Just picked up these sweet Mercury valve covers and I can't get them to not leak. Everyone seems to say that 2.5 lb/ft is the torque spec, so that's what I used...first time I just snugged them up...when that didn't work I took them off again and used another new gasket and I used 30 inch-lbs on a torque wrench. Seemed OK at first but no. Both times I used Gasgacinch to stick them to the valve cover...the driver's side is the only one I did a second time. I was thinking about using a bead of RTV on the head side and letting it dry before putting it on. Not sure on that, though.
Those are sweet!! I always use cork gaskets, with a couple dollops of either ultra black rtv or gorilla snot adhesive on the valve cover side like you did. Not sure on a torque spec but I just treat them like an automatic transmission pan as far as bolt torque. I snug them until you see the cork just start to squish/bulge. If it drools after a couple heat cycles I give it another 1/8 turn. You can try rtv on the head side but in my experience that usually turns into a mess.
I use Permatex#2 on the cast Thunderbird or stamped steel covers then a slight film of grease on the gasket to the head… none ever leak. They are cork. I’m not familiar with the Merc Y-Block cast aluminum, only the bigger 368”. Do they have the extra ridge that helps the gasket stay in place. You need them removable to set rocker arm to valve lash.
Nice covers, I’ve only seen those in the ads. Looks good. I do the same as jimmy six, and it’s pretty much what Ted Eaton does. You can torque the cast covers a little more, they won’t distortion like the sheet metal. Just don’t go so tight you squeeze even a glued gasket out.
About 7 or 8 years ago I bought a pair of Offenhauser valve covers for my Y block and they leaked also. I ended up leveling them up on the mill and taking a cut all the way around at the gasket surface. That fixed it but I know everyone does not have a mill. Careful with tightening them real tight, I was afraid I would crack the boss at the mounting hole. I think on mine they touched in the center but not at the ends if I remember right. I don't think you can make then straight by tightening down.
Thanks for all the advice. Some more detail...I used the Fel Pro cork gaskets and Gasgacinch'd them down to the cover. The oil seems to be coming out on the bottom corners....but that might be just where the oil would settle. I think there is the ridge that Jimmy6 is talking about...not sure. There is a lip all the way around it..but that Gasgacinch was pretty cool (once I read the directions and let it sit for 5 mins). When I took the OLD stamped steel covers off, the cork gaskets were stuck to the head...I don't think they were glued because they peeled right up in one piece. I had the old ones off a couple of times and they never leaked...when I'd put them back on, in the process of snugging them up, they would bottom out and, like I said, never leaked. I'm also running 10W30 which may change to 10W40, but that doesn't explain why they didn't used to leak, and may only "help." I'm a bit worried that they aren't flat. There's an old Bridgeport mill at work and a machinist who comes in every now and then that knows how to use it, and I'm sure he would, if I need that. I bought an inch-pound torque wrench on Amazon and it's not very good so I'll likely send it back...hard to tell what it's set at, which is KIND OF important. Anyway, I THINK I torqued them down to 30 inch-pounds (2.5 lb/ft) and ran around for about an hour yesterday and by the end of the hour is when I started noticing the oil. Today, on the advice of a past thread, I re-torqued the to (I THINK) 30 inch-pounds again and they needed about a turn or two- all 4. I'll see if that helps. I DO want to get a different inch-pound torque wrench just to have a better idea...and I ALMOST used a film of white lithium grease on the engine side when I put the drivers side one back together, but completely forgot! Maybe next time! Incidentally, these covers are made by a gentleman in Australia who goes by the name "Y Bloke." He's probably on here, too. I contacted him late last year about getting a pair and he was in the process of finding a new foundry and polisher...so they just got to me on 7/3. I'm pretty thrilled with the look. I've always adopted the motto "Chrome don't get you home," but when I saw these I fell in love- they're probably the first real aesthetic modification I've paid for (and they weren't cheap!) but I'm hoping I get this figured out.
I’m the 73 year old 150lb weakling. I don’t crank them down hard, but I think 2.5 ft/lbs is way to light. Maybe on stamped steel, but it’s still not much. You do need the grease on the head side and enough torque to get the cork to slightly deform to the head. With the lip and gasgacinch they aren’t going anywhere with a reasonable torque. I know the spec is down around 2.5 but I’m problem using closer to 10 on my cast ones. I’ve seen yblocks covers, but never installed. Nice. I’m running a set of Ace Customs NZ in the Mercury script.
When I had Carpel tunnel surgery I had the doc set my right wrist so it clicks at 5 pounds, the left one at 15. I just have to remember which hand to use for which job. I have found that cast aluminum valve covers can do down pretty snug. Not so much on tin and chinesium chrome. Love the valve covers! Get it hot and cinch em down.
I afixed the cork gasket on mo ohv banger with 5699 Loc***e gasket sealer...it is silicone gasket maker and it fixed the leaks plus it stays in place for the next valve adjustment. It has an aluminum valve cover that fastens thru the center top ends like your Y block...With the aluminum cover you should probably go higher torque than the spec for the stock sheet metal ones..... good luck
Have you made any modifications to the engine to direct more oil up to the rocker arm ***emblies? Are the oil drain-back holes in the heads free and clear? If you're using any sort of RTV sealant have you tried letting it sit overnight to dry before before adding oil or driving the car? If you have a work bench or counter top with a known flat surface, check the gasket surface of the covers for any signs of warpage or twisting. It looks like these attach with studs and acorn nuts. Make sure the studs aren't too long and that the threads in the nuts are deep enough so that nothing is bottoming out and giving you a false torque reading.
I would set the valve covers on a flat surface and make sure they sit flat all the way around. I've had a Y block for 27 years with the cast T-Bird valve covers and no leak. I always use cork gaskets, glue them to the valve cover, and coat them with a light layer of grease. Did the same on the Corvette valve covers on my sprint car.
I heard back from YBloke- the gent who sells them and he suggests 5-6 lb/ft. I'll try that first, then if it still leaks, I'll change the gaskets again and keep playing around. Thanks to all. Fingers crossed.
If you keep having leaks, use the cork with a thin film of RIGHTSTUFF silicone on the cover side and a heavier bead on head side, make sure you clean with acetone or similar, let set for 24 hrs. Regular silicone , gasket cinch doesn't come close to to truly filling voids/gaps like RS, expensive but worth it.
When you have the covers off, use a straight edge on the mounting surface to see how unflat it is. While I don't think you will have a problem at 5-6 ft lbs on the bolts, too much could crack the casting around the bolt holes. I know these covers ain't cheap, I paid about $350 for my Offenhauser covers from Speedway. After I found the problem and fixed it I called them just to ***** a little, they gave me $50 credit.
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