green96ta

Ok ill be using a factory 4 bolt block and a factory crank. Here is the list of components...

Bottom End
Factory Crank
L2256 Forged pistons
Forged i beams
Factory 4 Bolt
ARP Main and Rod Hardware

Top End
1.6 NSA Roller Rockers
Hardened pushrods
Guide Plates
Ported Factory castings (just got CNC ported heads-see below)
CC306- but been leaning a lil more twords custom cam lately
150-200 Nitrous Outlet Plate Kit

I know there is a lot more small stuff i need, but that is the gist of the idea i got goin on. im thinking somewhere in the 390-410 RWHP N/A range and then with the nitrous depending on size of shot in the 550 RWHP range. Hoping to score some mid 10's. I would also love to hear suggestions on shot size too.
Got the heads in today. everything looks great. I cleaned the heads up, and took some pics. they are going to the machine shop tomorrow to get the deck checked and the chambers cc'd. they are gonna clean them up too. I cc'd the intake runners and got 200 cc. so give or take a lil. even though i measured conservatively. Also the heads have been stamped with a JR. CNC ported. 2.00 and 1.56 valves that as you can tell from the pics have been un shrouded.

my1994z28

Im sorry but,its very hard to tell that those have been cnc ported.

camaro69z

those heads will help a lot. I wish I had the money to really port mine but im still in college haha.

green96ta

i REALLY tried to get the track marks in the pics but they just wouldnt show. ill try and snap a few more

Got it in this one...

my1994z28

Did you have them flowed yet?You are going to need a rear end that will hold the hp you are going for.Also need to upgrade the suspension.

green96ta

im still on the fence whether to flow them or not. im an a4 with a 3600 stall. i will use a progressive controller to limit the spray out of the hole. we will see how long the 10 bolt will last. its been built, and suspension will handle this set up

green96ta

It is now official- 62cc chambers and 200cc runners.

Injuneer

Did you calculate your compression ratio, based on the larger than stock chambers?

Why did you pick a stock crank? Has it at least been cleaned up, polished, radiused? I would think with good heads, a big shot of juice, and the 4-bolt block, it would only be logical to opt for a forged crank.

green96ta

Yes i have-with felpro 1074 .039 gaskets ill be looking right at 10.4 to 1- the stock ratio.

The build hasnt went together yet. still making final decisions. Ive actually had pretty positive response on using the stock crank. the crank has 5000 miles on it. it will be cleaned, polished and radiused if i use it. I feel that the stock crank is a whole lot stronger than people give it credit. I just hate to spend 500+ on overkill.

bw_hunter

What are people telling you about the stock crank? With ported heads, the proper compression ratio and good tuning, that CC306 is going to make over 400 rwhp, that's 465-480 at the crank. Add your 150 shot of nitrous and you're well over 600 at the flywheel. That sounds like an awful lot for a stock crank to me.

It's only overkill if it will never break the way it is....

slomarao

Look on the list of the fastest LT1's, theres a guy running a 355 H+C+I+300 shot......On a stock crank......Runnning mid 9's @ 140ish. (not exactly sure but its dam fast)

I wouldnt worry about it. How many times have you heard about one breaking? You hear rod bolt, piston, ringland, etc. Very rare that its a stock crank going.

Injuneer

Its like anything else.... you're shooting craps. The higher the loads on the crank, the more likely its going to fail. When it does fail, the results will be disasterous. Some people like to gamble, others don't.

Guest47904

Don't think the people having the problem are going to knock on your door to tell you they had a failure. You have to pay attention to what's going on around you. There are several that have had a known problem with spun bearings. A simple search would find the pages and pages of them. Including our own Shoebox.

Now load the crank and what do think the chances are that problem is more likely to occur?

Bigbuds1

Here is what my mostly stock motor with 325ish hp did to my stock crank. This happened from missing 3rd gear.
Look at the carnage video.
http://www.youtube.com/watch?v=kyoU1Xc9hQ8