How to make a little cam act big
Thread Starter
TECH Senior Member
Joined: Nov 2001
Posts: 10,341
Likes: 1
How to make a little cam act big hey guys,
I have a Q for you
Right now I am running a 230/230 XE-R based cam with zero advance and 112LSA. The car runs great with this cam (11.30@122mph at just under 3400 pounds with the sixspeed)
I have a feeling the car will not pass smog but I am going to try
My question is how could I run a smaller cam and maintain the same intake valve opening and closing points as my current cam WHILE being emissions compliant?
I know I can get a 224/224 114LSA cam to pass emissions no problem in my car. What I would like to figure out is how much I have to retard the cam to get the intake valve closing point the same as my 230/230 112LSA 0 advance cam. (To maximize cylinder filling)
Right now with the 230/230 cam my peak RWHP is right around 6300-6400rpm.
I know patrick G did some testing with a real small cam that had similar valve opening/closing characteristics and timing as the 230/224 cam.
Also if I go with this type of cam I might custom ground it to .600 lift like the 230/230 cam I have now.
cheers,
Chris
I have a Q for you
Right now I am running a 230/230 XE-R based cam with zero advance and 112LSA. The car runs great with this cam (11.30@122mph at just under 3400 pounds with the sixspeed)
I have a feeling the car will not pass smog but I am going to try
My question is how could I run a smaller cam and maintain the same intake valve opening and closing points as my current cam WHILE being emissions compliant?
I know I can get a 224/224 114LSA cam to pass emissions no problem in my car. What I would like to figure out is how much I have to retard the cam to get the intake valve closing point the same as my 230/230 112LSA 0 advance cam. (To maximize cylinder filling)
Right now with the 230/230 cam my peak RWHP is right around 6300-6400rpm.
I know patrick G did some testing with a real small cam that had similar valve opening/closing characteristics and timing as the 230/224 cam.
Also if I go with this type of cam I might custom ground it to .600 lift like the 230/230 cam I have now.
cheers,
Chris
Re: How to make a little cam act big Just move to Tx or Florida and dont worry about it <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
Wish I could help, but still learning the cam spec thing.
Casey
Wish I could help, but still learning the cam spec thing.
Casey
Re: How to make a little cam act big Chris,
You're right-on trying to mimick the intake closing point of your big cam with a smaller cam to maximize your hp. That's what I did with my Thunder Racing Sleeper cam.
Your 230/230 112LSA +0 cam has an intake closing point of 47 degrees ABDC, giving you a power peak of around 6300 rpms. To get the same intake closing point with an emissions compliant cam will get you the following choices:
222/222 114LSA -2
222/222 116LSA +0
224/224 114LSA -1
224/224 113LSA -2
224/224 115LSA +0
All would be good. I like the first one the best. Another goody would be a 220/220 115LSA -2 if you really want to have stealth idle (like my cam) and decent emissions.
You're right-on trying to mimick the intake closing point of your big cam with a smaller cam to maximize your hp. That's what I did with my Thunder Racing Sleeper cam.
Your 230/230 112LSA +0 cam has an intake closing point of 47 degrees ABDC, giving you a power peak of around 6300 rpms. To get the same intake closing point with an emissions compliant cam will get you the following choices:
222/222 114LSA -2
222/222 116LSA +0
224/224 114LSA -1
224/224 113LSA -2
224/224 115LSA +0
All would be good. I like the first one the best. Another goody would be a 220/220 115LSA -2 if you really want to have stealth idle (like my cam) and decent emissions.
__________________
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
Thread Starter
TECH Senior Member
Joined: Nov 2001
Posts: 10,341
Likes: 1
Re: How to make a little cam act big Thanks Patrick that is great info <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
I am thinking the 224/224 114LSA -1 or 222/222 114LSA -2 on XE-R lobes would work the best for me. I am 360 ci so I can swallow a little more cam and still be emissions compliant.
In your opinion how would this affect power after RWHP peak. Would there be a drastic drop off compared to my current 230/230 112LSA cam? Or relatively similar? I dont mind losing 3-4RWHP past 6300rpm if I can remain emissions compliant but much more than that and I wouldnt be happy <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Also what rpm do you think I could get both cams to idle at?
Thanks again,
Chris
I am thinking the 224/224 114LSA -1 or 222/222 114LSA -2 on XE-R lobes would work the best for me. I am 360 ci so I can swallow a little more cam and still be emissions compliant.
In your opinion how would this affect power after RWHP peak. Would there be a drastic drop off compared to my current 230/230 112LSA cam? Or relatively similar? I dont mind losing 3-4RWHP past 6300rpm if I can remain emissions compliant but much more than that and I wouldnt be happy <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Also what rpm do you think I could get both cams to idle at?
Thanks again,
Chris
Re: How to make a little cam act big Chris,
Just because you're 360 cubic inches, remember, a sniffer is looking for the total number of ppm's of what the exhaust pipe expells...you are already at a 14 cubic inch disadvantage to start off with. Just 'cause a bigger cam will idle smoother in a bigger motor doesn't mean it's going to put out less emissions than the same cam in a smaller motor.
That said, I like the 222/222 114 -2 best for emissions compliance and strong power. You will still make peak power at 6300 and it will carry the power strongly to 6600, then be done by 6800. The real key to this is maintaining the intake closing point of 47 degrees ABDC and running a lot of lift with an XE-R lobe. The 222/222 114LSA -2 cam will sound very nice at a 750 rpm idle in your 360, but for emissions compliance, it's better to have a higher idle speed. LS1s that fail the smiffer test always do it on the idle test. Even though a 750 idle would sound the best, raising the idle to 900 would practically ensure a "pass" with the sniffer.
