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Billionth Leaking Valve Cover Question
Posted by: wittsend ()
Date: November 15, 2022 12:27PM

As I have done through out my engine assemble I researched for hours trying to glean as much as I can each step of the way. Thus when it came to my valve covers I made sure the edges were straight, smooth and true. I ran a straight edge over the 'head to valve' cover surface and did not detect anything that was a cause for concern. I even dry fit the covers to the head (no gasket) looking for any rocking and distortion and found none.

The cork/rubber gaskets I used were not thin. Probably typical of what is sold today (they came from Rafee). I put a light, thin coat of silicone on both surfaces and brought the bolts to a "snug" condition. There was no deformation of the cover. A check showed that there was full gasket contact with no shifting or bulging in or out. The next day I ever so lightly tightened the bolts. This was reported as a successful method by a number of people on the Forum. I used this method on the oil pan and have absolutely no leaks there.

The car then sat (engine yet to be started) about 3 months. Yesterday I filled the crankcase/filter with 5 Qt's of oil. Shortly thereafter I noticed that the front lower corners of both valve covers were dripping oil (the engine has a 1" forward rake over 24" as the car sits on jackstands). I would say in a 16 hour period each side has dripped about 3 tablespoons.

Three times now I have slightly tightened the bolts. However it is getting to the point that the cover is starting to distort (see circled area). One thing of note is that the center of the clamp (hole) is still off the surface of the valve cover about 1/8"-1/16" (see arrow). I read one post that stated that the portion of the clamp that the bolt goes through should touch the valve cover. If I tightened it that much it would severely distort the valve cover!

So, I'm at a loss as to what more I can do??? I followed general advice that had worked for others (and like I said, it worked fine on the oil pan). Any thoughts?

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Re: Billionth Leaking Valve Cover Question
Posted by: RobertC ()
Date: November 15, 2022 12:43PM

Never seen that. And, obviously, the valve cover should not be dented.

Think your valve cover "clamps" are bent / distorted. I would throw (all of) them away.

And, find some better ones? California Corvair? Corvair Ranch? Club member?

FWIW To add another "version" to the "thousands" that are out there.

NEVER used silicone (same for oil pan)...

"Glued" the valve cover gasket to the valve cover using 3M 77 spray adhesive (clothes pins to hold gasket in place).

Put cover on head - nothing on the surface touching the head.

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Re: Billionth Leaking Valve Cover Question
Posted by: RobertC ()
Date: November 15, 2022 12:54PM

Should add - use "GM" / rubber valve cover gasket.

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Re: Billionth Leaking Valve Cover Question
Posted by: jamesolefjensen ()
Date: November 15, 2022 12:59PM

I run the cover screws down until the center of the bar is touching the cover but not much more (maybe a 1/16th of a turn).

I have never seen a cover flange deform like in your pictures. Is the bar hanging over the edge of the cover flange?

James
65 Corsa
SF Bay Area

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Re: Billionth Leaking Valve Cover Question
Posted by: RobertC ()
Date: November 15, 2022 03:15PM

Thought I had a couple for a pic, but I cannot find them.

Yours in pic looks "bowed out".

The bar between the two ends should be straight.

The metal is come kind of "spring" material - easily bends when tightened.

I use 1/4" drive. I tighten them so that the bar does not touch the valve cover.

Surprised you have not stripped the hole.

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Re: Billionth Leaking Valve Cover Question
Posted by: RobertC ()
Date: November 15, 2022 04:06PM

Just noticed another issue in your pic:

Looks like the rim / corner of your valve cover is sitting on top of the head gasket surface.

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Re: Billionth Leaking Valve Cover Question
Posted by: aircooledairhead ()
Date: November 15, 2022 05:33PM

Agree with RobertC.

The whole valve cover edge (lip) should surround the head surface, not sit on it. If the thin edge is sitting on the head surface, the thin outer lip will distort when tightened down, which is what it appears has happened in the circled area in your right hand photo. The correct fit is like a shoebox lid (the valve cover) on a shoebox (the cylinder head).

If that has happened you can try to straighten things out or take the easier route of picking up a good set of valve covers. This would definitely cause a significant leak.

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Re: Billionth Leaking Valve Cover Question
Posted by: jjohnsonjo ()
Date: November 15, 2022 05:52PM

I'm not there to see it close up, but Corvair heads can distort an unbelievable amount. I would pull the valve cover and find something big enough to cover the entire surface and known to be flat such as plate glass or mirror. Then you can see how untrue the surface might be.

