of your parts and installation tab. Maybe you can get a friend to run some simulations for you.
My experience in using one of these on race motors is that they always indicate which is the best combination of heads/cam etc. You may or may not hit the actual HP/TQ numbers exactly on the nose but they do a great job of predicting relative performance between various combinations.
The programs which have a great amount of input detail are somewhat more expensive than the simpler ones but any of them is a small percentage of your parts and installation tab. Maybe you can get a friend to run some simulations for you.
Tech Contributor
Joined: Mar 2003
Posts: 12,094
Likes: 197
From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Originally Posted by mfoti
Thanks Spin. You are 100% correct. The only problem i run into is that i don't see many head/cam packages with mild cams like 220/224. Most vendors team their heads up with much more aggressive cams.
Based on everythign i have read I am really focused on a 220/224 .561 114LSA cam. Is it bad to pick a cam and then find a suitable head? So assuming this is a good choice for me then would i be dissapointed if i went with a livermore stage 1 or 2 head over an AFR or lingenfelter? 5 or 10 extra hp isn't worth another $1000 to me. This is where i am struggling..matching a cam/head.
In the end although i will be doing the work myself, I will be going to a local tuner/vendor for advice. Vinci high performance and Next Level performance are just a few miles away. I am really trying to educate myself as much as i can in advance. I don't want to "assume" the tuner is going to pick the best cam for me.
As always thanks for the advice spin.
Based on everythign i have read I am really focused on a 220/224 .561 114LSA cam. Is it bad to pick a cam and then find a suitable head? So assuming this is a good choice for me then would i be dissapointed if i went with a livermore stage 1 or 2 head over an AFR or lingenfelter? 5 or 10 extra hp isn't worth another $1000 to me. This is where i am struggling..matching a cam/head.
In the end although i will be doing the work myself, I will be going to a local tuner/vendor for advice. Vinci high performance and Next Level performance are just a few miles away. I am really trying to educate myself as much as i can in advance. I don't want to "assume" the tuner is going to pick the best cam for me.
As always thanks for the advice spin.
I cant stress enough to not try to combine parts by yourself and come up with a formular all your own. Pick a head cam combo and dont make any changes. AFR/224 cams are hardly any different than a 220 xer. The use of XER lobes is a must. The lift is dictated by the duration picked.
Be sure to run the correct DCR with the parts you choose. That will ensure the best low end TQ.
Tech Contributor
Joined: Mar 2003
Posts: 12,094
Likes: 197
From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Originally Posted by HITMAN99
With only .561" lift, you don't need heads with killer flow numbers; port velocity is much more important.
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Verdad Gallardo
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
Originally Posted by SpinMonster
Great heads outflow average heads at all lifts not just peak lift. A ported head will gain over 25-30rwhp a stock head even with the stock cam even under the curve. While its probably not what you meant, large lift cams arent what dictates needing great flowing heads.
with SpinWe can all get bent out of shape with numbers, (duration, lift, flow rate) and terminology ( spit, reverse, ect.)
We read all kinds of things on this forum then go over to another forum and forget what we learned here. It gets very confusing
So much so that we forget to figure out "what we want our car to do?" 
Is you car set up for Drag racing? Road Racing /HPDEs? weekend cruzing? or just so good 'ol fun? or plain ol bar and bench racing bragging rights??
So ask yourself the realistic question, "What Do I want My car to do?" and "do I want reliabilty?" Then go find a respected tuner and let them know what you want the car to do and talk about it.
Between your desire for your car and the tuners abilties the two of you will come up with a great package.
Good Luck
Thread Starter
Instructor
Joined: Sep 2006
Posts: 233
Likes: 1
I can't argue with this advice. I concede
I have never been in another car with a non-stock cam so that is big problem. I will hook up with some local guys and go with their recommendations.
Thanks guys.
I have never been in another car with a non-stock cam so that is big problem. I will hook up with some local guys and go with their recommendations.
Thanks guys.
Racer
Joined: Jun 2006
Posts: 365
Likes: 0
From: Winter Park (Orlando) FL
Originally Posted by mfoti
Thanks Spin. You are 100% correct. The only problem i run into is that i don't see many head/cam packages with mild cams like 220/224. Most vendors team their heads up with much more aggressive cams.
Based on everythign i have read I am really focused on a 220/224 .561 114LSA cam. Is it bad to pick a cam and then find a suitable head? So assuming this is a good choice for me then would i be dissapointed if i went with a livermore stage 1 or 2 head over an AFR or lingenfelter? 5 or 10 extra hp isn't worth another $1000 to me. This is where i am struggling..matching a cam/head.
In the end although i will be doing the work myself, I will be going to a local tuner/vendor for advice. Vinci high performance and Next Level performance are just a few miles away. I am really trying to educate myself as much as i can in advance. I don't want to "assume" the tuner is going to pick the best cam for me.
As always thanks for the advice spin.
Based on everythign i have read I am really focused on a 220/224 .561 114LSA cam. Is it bad to pick a cam and then find a suitable head? So assuming this is a good choice for me then would i be dissapointed if i went with a livermore stage 1 or 2 head over an AFR or lingenfelter? 5 or 10 extra hp isn't worth another $1000 to me. This is where i am struggling..matching a cam/head.
In the end although i will be doing the work myself, I will be going to a local tuner/vendor for advice. Vinci high performance and Next Level performance are just a few miles away. I am really trying to educate myself as much as i can in advance. I don't want to "assume" the tuner is going to pick the best cam for me.
As always thanks for the advice spin.
I would also definetely recommend stopping by and chatting with Chris or Robby at "Corvette Masters" in Maitland. They are right behind Rogers Corvettes, between the adult video store and Rogers. I had work done there and had a great experience. Awesome awesome customer service. Nice guys too! www.corvettemasters.com
Drifting
Joined: Jul 2003
Posts: 1,796
Likes: 1
From: Annandale VA
Originally Posted by SpinMonster
Great heads outflow average heads at all lifts not just peak lift. A ported head will gain over 25-30rwhp a stock head even with the stock cam even under the curve. While its probably not what you meant, large lift cams arent what dictates needing great flowing heads.
Drifting
Joined: Nov 2002
Posts: 1,651
Likes: 125
From: laguna niguel ca
If you stay with durations in the 218/224,220/224, you might want to stay with stock heads. 224 and up the advantage is evident with better flowing heads. I'm only using the 224/228/581/588/114 with ET heads, FAST 90 etc and am making 461rwhp/435rwtq. I believe it's an entry level cam that requires better heads to max the potential of the combination. Mine's a daily driver and I didn't need a paint shaker on the street.
Thread Starter
Instructor
Joined: Sep 2006
Posts: 233
Likes: 1
Originally Posted by mikejfl
I would also definetely recommend stopping by and chatting with Chris or Robby at "Corvette Masters" in Maitland. They are right behind Rogers Corvettes, between the adult video store and Rogers. I had work done there and had a great experience. Awesome awesome customer service. Nice guys too! www.corvettemasters.com
Thanks, i will check them out along with the adult video store
