Head gasket remnants

[dn010]

I'm having a hell of a time here trying to remove remnants the head gasket has left on my heads and block. I tried using different razor blades and scrappers and its either not digging into the material to get it off, digs in a tiny bit to make a little dust pile but not remove everything, or digs enough to begin gouging. I'm getting frustrated and I don't want to ruin anything - I've never had a gasket leave material that is such a pita to remove like this ever! Any suggestions? Anything I can do chemically to soften this crap up? This is on my EFI B280F, not a stock engine, I'm trying to rebuild it prior to going MS but this is holding me up big time! Thanks in advance -----Dan

[opethmike]

You can get gasket softeners at just about any auto parts store. I forget the brand name, but the one I like to use has a brush on the tip so you can neatly brush the chemical on to the surface.

It is a chore - apply the softener, let it do its work. Scrape off some gasket. Apply more softener. Repeat.

[Josh]

If you have everything disassembled you can use a rotary scotch brite pad. Put it in a hand drill and it makes short work of gaskets. But I wouldn't do it on a short block as the pads disintegrate slowly and and cause internal damage. There are too many places for the remnants to get trapped.

[dn010]

I will order some gasket "softener" remover, I have read some negative reviews on stuff made by "permatex" or "CRC" on gaskets other than paper/RTV so I was hesitant but if it helps even a small amount; I'll take it!

Thanks Josh, the engine is in pieces with nothing assembled whatsoever so I guess I'm in luck - I will find where I can get the rotary pad and see what happens. I'm ready to try anything at this point to make work easier than what I was dealing with earlier. I'm glad I took a break, relaxed and let suggestions come in before I got irritated enough to make irreversible mistakes.


If you have everything disassembled you can use a rotary scotch brite pad. Put it in a hand drill and it makes short work of gaskets. But I wouldn't do it on a short block as the pads disintegrate slowly and and cause internal damage. There are too many places for the remnants to get trapped.

[David T]

I will order some gasket "softener" remover, I have read some negative reviews on stuff made by "permatex" or "CRC" on gaskets other than paper/RTV so I was hesitant but if it helps even a small amount; I'll take it!

Thanks Josh, the engine is in pieces with nothing assembled whatsoever so I guess I'm in luck - I will find where I can get the rotary pad and see what happens. I'm ready to try anything at this point to make work easier than what I was dealing with earlier. I'm glad I took a break, relaxed and let suggestions come in before I got irritated enough to make irreversible mistakes.

Be careful with chemical gasket removers. They are very toxic.

[jawn101]

Use one of these. I've never seen a gasket come apart quite like it did under one of these in a drill.

[Josh]

This is what I have. Got it from a local auto parts store
27219

Sent from my SGH-I747M using Tapatalk

[krs09]

Use one of these. I've never seen a gasket come apart quite like it did under one of these in a drill.

A Big + 1

[dn010]

Thanks guys! I'll be heading to Napa to grab these and give it another try.

[jangell]

Use one of these. I've never seen a gasket come apart quite like it did under one of these in a drill.

I used one of these (a bristle disc) to get the gasket off my oil pan. The disc wound up breaking at the Roloc adaptor that holds it onto the drill, so I bought a 10 pack after that. It worked very well, and since it's plastic didn't damage the aluminum. I wrote up the whole thing here: https://joe-angell.squarespace.com/repairs-and-maintenance/2014/5/11/cleaning-the-oil-pan-and-lower-crankcase.

I got the idea from this thread: http://dmctalk.org/showthread.php?7419-How-To-Resealing-the-PRV-s-oil-leaks

-- Joe

[dn010]

Well I picked up a disc at Napa but didn't realize I needed an adapter too, and the adapter I cannot seem to find locally. So I'll be delayed as I need to order it online and wait.

[jangell]

That got me too. If you have a Harbor Freight nearby, they sell cheap kits of sanding/polishing discs that include a Roloc adaptor that will work with these.

-- Joe

[vwdmc16]

Use one of these. I've never seen a gasket come apart quite like it did under one of these in a drill.

+1 I use this 3m Roloc bristle disc on the race motors at my work, it is the bees knees. You must be gentle on aluminum however, they do make a softer compound that is white in color but I think it is too soft to really cut into anything.

[jangell]

This was my first time using bristle discs, and I was not that gentle; my seal was pretty much bonded to the aluminum, and would only come off in very tiny pieces as I tried to scrape it away with plastic tools. After using the disc, I have light swirling patterns on the metal, but it seems entirely superficial -- that are no nicks or deep damage to the metal, and no visible low points or anything like that. Still, I haven't laid a straight edge along it to be absolutely sure, although I'm not sure how I would have gotten the gasket off otherwise. I did grind the discs down pretty good (but didn't break any of the "pins" off of it), but that's kind of the point -- the discs go before the metal does.

I would recommend taping paper towels or trash bags or whatever along the edges of the engine to keep from making a mess. I was removing the gasket from my lower crankcase and oil pan, neither of which were on the engine at the time, and I got debris (dust, mostly) everywhere. Luckily they were easy to clean, but it would be bad to get that stuff inside your assembled engine.

-- Joe

[jangell]

Reading up a little more, it seems like I probably used too much pressure and may have worn my surfaces too much. I'll have to put a straight edge on it next time I'm at the garage, and see how well the surfaces fit together so I can see if there are any depressions. As I said, there are no nicks or anything -- a fingernail won't catch on anything, for example -- but that doesn't mean I didn't make some low areas from the pressure.

Oh well, guess I'll find out.

Here's a thread I found where people were talking about using bristle discs and some of the dangers if you use too much pressure. There's also discussion of using pads, which is definitely not recommended: http://www.garagejournal.com/forum/showthread.php?t=156558.

