coolchevy

we built a 427 stroker based on an LS3 block but the power is not what was expected, I'd like to hear cam choices to get this as radical as possible as neither idle quality nor drivability is the main concern. It should be able to be driven on street of course but it can have its edges........

here the built list:
-LS3 block with 0.005 cleanup, 11.8:1 CR
-4.1" stroke crank
-ETP 255 CNC heads
-FAST90 intake + 90mm LS2 TB
-cam 114 LSA, 248/256 @ 050, 0.62/0.63 valve lift w/ 1.7 Harland Sharps
-full length headers, VaraRAm with 100mm MAF

tune is spot on but it feels like there could be a lot more.

what would one expect regarding expected output with above combo?

Tom@SpeedInc

iTrader: (5)

what kind of power did it make?

where did power peak at?

havea copy of the dyno graph?

automatic or M6?

coolchevy

have a sheet but on the workshop laptop. On a Mustang like dyno it had 455 rwhp @ 5800 rpm and just 440 rwtorq @ 5300. It is a M6

i was expected 500+ rwhp

bandit1

iTrader: (12)

WOW something dont sound right my LS7 based 427 build up which used a set of stock off the shelf L92s and L76 intake with a mild 238/254 cam and a stock 99 78mm maf made 505 rwhp and since I have changed to the ported LS7 heads adn ported LS7 intake and a mid 240 in high 250 650 lift 110 lobe sep cam and no maf speed density tuned Im making alot more now.

03 BUSA

iTrader: (25)

Tsp 263/270

Wnts2Go10O

iTrader: (12)

is it acting weird? also you hve to remember md's read lower than dj's. if power really is down take a look a the tune.

coolchevy

no acting weird at all, very enjoyable to drive just low power output which does not seem to fit actual performance. Tune is spot on i'd say

99blancoSS

iTrader: (115)

How much more did you dyno?

needadvice

Go to another dyno.

Thats not just low on power, its horribly low. You're 100-160 hp low, depending on who built it.

There's a bunch of head/cam/exhaust C6 Z06's putting down 580-615 RWHP through M6's.

325trooper

iTrader: (2)

I don't think the cam is your problem. I made way way more power with an LS1 427 with ported 6.0 truck heads and slightly smaller (244/250) cam. Put it on a Dynojet and see what it does.

78novacaine

iTrader: (2)

i would think that with a cam that large you would need to spin a lot more than 5800 rpm's to get full power out of it, i mean, stock cam cars with full exhaust peak about that high, but i would think that cam would need a LOT more rpm

KingSS

iTrader: (1)

Do a compression test, I don't think a cam is gonna pick you up 100hp. Are those LS7 etps? If not you might try grabbing some LS7 heads, for the 427's they seem to do pretty well. 455 on mustang dyno would ~500rwhp on a dynojet, I still think that might be a little low for a 427 with an aggressive heads and cam setup, good luck finding the hiccup.

GoFast908Z

iTrader: (12)

any updates on this?

Dutchman427

iTrader: (1)

subscribing...

LS1-NAVY

iTrader: (1)

seems like alot of ls3 427 seem down on power lately

GoFast908Z

iTrader: (12)

I'm trying to figure out that very thing with mine.

UVETTYA

iTrader: (-1)

That's not very encouraging. I'm putting a NA Ls3 427 with an Ed Curtis custom grind CAM, AFR 225's, ported FAST90, 48# injectors in my '04 Z and it should be ready to dyno by mid week. I better get 520+.

Jimbo'sZO6

iTrader: (1)

I bet you'll get damn near 550 Steve,,,,,remember, it's all about the combination of parts, and you got the right cam and heads for the job!

Jimbo

UVETTYA

iTrader: (-1)

Thanks Jim. I hope you're right buddy.

And thanks for relaxing my face.

Jimbo'sZO6

iTrader: (1)

No worries brother! Ed C. knows his *****! Getting the heads and intake ported IS going to make it all work together! You are going to be pleased, especially when you get it to the track!
What oil are you going to use for break-in? I'm still running Rotella in mine and will continue to use it until I hit 5k miles. (at 3300 right now).
Jimbo