HELP, installed heads and new cam, knocking like hell!!
HELP, installed heads and new cam, knocking like hell!! I got the car all done tonight and I started it up and it makes a LOT of noise, a knocking noise around the intake area. I checked the lifter preload to the best of my knowledge, it seemed the 7.35 pushrods that I put in were too short, so I took them out and put the 7.4's in, restarted it and it still made the noise. Maybe I am not checking it right, maybe I need a shorter pushrod than the 7.35, what do you think it could be? The car idles fine, revs fine, but just knocks LIKE HELL!!! I'm bummed!
Here's a list of what the car has on it now....
PRC Stage 3 5.3l heads with 2.055/1.60 valves, not milled, just a deck clean
Cometic .040 gaskets
Comp OE 850 lifters
7.35 pushrods/7.4 pushrods in now
Custom Ed Curtis cam 236/240 .630/.608 on 113lsa (he said it would clear without flycutting, I told him what I had and wanted)
LS6 intake
QTP 1 7/8's headers
ANY idea what I should try next, I don't feel like taking the heads off, I don't think it's hitting (PTV), when I took the 7.35 pushrods out none were bent or anything.
It's just weird how it idles great and revs FAST! Just SOOOOO ******* loud!!! Please help!
Here's a list of what the car has on it now....
PRC Stage 3 5.3l heads with 2.055/1.60 valves, not milled, just a deck clean
Cometic .040 gaskets
Comp OE 850 lifters
7.35 pushrods/7.4 pushrods in now
Custom Ed Curtis cam 236/240 .630/.608 on 113lsa (he said it would clear without flycutting, I told him what I had and wanted)
LS6 intake
QTP 1 7/8's headers
ANY idea what I should try next, I don't feel like taking the heads off, I don't think it's hitting (PTV), when I took the 7.35 pushrods out none were bent or anything.
It's just weird how it idles great and revs FAST! Just SOOOOO ******* loud!!! Please help!
It is very possible that you're getting a collision with the valves/pistons. I'm looking for a cam with my heads that have 2.055/1.57 valves and for what I've found out thus far, the largest cam i can go with is no where near the size that you're running and you're even worse off because you have less clearance with the 5.3l heads. I would highly recommend that you take a head off and see what the valves/pistons look like....HIGHLY RECOMMEND, before you do anymore reving/starting of the engine. It would be a world of **** if this is happening... Best of luck to you!! Let me know if it has fit, or if something bad is going down in there.
Peace,
Adrian
Peace,
Adrian
Originally Posted by Orange Peel
I got the car all done tonight and I started it up and it makes a LOT of noise, a knocking noise around the intake area. I checked the lifter preload to the best of my knowledge, it seemed the 7.35 pushrods that I put in were too short, so I took them out and put the 7.4's in, restarted it and it still made the noise. Maybe I am not checking it right, maybe I need a shorter pushrod than the 7.35, what do you think it could be? The car idles fine, revs fine, but just knocks LIKE HELL!!! I'm bummed!
Here's a list of what the car has on it now....
PRC Stage 3 5.3l heads with 2.055/1.60 valves, not milled, just a deck clean
Cometic .040 gaskets
Comp OE 850 lifters
7.35 pushrods/7.4 pushrods in now
Custom Ed Curtis cam 236/240 .630/.608 on 113lsa (he said it would clear without flycutting, I told him what I had and wanted)
LS6 intake
QTP 1 7/8's headers
ANY idea what I should try next, I don't feel like taking the heads off, I don't think it's hitting (PTV), when I took the 7.35 pushrods out none were bent or anything.
It's just weird how it idles great and revs FAST! Just SOOOOO ******* loud!!! Please help!
Here's a list of what the car has on it now....
PRC Stage 3 5.3l heads with 2.055/1.60 valves, not milled, just a deck clean
Cometic .040 gaskets
Comp OE 850 lifters
7.35 pushrods/7.4 pushrods in now
Custom Ed Curtis cam 236/240 .630/.608 on 113lsa (he said it would clear without flycutting, I told him what I had and wanted)
LS6 intake
QTP 1 7/8's headers
ANY idea what I should try next, I don't feel like taking the heads off, I don't think it's hitting (PTV), when I took the 7.35 pushrods out none were bent or anything.
