racerseks

Just got through with a bunch of stuff, including repainting my valve covers, and putting in new gaskets, as they were leaking.

I got Fel-Pro Perma-Dry, and after starting it up for the first time in a few months, I have a leak on the passenger side. I checked the valve cover with a straight edge before putting it back on. Didn't notice any gouges on any of the surfaces. Didn't use gasket cement as per the instructions. Didn't go very tight at first...tightened a bit after discovering the leak, but it's still there. Any tips/suggestions? Guessing I'll have to yank it off there again, but man I hate messing with that EGR pipe...and inspect it. Other than checking the surfaces for gouges and straightness, and inspecting the gasket, what should I look for?

Thanks!

Cliff Harris

Do you have an early '86 with cast iron heads? I do, and I have found that the valve covers don't seal very well at the location of the valve cover studs.

racerseks

Yup, I sure do! If I remember correctly, yours is same era, bought new...right?

Yea, when I was cleaning it up it had goop on the studs. Any solution? Have a new set of perma-drys to pick up tomorrow. Other than that, I might try different valve covers...

Thanks!

oldguy'sc4

In my youth, I and friends owned early Z28's and we regularly checked valve lash. One good set of gaskets would last for years and never leak as often as we had the stock covers on and off. But darned if I could get my 85 to stop leaking, and as you all know, changing out the gaskets is a pain. I got disgusted after the 2nd set of gaskets failed to hold and installed a set of solid aluminum aftermarket covers as an experiment. No more leaks so far.

Dt86

Which valve covers did you go with? I think mine are the culprit as well. After three tries with three different gasket types they just won't seal.

Joe C

(my 2-cents, FWIW) -- this is one area where you don't want to take shortcuts or skimp on the quality. first of all, early iron head VC surfaces are not machined for gaskets. felpro does offer a set that seem to overcome the short comings of the cylinderhead/VC mating surface issues. fel-pro 1628 are .250 thick (blue) silicone rubber - ribbed on the upper and lower surfaces. as the old saying goes, ribbed for your pleasure, and your pleasure will be not having to screw around with these things anymore. because of the gasket thickness, you may have to go with slightly longer studs. moroso has the perfect replacements (PN 97020). the gaskets are steel cores that limit over-torque, and there is no need for any additional sealing goop. torque to 50 lb,in. make sure both surfaces are in good condition without surface flaws and squeaky clean. bring the torque up slowly - say 15, 30, and 50 inch pounds increments, criss-cross pattern and with a torque wrench. double check after a day or two with several heat cycles. do not be tempted to over-torque the hardware. give it a try. good luck.

racerseks

Thanks...I went with the best ones I could find locally...They're Fel-Pro Perma Dry. They were about $30, but I did get a good discount on them. They came with spreaders, which of course could not be utilized. Do these differ a lot from the 1628's you mention? They got pretty good reviews consistently, so I went with them.

I must admit, I went "by feel". Only used a 1/4" ratchet and just got them snug. Bone dry on the driver's side. I gave into temptation and did tighten a bit more...didn't go nuts, but still leaks on that side. Bought another set of the same. Think I should try 'em?

Thanks!

Joe C

can't comment on the perma-dry gaskets - no experience. spreaders are usually used with (stamped) steel VC's. the thick mounting flange of the magnesium covers should be sufficient to spread the load, so you're correct - not needed. i'm not sure how they differ from the 1628's which BTW are around $50, but I do know the 1628's work. as for the "by feel" thing, all I can say, is inch pounds are hard to feel, and even harder to feel evenly across the four VC nuts. remember, part of the reason for torque values is to even out the clamping force of the hardware. IMO, this is one area where you have to be **** and do it by the book.

as the old saying, it doesn't cost any more to go first class, ya just can't go as far...

Cliff Harris

I had leaks in the areas of the valve cover bolts. I put some RTV in that area to seal it and that seems to have fixed the leaks. I also put RTV on the valve cover studs to keep oil from traveling up the studs. Ignore the sludge -- I had a head gasket leak.



