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J

Jim

Guest
I've got one for ya! I own a 90 that had / has a nosey top end (CLACK!) I replace the lifters-pushronds- guideplates-rockers-springs and had the heads done and also replaced the injecters, STILL nosey! I thought it might be the lifter retainers smacking the block but I've heard other 90's that don't clack and some that do. I do know that it is coming from the valley ( strong clacking from intake area) and the injector sound is different. Any help on this one???
 

c4c5specialist

Technical Advisor
Joined
May 29, 2001
Messages
3,682
Location
New Haven, Ct. USA
Corvette
Nope, but someday.
A few questions??

Wow, sounds like you have been battling this for a while.
Ok, first, when the pushrods and the upper valve train were done, did the noise disappear for a while, and then gradually come back??
Then, has anyone put a vacuum gauge on the engine, as this will tell you if any valves are out of adjustment/ As you should have 19 in of mercury at idle, and the needle should not bounce at all. It should be rock solid.
Next, has anyone checked you distibutor drive gear??
Did you mechanic also check timing chain stretch??
Please answer these questions and we can proceed, as I am suspecting collapsed lifters here, but I would need these answers to proceed.
Best to you, c4c5
 
J

Jim

Guest
No it's been nosey from the get go! and my vacuum is solid around 18 / 19. Checked the distibutor when it was out and it's solid no gear wear or play in the shaft or gear. The timing chain or gears were not checked and by the way I did the work myself and I wasn't into dropping the oil pan. Valves were adjusted to Zero lash and 1 turn, BUT! the Crane golds are strange you can adjust to zero lash and center with your fingers!? I though this was strange! But the car runs great no missing. Talk again in the morning. Thanks Jim
 

c4c5specialist

Technical Advisor
Joined
May 29, 2001
Messages
3,682
Location
New Haven, Ct. USA
Corvette
Nope, but someday.
Ok, the next move will be to confirm that the noise is the lifters or not.
You will need a set of rocker stoppers, and a large hammer. Next, you will have to remove the valve covers. Have a friend start the car, and what you want to do, as the car is idling, push down with the hammer handle on the pushrod side of the rocker arm.
If the noise decreases or goes away, you know you have played out lifters, as you are removing the clearance between the lifter and the pushrod.
Please keep me posted, c4c5
 
J

Jim

Guest
That brings up an interesting point!!!!! as I said I thought the adjustment on the Crane golds was a little strange! with fingers for zero lash and 1 turn to center, BUT! after my valves where adjusted I could push down on the back of the rocker and there was play in the lifter! I didn't think this was right but I didn't want to crank down on them and collapse a lifter. I'll pull a valve cover tonight and see if it's still there. I know my power is down so I bet my valves are't opening enough!
 
J

Jim

Guest
PLAYED OUT, please don't tell me that means bad! these puppies are new!
 

c4c5specialist

Technical Advisor
Joined
May 29, 2001
Messages
3,682
Location
New Haven, Ct. USA
Corvette
Nope, but someday.
HI ,
Did the noise subside after you pushed down on them????
You will be able to push them down a little, however, if the noise was the same, then no, leave them.
If the noise went away, then yes, you will have to either readjust to change the clearance, or you cannot, and you will have to change them.
Let me know, c4c5
 
M

motorman

Guest
are you using both hardened push rod guide plates and rockers with valve stem tip guides? if you are you are trying to line up 3 points.push rod guide plate,the rocker stud and the rocker tip guide. you can not do this and i have found this to be a problem that causes the ticking sound.
 
J

Jim

Guest
when I pulled the valve covers I noticed that all the valves seemed to be closed with #3I and 5E depressed alittle. the rockers were solid no play on the back before starting and it didn't go away with pressure. The main reason I replace the top end was because it was doing this before, all new components and no change, as a matter of fact I think it's a little louder. I'm begining to think its not the valve trian but something else, but sure does sound like a bunch of lifters rattling. The day I bought the car I went over to my brothers ( mechanic 30 years) and he said man that top end is nosey!

Motorman
I'm using nonalineing rockers
 
M

motorman

Guest
oil passage restrictors

make sure no one has put oil gallery restrictors in the back of the block. this will also cause lifter tapping because of lack of oil flow.
 

c4c5specialist

Technical Advisor
Joined
May 29, 2001
Messages
3,682
Location
New Haven, Ct. USA
Corvette
Nope, but someday.
Ok,
So the valvetrain is solid, what type of lifters did you use??
And, you can use a long screwdriver, on the top of the injector, and see if the noise is the same as the ticking that you are hearing.
Best to you, c4c5
 
C

Chick

Guest
geez

I believe you have a piston and or bottom end problem.
I would try dropping one cylinder out at a time and see if the noise changes at all, by removing one spark plug wire at a time.
Give it a try you might be surprised and finally know how to fix your problem.
I've seen people chase what they think are valve noises and they are actually piston noises. It's a mimicking noise.
 
M

motorman

Guest
valve train noise is at 1/2 engine speed and any other noise would be at engine speed.
 
C

Chick

Guest
back to ya

Thats the usual but it doesn't always work out that way!
 
J

Jim

Guest
Chick
I think your right!!!!! Like I said it did this before I installed all the new parts. I'm probably looking at wrist pins or rod bearings I heard both are weak in the L98 and as you said it's a mimick noise coming to the top. I'm going to do the old vacuum tube to the block and oil pan test tonight and I bet it's going to be a little noise down there! Having the heads done has only increased the pressure on the pistons and rods and made it louder. Most likely rod bearing I had zero scuffing on my cylinders. Now if this is the case what to do? in frame or new motor? Some 50wt oil smooth things out until I get the new one bulit. THE WIFE IS GOING TO LOVE THIS!
 
J

Jim

Guest
Motorman
It's loudest at 1500, on the the road it smooth no noise and sweet at 60+ Jim
 
M

motorman

Guest
you do not have rhodes lifters or some other type of bleed down lifters that change the cam duration as these tick like crazy.
 
J

Jim

Guest
No there not rhodes, I had the same thought when I pulled it down that somebody put rhodes in this thing or the lifters are bad, but they were stock rollers and I put the same thing back in. If I remember right I think they are Federals same thing as Comp-Crane and many others market as there own.
 

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