FNQWK

Thinking of opening the engine and going the forged route. maybe swapping a 4.100" crank in there to up it to 440ci. will this be a noticable increase in hp/tq? or am i wasting my time/money?

J HEBERT

Depends on what u want from the motor. U will gain seat-of-the pants torque, and u will see it on the dyno. If u are looking for even just 15 peak hp u won't find it. U will be impressed at the peak AVERAGE HP and how the torque looks. The cost will be the wall u hit around 6700rpm that tells u to shift 'cause the party is over for that gear. This only matters when u are trying to trap 150+ and all u have is 6800rpm and 3:42 gears. Unlike Ron Jeremy u will come up short. For a N/A street motor the 440-441 is tough to beat. My cranked out 589rw and just over 550ftlbs. I have seen dyno hp#s higher than mine, but I am torque king and would put my combo against ANY 427 rwhp dyno-queen at the track any day. I want to see what the LSXR manifold does for us.

BADZ

My bro's tq king car...


http://forums.corvetteforum.com/c6-z...r-600rwhp.html

jgaches

That's great info right there!!

obzidian

So, and even though its only 300rpm... can you adjust your cam spec to spin it higher or is the stroke/bore configuration doesn't like to be revved that high?

J HEBERT

Piston speed will be high, but it would rev if the intake would flow the #s, but it won't. A Sheet-metal or 4500 type intake would but u loose the streetability.

Frans96ss

We are doing one in a month or so. We are gonna do a 438 cu in that way we keep the same bore b/c its gonna be a nitrous motor. We are hopeing for 625rwhp.

obzidian

That's not with a LS7 block, right? If so, you sleeved it?

Frans96ss

Yes thats stock LS7 block. 4.100 stroke with a 4.125 bore is a 438 cu in. If you do a 4.130 bore its a 440

J HEBERT

Thats going to be a tall order N/A w/ the stock intake, ported or not. Just watch the kpa at the top of your pulls on the 427s, it only gets worse. The LSXR should do better, at least over 600 rear wheel. That's more than any other "trusted" dyno run I have seen. If u don't need the last couple hundred rpms, it's worth doing when u forge the bottom end. IDK what anybody says. There is a limit however, too much stroke on the stock block and u start to run out of cyl. sleeve at the bottom, loosing control of the piston at BDC. On top of that, u can only put the wrist-pin so high (comp. hgt) and then u have to give up rod length to fit the stroke in (so much for 4.250 stroke stock blocks) and then u get a bad rod/stroke ratio. For u people there are tall-deck blocks

obzidian

I would like to do a 4.130" Bore and keep it the stock stroke eventually. I really like the 7K rpm range of the Z06 and think its one of it's favorable traits.

Randy@RaginRacin

I'll take a 454 LSX block with a 300 shot!!!! LETHAL Cam of Course

EdwardETraylorIII

What you want to do is within the realm of reasonability. Most folks see 615 peak RWHP (give or take 5-10 RWHP) with the setup you mention.

However, if there is ever any chance you'll put Nitrous or FI on the car, then keep the stroke where it is. Piston get's too darn small beyond the OEM 4" stroke for FI applications.

Perhaps you should consider forging the bottom end (maintaining OEM stroke), dropping the compression a little and going with some type of power adder - be it N20 or FI...?

J HEBERT

In my case, I used a piston for a 4" stroke w/ a 6.250 rod, then used a 4.125 stroke and a 6.192 rod to keep a healthy piston deck.Build the motor to run N/A and use N20 for the power-adder. I been doin' this for a while, it always works and for me, the LEAST maintenance per mile u can get having mega-power. Filling bottles sucks, but they will idle all day in 100deg heat and not complain, something not all F/I cars can do.

EDS ZO6

I made 603rwhp & 563rwtq with my LS7 440ci on 93 pump gas and its just a street car, 200 shot will be next


http://forums.corvetteforum.com/c5-t...idle-clip.html

J HEBERT

I got u by 1 cubic inch and u got me by 4ftlbs Nice

AtomicZ

Those are some darn impressive numbers. Must be a pretty aggressive cam. How does it idle and is it streetable.

I have a stoked block with a mildly aggressive cam - mainly for road course duty - but I drive it on the street as a daily driver when weather permits.

I am putting down 580rwhp/540rwtq.

EDS ZO6

Yes it is a pretty aggressive CAM shaft. When I started the project with Mike and Ron at Vengeance Racing we pulled out all the stops to make all the power that we could; the only stipulation I had was it had to run on 93 octane gas. I drive it on the street but you definately know you have an aggressive set up.


http://www.youtube.com/watch?v=voJ9sNN7Pnw

AtomicZ

Thanks. Sounds nice and aggressive.

J HEBERT

The big difference in that motor and mine is cathedral-port heads and fast intake on the other motor. And people said those ports were junk when they came out