# Question on BOP 1-piece Oil Pan Gasket



## tiretread (Sep 28, 2015)

Just purchased a BOP 1-piece Oil Gasket for my spanking new BOP anodized oil pan. I have a tube of ultra-grey as well. Is it needed with the 1-piece? If so, where, and on both sides of the gasket?

I know this is a pretty common task for most people but I really don't want to mess this up and have to pull the engine to fix any mistakes. Much thanks ahead of time.


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## BearGFR (Aug 25, 2008)

Hey there! I'm in the middle of working with one of these myself and I've talked with the BOP folks a few times. Those are gorgeous gaskets. If you have a problem, it's likely to happen at the front joints where the pan, block, and timing cover meet --- at the rear next to the edges of the rear main cap, or on the arch over the rear main cap. I think it's "worse" if you have an aftermarket pan whose arch may not follow the rear main cap as closely as it should. I've been told that if you use sealant at all, to use either the Ultra-Black or better - GM #12378521 sealant.

I'd put it all together first completely dry and visually check the fit, especially around the arch. If if looks passable, do the hang test: Fill it with oil and hang it from your hoist at a steep enough angle to make sure the rear of the crank is completely submerged, and let it sit overnight. If it stays dry, you're probably good. It takes longer to get done but I think it's worth putting in the time to do this test, even if you find a leak and have to start over.

Bear


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## tiretread (Sep 28, 2015)

Thanks Bear! I have some ultra-black as well but was told that grey was better. Damn internet! lol. I will definitely be doing the hang test prior to putting the 389 in my Tempest. New rear seal was installed as well and I want to make sure that is GTG as well.


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## BearGFR (Aug 25, 2008)

Just repeating what someone told me, so don't take it as infallible. The grey might be fine. 

Bear


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## AJFrechette (May 25, 2011)

Mine leaked around the rear arch. I pulled the engine thinking it was the rear main seal, not. I am using right stuff on the way back in.


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## bigblock (Nov 4, 2015)

*Check the new pan fit*

Test fit the pan first , check the bolt hole alignment and the fit at the front and the rear . I recently tried 2 new oil pans and went back to my old pan .


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## BearGFR (Aug 25, 2008)

A friend of mine told me this is the stuff Butler uses on all their engines because they can't afford to have customers complaining of leaks, so I bought some. We'll see how it goes. 

Bear


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## tiretread (Sep 28, 2015)

^^^Guess I'll be picking this up as well. Definitely want it done right (or as right as possible) the first time!


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## BearGFR (Aug 25, 2008)

I'm going to be attempting "Round 2" of getting mine sealed up in the next day or two, if you want to wait and see how things go for me.

Up to you of course...

Also, there are several different AC Delco sealants that all come in nearly identical containers like this, so if you buy some be careful with part numbers. (Yeah, that's another "ask me how I know" thing....  )

Bear


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## 1968gto421 (Mar 28, 2014)

Thank you for the great info, Bear. I, too, have leaks I need to deal with.

Always something.


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## BearGFR (Aug 25, 2008)

On my "Round 1" attempt there's a good chance that I didn't allow the sealant I used that time (Right Stuff) to cure long enough before I put oil in it. I'm not going to make that mistake this time. (Instead, I find other mistakes to make, probably....)

I do still need to edit that 1-piece rear main seal video together..

Bear


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## BearGFR (Aug 25, 2008)

Round 2, part 1. I cleaned all the surfaces with a Brakekleen to make sure there's no oil residue on the cap or the gasket, cut the tabs off the gasket (my main cap has the locating groove so they aren't needed), then laid a small bead of that GM sealant into the groove. Next I seated the gasket into it and used some bodyworking dollies to hold it down. I'm going to let this cure up before continuing. Yeah, this is going render the gasket non-removable without tearing it up, but that's a price I'm willing to pay if I can get this sucker sealed.

(The black stuff on the gasket is leftover 'Right Stuff' from Round 1. I've cleaned it off as best I can to make the surface smooth and uniform.

