Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4??
 

The specs on the CC 07-306-8 are as follows..
Duration: (advertised) 290int., 307exh. and @ .050: 230int., 244exh. Lift: .510int., .540exh. 112deg LS.

1) Since cams of this cut like to rev into orbit, where is your rev limit set at?? - or where do you shift??
2) Have you built your bottom end to take the revs, or will the stock hold up to say 6500??
3) Is a vacuum canister needed?? :D
4) How long between valve spring replacements??

All comment welcome!! - The good/bad/ugly...

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (Admiral)
 

You would need to cut the valve spring pockets for larger diameter dual springs. You may have to use a rev kit as well to prevent lifter collapse at high rpm's. You should see about 6400-7000 RPM's with this cam and the proper spring setup.

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (Admiral)
 

TTT.
All ancillary components (stage II heads, valve train, intake, exhaust,gears,etc.) will be able to handle this CC306. Just wondering if our stock bottem ends will handle the 6500rpms that this cam needs and if anyone has found a vacuum can necessary when going this big??
:)

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (Admiral)
 

Correct me if I am wrong, but I believe that the bottom end of an LT1 tends to come apart at ~6400 RPM.

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (Admiral)
 

That's a lot of cam for a stock displacement LT1. I'm running a CC305 220/230 .544/.544 w/1.6RR and it needs a lot of computer tuning to run good. There's no hiding the fact that I've got a cam. Shift points are 6200 with 6600 rev limit on the stock bottom LT1.
:chevy

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (Knight Ryder)
 

No one ever told me about a 6,400 rpm ceiling on a stock bottom end LT1. Currently my rev limiter is set for 6,700 rpm, a previous programmer (before I got LT1Edit) had the rev limit set at 7,240 rpm!?!? - by accident I have flashed it to the mid 7,000 rpm zone in the burnout box. So far all that should remain inside my engine has done so - but I have gone through a few valve springs.

Thomas

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (Half Fast)
 

I totally agree that the CC306 is a very agressive cam for 350ci. But, I have seen a couple of mean fbodys at the track with this cam running some very impressive et's. Since I will be a 6spd with 4.10's and not concerned with streetability and smog this cam fits my ticket... Plus I would like to have the heads taken down a bit to bump compression to around 11.0:1 or higher if possible. I LOVE big cams and high compression!

I suppose I could take the "try and see" approach with regards to the vacuum cannister, but I like to have my projects planned out before I begin. So, one more time. - Anybody know if a vacuum can will be needed for this cam??? Thanks! :chevy
-Chip

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (Admiral)
 

I ran this same cam in my '93 Trans Am. I was alos using 1.6 roller rockers. As for the valve springs, CompCam and Crane make springs of the same diameter to handle the additional lift. Also, I shaved the heads .015 to increase the compression a little, but you can do the same using the Impala SS head gaskets. As for the bottom end, I never had a problem with it. In fact, I was spraying a 150 shot and ran a best of 11.15 at 124 mph. I think it was over geared and 3.73s would have been better. Oringinally, the car had a M6 in it. Vaccum was not a prob. Later, I swapped to an A4 and sometimes the brake wouldn't hold the car during hard burnouts with 26x11.5x15 ET Streets on 15x10 Welds. FWIW, 114 lobe sepertion would be better. You can order that instead of the 112 lobe seperation if you're interested. Since you have the M6, you should not any porblems even with running the AC. BTW, my best in the TA with 4.10s was 11.91 et at 117 mph.

Good luck.

Rob

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (Admiral)
 

oh yeah, I was shifting at 6500-6800. Ed Wright set the rev. limiter to 7k.

Rob

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (rguy)
 

I run a grind from CC very similar to the 306, but it is a 230/238, .510/.540 (1.52RR), 114. Nice little cam for a 396. Lot of F-body guys run the 306 cam in stock displacement LT1's. I used to run a CC305 cam in the 396 and it was real mild for that many cubes (shift points ~6000). I run it to 6300-6400 shift points with the 230/238 now.

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (Denny McLain)
 

Great info. Thank you all!! :cheers:

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (Vette92)
 

Chris,
I see that you are running a hyd. roller cam again. Why did you switch back from the solid? How's the 230/238 run/idle compared to the solid?
Thanks,
Mike Renfro
Honolulu, Hawaii

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (MJ)
 

The 230/238 idles close to the same as the 240/250 solid roller. Nothing like the 256/264 though. I kept having lifter failure because I was running too high spring pressures for the lifters so instead of changing springs and the cam again, I decided to go back to the hydraulic setup. The power gains were not worth the hassle and the noise.

Re: Anyone running the Comp Cams 07-306-8, or similar BIG cam in your LT1/4?? (Vette92)
 

Thanks for the info Chris.



Mike

i'm putting in a comp 306 and was wondering if i'll need larger injectors. any info on this would be helpful. thanks

I believe you are already aware, but there is a TON of f-body guys running the 306. Some are even using stock heads. No shortage of information if you look in the right place. I have not heard of anyone needing a vacuum canister.

Good luck!

My 383 LT4 ran a custom ground comp cam that was 232/236 @ .050 on a 112 IIRC.I shifted at 6500 regularly.Car was sold so I can't tell you how long it lasted.

:iagree: and this is an old cam, I would think there would be better choices now.

Mine: stock bottom LT1, 6800 limit, 230/230. .6 lift, 106lsa. Runs fine, 135k, no vacuum issues.

It's a great cam with correct gears & compression. my previous 355 with .125 domes 64cc heads making 10.3 you need matching springs. As above they need pockets cut. And stems cut for seals. on a Holley SR 30 lbs Inj lots of timing 3.73 gears. 5 speed. No vacuum issues. It has a galloping idle.

look, I know that stock small blocks have thrown rods, even broken cranks, but the lower end isn't really the rpm limiting factor, it's all that monkey motion up on top.