Ls1 346ci SS

Wow, this topis comes exactly on time for my decision on the cam I want on my ARE 382 all bore. I currently have the MMS 224v3 cam 224/224 .566/.566 114. I know that with this cam I can pass emmissions when I move to illinois late this year but I wonder if this cam can help me to run low 11's on motor. the car will be sprayed a bit with a 200 shot. nick recommended either staying with the cam I have or for the nos a 224/236 .556/.572 112 cam but since I have an A4 I don't know if I will pass the emmissions test with the car at idle. I want a cam that will kick butt on motor and really turn things loose with the nos. so I am still thinking.

LS1derfull

LS1346ciSS, to answer your question, 224*/236* on a 112* will not pass Im240 emission test dont kid yourself this cam makes HOTCAM look mild. <img src="gr_images/icons/cool.gif" border="0">

LS1derfull

One of the reasons LS1 likes single pattern cams is the 1.7 rocker ratio.This quickens valve action considerably, great on the intake but not really needed on exhaust to make good power.Cam manufacturers could design less agressive exhaust lobes to work better with 1.7 ratio, but they dont seem to have done this. Thats why extra exh. duration can hurt performance.Also exh. port is the best design GM has ever put in production!
One other point id like to make is choosing cam lift based on max flow lift of headscan be rethought. What i mean is lift that goes beyond heads max flow#'s exposes more of sweet flow area to motor. By passing this point in cam lift you have more actual duration at max head flow lift .
Read this several times to understand, this has to be worth more power. Any one agree dis- agree? <img src="graemlins/camaro.gif" border="0" alt="[Chevrolet]" />

Carlitos

[quote]Originally posted by SuperSport2000:
<strong>I am thinking of doing a solid roller cam conversion. I am going to get ARE stage II heads TandD adjustable rockers and a 620. lift 230. duration 112LSA. I am doing this all on my stock 346cid. I am also replacing lifters and all the other crap. My question to you guys is how much duration you think I should go with?
Thanks
Jasen</strong><hr></blockquote>

Be very careful when using high lift with larger durations. I'm not sure what the limits are, but clearance becomes an issue with high lift + large durations. Make sure you have the springs to get those valves closed when they are supposed to. Just because the clearance issue looks good on paper, doesn't mean you're in the clear. Valve float will cause those valves to stay open way longer than they should just when the piston is approaching.

'Los

Blackbird

here's a twist. how about when you add FI to the equation?

any opinions on that?

DG Gordon

I hear a lot of good things on the 224 cam, however I know a guy that put one in his car and it did pick it up but I could still pull him by over 1/2 a car in the 1/4mile. He had headers gears and a a-4 I had gears and stock manifolds and cats and no cam. I put in a comp. 222-226 w/566-569 @114 and he will now be no contest. I also added headers and no cats. This cam doesnt seem to be an stronger till top of second and then it really goes. I think the splt duration was the cam for me.

WhiteDiamond

This has been a very interesting topic, but I believe several of you are definately on the right track with the real answers. The people who can answer those questions, however, are not here to provide that detail. The trick in the LS1 based motors is the ramp rate. I think we can all talk till we are blue in the face about 218/218 vs 229/229 at .xxx/.xxx lift blah, blah, blah......but that isn't the secret. The LS1/LS6 heads have such awesome flow characteristics below .550" of lift and the base circle of the LS1 cam is larger than other GM V8s, that there is a real possibility the trick is done before the cam profile ever gives you .400" of valve lift. Now, don't get me wrong, running only .400" of lift isn't going to get you very far, but the ramp rates getting through the "low lift" area of the profile are the important issue.

Speed is the issue in the robotics and servo maintenance I do. The trick isn't how far we can move it, but how fast we can "precisly" move it. If you ramp something extremely fast and then slowly bring it to a rest(say peak lift), you can still have excellent control of the valvetrain. I believe this is the trick on the LS1/LS6 motors, based on head flow characteristics. Cam profile gets you nothing, if you can't match it to the heads(been said, I know, but sooooo worth repeating).

With that said, I had the B1 cam in my set up. Tuning makes the difference here, as I still cringe when I see some of these posts this cam isn't everyday driveable. Give the idle a few extra RPM and richen the table a hair...see what your idle is like then!!! Hard to tell from stock! I drove mine everyday, hard! Loved it. I like some of these 224/224 cams, but I have to remain in emissions compliance. The B1 did pass the IM240 test. A 224/224 on 114 degrees may pass, but it will be fairly high in the results(in my opinion).

