curvesman

Took off valve cover installed a cometic gasket (with (new to me) load spreaders and STUDS) was not sure how too installed them with the camel hump down which was approx. 2"s from center bolt still leaking .Am I installing these load spreads correct? These are stock sheet metal covers 327 300hp put on a flat surface look even. LEAKED
second try put gasket sealant on the far ends of cover ( let dry over night with clothes pins holding in place) LEAKED
now taking apart again and going to seal the whole gasket to cover( big headache)simple job LOL
Thanks in advance for any input
FIXED ended up taking my time straightening out the cover 100% installed the cometic. gasket with no seal used load spreaders & No leaks.
THANK ALL that chipped in!

Redbird

Buy the thick cork gaskets and make sure your valve covers are flat. Don't over-tighten the bolts.

curvesman

Thanks for your input!!

ChrisBlair

I am a veteran of a hundred valve cover swaps on various GMs and my SBC slapped me hard re: v/c gaskets. I was dumbfounded. Wasn't a leak, the oil went directly onto the garage floor like I poured it there.

The thick cork gaskets were the answer. Never again will I use anything else on an SBC.

Armedanddangerous

Do you use any sealer?

Chalie M

This is what worked for me.

1. remove old gasket material from valve cover/s, take some acetone on a rag clean old valve cover surface use scotchbrite pad go over old gasket surface with pad & wipe down again with acetone, assure all old material is free from surface & it’s back to it’s original surface again.
2. put a bead approx. 1/4” in size around the entire gasket surface using “the right stuff” sealer (follow directions on tube for set-up time) apply CORK gasket onto surface & press it into place with your fingers let it set up some then turn it over onto a flat surface/work table push bolts thru with your fingers just to be sure holes in cover match up to the gasket & let cover/s sit over night with bolts sitting in holes, would help if you could add some light weight on top of covers just to assure the sealer & gasket are making a firm bond.
3. take a small pic & go into each bolt hole in head for valve cover bolts & clean out all old material in there u will be surprised clean the hole with acetone or brake clean you will be surprised of all the old crap in them
4. SMEAR A SLIGHT BIT OF CLEAR SILICONE LUBE ON THE VALVE COVER SURFACE OF THE CYLINDER HEAD then install cover/s, I never use to TORQUED VALVE COVER/S BOLTS BEFORE I ALWAYS USED a 1/4” rachet wrench in my palm with small extension & used the good old hand tight style method.. I NO LONGER USE THAT METHOD I NOW USE A INCH LB. TORQUE WRENCH & TORQUE BOLTS to 20” lbs. START OFF WITH 10LBS GO ALL AROUND THEN UP THE TORQUE TO 20” lbs. I know the 20 Inch lbs. doesn’t sound like much I thought so too:-)..
5. start engine let it get up to temperature shut car off let it cool MUST be cool (best if it sits over night) & go over all the bolts again with the 20” lb. Setting again u may be surprised how loose the bolts are.. after you are done must go back over the covers AGAIN with the 20” lb. these steps are critical.
   ** when I first did this method I only tightened/torqued the bolts down 1 time & had a smalllll leak coming off the starter after days of driving found it was the r/s cover leaking sooo slightly in the rear. I re torqued all the bolts down again to 20” lbs & to my surprise they all needed to be torqued again, I let it sit over night went over all the bolts again they were all perfect at 20” lbs… BONE DRY FOR CLOSE TO A YEAR NOW…

I know some people may think it’s over kill but I’m 65 years old retired auto tech/mgr. but it took my stubborn self to try the these methods So far no leaks or film of anything around bolts or covers bone dry it speaks for itself:-).. ps I haven’t used them spreader bars in years u can if u want no need too (memory serves me correctly they get installed with the tips/ends up)


Bone dry:-)..