If you're using the Perma-Dry gaskets, make sure they are oriented correctly:

VikingTrad3r

i realize im in the minority (a singularity? haha) here but cork with hylomar is what i have used on an 85 iron and 87 aluminum. i can take it apart and reinstall because of hylomar and it seals better than anything because of hylomar.

i tried the plastic/rubber ones but i think are garbage.

racerseks

Thanks for clearing that up. Hoping to give this a shot tomorrow afternoon. Going to go by the book on it...don't want to have to do it again...thanks!

racerseks

Thanks...I might try a very small amount in that area as well...

racerseks

I saw some really thick cork ones today...got me thinking that might work good if my warp is small. Just might have a little more "give"...but planning to try new valve covers first. I'm just kinda mad at those things now, LoL...so much time, and with all the materials, I spent about as much trying to hang onto 'em...I say "adios"...unless I have clearance issues. Thanks!

81c3

can't comment on the perma-dry gaskets - no experience. spreaders are usually used with (stamped) steel VC's. the thick mounting flange of the magnesium covers should be sufficient to spread the load, so you're correct - not needed. i'm not sure how they differ from the 1628's which BTW are around $50, but I do know the 1628's work.


So is the general consensus for the cure on this? I want to try to do this on the first attempt.... Ive never had issues with V/C gaskets on any other SBC.... why is the Vette so different? Is it the covers cast imperfectly?

Joe C

I think the issue with the iron head L98 (and the L83) is the mating flange on the VC. it is designed for a bead of RTV and not a gasket. some care should be taken to clean the factory painted, textured, finish of the VC flange prior to using a gasket. using a gasket with the VC flange as pictured, would be hit or miss at best...



i'm not sure if it's the "general" consensus, but the fel-pro 1628, longer studs, and torqued to spec, DID work for me. I did take extra care to prep the VC flange for use with a gasket. others have had success with cork, rubber, RTV, or whatever, and some not. as I said, because the repair is such a PITA, this is one area where one shouldn't skimp or take short-cuts. **** and by the book are in order here.

edit: one thing I might add here is prior to the VC/gasket thing, I bead blasted the factory magnesium VC's for refinishing, including the gasket flange. that VC flange surface was relatively smooth and free from any paint or texture prior to assembly.

Cliff Harris

I used to use neoprene valve cover gaskets back in the '70s or '80s (been too long to zero in on the exact time period). Those things NEVER leaked. Can't find them any more.

The problem I've had with cork gaskets is that the oil seeps through the cork and leaks...

Joe C

i'm thinking "Proform (Valve Cover) Gaskets are marketed as neoprene. I would think with the vast market for SBC's, they are still available somewhere - ???

still convinced the VC flange is the weak link in the chain. not the flange itself, but the factory finish on that flange. (carefully) cleaning the surface down to bare metal should solve most problems.

81c3

I picked up the Perma Dry gaskets today at my local NAPA. I was wondering if the car came with studs on all 8 positions, or were just the top (closest to the intake manifold) studs and the bottoms ones bolts? Mine are like this... it doesn't look stock.... am I right?

The EGR band clamp is pretty loose on mine. I can spin it a bit in either direction.... looks like I can remove the two torx bolts and just turn it out of the way....??

Im going to bring the studs to my NAPA store and see if they can match them up with a little longer set.

racerseks

I'm waiting on my valve covers to come in on Friday. Hoping to get this done too. I have perma-drys as well, so we'll have two opinions on those before long.

Is your car an early '86? That's what mine is, and it has studs on top and bottom. That's stock, from what I've compared. "Cliff" has an early '86 as well, and pretty sure his are studs top and bottom too. I would say maybe you stumbled onto the cure, but I assume you're here since yours are leaking too, so I guess not...

My EGR tube was like that. I was so happy I didn't have to take it off, but be careful with it. Mine eventually came loose after too much movement. Then you'll spend your time finding out what an "Oitiker" clamp is...not a lot of fun. Good luck!

81c3

yes, mines an iron head early 86 as well.... and yea, its leaking and has been from the looks of it. The gaskets came with the longer load spreaders... has anyone used those as well?