#1  
Old 08-21-2020, 05:47 PM
John V. John V. is offline
Ultimate Warrior
 
Join Date: Sep 2005
Posts: 4,520
Default Valve Cover Leak

This started in my Oil Filter thread:

http://forums.maxperformanceinc.com/...d.php?t=840361

That thread morphed into my valve cover leak (both sides) so I decided to start a new thread focused on that.

Original GTO covers, they were rechromed.

I finally pulled the left side valve cover. It was not leaking quite as bad as the right side but decided to check it first. The bolts were snug at best. I was tempted to simply snug them but since I already purchased the Edelbrock 7590 composite 5/16" thick multi-layer gaskets, I pulled the cover. Existing black gasket seems to be very thin, 3/16" thick at best. Glued to the cover with black sealer. Scraped it all clean, wiped down with mineral spirits. Cover is now squeaky clean.

But now my dilemma. The bolt holes are dished. I have worked on them with a hammer and blocks of wood. I may have flattened them a hair. From the top, I can feel a slight dish although it is not visibly very obvious. The cover itself does not seem bowed at all, but using a straight edge, I get a gap between the bolt holes on both sides of the cover of about 0.025", less than 1/32". Uniform gap with the feeler gauge from bolt hole to bolt hole.

I can continue to work at the holes to try to flatten them. But I'm concerned that hammering the holes flat may do more damage than good.

The area around the hole is stiffened by the forming in that area, afraid that hammering on it will distort the rest of the flange.

Is it super critical to get the holes perfectly flat or am I close enough?

  #2  
Old 08-21-2020, 06:48 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 28,712
Default

Get two washers, a piece of threaded rod, and two nuts and instead of pounding on the
valve covers, apply clamp pressure with your device and flatten the covers out gently.
You have created a small valve cover VICE.
Might be the easiest and safest solution to correct the leak.

Then install your fasteners and gently snug them up so the cover does not leak.

Tom V.

__________________
"Engineers do stuff for reasons" Tom Vaught

"There is nothing more fun than Learning"
Barney Navarro (Engineer, Fabricator, Machinist,
Racer, Inventor, one of the Original "Boost Guys"
If you are Talking, You are not "Listening", you can only LEARN by LISTENING. LLM
  #3  
Old 08-21-2020, 08:55 PM
John V. John V. is offline
Ultimate Warrior
 
Join Date: Sep 2005
Posts: 4,520
Default

Tom, sounds like a good idea. And I don't think a threaded rod is necessary, just a short 5/16" machine bolt.

I grabbed some hardware to test it out.

I put the nut at the top and as the nut is tightened, in theory, the metal would be flattened if the top side washer could bear on the raised area beyond the dished hole.

But in practice, it looks like I'd need something other than a washer. There isn't room for a large enough washer that would bear on the raised top side of the lip. It would need to be a very rigid rectangle that would bridge over the hole so that tightening the nut would pull the hole upwards, flattening the bolt hole area. The washer under the bolt head will bear on the underside of the dished area. I suspect I would need to use a few washers to make it stout enough. That is no issue, just increase the length of the bolt as needed.

But the largest washer that will fit would simply bear on the dished area at the hole on the top side. Clamping down would just squeeze the dished bolt hole area, not move it.

I also wonder if I could torque a 5/16" bolt enough to actually flatten that area.

Assuming the valve cover bolt holes did start life flat with the rest of the lip, I guess the only way the holes got dished was to over-torque the 5/16" bolts. If they didn't snap as the holes dished, I suppose a 5/16" bolt wouldn't snap while flattening the hole area.

But I still would need to machine a suitable "bridge" to apply the clamping pressure in the right place.

I wish I had thought to fix the holes before getting the covers rechromed. It might be a bit easier to flatten the holes if I had no fear of damaging the chrome.

If somebody can think of a standard piece of hardware that could be used to act as the "bridge" across the bolt hole, please chime in.

  #4  
Old 08-22-2020, 09:55 AM
Rich-Tripower's Avatar
Rich-Tripower Rich-Tripower is offline
Chief Ponti-yacker
 
Join Date: Oct 2002
Location: Waverly, NE
Posts: 652
Default

I've always just put a ball bearing which is larger than the hole in the hole and tapped it with a hammer and it removes the dish in the bolt holes with a few judicious taps. Support the top side of the cover with a block of wood. You won't damage the outer flange of the cover unless you get carried away with your hammer taps. Unless the chrome is ridiculously thick it should flex along with the underlying steel without any issue.