-- Joe

[dn010]

Thanks for that link. They suggest the white disc for aluminum heads so I might as well order that while I'm ordering the adapter although I'll hang on to the green one for future projects.

This all has me a little worried now, I definitely do not want to ruin the heads but I guess I have so many of them laying around I can just use one as a "test subject" and see what happens...

[dn010]

Damn, after reading further I'm deciding not to use the disc on the head gasket surface. I guess I'm just stuck with scrapers and removers :dead:


Thanks for that link. They suggest the white disc for aluminum heads so I might as well order that while I'm ordering the adapter although I'll hang on to the green one for future projects.

This all has me a little worried now, I definitely do not want to ruin the heads but I guess I have so many of them laying around I can just use one as a "test subject" and see what happens...

[jangell]

I should mention it took me two hours to get all of the gasket off with the disc -- they were REALLY on there. I have no idea how long it would have taken with the plastic scrapers I was using (I specifically avoided metal scrapers for fear of nicking the metal). I'd probably use the bristle discs if I had to do it again, although more gently.

-- Joe

[jangell]

I made it to the garage today and checked the straightness of the lower crankcase that if beat on with a green bristle disc for two hours. I used a known straight metal ruler (I tested its straightness against my aluminum laptop) -- it appears to be perfectly straight, with no warping or depressions at all from the disc.

Of course, this part doesn't have the fine tolerances of the heads, but I'm quite confident that I did not do any damage to the lower crankcase/oil pan seal.
2759627597

-- Joe

[jawn101]

I made it to the garage today and checked the straightness of the lower crankcase that if beat on with a green bristle disc for two hours. I used a known straight metal ruler (I tested its straightness against my aluminum laptop) -- it appears to be perfectly straight, with no warping or depressions at all from the disc.

Of course, this part doesn't have the fine tolerances of the heads, but I'm quite confident that I did not do any damage to the lower crankcase/oil pan seal.
2759627597

-- Joe

Green bristle disk for the win!

I'd use that thing again in a second for jobs like this.

Make sure to get DPI Josh's oil pan gasket - the others on the market just don't seal. Ask me how I know.

[jangell]

I have Josh's oil pan gasket and his 3.0L gasket set on order -- he's waiting for a few bits before he can ship them to me. I'm hoping to get them sooner than later -- I'm running out engine parts to prep.

-- Joe

[dn010]

Well I tried just about everything. Acetone - too caustic and doesn't do enough so its not worth it. Engine "foaming" degreaser - worked but takes forever to react. Tuff Stuff upholstery cleaner - I believe this worked the best out of everything that doesn't ruin aluminum but you have to use it, scrape, repeat. Easy-off - tested it on another aluminum head - you can put it on and blow the gasket pieces off with water but it eats and etches aluminum so you can't use it.

After hours of wasted time I got pissed off and drilled a hole through the middle of my green Roloc disc, but a bolt through it and then a nut on the other side and clamped that whole rig down in the chuck of my drill. I didn't feel like wasting more money and time buying the adapter! That took some doing but worked well also and if you're not careful it WILL chew up the aluminum so I wouldn't use that either for a deck or head gasket surface.

Now for the kicker:
After all this time and effort - I now have a nice shiny clean head, gasket is all gone. Then, I look at the gasket surface, and I have an indentation next to one of the water ports & cylinder area! A gasket will blow out if I leave it. So, I have to laugh, because after all of this - this head will need to be milled in order to be usable :angry:

Not sure if I should deal with milling or just go on to the next head that I have since I have 3 pairs total plus the original heads...

[hmcelraft]

How much milling will change the cam timing?

[dn010]

How much milling will change the cam timing?

I've got to stress that this is not a stock DeLorean engine, this is a B280F; so this may not apply to the stock engine. You are allowed certain limits with milling the heads. I am not sure how much it will change any timing, my deepest concern is, will I require any kind of spacer or milling on the EFI intake...

[David T]

Well I tried just about everything. Acetone - too caustic and doesn't do enough so its not worth it. Engine "foaming" degreaser - worked but takes forever to react. Tuff Stuff upholstery cleaner - I believe this worked the best out of everything that doesn't ruin aluminum but you have to use it, scrape, repeat. Easy-off - tested it on another aluminum head - you can put it on and blow the gasket pieces off with water but it eats and etches aluminum so you can't use it.

After hours of wasted time I got pissed off and drilled a hole through the middle of my green Roloc disc, but a bolt through it and then a nut on the other side and clamped that whole rig down in the chuck of my drill. I didn't feel like wasting more money and time buying the adapter! That took some doing but worked well also and if you're not careful it WILL chew up the aluminum so I wouldn't use that either for a deck or head gasket surface.

Now for the kicker:
After all this time and effort - I now have a nice shiny clean head, gasket is all gone. Then, I look at the gasket surface, and I have an indentation next to one of the water ports & cylinder area! A gasket will blow out if I leave it. So, I have to laugh, because after all of this - this head will need to be milled in order to be usable :angry:

Not sure if I should deal with milling or just go on to the next head that I have since I have 3 pairs total plus the original heads...

Instead of milling consider a little welding and then flattening the area so you don't have to mill the whole surface.

[DMCMW Dave]

How much milling will change the cam timing?

It retards the timing slightly, removes some margin in the tensioners, and makes the valve covers not fit since the heads are now slightly shorter than the timing cover. I agree if you want to save the head you should probably weld up the void before resurfacing, just to minimize what would need to be removed too solve the problem.

[dn010]

Thanks for the replies guys. After examining both heads in this particular set, both have either indentations or other defects on the gasket surface so I'm already cleaning up the next set. The only issue I have with the next set is they have 160K on them compared to the other set! So far the gasket surfaces look good though, and the head gasket remnants are coming off much easier than the other set :biggrin:. Now I just hope they aren't warped...