IH8FORD

iTrader: (6)

My car is fouling out #3,#7,#8 cylinder and smokes at idle. My engine has less than a 1,000 miles on it and ran a 6.88 @101 on motor and pump gas. So I don't think I have a ring/comp. problem. Its a 408 with ported LS3 heads. I too have replaced the valve seals, sealed the rocker studs, and even cleaned and put RTV under my spring locators just incase oil was weeping into the intake runner through the spring pads. This cleaned the plugs up for a about an hour of driving .and a trip to the track. when i got home the same cylinders were had the plugs wet with oil and its staring to smoke again. My PCV system has a catch can in between the Valve cover into the intake runner with a filter on the opening for the oil fill neck. I,m thinking valve guides my be my issue. one other thing I pulled the intake off and all the cylinders except the three that were wet with oil on the plugs have oil in the cylinders. The #3,#7,#8 cylinders are my problem ones and those runners are clean.

IH8FORD

iTrader: (6)

just pulled the valve spring from the intake valve on #3. New valve seal is torn in half just like before.

IH8FORD

iTrader: (6)

Is it possible I did something wrong when I installed them. I checked the valve guides and I don't think they could be causing the issue. Defiantly not enough to rip the top off the valve seal off twice. Anyone ever seen the keepers on the valve coming down and hitting the valve seal? maybe thats what is happening or a coil bind issue and the spring hitting.

1lejohn

iTrader: (9)

Theres a good chance thats the problem. I've had no problems with my engine. I used stock GM seals. There are two different types

IH8FORD

iTrader: (6)

I have been reading about the installed height of the patriot golds on LS3 heads. I found a thread where a guy checked his spring height and didnt have enough for a .645 lift. My cam is a bit bigger than that. I would assume the machine shop that assembled the heads would have done that but now I not so sure.

Keep the ideas coming.

1lejohn

iTrader: (9)

You should be able to spin it by hand and look and see. Maybe valve float got them? My cam is only in the 620 lift with 250 dur. You Sir have a serious cam in that car. Why all the lift?

IH8FORD

iTrader: (6)

With the dual springs and the rocker at its highest point I cant see through the springs at all to see if the keeper/ retainer is making contact with the valve seal. The cam specs are 247/259 .656”/.663” 112LSA +6 advance
Comp Cams LSK/LSK lobes. Its a nitrous cam for a 300 shot and a single plane intake. I got the cam speced by pat G in 07 so alot has been learned since then on these heads so I could probably use a new cam. But Even with the 3600 nitrous converter and a 3450 race weight the car ran a 6.82 in the 1/8 at 102 on 93 octane so decent #'s for a nitrous set up on motor. I'll give the cam a chance on the nitrous and see how it does before I go with a change.

litle88

iTrader: (20)

I think that cam is eating up those springs. I would switch to those new comp 926's or those PRC springs good for .700 lift and make sure your spring pressures are good as well as installed height

http://www.texas-speed.com/p-477-pre...pring-kit.aspx
http://www.texas-speed.com/p-457-com...pring-kit.aspx

The comps are good for up to .700 according to many sponsors here.

IH8FORD

iTrader: (6)

Do you think they could be letting the retainer or keepers hit the valve seal.

second_2_none

iTrader: (6)

Thats what I'm starting to think. I'm not sure about the rest of it, but I do think the springs are some of your problem....But on the other hand, if your springs aren't rated for the lift wouldn't that cause you to float a valve and in turn make piston to valve contact? What are your current springs rated for?

IH8FORD

iTrader: (6)

The springs I have now are rated for .650 lift. Got them with the cam kit. maybe a spring swap will make me some more power as well.

CAMSTER

iTrader: (10)

I believe your probably have not checked your retainer to seal clearance, at fully open valve position, remember clearances get tighter as temps rises.
You should have a healthy 100 thous there. you could save having to remove heads by getting a different retainer, i found Mast performance have some of the must compact I've seen.
I don't think your problem is due to float, cause when valves floats, they usually stay at part open and not much open aether, unless the springs are completely dead.

IH8FORD

iTrader: (6)

good deal I had a friend text me a tell me the same thing he ran into it on a Vortech SBC motor he was working on. Needed to know where to get some keepers though I'll check out mast. My springs probably don't have 800-1000 miles of run time on them I don't think they are worn out. I do believe that my spring not being at the correct installed height are causing a coil bind issuse which is causing valve float.