Just because you're 360 cubic inches, remember, a sniffer is looking for the total number of ppm's of what the exhaust pipe expells...you are already at a 14 cubic inch disadvantage to start off with. Just 'cause a bigger cam will idle smoother in a bigger motor doesn't mean it's going to put out less emissions than the same cam in a smaller motor.
That said, I like the 222/222 114 -2 best for emissions compliance and strong power. You will still make peak power at 6300 and it will carry the power strongly to 6600, then be done by 6800. The real key to this is maintaining the intake closing point of 47 degrees ABDC and running a lot of lift with an XE-R lobe. The 222/222 114LSA -2 cam will sound very nice at a 750 rpm idle in your 360, but for emissions compliance, it's better to have a higher idle speed. LS1s that fail the smiffer test always do it on the idle test. Even though a 750 idle would sound the best, raising the idle to 900 would practically ensure a "pass" with the sniffer.
__________________
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
Re: How to make a little cam act big You have a good idea Chris.FWIW,I run a 224-573 113LSA w/NO advance.It sounds stock and makes great power up to 6700.
Cartek uses cams like your talking about all the time.I always thought having some adv helped but lately I'm thinking Cartek was right all along.
Patrick was a real help when I thought about changing cams but he assured me my cam w/NO adv. was the one to run so I left it alone <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
JS
<small>[ November 26, 2002, 09:42 AM: Message edited by: JS ]</small>
Cartek uses cams like your talking about all the time.I always thought having some adv helped but lately I'm thinking Cartek was right all along.
Patrick was a real help when I thought about changing cams but he assured me my cam w/NO adv. was the one to run so I left it alone <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
JS
<small>[ November 26, 2002, 09:42 AM: Message edited by: JS ]</small>
Re: How to make a little cam act big is there any update on the Patrick Old man cam yet? sounds really intersting! also would the OMC pass emissions with the high idle? i am just looking to get rid of the smelly cam of my 230/230.
also i dont really like the buckling and cam surging of the big cam. will the OMC have the same effect or be smooth down low?
also i dont really like the buckling and cam surging of the big cam. will the OMC have the same effect or be smooth down low?
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Re: How to make a little cam act big I have been thinking about some similar issues. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Patrick: How will the power of the cams compare with wide LSA differences? For example your suggestions run from 222/222 116 to 224/224 113. How much will the 3 degrees of LSA effect where each cam makes power and where peak TQ occurs?
Patrick: How will the power of the cams compare with wide LSA differences? For example your suggestions run from 222/222 116 to 224/224 113. How much will the 3 degrees of LSA effect where each cam makes power and where peak TQ occurs?
Re: How to make a little cam act big Joel,
From what I've found, the wider LSA cams (114-116) tend to have flatter torque and hp curves. This means they will be good down low and up high, but may not peak as high as a narrower LSA cam (110-113). Here's what I'm talking about. Take two cams with the same intake closing point and same duration, but widen the LSAs. 222/222 112LSA -1, 222/222 116LSA +3. Look at the rwhp diffrences:
RPM 112LSA 116LSA
2000 145 155
3000 200 205
4000 275 275
4500 325 322
5000 375 370
5500 410 405
6000 425 420
6500 410 412
6800 395 400
The wider LSA cam made less peak power, but more power at the extreme ends of the rpm scale. This wider, flatter torque curve is one of the reasons OEMs use these types of cams. They don't produce the impressive peak numbers of their tighter LSA brethren, but they put down similar AVERAGE numbers under the curve.
From what I've found, the wider LSA cams (114-116) tend to have flatter torque and hp curves. This means they will be good down low and up high, but may not peak as high as a narrower LSA cam (110-113). Here's what I'm talking about. Take two cams with the same intake closing point and same duration, but widen the LSAs. 222/222 112LSA -1, 222/222 116LSA +3. Look at the rwhp diffrences:
RPM 112LSA 116LSA
2000 145 155
3000 200 205
4000 275 275
4500 325 322
5000 375 370
5500 410 405
6000 425 420
6500 410 412
6800 395 400
The wider LSA cam made less peak power, but more power at the extreme ends of the rpm scale. This wider, flatter torque curve is one of the reasons OEMs use these types of cams. They don't produce the impressive peak numbers of their tighter LSA brethren, but they put down similar AVERAGE numbers under the curve.
__________________
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
Thread Starter
TECH Senior Member
Joined: Nov 2001
Posts: 10,341
Likes: 1
Re: How to make a little cam act big Good info Patrick. What I meant by my 360 swallowing a bigger cam is that I can run a lower idle speed while maintaining a smooth idle. (Less misfires and HC readings)
What you are saying is true that the motor itself is at a slight disadvantage from the added displacement.
Cheers,
Chris
That 222/222 114LSA -2 looks like the best choice for me <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
What you are saying is true that the motor itself is at a slight disadvantage from the added displacement.
Cheers,
Chris
That 222/222 114LSA -2 looks like the best choice for me <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Re: How to make a little cam act big can you get these extremely agressive lobes from comp cam? the xe-r even? with durations of 218-222 and .600 lift? wow. not your ordinary cam profile! lol
6600 rpm clutch dump of death Administrator
Joined: Dec 2001
Posts: 4,983
Likes: 13
From: Texas
Re: How to make a little cam act big Patrick
Is that the dyno for your old man cam? I am still waiting to hear some dyno numbers... C'mon hook a brother up... <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
Is that the dyno for your old man cam? I am still waiting to hear some dyno numbers... C'mon hook a brother up... <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