I've addressed the bolt holes on my original chrome L79 valve covers and the rechromed GTO valve covers numerous times without any problems. An alternate method if you don't have any ball bearings lying around is the put the ball end of a ball peen hammer on the hole and tap the head of the hammer with another hammer.

  #5  
Old 08-22-2020, 11:46 AM
bill ryder's Avatar
bill ryder bill ryder is offline
Ultimate Warrior
 
Join Date: Jan 2011
Location: SOUTHERN ILLINOIS
Posts: 1,685
Default

Hi John.. I'm surprised Rich didn't say "grab the bridge that SBC's use on their valve cover bolts". Do you know the piece I'm referring to? Possibly even after market hold downs come with them. I bet Tom has one lying around!!!!

"Bill"!

  #6  
Old 08-22-2020, 03:21 PM
1_Wild_Cat's Avatar
1_Wild_Cat 1_Wild_Cat is offline
Senior Chief
 
Join Date: May 2012
Location: Idaho
Posts: 317
Default

Buick used them too. I've had to straighten them...which is pretty ridiculous on the Buick ones. They are probably an 1/8" thick.

  #7  
Old 09-05-2020, 03:39 PM
John V. John V. is offline
Ultimate Warrior
 
Join Date: Sep 2005
Posts: 4,520
Default

I tried suggestions offered here but got nowhere. So far only worked on the LH cover.

After aggressively trying to flatten the valve cover flange, I remeasured and saw that I've made almost zero progress. Might have reduced the gap between the bolt holes to 0.023" at best. Not really sure that is better than than the 0.025" I reported before, perhaps just more carefully measured. I'm stymied because the bolt hole area is too stiff to hammer it down from the inside. And trying to hammer the cover flange down from the outside got me nowhere. Finally just gave up. I've glued the gasket to the cover with Permatex Optimum and plan to use a smear of Hylomar Universal Blue non-hardening sealer to the head flange.

But now I have a new question, hoping you guys have an answer.

The new gasket is the 5/16" thick Edelbrock 7590. The old gasket is only 3/16" thick.

I think my existing bolts are reproductions. They are marked with a stamped "W" on the head. 5/16"-18 x 9/16" as best I can measure. Washer Flange Head with "dog" point tip. Shiny silver, not sure if coated or maybe stainless, they are magnetic. Not sure where my engine builder got them. Pic attached.

The originals were p/n 9776669 but I'm not sure what they looked like, finish, and length. Anybody have a picture?

Inline Tube sells a set similar to the ones I have. But the marking is "E". They describe as Chrome and silver zinc. Same 9/16" length by the description.
https://www.amazon.com/Inline-Tube-C.../dp/B06Y4C141R

On eBay, I found these with the claimed "correct W" marking but they are dull phosphate coated, not shiny.
https://www.ebay.com/itm/W-valve-cov...-/263099172381

I think I want a Washer Flange Head bolt 5/16"-18 x 11/16" with a shiny silver finish. I think the Washer Flange Head is critical to spread the clamping force and also will look as correct as possible.

Anybody know where I could find such a bolt?
Attached Thumbnails
Click image for larger version

Name:	IMG_1764.jpg
Views:	64
Size:	46.7 KB
ID:	548767  

  #8  
Old 09-05-2020, 04:46 PM
pfilean's Avatar
pfilean pfilean is offline
Ultimate Warrior
 
Join Date: May 2007
Location: West Des Moines, IA
Posts: 1,713
Default

Trying to remember back to 64 or 65 I think the bolts had some kind of shiney silver plating but maybe not chrome. Although t would be hard to do a good job of polishing chrome on a bolt head like that. But the problem I ran into with mine was that in tightening enough to try to stop leaks I caused leaks. The integral washer on the bolt would gouge into the slight radius where the flange was stamped out from the vertical portion of the cover. That caused a slight tearing at that radius under the bolt/washer with a resulting leak. It was like the integral washer was slightly too big or the hole on the cover was a little too close to the vertical portion of the cover.

  #9  
Old 09-05-2020, 05:09 PM
1_Wild_Cat's Avatar
1_Wild_Cat 1_Wild_Cat is offline
Senior Chief
 
Join Date: May 2012
Location: Idaho
Posts: 317
Default

Hi John -- You might try AMK for new bolts.

  #10  
Old 09-05-2020, 06:13 PM
John V. John V. is offline
Ultimate Warrior
 
Join Date: Sep 2005
Posts: 4,520
Default

pfilean, I half expected tearing around the bolt hole as I attempted to flatten it on the inside down to the cover flange. That's what convinced me I should stop.

