fbodyracing1

Ok so I bought a 07 z06 with a blown motor and found a ls7 fully built from what the guy told me. Dyno it today it only pull 467 to the wheels on a dyno jet the tuner told me a stock motor tune would be close to making tho numbers and I should be around 500 hp to the wheels but the motor dies at 6200 rpm the dyno graft fall. So this is what done stock exhaust with gutted cats air raid cai 160 deg stat . The motor has Molly fordge pistons, stock rods, ported heads with Stanless steel valves Howard cam 226/232 115 lsa .612/.621 with 1.8 rr and comp cam 918 springs. I look online and found out these 918 springs are not very good and are only good for .600 lift. Would anyone know if my car would get to the 500 hp mark with new spring and rev higher or are the valves holding it back to. Would like to know what springs to get if it would help and any other info I should do would be grate

eaglegoat

We'd need to see a graph, but probably.

Jimbo1367

SS valves is probably contributing to the 6200 valve float. Replace with OEM valves and get a proven cam and springs.

Tuskyz28

Cam specs look like it's meant for a cathedral head instead of a rectangular port head such as the LS7 head you running.

KCS

iTrader: (20)

Did you say stock exhaust, like as in stock exhaust manifolds too?

fbodyracing1

The dyno graft I got hard to see because my wife took them with her phone. Yes it has stock z06 exhaust manifold with gutted cat

fbodyracing1

I'll try and get some better ones soon

fbodyracing1

This is the cam specs

fbodyracing1

What springs should I be looking at that will work with the stainless valves. I call the guy I bought the motor from and he going send me the titanium ones but that means ripping it all apart again lol

Millenium Z06

So basically you have a stock LS7 with forged pistons and no head, intake or exhaust work, I wouldn't think you'd get more than 460-480 rwhp from that. Headers would put you close to 500

fbodyracing1

The heads are supposedly ported and has a cam In it but the power die at 6200 and the tunner said the valves are floating

MyFirstLS1

iTrader: (8)

i'd definitely try new springs, but that cam doesnt seem right

427zm

iTrader: (9)

You can screw Porting LS7 heads pretty easily. Your cam is ever so slightly bigger than stock, and I can tell you headers and PRC ported stockers would wake your motor up tremendously.

fbodyracing1

Ok so the cam doesn't look like it for my motor? Wrong springs and they should t have use stainless steel valves . Grate
What 'prc' ? . I read online that headers weren't worth the money for z06 because the manifolds flow really good

Millenium Z06

Well, you have a few things working against you:
Obviously valve float, whether it be from the springs, heavy valves or both
Cam is not the best selection for the motor
Stock exhaust manifolds
None ported intake

Who did the heads and what was done to them?

427zm

iTrader: (9)

Not sure what you're looking for, but I can tell you from experience with my car your stock heads ported by PRC w/ stock Titanum valves and stainless exhaust valves will perform well. My car when mods started first had the stock heads ported by PRC on their 265 program and a Katech torquer 116 (220/244 116+4) installed w/ stock exhaust manifolds. That put down 525/477. When headers were added power jumped to 554/480, and he torquer 116 provided stock drivability. Great setup.

I have since switched cams, to a 235/251 cam and milled the heads to near 12:1 static compression, and added a ported Fast 102 w/ NW 102 TB. Power is now 583/526 NA, 710/623 on a 100 shot. Driveability is still very very good, with more lope, and obviously more punch.

This should give you an idea of what to expect.

gnx7

iTrader: (28)

That cam is a joke.... if you do install a better cam/springs/headers/ported TB/cold air intake you will pick up easily 60-80rwhp. Ported heads are worth 35-55rwhp, FAST102 intake another 20-25rwhp.

Compression makes power. Run the highest compression you can for the octane fuel you will use.

My LS7 with only the exhaust ports cleaned up on the heads, 243/256 .650" lift cam, headers (nowhere near equal length or as good of quality offered for Vettes), cold air intake, tune for 91/e85 blend made 520rwhp/472rwtq. While I thought the number was low.... it still went 10.30's@138mph in a 2950lbs car (with driver). My motor was built in 2007 before any real CnC programs were available.

fbodyracing1

Well I'm going wate till winter and do some stuff. Going do headers for sure soon I didn't think they made that much difference on a z06 going change the cam. What cam should I go with? I need springs bad what ones should I go with? Do the stanless valve need to be change

DavidBoren

Ls7 valves are huge, and steel is heavy. As far as springs go, controlling those massive valves is going to take some stiff duals, in my opinion.

The cam you have would be a really nice cam for a LS1/6, not at all for your LS7. Something in or around the 235in/245ex duration @ .050" would absolutely give you better results.

Personally, I would use the heads you have now as trade in cores for some heads from someone who you can trust.

KW Baraka

iTrader: (7)

Nothing particularly 'wrong' with your cam. It's smallish for even a stock compression LS7 (OEM cam is flat-out tiny) and the exhaust duration is a bit light. But on the whole.....not the main cause of your issues.

But the valve springs are definitely an issue!! Change them and see if you can rev that puppy clean to 6800 RPMs without a drastic drop off in HP. I recommend the springs linked below....of similar.

http://www.texas-speed.com/p-473-pre...pring-kit.aspx

Also, as some have mentioned, you may want to look for some stock LS7 valves. I saw some (at least, intake valves) posted for sale recently. Ya may want to start there.

If all that fails, some VERIFIED head work and a new cam (along with exhaust upgrades) would be in order.

Best of luck.

KW