valve train noise with valve cover spacers

JohnM · #1 (**permalink**) 05-02-2003, 08:33 PM

Hello All,

This is an interesting one that I need help with. I have a newly built 351W with cast iron heads from power Heads. I nstalled roller rockers, the engine has been fired and broken in for the past year no problems. I installed the "tall" valve covers that are supposed to cover the rollers. I had to clearance the baffle inside the cover by pretty much pushing it up tight against the top of the cover...again no problem. Engine started, ran great etc. The only thing I noticed was that it took FOREVER to pour oil into the engine because the baffle was just about closed for clearancing.

Well, just because it took so long to add oil..... I purchased the spacers for the covers, 1" tall, installed them, no problems worked great....except when I fired up the engine I now have valve train ...lifter clackety clack.

My question is why now? Were the tight valve covers insulating the sound ???Is that possible? Or is it a luberication thing because the bottom of the valve covers are so high?

I will re-adjust the rockers...but just wondering if any one ran into this.

As always any info would be most helpful

John

KobraKarl · #2 (**permalink**) 05-02-2003, 08:42 PM

have you pulled them back off to have a look? is the sound coming from both sides?

Kk

JohnM · #3 (**permalink**) 05-03-2003, 06:02 AM

Hello Karl,

Yep, took off the valve covers and checked to make sure nothing is rubbing, everything is fine. I was thinking of taking off the spacers and reinstalling the valve covers after again closing down the baffles....just to hear it.

If after doing that, and if the noise quiets down what does that mean?

John

Ron61 · #4 (**permalink**) 05-03-2003, 06:33 AM

John,

I have roller rockers and Felpro makes a laminated extra thick valve cover gasket thet works great with the regular Cobra valve covers. I never even had to mess with the baffels and I have been running these gaskets since 1997. Once in a while I will pull a valve cover and check inside and never a mark. I also got the 1" spacers but they made the covers sit to high and I never put them on. They did have 1/2 inch spacers at Cobra Restorers a year or so ago but I never bothered to get any as the gaskets work great. As for noise, I really can't tell you if the spacers would cause that or not. If you would like to try the Felpro route let me know and I will get the number for you. I always keep an extra set in the garage just in case I should get an oil leak around one of the covers.

Ron

JohnM · #5 (**permalink**) 05-03-2003, 12:12 PM

Hello Ron,

I sent you an direct E-mail

Thanks

John

Thorin · #6 (**permalink**) 05-03-2003, 02:48 PM

Ron61

Please you post the part number for the Felpro laminated, extra thick valve cover gasket?

Thanks

Dave Lowell

Rick Parker · #7 (**permalink**) 05-03-2003, 03:34 PM

The Fel Pro # in question is #1645. 5/16" Thick Cork-Lam cork- rubber with steel core. They are fairly rigid and are not intended for use with sheet metal valve covers unless they are absolutely flat. The additional height is an added benefit.

I have previously used the 1"spacers described above. The locating holes for the valve cover bolts can effect how the spacers fit on a given head, some of the patterns are not very accurately done. The area of the rocker arm that contacts the spacer or cast aluminum covers in some cases is the area near the pushrod cup on the lower side of the rocker arm, not the top as you might think, or on the inner edge of the valve cover gasket sealing surface. Look at the area on the "End" of the rocker arm near the pushrod cup. When I used the spacers I had to relieve the area adjacent to each rocker arm about the width of the rocker arm. I used a sharp carbide 1/2" diameter cutter in a Makita. Spray the cutter with WD-40 or put wax on it so the aluminum doesn't build up.

Mark the area in question with a felt pen (after cleaning off with carb cleaner etc) install, run for a minute or two then pull the cover and look for an area where the ink is rubbed off by the rocker arm. Relieve as required.

Some of the later aftermarket head castings have the gasket rails raised to avoid the need for these aluminum spacers. It was good thinking on the design engineers part.

Rick

Ron61 · #8 (**permalink**) 05-03-2003, 04:13 PM

Rick,

I see you beat me to the part number. I had e-mailed it to John and you are correct about the valve covers having to be flat. I do know one person who took two of those gaskets and glued them together to get more clearance and he has never had a drop of oil come out. I have had really good luck as I have never had a drop leak through them and mine have been on since 1997. I have the trick flow aluminum heads and I think they may have helped me a little as my rollers just barely touched the baffel with regular gaskets. Also Cobra Restorers used to have 1/2 inch spacers but I don't know if they still carry them. I had a set of the 1 inch ones around here somewhere that I never used and if I can find them and anyone wants them they are welcom to them. I don't have a 7500 RPM motor either and that may helpme as mine rarely sees above 6400. How is the car coming along ?

Ron

JohnM · #9 (**permalink**) 05-04-2003, 07:23 PM

Rick,

Took them apart today and did the magic marker thing, put them back together and went for a drive. After cooling took it apart no rubb offs were found all of the ink was still intact.

Some friends say I am too noise sensative......probably true as this is my first build and I only have 60 miles on the car. I just got my title and plates on friday.

Anyway I will have someone who nows what they are listening to....listen .....and go from there.

Thanks all for your help and sugestions

John

Rick Parker · #10 (**permalink**) 05-04-2003, 11:21 PM

John:
If you are running solid lifter cam, be sure valve lash is correct. Even at that it will be noisier that a hydraulic lifter cam. At least you have eliminated the possibility of rubbing between the rockers and the covers.
Get a stethiscope or put a long screwdriver on the head, intake manifold and other various areas while engine is running with the other end to your ear. You can hear a lot this way. If you hear something abnormal check it out. They will never be as quiet as a current domestic V8.

Good luck
Rick