regards Chalie

R66

Stamped steel covers require special attention.
1.) check the holes in the cover to assure they are not deformed and counter sunk downward. A hammer and flat surface will straighten them out.
2.) Assure the covers are not twisted / bent and lay flat on a flat surface.
3.) Use the thick cork gasket or a soft neoprene gasket.Some of the neoprene gaskets sold are so hard they will not flex to fit the small discontinuities in the head rail.
3.) I recommend gluing the gasket to the valve cover. I use Permatex II or Indian Head Shellac.
4.) I put a very thin layer of silicone on the gasket surface that will mate the head rail.
5.) Install the covers and "finger tight" all 4 bolts / nuts to assure even tightening.
6.) The final torque on the cover bolts is 55 in. lbs. per the GM Service Manual. I recommend using an inch pound torque wrench and torquing in a minimum of three steps: Finger tight, 25-30 in. lbs. and finally 55 in. lbs. I use an X pattern to tighten them, but I don't know what is correct. Then after the final torque, repeat the 55 in. lbs. torque until no additional movement is obtained.
If you over tighten the bolts, the cork gasket will split at the rail on the head and you will have a leak.
Just $.02 or what ever it is worth.

ChrisBlair

I feel remiss in not mentioning that. Growing up, I assumed everyone used something like permatex gasket sealer. The awful red stuff that makes little stringies that go everywhere. It's what my Pop taught me to use and what I always did and I never had a leak, rebuilds, water pumps, timing covers, t-stat housings you name it....until this time lol. Some people don't use any and swear by it. I can only say that using it works for me, and it's hard for me to argue against my own success

Nowhere Man

I was taught to use Permatex Indian head Shellac

scowser

I've tried all sorts of combinations of gasket and sealer and the only one that works for me every time is Right Stuff and no gasket.

Clean everything, with particular attention to the threaded holes. Thread the bolts into the threaded holes, making sure that you can screw them all the way in without them bottoming out. If you can't do this with your fingers, there's dirt in them there threads and you have to clean them again. If they bottom out, they're too long.

Thread studs into the holes making sure that there is about an inch of stud protruding. Apply a bead of Right Stuff all the way around the contact surface on the valve cover, including a loop around the holes. Immediately install the valve cover using the protruding studs to guide it into exactly position pressing it home lightly. Remove the studs one by one, installing the bolts finger tight. Removing the stud cleans sealer from the hole and allows the bolt to go into the threads without dragging sealer with it. Torque it down gently gently then leave it alone. Next time you drive the vehicle, re-torque after it has cooled down.

Doing it this way, I've never had a valve cover leak and SBC's are prone to leaking.

Factoid

Unfortunately, that method doesn’t work well for those of us with solid lifters requiring periodic adjustment. I use the thick cork gaskets bonded to the valve cover ensuring the VC is completely flat. No issues.

ChrisBlair

Proving there's more than one way to do it 'right' and we need to figure out which is the best 'right' way for what we're doing

scowser

You're correct. My method gives a good seal but makes it difficult to regain access to the lifters.

Whichever method you use, installing studs to guide the cover into place makes things easier.

Re. cork gaskets. Several posts have recommended the cork gaskets. I've never had any luck with them. They seem to work O.K. at first but I find that after they've been torqued down they stay crushed and have no remaining elasticity. After a while mine have always leaked. It seems to me that the gasket needs to have some bounce back so that it stays pushing back against the torque to give a good seal. If they stay crushed and don't push back, it seems to me that this is why they leak.

silver837

In my experience the cork gaskets work best with the SHP aluminum fined valve covers as described by Factoid. With the stamped steel covers , the tendency of over tightening the nuts is
usually the problem as it deforms the covers. The spreaders definitely help.

lib

My torque wrench range is 25-250 IP. Will that 5 IP difference in your recommended 20 IP negate the correct install?- lib

BADBIRDCAGE

That’s the stuff I grew up with also. Great sealer and cheap high.

silver837

Yes I remember it in a glass container with a wire dobber attached to the screw on lid.

59BlueSilver

I did like Chalie in post 6 except after applying the gasket i turned the valve cover over and set on on a glass tabletop, weighted it down, and let it set overnight. That was two years ago…

rad-man

Years ago, my younger self took the easy way out and only replaced the driver’s side gasket (with a rubber one), but I just discovered my passenger side is leaking pretty badly.

my fuel filter has to come off in order to pull that side (not sure if this is normal or not). Anyway, I’m debating using the above method to seal them up, or just throw in a new set of rubber gaskets.… I have aluminum covers.

also, I found quite a bit of debris on each side - should I be concerned or the oil filter will do it’s job and catch anything that gets loose?

Vega$Vette

I use Felpro Blue with no leaks ever. Key on stamped is to make sure they are flat and the holes are not dimpled from over tightening, Which they usually are. Lol