transam1577

ok so ive had this build done for over 2 years now and have not had time to figure out wats wrong...but im ready to start racing it so its Time) lol but it a
5k mile lt1 350
cc503
le2 heads
comp r lifters
crane daul valve springs
1.6 pro mag S/A rockers
hardened push rods
le2 ported intake
42lb injectors
lt headers
full exhaust
and a 150 shot!!! if i can figure out what the prob is first!!lol

the AFR is perfect!! mail order pcmforless...
but the car stops making power at 5200rpm???
i will post the dyno graph ASAP
i am lost i dont know what could cause this???
it only puts down like 320rwhp and 345rwtq...throu a 6 speed?? any thoughts guys

myltwon

iTrader: (1)

maybe the springs are worn out causing valve float?

my stock heads cc503 car was still making power at 6400rpm, I imagine with some well ported heads it should peak somewhere around there as well

320rwhp is very low but then again you're likely leaving 1000rpm worth of power on the table. my stalled auto stock heads car made 325rwhp unlocked you should easily be in the 360 or so range with stock or near stock compression

transam1577

it has been doing this since day one!! i bought the spring kit brand new...but i put the car on the dyno 500 miles after breakin so do you think its posssible i got a bad batch??

TravisMcGill2000

iTrader: (2)

wat bout pushrod length.

transam1577

they are stock length... but ive never checked it..everyone that has my setup uses the stock lenth to as far as i know..

gregrob

iTrader: (8)

You need to check it. Who is "everyone" is that everyone on the internet, or did lloyd tell you to use stock length?

joelster

1. Could be an ignition issue or an opti- issue. The dyno graph would show it getting erratic at higher rpm.

2. Don't assume that the mail order tune has perfect AFR unless you plugged in an o2 sensor during the dyno run. It should be around 12.8 to 13.0-1 at WOT. If it is richer than that it won't make good power. They are usually a touch rich to be on the safe side.

3. What fuel pump?

4. Why 42lb injectors? Did you tell pcmforless that you are running 42lbers? You don't need them at that power level.

5. Put a fuel pressure guage on the car and do a nice pull, if it fluctuates AT ALL you have a fuel delivery problem.

6. How tight did you tighten the rockers? COMP R lifters are VERY SPECIFIC the way that you tighten them. THIS IS CRITICAL AND I CANNOT STRESS IT ENOUGH!!!!!!!. You adjust so that there is zero lash by the spin the pushrod method, AND THEN YOU TIGHTEN THEM NO MORE THAN 1/12th OF A TURN, not a half turn, not a quarter turn, not 3/4 of a turn, JUST A TEENSY TINY AMOUNT!!!. Basically you put the wrench on the rocker, tighten it until there is no lash, and then move the wrench from a 12 o'clock position to a 1 o'clock position, THAT'S IT!!!!!

sdm1234

iTrader: (8)

That's wierd to hear that the AFR is perfect but it's losing top-end power. Have you had your knock module de-sensitized or anything like that?

transam1577

well theses arent loydes heads!! they are mine i p&p heads and these are the same flow numbers as le2 heads.. so its just easier to say le2 cause everyone knows them!!lol anyways
its its stock compression
i just replaced every ignition part thinking that may be the prob...all ac delco!!
and i work at a performance shop so i have the luxury of the dynojet) and the afr is perfect all the way across!! i used the wideband..
and if it was loosing fuel pressure the car would go supper lean up top!!
so it is a stock fuel pump with 180k miles but ive ruled it out for that reason..lol
Now i did ajust the rockers to a 1/4 turn past zero!!! will that make that bigg of a def.?? cause i know i should be upwards 380hp!!lol and i only have the 42lbs cause im going to spray it!! 150 shot) witch should put me at about 600rwhp 600rwtq) so i think i might need them...

ss.slp.ls1

iTrader: (36)

Well the springs shouldn't be an issue. I have the same springs with the same cam and I pull wayyy past 5200 rpm.

It's strange that you have a perfect A/F ratio all the way through and yet you still lose power. I was eager to jump on an ignition or fuel problem.

I don't want this to come across wrong, but did you ever consider your portwork being the problem?

Any chance the clutch is slipping?

buzz12586

iTrader: (17)

"LE2 heads" and "I ported my own heads, but they flow like LE2 heads" are completely different.

transam1577

haha if i didnt have a sf-600 flowbench to check them.. then i would!! lol they are good the heads flow almost identical to Le2 heads all the way throu.. they flow 277cfm

stevema10631

unless the Le2 heads were decked alot the stock length pushrods should be very close for that cam. I agree on springs check for coil binding (shinny spots on coils that look like they rub) then you know either ur rockers are to tight or your rods are to long. just a thought

transam1577

thanks man ill check that btw how does you car run? 1/4 time n/a and on thr 150 shot?

SonicZRO

dont mean to hijack the thread but i am running the same cam and springs and summit 1.6 RR's and felpro gaskets on stock style heads, but the heads were milled ten thousands, and i dont have the money nor the time to order the push rod checker. so what size push rods do you think i need? thanks.

gregrob

iTrader: (8)

Wow...

SonicZRO

thanks for the help....

buzz12586

iTrader: (17)

The only way to really know is to get a push rod checker and measure them. I know thats not what you want to hear but thats the correct answer.

stevema10631

my car runs good i took it to the track with a cam exhaust ect... it ran a 12.99 with the untouched heads and a stock stall no spray stock tune. i am waiting for my performabuilt unit now to see what it will run with a 4k stall. overall though its a good cam i think you will like

buzz12586

iTrader: (17)

My car went 12.23 @ 111 with the cc503, stock heads, 3200 converter. You should be able to go high 11's easy with ported heads. I am also going to a 4000 converter soon and I hope it will go high 11's cam only.