xfi 292 cam
TECH Regular
Joined: Apr 2007
Posts: 420
Likes: 0
From: Kempner, TX
while i can respect that statment jake.. i will also disagree.. i know what my preferences are for my drivng style and my taste in general.. i love the way the big cams drive.. i've dd cars with solid roller. cars with over .600 lift etc.. i love it. im planning for down the road. i dont wanna rip apart my car again to do the cam and whatnot. i'd rather have a car with a big cam that needs better heads witch i can buy later down the road.
I was offering my opinion based on what you stated in your original post "stock heads".
If you're now going to change heads and that you like an over-cammed engine then that changes things.
Jake
ya i mean i totally can agree with you if i was just to leave it stock and then call it a day but im gonna do supporting mods as the money comes so i figure it can be overcammed for a little.. know what i mean?
TECH Regular
Joined: Apr 2007
Posts: 420
Likes: 0
From: Kempner, TX
With that healthy cam in a 350, there are a few other things to consider:
Vacuum reading so the power brakes continue to work properly
Need for a high stall converter if you're running an auto trans
Rear end gear change to better keep the engine in its new, higher power range
PCM re-programming will be a must.
Maybe someone who's running that (or a similar) cam in a 350 will chime in and share their experience.
Good luck.
Jake
I,m running that cam in my 12.3CR 383 with a well built bottom end. I have stock ported LE2 heads. The 918 springs that I am running are not enough for this cam. Getting ready to change them for a set of Golds. Im seeing valve float just above 6400 rpm so I am a bit limited at the moment. This cam does pull fairly hard. With fair track prep on high 1.50 60' the car will run low 11.50s all day long. I have seen a 11.38 run but it was only once. Extending the rpm range might get me really close to 11.00s. I know a few who have taken this cam into to high 10s NA. It is a good cam but the engine has to be set up for it.
Mec
Mec
There is the thing, this cam needs to see 7000rpms in a 383. I think your hope of dropping more than .3 with a valvespring swap is ambitious at best but uyou will gain something.
The 918s are insufficient because Comp's rpm ranges are so terribly far off. Believe they list this as good to 6200rpms, you are seeing float at 6400rpms and need to rev higher yet.
If you look at that Comp's spring recommendation is OK within their rpm recommendation. So the whole problem is they have a very wrong rpm recommendation, probably because they do not account for what the LT1 manifold does to the powerband.
With a 350/355 and a 7100rpm pcm limit and GOOD heads all you will need for duration is around 230degrees. Weak heads will choke a cam at a lower rpm.
The 918s are insufficient because Comp's rpm ranges are so terribly far off. Believe they list this as good to 6200rpms, you are seeing float at 6400rpms and need to rev higher yet.
If you look at that Comp's spring recommendation is OK within their rpm recommendation. So the whole problem is they have a very wrong rpm recommendation, probably because they do not account for what the LT1 manifold does to the powerband.
With a 350/355 and a 7100rpm pcm limit and GOOD heads all you will need for duration is around 230degrees. Weak heads will choke a cam at a lower rpm.
Mec
When you aren't clear you give the newbs the wrong impression.
You said.
To me it sounded like you though that one change would do it. Thank you for clarifying.
I bares repeating that you have a stroker that needs these rpms and a 350/355 would need to rev higher yet, meaning this cam is a poor choice unless looking to go to aftermarket management and wind it up past the pcm's capabilities.
You said.
Extending the rpm range might get me really close to 11.00s.
I bares repeating that you have a stroker that needs these rpms and a 350/355 would need to rev higher yet, meaning this cam is a poor choice unless looking to go to aftermarket management and wind it up past the pcm's capabilities.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote
My cam with 228 intake duration in a 350 is shifted at 7000 and pulls strong to the 71xx PCM cutoff.
So yes, OP.......that 292 is way too big, plus you need the valvetrain from hell to rev those xfi lobes anywhere near 7000 rpm.
So yes, OP.......that 292 is way too big, plus you need the valvetrain from hell to rev those xfi lobes anywhere near 7000 rpm.
if ur looking for a cam that drives well and makes good power on stock heads, i recommend the ai 226/234. thats what they are going to recommend if you call them. my car made 363rwhp and 356 ft lbs on stock heads with impala ss head gaskets. through a 12 bolt and it had a miss. i drive it everyday and is a very easy cam to drive with. braking was unchanged. and according to my snapon scanner, the map sensor shows more vacuum than stock
im looking at the ai cam. i havent found any clips numbers or anything of the such on it though.. mabey someone can provide that.. also they dont list a cost
Ai 230 / 238 - .575/.575 - 110 LSA Primary Operating Range: 2300-6400rpm
This is our largest stock long-block cam for M6 cars. Excellent for rebuilds with 11:1 compression. Lopey idle, good drivability with gears & tuning, and excellent mid-range with peak power at approximately 6300rpm. Properly tuned w/ supporting modifications, M6's typically produce 350-365rwhp SAE corrected.
Ai 230 / 238 - .575/.575 - 110 LSA Primary Operating Range: 2300-6400rpm
This is our largest stock long-block cam for M6 cars. Excellent for rebuilds with 11:1 compression. Lopey idle, good drivability with gears & tuning, and excellent mid-range with peak power at approximately 6300rpm. Properly tuned w/ supporting modifications, M6's typically produce 350-365rwhp SAE corrected.
Can't wait for gears/tires/re-tune and she'll be a lot more fun to drive. Still working out a few kinks. Idle below, been re-tuned since and idle dropped a bit more and more mileage on motor. Details of motor in video, with 500 miles on new motor I put down 330 rwhp and 350 torque. New dyno numbers in March.
http://www.youtube.com/watch?v=trRIIr4vnb8