Todd

Top Fuel

iTrader: (8)

[quote]Originally posted by BLK 98WS6:
<strong>The B1 did pass the IM240 test. A 224/224 on 114 degrees may pass, but it will be fairly high in the results(in my opinion).

Todd</strong><hr></blockquote>

correct me if I'm wrong, but shouldn't you look at advertised duration when considering a cam for passing emissions?

taking the 2 cams that you mentioned for an example:

TR224: 224 duration @.050, 275 duration @.006
B1: 221 duration @.050, 280 duration @.006

shouldn't the TR224 pass easier because of less overall duration?

later,
Steve (I'm definitely no cam expert) <img src="gr_grin.gif" border="0">

Ram Air Tony

iTrader: (2)

we need to get LG in on this....as his G5 cam, thru hooker long tubes, a custom Y and a Yank ST 3200 in my A4 WS6 put out 392 rwhp and 377 rwtq with NO .... let me repeat NO head work.....I did have custom PCM work and it idles at 950, but it is tame until ya mash that bitch !!!!!!!

thanks

Carlitos

[quote]Originally posted by Top Fuel:
<strong>

correct me if I'm wrong, but shouldn't you look at advertised duration when considering a cam for passing emissions?

taking the 2 cams that you mentioned for an example:

TR224: 224 duration @.050, 275 duration @.006
B1: 221 duration @.050, 280 duration @.006

shouldn't the TR224 pass easier because of less overall duration?

later,
Steve (I'm definitely no cam expert) <img src="gr_grin.gif" border="0"> </strong><hr></blockquote>

Not necessarily. The B1 has a 114 LSA. The TR224 with a 114 LSA should be 'cleaner', but with a 112 LSA it may not be. You would really have to compare the overlap areas to be sure.

'Los

WhiteDiamond

I did these cam swaps back in 99. I knew very little about the possible ramp rates and such at that time and based a lot of my cam spec choices off of "old motor knowledge."

Without the cam cards in front of me, I still think a 224/224 on 114 degrees would have more overlap than my B1(also on a 114 degrees seperation) did, but, there is a lot of room for ramp rate to affect the overlap tremedously.

It would be nice if we had a CompCam, or cam company rep, who participated on these boards. They could discuss the ramp rate "technicals" with us as they apply to this motor. I believe that is the trick with power and the LS1/LS6 motor.

RAT: I think we are all very impressed with the results of your "cam only swap", that included everything BUT head work, but those numbers have been achieved with other "cam only swaps" by other cam makers(2 stock head LS1s posted on LS1.com in the 390+rwhp range with no head work). Nothing against LG Motorsports, but they are of no help right now, as their cam specs are "classified." That is pretty rediculous, I am sure MTI would agree with this, as somebody is going to nail the specs and post them on all the boards very soon. Happened to MTI, going to happen to LG.

Todd

[ January 29, 2002: Message edited by: BLK 98WS6 ]</p>

Nine Ball

iTrader: (38)

Todd, there are actually a handful of cars making 390-400 rwhp with stock LS1 heads. I know of at least 3 with 221/221 cams also. And, these cars were not dynoing with open longtube headers like RAT did. Those cars also did not have custom PCM tuning, which is even more amazing to me.

Its all about getting a good combination of parts and tuning, there really is not a "magical" camshaft from what I've seen. Proven cams yes, but nothing that stands out above all the other cams as the "best". Everyone has different requirements when cam-shopping. Some guys need emissions compliance, some guys like less lope, some guys want all-out performance with no drivability.

Tony

Fireball

iTrader: (21)

the problem with RAT's car is that he made big numbers through an A4 with only a cam <img src="gr_eek2.gif" border="0">

ibjamin

iTrader: (6)

OK, I read the previous posts (good information but some of it is past me). <img src="images/icons/confused.gif" border="0"> I'm considering a cam change on my 99 Z28 1LE 6-speed. Looking for suggestions.

I need:

RELIABILITY!!! I don't want to do a lot of messing around.

The car is a daily driver and road race/auto-x car. Don't care about drag racing or getting max peak hp. I don't want to rev it much more then 6200 rpm because a 25 minute session on a road course is hard enough on the car. Power band is more important then peak power. I will use the best springs (918's?) and titanium retainers as well as replace the pushrods.