J.O.

65 Corsa Turbo Vert
79 Honda XL 500S
69 Honda CL 160 D
2010 BMW F 650 GS
2003 Bounder 36D
2013 KIA Optima SX turbo-AKA ZIPPY (wife,s car)
69 Newport Holiday Sailboat
Baja 150 dune buggy cart
Coleman HS 500 UTV
2016 KIA Sorento SXL Turbo

Bethlehem,Pa


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Re: Billionth Leaking Valve Cover Question
Posted by: wittsend ()
Date: November 15, 2022 06:13PM

The valve cover does clear. The picture gets distorted.

I THINK those were the clamps that were on the car when I got it (28 years ago). The (basket case) car has sat all that time until the recent rebuild. The only pictures I have are shadowed by the torn rubber seals for the side tins. There is a small possibility that the clamps weren't on the car at all and there were just bolts (in 1961 did they use clamps?). They are one of the few parts I didn't paint so maybe I got them elsewhere??? The project dragging out three plus years and my mid 60's brain makes my memory cloudy at times. Regardless, I have other sets of clamps and will try them. The existing just seem very thick and as noted "bowed".

The other cars I've owned never used the clamps so I was unsure exactly how they should look but logically something seemed off with the bolt area not contacting the valve cover and just filling the crankcase with oil reveled that. I'm glad I didn't clamp them down any tighter. I'll try a different set and see what happens.

------------------------------------------------------------------------------

***'61 Lakewood, a "Freebie" in hibernation for 27 years - In the process of applying CPR.***

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Re: Billionth Leaking Valve Cover Question
Posted by: wittsend ()
Date: November 16, 2022 02:02PM

Update:
The "other" valve cover clamps I had were only five and frankly not as good as the ones on the car already. So, I removed each clamp individually (starting where the leaks were) and modified them on the belt sander. I basically sanded them until there was about a hair of gap at the center bolt hole. When I reinstalled the first two where the leaks were - the leaks stopped. So, I proceeded with the other six. Frankly the way the unmodified clamps contact the cover seems rather small and liable to indent it. When I finished modifying mine the contact area as about 3/8"-1/2" wide and that seems more effective to preventing deformation.

Regarding the section of the valve cover that looked like it might be hitting the head, there was seemingly a razor blade of clearance. So, to be safe I used a thin Dremel cut off disk and slightly notched the head to be sure there was clearance. The head seemed to have a minor casting bulge near that corner.

I'll know better this weekend when (hopefully) I start the engine for the first time and hot oil is slinging about. But at least right now it looks encouraging.

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Re: Billionth Leaking Valve Cover Question
Posted by: irfgt ()
Date: November 16, 2022 04:20PM

I only use the rubber gaskets and no sealer of any kind. Use factory spreaders and tighten them until the center is just touching and a resistance is felt on the wrench.

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Re: Billionth Leaking Valve Cover Question
Posted by: Layton Curtis ()
Date: November 17, 2022 04:40AM

Your problem could be that you are using the thin early valve covers. In my IMHO that is not possible using the late model covers,the bolts will strip out before the covers will ever look like that.

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Re: Billionth Leaking Valve Cover Question
Posted by: isucorvair ()
Date: November 18, 2022 06:17AM

wittsend Wrote:
I removed each clamp individually (starting where the leaks were) and modified them on the belt sander. I basically sanded them until there was about a hair of gap at the center bolt hole.

Why are you sanding the clamps down, effectively reducing their clamping pressure? I use whatever gaskets are laying around (rubber, cork, rubbery cork, silicone), and zero glue / silicone, etc on them, clean flat head surface, straight valve cover, and tighten until the center of the clamp just touches the aluminum. No leaks - lots of engines done this way.

Looking closely at the aluminum edge of the head that I can see - it looks like it has some dents / gouges that may extend into the gasket surface?


Eric P.
DeWitt, IA

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Re: Billionth Leaking Valve Cover Question
Posted by: wittsend ()
Date: November 18, 2022 09:40AM

"Why are you sanding the clamps down, effectively reducing their clamping pressure?"

- Because those clamps had zero deflection that I could see. Whether they had the roughly built in 1/8" (.125) gap at the center or .010 gap at the center the clamping force would have been the same because there was virtually no deflection in the clamp.

- Because the rounded outer edge of the clamp had about 1/16" contact with the valve cover. The narrow contact point was like 'a knife through butter' (so to speak) in terms of the easy with which the cover lip would indent. Spreading that contact point out over roughly 1/2" prevented the indentation and generated a force that stopped the leaking. The proof is, the leaks stopped when I did what I did.

