Most roller rockers are a bit noisy. You may have them adjusted a little on the loose side.

 

I followed the specs by getting them to seat then torquing to the correct spec and ensuring no more than 3/4 rotation of the bolt head for each one. (I ensured the cam lobe was out of the picture for each valve). Should I retorque to a higher setting?

 

What kind of aluminum valve covers? Some have clearance for roller rockers, some don't. The ones that don't are designed to be low to clear the intake on EFI motors. You're running the carb, right? If so, you can run any tall valve cover.

Just for peace of mind, you might pull the covers, wipe them down, and examine the inside for any evidence of interference from the rockers. If that is it, new valve covers (taller) might solve the problem.

Also, if you do find evidence of interference, examine the rockers closely to make sure they are undamaged.

Hope this helps.

AJ

 

Do you have pedestal mount or stud mount rockers?

 

Sounds to me like you went with the Crane "Cobra" 1.7 roller rockers. If so, these are pedestal mount style that are the same as the ones Ford put on the 93 Mustang Cobras.

I had a set of these and they were pretty noisy. some of the noise appeared to be attributed to the rocker body moving side to side on the roller trunion assembly. There's some clearance inbetween the rocker body and the clips on the sides of the roller trunion assembly and they tend to slide from side to side and "slap" the clips when the engine is running.

Do not add more lifter preload. Not only will it not help the noise go away, but it will cost you power and could potentially cause damage.

Just make sure your lifter preload is not excessive, and that the rocker body is as straight as possible when you torque them down on the pedestals.

Other than that, make sure you don't have one of the rocker arms whacking the inside of the valve covers at the support bosses in sides of the cover, or at the top of the cover near the oil fill baffle. You need to remove the baffle plate and grind down the bosses in stock and some aftermarket valve covers with most roller rockers.

 

Gordon, these are pedestal mount on a 1988 5.0 roller cam motor. AJ, I have tall rocker covers from Edelbrock. Definitely no interference.

 

Pedastal mount...so you're using 'standard' (non-hardened) pushrods with no guideplates?

 

The motor is mainly stock. I changed the heads to ported, changed the cam to the F303 and put on the roller rockers. The guide plates are in place. Push rods were not changed.

 

Your noise is from when the valve job was done on the heads. The stem heights have to be pretty much right on or you will get valve noise. With pedestal mount rockers you can use shims to space the rocker if they are to tight, but if they are to loose, there is really nothing you can do about it except live with it.
One thing that you can do is get a longer push rod, say .030. Then use a shim kit to get them adjusted just right.

 

Guide plates? Are you sure you are running guide plates, or are you talking about the channels that the pedestals sit in?

You do not run guide plates with pedestal mount rockers. If you really did bolt guide plates under those rockers, your valvetrain geometry is going to be wrong, and your rockers are mounted too high.

I don't think you would be able to get enough preload with stock pushrods if you really did this.

Also make sure if you are running the Crane "Cobra" or vacuum formed, Cast aluminum rocker arms, the rocker bodies are pretty thick at the roller tip. Some valve and retainer setups have shorter valve stem tips and the rocker body may actually contact the top of the retainers. This is bad, unkay....ask me how I know.

 

If you can determine if there is enough preload or not will be helpful. If there's not, longer pushrods could help, as mentioned earlier. Depending on the measurements and the amount of add'l preload you need (assuming that's the problem)a competent machine shop may be able to shorten the pedistals by grinding some off the flat bottom surface. This has the same effect as longer push rods, as long as the amount of material that needs to be removed isn't excessive.
Good Luck
Hhssss

 

I had the same issue used a sightly longer push rod and shims. I did just as Gordon suggested - he actually told me what to do! .

If you pull the valve covers and check each push rod for it to be loose - clearance between the tip of the rocker and the valve. There should be none - zero lash. I bet you have a little as Gordon said, after your valve job.

I finally switched to Seeda adjustable roller rockers that are mounted in pairs, and are adjustable for valve clearance.

Took care of valve jobs clearance problems. BUT if you want a set of .030 push rods send me an email and I'll send them off to you.

 

i have the cobra 1.7s in my car. i would not say they are noisy. i would check for clearance with the valve covers. good luck.

james

 

I'll pull the rocker covers and check the lash. I'm 100% sure the rockers make no contact with the covers.

 

Wurf nailed it. Don't run guideplates with stock pushrods. Using pedastal rockers, you must use stock (or non-hardened aftermarket) pushrods with no guideplates.

 

I agree...no guide plates...also , for $6 at the local flea market , (or Harbor Freight) , you can buy a mechanic's stethoscope....If you touch the tip to the rocker covers , you will hear if the rockers are hitting the covers without pulling them.

 

Had the same problem, ordered rockers from Summit and was told I would need guide plates and hardened pushrods that were slightly longer. Well the car ran great but the valve train was noisy, turned out since I was using pedestal rockers no guideplates were needed. Went back to standard length pushrods after removing the guideplates, ran great, no more noise.
mannyjoe

 

Hey Steve....stop using terms no one understands
"roller trunion assembly." What the "L" is that?

[ April 13, 2004, 08:06 PM: Message edited by: Knight ]

 

Please correct me if I am wrong but when I did my pedestal mount roller rockers I did not go 1/2-3/4 turn after "0" lash but instead torqued each rocker to FMS specs which I believe were 17-21 lbs. If 21 lbs did not work I was advised to use shims but it worked fine at 19lbs. When I did my stud mounts I went 1/2-3/4 turns after "0" lash.
Should 2savage use the torque method with pedestal mounts ?

 

Jam,
good catch! I believe he mixed up the torque procedure with the 2 types of rockers. I have the full roller billet pedestal 1.7 rockers that I bought from Saleen years ago but never used until I built the Cobra. When I rebuilt the engine with new Edelbrock heads and internals, I bought standard length "hardened" pushrods. I know they are not necessary without the guideplates, but the price wasn't that much more than standard, so I figured they couldn't hurt. My thinking was that they would be more resistant to bending. For what it's worth, I bought the shim set "just in case" but never needed them. I thought I had a lash problem, but it was just that the roller lifters didn't have oil in them, so they weren't pumped up - doh! The valve train runs very quiet, at least compared to my exhaust!

Brian

 

Actually I used a combination of both. The instructions for the rockers said to turn the bolt of the pedestal to zero lash then torque to 20 lbs. The bolt should turn 1/2 a turn, but no more than 3/4 turn. If I was outside of these specs I should get longer rods or use shims, depending on which way I was out.

As it turns out all of them torqued within specs.

 

2Savage it sounds to me like you did it correctly, that is unless you bolted guide plates under your rockers. We're still waiting to hear whether you did that or not.

 

All I put there is those channel plates that were under the stock items. I thought that was called a guide plate but I guess not.

 

Originally posted by Wurf:
Also make sure if you are running the Crane "Cobra" or vacuum formed, Cast aluminum rocker arms, the rocker bodies are pretty thick at the roller tip. Some valve and retainer setups have shorter valve stem tips and the rocker body may actually contact the top of the retainers. This is bad, unkay....ask me how I know.

This happened to me. I thought that the noise was normal for roller rockers. The edge of the rocker arm was actually pushing down on the spring retainer before the roller tip contacted the valve stem. This caused the little retainers to rub themselves smooth and I dropped a valve. I replaced the Crane roller rockers with FMS and had no further interference. It is worth checking. You will be able to see the rub marks on the top of the spring retainer.

My roller rockers are not noisy.

 

That would seem logical to me if I didn't know better. Guide plates guide the pedestals on the rocker pads, makes sense to me.

It sounds to me like you did everything right on the installation.

Did you have the heads decked or surfaced? Did you get a valve job on the heads? Did you have the block decked?

If you were able to torque the rockers to spec within a half turn with stock length pushrods in the motor, I think you have limited options at this point.

My personal experience has been these rockers are just plain noisy. I have Omega rockers on the same heads that I ran those Cobra rockers, and they are much quieter. There is still some noise when the oil heats up, but it's not like it used to be.

You might check the wear pattern on your valve tips to make sure your rocker geometry is correct.

Get the motor to TDC, remove the #1 intake rocker, clean the top of the valve stem with alcohol, and use a permanent marker to make it all one color. Blue or black works well. Bolt the rocker back down and torque to spec. Turn the motor over by hand a few rotations, remove the rocker again, and check to see if the wear pattern is centered in the middle of the valve stem.

If not, you need to consider longer pushrods and shims to correct it. If you leave it with bad geometry, you'll likely have accelerated valve guide wear.

Good luck

Steve