I found these bolts and ordered them.
https://www.ebay.com/itm/64-79-Ram-A....c100009.m1982

They are from Inline Tube and advertised here as 11/16" long. At the Inline Tube site however, they are described as 21/32" long. That's a big difference so I'm hoping they will be long enough even though they may only be 3/32" longer than the one's I've got vs. the gasket being 1/8" thicker.

I am a bit worried that the bolt on the RH cover that passes thru the oil dipstick tube tab will really need the extra 1/32" length. But I'll cross that bridge when the time comes.

The '65 Shop Manual shows 65 in-lbs. +/- 15 so I have my 1/4" drive torque wrench ready to torque them properly.

  #11  
Old 10-16-2020, 09:25 PM
John V. John V. is offline
Ultimate Warrior
 
Join Date: Sep 2005
Posts: 4,520
Default

The long saga is finally over. Took a 60 mile drive down, around, and up the mountain today.

The Inline Tube longer valve cover bolts worked great, long enough for attaching the dipstick tube bracket and also the wire loom bracket attached to the upper bolts of the RH cover.

Package shows product no. INL11169 and description on the label claims 11/16",

Plenty long enough for the Edelbrock 5/16" thick 7590 gaskets.

After giving up on my attempt to do any straightening of my original (not repro) covers, I glued the gaskets to the covers using Permatex Optimum Max Flex Black gasket maker. Placed the covers on a wood board and wrapped a bungee cord around the board and cover to put a little compression pressure while the sealant cured.

I then put a thin film of Hylomar Universal Blue non-hardening jointing compound on the head gasket surface.

After the Hylomar started to set-up for a couple minutes, I installed the covers and torqued the new bolts first to 35 in-lbs, then to 65 in-lbs.

After about 10 minutes, I retorqued at 65 and several minutes later, retorqued to 70 in-lbs. Recommended torque is 65+/- 15 so I erred a little to the high side.

I also took care of my Muncie trans fill plug leak. Removed the plug, wrapped a few turns of teflon tape followed by a thin film of pipe sealing compound. Reinstalled the plug and snugged it up (no torque wrench). I made it tight with a small crescent wrench, I'm a relative lightweight so I did not try to over-muscle the plug, just a bit tighter than I would make an oil fill plug.

Idled it for about 10 minutes looking for any leaks. Found none.
An hour later, I took it for a good drive at speeds up to about 60. Upon return, reinspected. No leaks at the valve covers or the trans fill plug.

I am very happy. I'll be watching for any continued leakage. The rear main might still be leaking.

I was getting some clutch chattering at a light well into the drive today.

If the main is leaking I'll probably need to address that issue one day.

But for now, I'm upbeat.:

  #12  
Old 10-16-2020, 10:32 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 28,712
Default

Nice Work John.

Tom V.

__________________
"Engineers do stuff for reasons" Tom Vaught

"There is nothing more fun than Learning"
Barney Navarro (Engineer, Fabricator, Machinist,
Racer, Inventor, one of the Original "Boost Guys"
If you are Talking, You are not "Listening", you can only LEARN by LISTENING. LLM
  #13  
Old 10-17-2020, 03:19 PM
Dick Boneske's Avatar
Dick Boneske Dick Boneske is offline
Ultimate Warrior
 
Join Date: Mar 2004
Location: Winneconne, Wisconsin
Posts: 5,070
Default

I'm late to the game here. Ames has valve cover bolts 21/32" long for use with the thicker gaskets. They are bright zinc plated.

My method of straightening the dimples at the bolt holes in the valve covers is to use a 2X4 board standing on edge to set the valve cover on. use another wood block placed over the bolt hole to flatten the area. Sometimes, it's necessary to turn the valve cover over to hit from the other side. The wood prevents damage to the valve cover. This works very well--I've used this method for many years. I've also had better luck with rubber gaskets than the cork versions. Use sealant to adhere the gasket to the valve cover. No sealant is needed on the cylinder head.

As a side note, the '64-'67 GTO engines all got black valve cover bolts.

__________________
BONESTOCK GOATS

'64 GTO Tripower Hardtop (Wife's Car)
'64 GTO Tripower Post Coupe (My Car)
'08 Grand Prix GXP LS4 V8 (Wife's Car)
'09 Pontiac G8 GT 6.0 V8
  #14  
Old 10-17-2020, 05:58 PM
John V. John V. is offline
Ultimate Warrior
 
Join Date: Sep 2005
Posts: 4,520
Default

I still don't get it. Dick, among the many methods I tried, i did try with the blocks of wood as you described. On the upper flange with the turned up lip, I used a narrow block that fit between the lip and cover as a backer. No matter how hard I pounded on the reverse, I saw no change in the dimple or flange. Didn't matter if I used a block of wood or hit the dimple directly with a hammer against the wood backer. Same for trying to flatten the dimple with the ball peen hammer laid in the hole and whacking it with a 2nd hammer.

