Knock....? (With video)
Thread Starter
Teching In
Joined: Jul 2013
Posts: 4
Likes: 0
Knock....? (With video) http://www.youtube.com/watch?v=wuD5F...ature=youtu.be
I was idling at 750 RPM in the video.
It is there all the time, cold or warm. It increases speed with RPMs but doesn't change pitch or get louder. Sounds loudest when listening from under the engine. I've listened to the motor all over with a screwdriver to my ear but I can't seem to isolate it. I set lifter preload again but no change.
I'm just wondering if this is recognizable to any of you...
Info on motor;
'98 Vortec block and heads, stock rockers, untouched heads, stock rods, new stock replacement crank
This cam: http://www.summitracing.com/parts/cc...make/chevrolet
These pistons: http://www.summitracing.com/parts/sl...make/chevrolet
These valve springs: http://www.summitracing.com/parts/crn-10309-1 (Made to provide retainer to guide clearance for vortec heads up to.550" lift)
Thanks a bunch.
I was idling at 750 RPM in the video.
It is there all the time, cold or warm. It increases speed with RPMs but doesn't change pitch or get louder. Sounds loudest when listening from under the engine. I've listened to the motor all over with a screwdriver to my ear but I can't seem to isolate it. I set lifter preload again but no change.
I'm just wondering if this is recognizable to any of you...
Info on motor;
'98 Vortec block and heads, stock rockers, untouched heads, stock rods, new stock replacement crank
This cam: http://www.summitracing.com/parts/cc...make/chevrolet
These pistons: http://www.summitracing.com/parts/sl...make/chevrolet
These valve springs: http://www.summitracing.com/parts/crn-10309-1 (Made to provide retainer to guide clearance for vortec heads up to.550" lift)
Thanks a bunch.
Last edited by SBCWes; Sep 19, 2013 at 08:16 AM.
A few questions.
1. You used that cam and its a retro fit cam yet you have a 98 vortec block which is a factory roller block which uses a step nose cam. So you threw a cam button in the front and a wear plate?
2. You used those crane springs and they have and I.D. of .870, I've read where the guide boss is .860 that's .10 to play with. That is kinda tight. That might be some of the noise you are hearing.
The old beehives for LS1's do the same thing for vortecs and have a better I.D.
3. Your piston link doesn't work.
1. You used that cam and its a retro fit cam yet you have a 98 vortec block which is a factory roller block which uses a step nose cam. So you threw a cam button in the front and a wear plate?
2. You used those crane springs and they have and I.D. of .870, I've read where the guide boss is .860 that's .10 to play with. That is kinda tight. That might be some of the noise you are hearing.
The old beehives for LS1's do the same thing for vortecs and have a better I.D.
3. Your piston link doesn't work.
Teching In
Joined: Jun 2013
Posts: 48
Likes: 1
From: Louisiana
If you know anyone with a tech 2 you use the special function and cancel out the cylinders and the noise will change once you cancel the bad one. At least you will know what cylinder to go after! Or I have had cracked flywheels make the same tick or tap noise! That's coming from a techs point of view
Thread Starter
Teching In
Joined: Jul 2013
Posts: 4
Likes: 0
A few questions.
1. You used that cam and its a retro fit cam yet you have a 98 vortec block which is a factory roller block which uses a step nose cam. So you threw a cam button in the front and a wear plate?
2. You used those crane springs and they have and I.D. of .870, I've read where the guide boss is .860 that's .10 to play with. That is kinda tight. That might be some of the noise you are hearing.
The old beehives for LS1's do the same thing for vortecs and have a better I.D.
3. Your piston link doesn't work.
1. You used that cam and its a retro fit cam yet you have a 98 vortec block which is a factory roller block which uses a step nose cam. So you threw a cam button in the front and a wear plate?
2. You used those crane springs and they have and I.D. of .870, I've read where the guide boss is .860 that's .10 to play with. That is kinda tight. That might be some of the noise you are hearing.
The old beehives for LS1's do the same thing for vortecs and have a better I.D.
3. Your piston link doesn't work.
2. Interesting point.
3. Link fixed
The noise has not become much louder/more noticeable over the course of 2000 miles. Maybe a lifter that bleeds off too much or pumps up too slowly?
@fastcoonass I will try to isolate it to a cylinder as you mentioned.