I seem to have "Life Dyslexia" (a made up term) in that whatever seems to work for others, doesn't work for me. You don't know the times I have followed procedures to a "T" and had things not work out. Then an "Expert" becomes involved (thinking the situation is easily correctable) and shortly thereafter there is an audible "Hummmm...," and they too are perplexed. This handicap thankfully is often worked around by using unconventional means my brain conjures up. But I'm often left with the difficulty of getting others to accept that I needed to do what I did - and that it worked.

Perhaps in this case it was very stiff clamps and as someone mentioned, early thin covers (I didn't know the early covers were thin) that was causing the problem. In any case the remedy work.

------------------------------------------------------------------------------

***'61 Lakewood, a "Freebie" in hibernation for 27 years - In the process of applying CPR.***

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Re: Billionth Leaking Valve Cover Question
Posted by: aircooledairhead ()
Date: November 18, 2022 10:32AM

There are too many variables in working on 50-60 year old cars that there is one perfect solution that works in every case. The group on here is very helpful and often comes up with a solution. Many of us have been in a position where something unorthodox solved a problem.

My solution was gobs of Permatex #2 and the rubber gaskets. I went to this after trying the cork gaskets which leaked. It worked. A few years later I had to do a reseal and had a horrible time getting the covers off.

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Re: Billionth Leaking Valve Cover Question
Posted by: Frank DuVal ()
Date: November 18, 2022 05:59PM

Quote
wittsend
Whether they had the roughly built in 1/8" (.125) gap at the center or .010 gap at the center the clamping force would have been the same because there was virtually no deflection in the clamp.

That makes no sense from a vector force diagram. The 1/4" bolt being closer to the head by .115" has to apply more force through the spreader.

In almost 50 years I have never had to sand spreaders. I've never had them dent the valve cover either. Must be the very early six hole valve covers that were used with tiny triangular spreaders? If so, get another set of valve covers is the cure.

Frank DuVal

Fredericksburg, VA

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Re: Billionth Leaking Valve Cover Question
Posted by: American Mel ()
Date: November 18, 2022 07:01PM

Get new covers?
Why? confused smiley
He has resolved his issue. cool smiley

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WA. state, 1 mile south of the Canadian border, I am not at the end of the world, but you can see it from here.

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Re: Billionth Leaking Valve Cover Question
Posted by: wittsend ()
Date: November 18, 2022 09:10PM

"Must be the very early six hole valve covers that were used with tiny triangular spreaders?"

Correct, it is a six hole cover (1961 heads). The center holes had a triangular.., I more say like a washer (with Philips screw) than actual spreader. What I don't recall is if the spreaders were on the outer bolts (they were bolts, I remember that)..., or if I picked the spreaders up somewhere else. I remember that it seemed odd that the center fasteners were Phillips screws and the outer fasteners bolts. Even though I "Bag N' Tagged" everything the spreaders were always loose. I looked at the pictures prior to disassembly but unfortunately the rubber compartment seals hung down and obscured the fasteners. It was three years ago (prior to Covid) I started this project.

At this point I'll go back to my premise I made a few posts up. The valve covers are (now confirmed to be) the thin version and the spreader clamps are likely not "Corvair" and are VERY stiff. I bore all my weight on one and never saw it deflect. I struck the center with 5 pound sledge hammer on an anvil and the 1/8" bow never changed. The worse of two parts coming together in a confounding way.

------------------------------------------------------------------------------

***'61 Lakewood, a "Freebie" in hibernation for 27 years - In the process of applying CPR.***

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Re: Billionth Leaking Valve Cover Question
Posted by: Frank DuVal ()
Date: November 19, 2022 04:01PM

The spreaders are only Corvair parts. Sure, Mr. Gasket and others sold a chrome version, but that was a GM part they chromed to dress up other Chevrolet valve covers. And people bought the Corvair part from the dealer to "fix" leaks on other small block Chevys too.winking smiley

Of course someone 30 years ago could have put the spreaders on the 4 outer holes and used bolts. Lots of stuff happened when these were cheap used cars.

Frank DuVal

Fredericksburg, VA

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Re: Billionth Leaking Valve Cover Question
Posted by: RexJohnson ()
Date: November 19, 2022 06:57PM

It seems like the '60 cars used Philips head bolts with the triangles on all 6 holes.

RJ tools
Salem,Oregon

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