I honestly don't know how you can move that metal without a sizable press given the forming of the cover around the holes. I feared I would tear or crack the metal around the dimple while beating on it so I stopped and concluded that the dimples at the holes created a gap between the cover flange and the head gasket surface so much smaller than the gasket thickness (even if I was using 3/16" thick gaskets in lieu of the 5/16" thick gaskets I installed) that the gasket would easily seal.

In hindsight, I suspect the original leak might have been sealed by retorquing the bolts although the worst leak was the RH cover and on removal it appeared that the gasket was cut/split in one spot and sealer used to seal that area. Even so, it might not have leaked if the bolts were retorqued. I'll never know now but I feel better having carefully done it myself, removing any doubts I may have had about the workmanship or quality of materials used.

Dick, interesting point about the factory use of black finish on the bolts. Good to know but I doubt I'll ever have my GTO points judged. I once hoped for that but it just didn't turn out nice enough and still has numerous issues.

I just checked Ames.

Looks like the short bolts used on mine with the 3/16" thick gaskets were from Ames, as they have the same "W" head marking. No surprise, we used a lot of Ames parts in the resto.

https://secure.amesperf.com/qilan/De...A&web_access=Y

But Ames might have discontinued the longer 21/32" bright zinc bolts.

https://secure.amesperf.com/qilan/De...A&web_access=Y

If these are the ones you mentioned, the FN651C shows Discontinued when I looked on-line.

However, they do show these:

https://secure.amesperf.com/qilan/De...A&web_access=Y

They say correct plating and length for the RAIV and 455HO application but no specifics. I assume 21/32" length. $14 for the set. NL head marking also claimed to be correct but I'm guessing would not be correct for a '64.

Of course, I don't know if the "E" head marking on the bolts I got from Inline Tube are correct on a '64 either!

I'm good with my repair outcome but one day, maybe somebody will post pix before and after flattening the dimples at the bolt holes for the '64-'66 valve covers. I'm feeling a bit inadequate because I was unable to flatten the dimples on mine.

  #15  
Old 10-18-2020, 12:22 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 28,712
Default

I have put a piece of 3/4" OAK dowel in a vice installed vertically.
Then I found a second piece of oak that fit inside the valve cover lip.

I had a helper hold the valve cover flat to the 1" dowel surface.
Then I gave the smaller dowel a SHARP WACK with the smaller oak dowel impacted by
a large head hammer and then the valve cover hole in that position was basically flat.

I repeated the process 7 more times. No damage to the chrome or the valve cover.

Tom V.

__________________
"Engineers do stuff for reasons" Tom Vaught

"There is nothing more fun than Learning"
Barney Navarro (Engineer, Fabricator, Machinist,
Racer, Inventor, one of the Original "Boost Guys"
If you are Talking, You are not "Listening", you can only LEARN by LISTENING. LLM
  #16  
Old 10-23-2020, 06:22 PM
geeteeohguy's Avatar
geeteeohguy geeteeohguy is offline
Ultimate Warrior
 
Join Date: Dec 2009
Location: Fresno, California
Posts: 4,614
Default

I've flipped the covers over, laid the lip against a workbench, and hit the bolt holes with the ball end of a ball-peen hammer for decades. Works in a flash for trans pans, oil pans, valve covers, what have you. Very simple, very effective. Never had to resort to boards or presses or studs or anything else. Late to post here, by a bunch, but for future reference.......

__________________
Jeff
  #17  
Old 10-23-2020, 06:55 PM
gto19's Avatar
gto19 gto19 is offline
Senior Chief
 
Join Date: Dec 2002
Location: Salinas , ca
Posts: 422
Default

Did they use a gasket sealer or just the gasket only from the factory back in the 60s ?

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 06:36 AM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 

Cold Case Radiators

Cold Case Radiators is a Max Performance company that produces high end aluminum performance radiators at a price point that won't break the bank. Polished and stamped tanks. 2 rows of 1" tubes. Lifetime Warranty.

GTOG8TA.com

GTOG8TA.com is a Max Performance company that manufacturers parts for the 04-06 GTO, 08-09 G8, and 93-02 Firebird/Trans Am platforms.

Copyright © 2017