Bear


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## Shake-N-Bake (Jun 16, 2015)

Bear,
Hope the second time does the trick...but if not then you might consider the Ford TA-31 sealant. We use it for our fleet diesel engines to seal up the oil pans since they don't use a gasket. Stuff works very well....dries pretty hard though so be sure you are ready to lock it down since removing it later takes some effort.

http://www.dieselorings.com/shop-supplies/13-017-ford-grey-silicone-gasket-sealant.html

International Harvester makes the same stuff but usually about twice the price...just an FYI...

Sent from my XT1585 using Tapatalk


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## tiretread (Sep 28, 2015)

I will be doing mine this Monday. I'm using a BOP anodized oil pan. Hoping the arch works out. If not, I still have the original as well (it has some pitting in it). I'll test fit tomorrow or Sunday and then get knock it out on Sunday. Then I have to put the heads back on. Never ends but I'm having a ton of fun.


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## BearGFR (Aug 25, 2008)

Round 2 underway. I'm feeling optimistic on this one. 
Bear


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## BearGFR (Aug 25, 2008)

Dang it...

Ok... Round 3 to come. Considering that the problem is too much space between the pan arch and main cap, I'm considering trying to cut a strip of sheet metal and weld it into the pan arch to tighten up that gap so it will put more pressure on that part of the gasket.


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## tiretread (Sep 28, 2015)

Man, you'd think that putting on an oil pan gasket wouldn't be so....eventful. I'm heading into the garage to mock mine up prior to inevitable sadness that is bound to follow. 

Good luck on Round 3!!!


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## BearGFR (Aug 25, 2008)

tiretread said:


> Good luck on Round 3!!!


Thanks --- yes it's an aftermarket pan but I think also contributing to my particular problem is the fact that this block has been align-honed twice, which means that main cap has had some material shaved off the block mating surface twice, making the "top" of it a little farther away from the pan than it originally would have been.

Bear


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## tiretread (Sep 28, 2015)

Just got done mocking up the gasket. I have just a scooch of a bend (too much material) near the rear. I think with the pan on and everything bolted up it should be good. Of course, I'll be applying some RTV in that area. 

Quick question as well: 

I have the bolts but I don't remember what sequence I took them off the pan. I believe the 2 bolts to the left are used on the corners with the reinforcing metal straps/plates, and the 4 bolts with washers to the right are used on the front by the timing cover. Am I correct? Thanks!


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## BearGFR (Aug 25, 2008)

I don't think that the tightening sequence on the oil pan matters very much at all. A friend of mine though have a great suggestion. Put whatever sealer you're going to use on and then just very lightly start the bolts. Let the sealer cure before you finish tightening the bolts that way it will be firm and when you tighten them, it should help seal. 

I talked with Wade at BOP earlier. He has a great idea. Instead of trying to weld a piece of metal into the pan, use my welder to lay a bead of welding material around the arch and build it up. That way I can put as much as I need in there, shape it with a grinder, and not have to worry so much about creating another leak path. Duh...

Bear


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## 64GTOConvertible (Aug 28, 2016)

Maybe shim the main cap out to the original height...

:shutme


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## BearGFR (Aug 25, 2008)

64GTOConvertible said:


> Maybe shim the main cap out to the original height...
> 
> :shutme


No no... very bad idea. :frown3::surprise: That would screw up the correct main bearing clearance.

Bear


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## 64GTOConvertible (Aug 28, 2016)

:lol:

Um Bear? You need to get your sarcasm-o-meter recalibrated...


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## BearGFR (Aug 25, 2008)

64GTOConvertible said:


> :lol:
> 
> Um Bear? You need to get your sarcasm-o-meter recalibrated...


You weren't serious? Whew --- sorry --- I've been involved in no small number of let's say "lively" discussions lately on 'other social media platforms' on some emotional topics and I guess the Bear has been a little on edge here lately. :crazy:

I tried welding up and grinding/shaping my pan last night and so far it's not going as smoothly as I'd hoped (does it ever?), but it's not yet to the point where it could be called a failure. We'll see.

Bear


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## 64GTOConvertible (Aug 28, 2016)

:lol:

How much do you think you changed the main cap height by? I was thinking that trying to weld a bead in there was gonna be a beyotch, because how are you going to get it 'round' again? But maybe lay a bead of old fashioned cork gasket on the pan (stuck with Permatex), then a layer of silicone, new gasket, and silicone again? Might work...