It's just weird how it idles great and revs FAST! Just SOOOOO ******* loud!!! Please help!
The pushrods are not bent cause they are hardened pushrods. they are harder than the valves, so the valves are the ones that are bent.
I just ordered the new AFR 225 small bore heads milled to 63cc. When I ordered them, he told me to be ABSOLUTELY certain that I fly cut the pistons because they wouldn't clear with the lift on my cam (.598). I'd be a little pissed at the guy you ordered it from if he told you you wouldn't need to fly cut with a cam with that much lift.
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yes, as ALL the others have said, youve probably got 8 bent intake valves. Sorry man, I dont know what Ed was thinking but thats a monsterous cam to run even on stock heads and stock sized gasket.
Banned
Joined: Aug 2005
Posts: 154
Likes: 0
From: ohio
You probably do have bent valves. We do not recommend anything larger than .228 @.050 with our 5.3 head with a 2.02 valve. One thing to be aware of which Ed may not is the 5.3 valve seat is about .030 closer to the deck of the head than a 5.7 which automaticllay gives you .030 less clearance before any milling. You will have to pull the heads replace your intake valves and flycut your pistons.
HMM...you've got a decent sized problem. All of your pistons are going to be banged up, plus the valves. I wouldn't run it anymore and risk a valve breaking and you needing a new engine.
Are you SURE it's idleing great and revving fast? 
If so... somthin's up.
Everytime I've done a cam swap I'll get the lifter/valve noise until it builds full oil pressure that's loud and "can" sound like knock(even when spinning the motor w/out fuel/spark to build pressure). How long did you run the motor?
Agree w/the above posts..... unless you got a much smaller cam than ordered....or the flycut fairy made a visit you've got some trashed parts in your motor.
Pull a head and have a look.....
If so... somthin's up.
Everytime I've done a cam swap I'll get the lifter/valve noise until it builds full oil pressure that's loud and "can" sound like knock(even when spinning the motor w/out fuel/spark to build pressure). How long did you run the motor?
Agree w/the above posts..... unless you got a much smaller cam than ordered....or the flycut fairy made a visit you've got some trashed parts in your motor.
Pull a head and have a look.....
Originally Posted by PREDATOR-Z
Just another victim of "dot to dot", I do not degree my cam.
Sorry, but what can I say, it is not ED's fault.
Sorry, but what can I say, it is not ED's fault.
Teching In
Joined: Dec 2003
Posts: 47
Likes: 0
From: Texas
Agree with everyone else and the damage is already done to the valves and may have scored the piston. Its a bead deal but your gonna have to pull the heads. Post some pictures when they are off. Like everyone has said do not run the car anymore!!!!!!!
Goodluck!
Goodluck!
Originally Posted by PREDATOR-Z
Just another victim of "dot to dot", I do not degree my cam.
Sorry, but what can I say, it is not ED's fault.
Sorry, but what can I say, it is not ED's fault.
Well I have ALL my emails telling him I had the above parts listed, I DID NOT WANT to flycut, and I asked if I can dot to dot, and he said with a good timing set which I have. I turned it over SEVERAL times by hand and heard nothing, felt nothing, so I took his word. I don't know how to degree cams in, I KNOW it was dot to dot, I checked it a million times, this is my 3rd cam swap, no issues before.
I will pull a head and see what it looks like, definitely sucks. He said he has done a bigger cam than this and it cleared fine.
And I'm POSITIVE it idles PERFECT and reved EXCELLENT, just makes noise, it didn't stall, backfire, stumble, NOTHING, even on decel off the rev, just knocks.
I will pull a head and see what it looks like, definitely sucks. He said he has done a bigger cam than this and it cleared fine.
And I'm POSITIVE it idles PERFECT and reved EXCELLENT, just makes noise, it didn't stall, backfire, stumble, NOTHING, even on decel off the rev, just knocks.