Reckless

iTrader: (9)

Since I created additional inspection ports in my block at the N/S Shootout, I need to assemble a new short block. I am going to go with forged rods and pistons (with valve reliefs) and shoot for about 12.5:1 compression with a stock crank (possibly offset ground). This will be in a iron block bored to 4.030.

I need to get a bigger cam. This will be mostly a race car, with occasional street use, so I want a radical cam That will make big power and tolerate a little bit of nitrous (up to 150). Also need advice on the best valve springs to use.

Which cam?

Which springs?

The heads are going to Jay at Absolute Speed. The #1 intake valve was a casualty, so I am going to have him fix that (current are 2.02/1.57), or upgrade the valves to 2.08/1.60 and install some good springs also.

Do I really need to upgrade valves for this bore size?

Thanks for the help in advance from the greatest tech board around!

Reckless

iTrader: (9)

35+ looks and no opinions?

DaveSchott

iTrader: (5)

Todd, sounds like a 7,000rpm monster in the making! I'd ask your head guy for a comparison of flows for each valve configuration, if he has done allot of heads he should have this on file for a given port configuration.

Without hard data its opinion only, and mine is big valves tend to cause loss of low end torque, but are needed in high rpm motors to move the air given the dimishing time to fill the cylinders at very high rpm. You'll be launching at 6 grand anyway...

JayLS1-327

iTrader: (2)

How about a nice fat solid roller ?
I would try and contact Futral for a cam recommendation.

Reckless

iTrader: (9)

Good idea Jay...Alan is a first rate dude. I would love to go solid roller, but sheesh, the extra parts will kill me!

Dave...how's that car running? OBTW, you got way too techinical for me on that post

Liquidnutz

Todd, dont know if you would like this one or not for your application but a Lunati 237/242 595/595 112 lobe sep. Turns up to around 7400 with ease, at least it does in mine lol. Cam has awesome mid and upper rpm power. Would say use the rev 1116's and some yella terra rockers so you dont run the risk of rocker arm flex at higher rpms. Hope this helps and best of luck on your new setup.

Reckless

iTrader: (9)

Is that the cam you are running? If so, do you have valve reliefs and how much is shaved on your heads? (Compression ratio?)

I just talked with Alan at FMS, he also recommended a 240ish hydro cam. Solid stuff just adds unecessary expense.

ONEBADWS6

iTrader: (22)

I would do a 239/242 XER lobe with .620 lift on a 111. Keep the valves the same size.

Reckless

iTrader: (9)

Thanks! Anyone else?

Pro Stock John

iTrader: (34)

I strongly reccommend looking at the cam and cubes of the motor first, and then ordering the valves and springs. You might need custom length valves.

I think 2.05/1.60's might be fine. You will need new seats. But you might need to machine the spring pockets for new and bigger springs anyhoo.

If you turn the motor over 7000 with a hydraulic I'd definitely talk to one primary source, someone like Alan, to figure out how to safely run the combo.

I have an FMS 230/230//115 in 9:1 FI motor, and it's set up to turn 7400 if we have to. I am running Comp R lifters at .010 preload and Crane springs (from FMS).

T/A Medic

iTrader: (1)

Im running 232/230 .595/.591 114 cam
CompCam 977s and Modified lifters ( http://www.hometown.aol.com/jallensh...ingProduc.html )...

i shift at 7k, and Jay at Abs Spd did my heads.