Stock heads for now and stock manifolds (maybe Mac's in the future). Only other mods would be a lid, and the Borla.

Must pass emmissions (im-240?) Don't really want to reprogram, etc.

I'm guessing something in the B1 range? What is the TR220? Any help would be appreciated.

George E.

WhiteDiamond

[quote]Originally posted by ibjamin:
<strong>OK, I read the previous posts (good information but some of it is past me). <img src="images/icons/confused.gif" border="0"> I'm considering a cam change on my 99 Z28 1LE 6-speed. Looking for suggestions.

I need:

RELIABILITY!!! I don't want to do a lot of messing around.

The car is a daily driver and road race/auto-x car. Don't care about drag racing or getting max peak hp. I don't want to rev it much more then 6200 rpm because a 25 minute session on a road course is hard enough on the car. Power band is more important then peak power. I will use the best springs (918's?) and titanium retainers as well as replace the pushrods.

Stock heads for now and stock manifolds (maybe Mac's in the future). Only other mods would be a lid, and the Borla.

Must pass emmissions (im-240?) Don't really want to reprogram, etc.

I'm guessing something in the B1 range? What is the TR220? Any help would be appreciated.

George E.</strong><hr></blockquote>

George,

My MTI B1 cam set up(heads, MAC headers with 3" collector mod and 3" in/out cats in the y-pipe) passed the IM240 test very nicely. I would go with a "hammer" cam grind next, although I want the lobe seperation custom spec'd up to 114.

As far as tuning is concerned, I think everyone is in for some new information on tuning and any cam/heads changes to the motor. LS1 Edit is now out there and at least one post on LS1.com is showing what I consider to be normal. Adjusting the fuel tables to match the mods will result in much better drivability and mid range power. Steve Cole tuned my set up directly and I have maintained since day 1 that the B1 cam is everyday drivable. I know others have as well, but some people still think even a B1 cam isn't streetable, daily. I would consider "custom tuning" a must for all cam/head mods.

Todd

gfbrown

Greetings to one and all. I am new to this list and find most of the threads have been VERY helpful - this thread in particular.

I have decided on the MMS Stage 2 heads but I can't decide on whether or not to get the MMS 218 or 224 cam (both w/ 114 lsa. My concern is with emissions here in California and idle as my C5 has an A4. It is also my daily driver.

Any thoughts?

Gary

VINCE

iTrader: (1)

Well I had custom tuning when I dyno'd 390rwhp, but I had a full exhaust and no cutout. No shortbelt or anything else.. Now I would like to address gains or losses with changing from the T1 to the Pig Cam? Do I have to worry about piston to valve clearance with a 591lift on stock pistons? I am using stock pushrods as well.. 2.08 x 1.60 valves on 5.3L heads..

Carlitos

[quote]Originally posted by vmoore:
<strong>Well I had custom tuning when I dyno'd 390rwhp, but I had a full exhaust and no cutout. No shortbelt or anything else.. Now I would like to address gains or losses with changing from the T1 to the Pig Cam? Do I have to worry about piston to valve clearance with a 591lift on stock pistons? I am using stock pushrods as well.. 2.08 x 1.60 valves on 5.3L heads..</strong><hr></blockquote>

Kind of depends on the heads/compression. I'm running .581/.588 lift with stock heads/compression. If the heads are milled too much you may have some issues. Basically the same idea with the 5.3L heads.

'Los <img src="graemlins/camaro.gif" border="0" alt="[Chevrolet]" />

LS1derfull

I think Black 98WS6, is right with his focus on ramp rates being decided factor on more less power with ls1. I have played with ramp rate cam changes on my 650+hp 68 Nova, and at that level nothing changed. Cam specs were 288*/292*@.050.
When cam timing(duration) are optimized this is much less important than when a all around performer cam is chosen.Street,emmissions,driveability,combination seems to be much more sensitve to airflow delivery and timing.Unfortunately we all dont have CAM DOCTOR analysis equipment, so we have to rely on info bled out from those who do. BTW i do feel that increasing static compression is fairly nice way of fixing up less than optimum cam choice. <img src="gr_stretch.gif" border="0">

VINCE

iTrader: (1)

My 5.3's were not milled, just cleaned up a little. I know GTP uses this cam with their setups on milled 5.3's..