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## BearGFR (Aug 25, 2008)

Yeah, it might - but for now I'm committed to this approach. I have one of those contour copying tools that I can use to get the shape right, or at least close enough for that GM sealant to make up the difference. 

If I can't get it right, then I reckon I'll be buying another pan because at this point I'm sorta committed to this style - the new oil pump I bought from Luhn has its pickup depth specifically tailored to this pan - :cryin:. 

I'm not positive the problem is the align-honing, right now that's just an educated guess because for some reason I don't want to believe that Milodon pan could be off that much (hey, look at me - defending how aftermarket parts fit - the end of the world must be near :surprise. I still have an original stock pan laying around so maybe among other things I'll plop it on there and see if it has the same issue. That might tell me something.

Bear


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## Goat Roper (Oct 28, 2014)

I have a steel fabrication table I use to work the metal on the pan.
You can do this on the edge of any work bench.
Hold the edge of the pan on the edge of the bench and take a ball peen hammer and tap the holes the bolts go through back down.
Hold a straight edge along the edge to make sure they are flat or slightly concave to make sure their are no gaps in the gasket when you tighten it.


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## tiretread (Sep 28, 2015)

Hey Bear/or Anyone, my pic on the previous pages shows four pointy bolts with free washers on them. I'm still not sure where they go. On the front over the timing cover or on the rear corners on top of the metal reinforcements. Any insight is appreciated!


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## PontiacJim (Dec 29, 2012)

tiretread said:


> Hey Bear/or Anyone, my pic on the previous pages shows four pointy bolts with free washers on them. I'm still not sure where they go. On the front over the timing cover or on the rear corners on top of the metal reinforcements. Any insight is appreciated!


I am thinking the "spikey" bolts go in the center 2 holes on your timing cover, but test fit them to make sure they thread correctly. It looks like 4 of the slightly longer pan bolts if I am seeing it right. Those should be used on the pan reinforcements to compensate for the additional thickness of the reinforcements - like a washer. To double check, simply insert a long bolt through a reinforcement and then take a short pan bolt, turn it upside down, and place the bolt next to the long bolt. The bottom of the long bolt will be placed under the head of the short bolt, and the bottom of the short bolt should be setting on the reinforcement plate (or pretty darn close) - ie, the thread length should match between the two bolts.


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## tiretread (Sep 28, 2015)

Jim, 

There are 4 of the longer bolts with free washers on them and two longer bolts with the washer head. Those are the guys causing me concern. Thanks for the tips and I'll check it out on Weds.


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## PontiacJim (Dec 29, 2012)

tiretread said:


> Jim,
> 
> There are 4 of the longer bolts with free washers on them and two longer bolts with the washer head. Those are the guys causing me concern. Thanks for the tips and I'll check it out on Weds.


OK, I know every book states the longer 2 bolts go in the rear corner with the reinforcement strap. Kinda odd that it is not all 4, but who knows. I would just make sure you have enough thread so as not to strip them out when torquing and yet not too long that they bottom out and don't torque. The 4 bolts may indeed go up front. Take a look at the casting on the timing cover. Again, make sure the threads are correct and you can easily tighten them up and see what kind of stick out they have, and then figure to add the pan & gasket thickness. 

With older engines like this, it is quite possible that work was done and some of the bolts were lost/ replaced, or a longer bolt was used due to threads being stripped out or cross threaded - longer bolts can sometimes grab what is left and work. Me, if I screwed it up and longer bolts fit, I'd put a nut on the other side as long as it did not interfere with anything and tighten 'em down - gotta be creative sometimes. LOL

Take a look at your 326, maybe that would help with the timing cover/pan bolts. :thumbsup:


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## tiretread (Sep 28, 2015)

Thanks once more, Jim. I will definitely get under the car and look at the bolts on the 326 as well. I'm just getting old and crickety and was looking for the easy answer. lol.


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## BearGFR (Aug 25, 2008)

I posted an update on my main thread - here's a link:

http://www.gtoforum.com/f170/re-building-my-engine-finally-122594/index5.html#post846841

Bear


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