Formula96

What is the largest cam i can put in without having to fly cut the pistons?

mighty mex

iTrader: (3)

if im not mistaken...the 306 cm is the wildest off the shelf cam made for the LT1. anything bigger and wilder would have to be a custom grind.

nspr8td lt1

gm 847 and cc306 are pretty big. im in the process of installing the cc306 myself.

you can get the 847 fairly cheap from jason cromer. i know someone here would have the #.

S8ER95Z

iTrader: (3)

I think its the GM 847. Im not an expert at Cams though...could be wrong.

Formula96

I also will be running nitrous and stock ported heads. Do yall know the exact specs for those cams (lift, duration)?

S8ER95Z

iTrader: (3)

I found this for the 847 (could be wrong..but I think thats correct)
GM 847
234/242 I dont know the LSA for the 847.
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574/595 with 1.6

CC306
230/244 112 LSA
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541/576 lift with 1.6s.

TwoFast4Lv

iTrader: (8)

I have been running the GM 12370847 for a few years no problems. this cam is also readily available from Crane under there number

I have ran it with 1.6 rockers intake and 1.5s Ext with the Imp. gasket

Edit: See what hapens when you drink and post

S8ER95Z

iTrader: (3)

Ah thank god someone knew the number!! You cant find a whole lot of info with just 847. LOL

Formula96

Thanks for the info, i plan on having comp cams custom grind me one.

Sunsceamer

What are the best springs to run on a 847 with stock heads?

SprayedLT1

iTrader: (8)

You sure about the part number? I find it listed under part number 12370847

BizZzatch350

iTrader: (33)

You can go bigger, SAr2Ks cam was a lot bigger than an 306 or 847, these arent LS1s were thats an issue.

-PEPE-

iTrader: (10)

Crane 99893 Springs or their newer set that just came out, will have to get the PN from my book in the car, I'll repost the new PN though, it's just a little beefier spring rate. The 99893's are excellent springs for the 847 and lasted an entire year with 1.7 RRs prior breaking 3 springs and collapsing 1 CompR lifter. I no longer use the 1.7s due to changing out a bunch of junk again they worked good for a year though but the 1.6s are a little less stress on your valvetrain geometry.

Heres the info someone was looking for earlier:

Jason Cromer: 877-726-8295 or 850-243-8826 (direct parts dept ph #)
email: gmparts@samtaylor.com
Sam Taylor Buick/Cadillac Ft. Walton Beach, FL
$209.00
* Crane Cam 109841 grind # HR-296-2S-12 IG (CAM) $209.00 from Jason
* KM# 16214681 $29.95 from Jason - 96 Corvette 5.7 L w/55 LT4 Knock Sensor
* Crane Kit #10308-1 (SPRING KIT) Includes retainers & locks.
* Crane 99893 - Springs alone.

TwoFast4Lv

iTrader: (8)

We have had the BEST luck with K-Motion K-800s on high lift cams like this. The Crane kit started to valve float after only a month and the Comp springs were not happy at all.

Elysian

You're planning on running the GM847, ported heads, !AND! nitrous? You don't plan on doing that with the stock shortblock, do you?

-PEPE-

iTrader: (10)

Good point, better not do more than a 75 wetshot....100 at the most....not even sure I'd do either depending on the miles. They Hypershittypathetic pistons won't hold up.

stik6shift93

Right now I'm running a cms 236/245 115 lsa cam I don't remember exactly but lift is somewhere around .555/.575 and I haven't run into any issues. I have also run through 2 bottles on a 150 shot without any problems. Chevyguy3 off of here ran a 200 shot on a heads cam stock shortblock. I believe he went a best of 10.55 with a 6speed, he also ran that setup for a while without any troubles.

Quickshotkimber

iTrader: (1)

You can go bigger than the 847

Mikey 97Z M6

iTrader: (37)

Ellis,
Which comp springs were you running with it? 986, 987?

Mike

SAR2K

iTrader: (4)

242/252 .594/.612 and had PLENTY of PV clearance with the factory pistons. For the most part LT1/SBC can get away with some pretty aggresive valve timing thanks to the standard reliefs... poor LS1 guys are VERY limited with their true flat tops from the factory.
Remember that the MAIN issue in piston to valve is cam timing not gross lift #'s.
Steve...