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Small block valve cover gasket

Started by 73chalngr, April 25, 2020, 08:27:51 AM

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gzig5

Quote from: nsmall on May 03, 2020, 02:41:51 PM
Quote from: MOPAR MITCH on April 27, 2020, 07:20:04 AM
Sealants?... best installed dry, especially rubber to be installed dry!  The gasket does the sealing... not the chemical.   

The steel cored gaskets are stable and align easily.

Non-steel-cored gaskets are a bit flexible and ... for alignment purposes only... can use a quick-drying contact cement to attach it to thew valve cover.

I prefer to use studs in the cylinder heads.. helps with aligning the gaskets.

Some gaskets (non-steel-cored) will have little outside tabs that are intended to fit inside the factory stamped steel covers... for attachment and alignment purposes.

@MOPAR MITCH   Sorry, just to confirm, you dont have to use a sealant for these covers to seal properly?  I have the mopar performance aluminum valve cover and I have read good things based on your tip in this thread to use these felpro 1646 gaskets.  I have a small leak on my passenger side near the firewall on my stock 340.  Thank you.

Neil

I used these FelPro gaskets on my J-heads and with aluminum covers.  Once I had the clearance ground into the VCflange to miss the intake runners, they sealed perfectly with no sealant.  I torque them, then come back the next day and do it again because they will take a bit of a set.

MOPAR MITCH

Neil -- regarding the small leak on the passenger side valve cover, look to see if the mating surfaces are good.  I've seen cylinder head flanges with slight dips and irregular casting surfaces.  Same goes for the valve covers.. regardless if stamped steel or cast aluminum.   If stamped steel, the flanges could become distorted from over-torquing and making the flange no longer flat.  The use of load spreaders (such as commonly found on older GM covers) would help spread the load.

Also, sometimes the threadings in the cylinder heads may not be cleaned well enough... or tapped deep enough... to allow full clamp load.  I prefer to use studs instead of small bolts... the studs also help alignment of the gasket... keeping it in its place.

IF all else fails, you could apply a small dab of RTV (red is preferred for better its better heat specs) at that suspected leakage area, allow it to dry about 24-hours, then keep your fingers crossed.... but it may possibly still leak down the road in some time.

nsmall

Quote from: MOPAR MITCH on May 05, 2020, 09:37:22 PM
The use of load spreaders (such as commonly found on older GM covers) would help spread the load.

Also, sometimes the threadings in the cylinder heads may not be cleaned well enough... or tapped deep enough... to allow full clamp load.  I prefer to use studs instead of small bolts... the studs also help alignment of the gasket... keeping it in its place.

IF all else fails, you could apply a small dab of RTV (red is preferred for better its better heat specs) at that suspected leakage area, allow it to dry about 24-hours, then keep your fingers crossed.... but it may possibly still leak down the road in some time.

Sorry to keep asking.  Its just that I have already broken one of my cast aluminum mopar valve covers so I am trying to not waste a bunch of money and time.

I have the load spreaders.

I have the new gasket you recommended.

So @MOPAR MITCH  How do i clean the threading?  I dont want to run a tap in there, but I did use silicon a couple of times on the bolt on my past failed attempts to correct this as I hoped that would stop the leak.  There could be some silicon in the head threads.

Final questions, I will check the valve covers and the heads to see if they look straight.  I was thinking I should use the new gasket you recommended with no RTV for the first try, but you are recommending using some RTV if I notice a leak? As in put a dab on the head where it is not straight if I notice any straighness issues?  I dont have a torque wrench, I do have some nice 1.25 ARP bolts to use as my others were only like 3/4 so I dont know how significant that is, I was just going to snug each bolt evenly one by one.  Thanks again. Really appreciate everyones help.


MOPAR MITCH

NS -- I can say that if you don't prep the threadings.. tapping or wire-brushing the fasteners... it'd be like a doctor not washing his hands before an operation... or a painter not prepping the surface before applying the final coats.

If you've applied RTV (silicone) to the threadings of the fasteners, then you're not getting proper clamp load.... it must be cleaned/removed...  RTV silicone is the most mis-used, abused and over-used chemical in the automotive marketplace.  It should be used as filler of gap, such as at intersecting corners (intake mfld, oil pan, etc.).  IF there is out-of-flat conditions (non-straight), it should be re-surfaced, or replaced... as needed.

73chalngr

I was watching one of those car shows and the mechanic ran a tap and die over new parts to make sure they go together correctly.

jimynick

Be careful trying to use 1.25" bolts, as they're likely to bottom out and you'll strip the thread and then you've got fun! Rough and dirty, stick a toothpick down the hole and mark where the edge comes to on it and then measure it and the cover and gasket and you'll have a rough idea of how long a bolt you could use. Remember that the gasket'll compress a bit and give yourself a small fudge factor to be safe.  :cheers:
In the immortal words of Jimmy Scott- "pace yourself!"

nsmall

Thanks a lot for your help everyone.  I really appreciate your time and advice.   :bradsthumb: