Head Gaskets and sealer
Printed From: TheAMCForum.com
Category: The Garage
Forum Name: AMC V8 Engine Repair and Modifications
Forum Description: AMC-made V8 engine mechanical, ignition and fuel from basic repair to high-perf modifications
URL: https://theamcforum.com/forum/forum_posts.asp?TID=27300
Printed Date: Apr/18/2024 at 1:48am
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Topic: Head Gaskets and sealer
Posted By: 70AMX401
Subject: Head Gaskets and sealer
Date Posted: Mar/05/2011 at 4:08pm
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I'm about to put my heads back on. I'm cleaning up the block and head surfaces with lacquer thinner. I'm noticing black silicone around the coolant ports on the block. I've only done a couple of engines in the past and they were SBC. We never used sealant with head gaskets. It looks like the previous builder did on this? Is this common? If so what would you use, this looks like plain old permatex #2. Sucks thought I'd have it buttoned up today until I noticed this and it threw me for a loop. Engine is 11.2:1 401, iron heads, felpro Permatorques.------------- 70 AMX 401/727 66 Rambler Classic 770 |
Replies:
Posted By: SKeown
Date Posted: Mar/05/2011 at 5:15pm
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Clean surfaces thoroughly amd use the gaskets only with proper torque sequence.
SKeown
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Posted By: SC397
Date Posted: Mar/05/2011 at 6:50pm
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A AMC engine is not a SBC so, don't even compare them. I use a spray copper coat (KW COPPER COAT GASKET COMPOUND)on both sides of the head gasket and I do not use any silicone anywhere. Torque the head bolts in the sequence that the TSM tells you. Wait over night and check the torque the next day. I have never had a problem with this method.
Now, if you are talking about installing the intake manifold I use a little different procedure. |
Posted By: 70AMX401
Date Posted: Mar/05/2011 at 8:45pm
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Would you consider the spray on copper that permatex has as an equivalent? I know I can pick that up tomorrow morning. I know if sounded like a dumb question but when I seen the black silicone around those water ports it threw me off. ------------- 70 AMX 401/727 66 Rambler Classic 770 |
Posted By: SC397
Date Posted: Mar/05/2011 at 9:46pm
| Yes I think that the copper Permatex is the same type of stuff. |
Posted By: Hurst390
Date Posted: Mar/05/2011 at 9:58pm
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X2 on the spray or brush sealer on the steel side minimum... ------------- SC/Hurst Rambler 11.62 120 100% Street Legal |
Posted By: jayson738
Date Posted: Mar/06/2011 at 2:30pm
| I haven't built as many engines as most but my rule of thrumb is clean heads and block and install the gaskets with no chemicals. They don't at the factory so why start now. |
Posted By: JavelinRob
Date Posted: Mar/06/2011 at 2:37pm
yes just clean surfaces thats all I have ever done and no leaks , the only place I use a little silicone is the corners of the oil pan gasket where it meets the rubber seals , then intake manifold corners where it meets the head and block , thats why you have gaskets !!!!!!!!! -------------  1970 sst 421 shivvy
1970 amx 390 4spd go pack |
Posted By: SKeown
Date Posted: Mar/06/2011 at 2:43pm
That's exactly correct. unless you're using metal shim gaskets on a rough machined surface, ther's absolutely no need for copper coat. I recommend ROL gaskets in the first place, you can use less bolt torque which creates less bore distortion.
SKeown
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JavelinRob wrote:Posted By: Peter Marano
Date Posted: Mar/06/2011 at 4:04pm
| The factory coated head gaskets with sealer, both sides. |
Posted By: ROGUE66
Date Posted: Mar/06/2011 at 4:24pm
| and what kind of sealer?????? |
Posted By: ramblerman390
Date Posted: Mar/06/2011 at 4:59pm
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this is new to me... i never used sealer on a head gasket, but i have used sealer on the head bolts only if they go through water jacket such as a Chevy block. ------------- want to go fast... get an AMC! |
Posted By: Peter Marano
Date Posted: Mar/06/2011 at 4:59pm
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It was a tan goo, but now that I think about it maybe it was used only on the intake manifold gasket. It was applied with a pair of rollers like a wringer on an old washing machine. I remember that I went to high school with the guy that worked at that station. And that he put shaving creme in the coolant holes to prevent any foreign material from falling out into the engine. Upon further review, at that station, the operator installed the cylinder heads and intake manifold gasket after running it through the rollers to apply the sealer. The intake manifold gasket went through twice, just the ports were coated. |
Posted By: poormansMACHINE
Date Posted: Mar/06/2011 at 5:50pm
Any one brand favored over another? |
Posted By: amx39068
Date Posted: Mar/06/2011 at 6:33pm
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I have taken apart dozens of virgin engines and there was very little sealant used anywhere. When assembling I no longer use the #$%#$^ rubber end gaskets on the intake and use a bead of Super RTV instead. The trick is to install just enough so it compresses but not enough so that a blob will fall into the valley and clog something up. When the engines were brand new I am sure the rubber intake end gasket worked great on new metal but I have had vacuum leaks arise after the block has been decked and the heads have been planed so the fitment of those pesky rubber end gaskets no longer works on the intake due to the differences fitment resulting from rebuilding the engine. ------------- Dan Curtis-Owner and CEO AZ AMC Restorations; Facebook: https://www.facebook.com/amcmusclecars/ & Curtis Real Estate Development 
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Posted By: JavelinRob
Date Posted: Mar/06/2011 at 6:49pm
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his yes that is true when you machine the heads deck the block you also need to do the intake ends or ditch the rubber seals and use some rtv silicone I use permatex called the right stuff its black and very sticky holds up well to oils ------------- 1970 sst 421 shivvy
1970 amx 390 4spd go pack |
Posted By: JavelinRob
Date Posted: Mar/06/2011 at 6:53pm
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the only time I have used sealer on a head was on a flt head six in an old pontiac it had a stubborn antifreeze leak and the only gasket you could get was a steel shim gasket , I used permatex brush on aircraft sealant its like a blackish brown gooky sealant let it dry for a week before adding coolant 10 years later still running and no leaks ------------- 1970 sst 421 shivvy
1970 amx 390 4spd go pack |
Posted By: FuzzFace2
Date Posted: Mar/06/2011 at 7:43pm
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What does the paper that came with the head gaskets say to use? IIRC when I did my junk 360 drag motor the Fel-pro gaskets said to use copper coat on the metal side(s). No sealer on head bolts.
I also followed the paper that came with the pan gasket. Drag motor no rubber end gaskets but the 360 street motor I did use them.
Dave ---- ------------- TSM = Technical Service Manual 75 Gremlin X v8 for sale 70 Javelin 360/auto drag car 70 Javelin 360/T5 Street car |
Posted By: 70AMX401
Date Posted: Mar/06/2011 at 7:53pm
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There was nothing in the box for instruction from fel pro. This was a whole engine gasket set.
I went ahead and sprayed both side of heads gaskets with permatex copper. I guess we'll see what happens. Like I said this is a first for me, usually I just clean surfaces good and use head gaskets dry. ------------- 70 AMX 401/727 66 Rambler Classic 770 |
Posted By: 69 ambassador 390
Date Posted: Mar/06/2011 at 11:05pm
------------- Steve Brown Algonac, Mi. 69 Ambassador sst 390 84 Grand Wagoneer 69 Cougar XR7 65 Fairlaine 500XL 79 F-350 Super Camper Special |
Posted By: 70AMX401
Date Posted: Mar/07/2011 at 2:18pm
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That's unfortunate for me. ------------- 70 AMX 401/727 66 Rambler Classic 770 |
Posted By: BassBoat
Date Posted: Mar/07/2011 at 3:52pm
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K&W. Spray it baby. I currently have a motor apart that previous owner did not use sealant, and both head gaskets failed in 5000 miles.
I also have a motor that has been run hard for 10 years with the same felproblue gaskets and 11 to one compression that is still sealed. I sprayed 'em.
bb
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Posted By: 70AMX401
Date Posted: Mar/07/2011 at 3:53pm
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metal side and blue side? ------------- 70 AMX 401/727 66 Rambler Classic 770 |
Posted By: SC397
Date Posted: Mar/07/2011 at 5:07pm
| I always spray both sides too. |
Posted By: jeremy0711
Date Posted: Mar/07/2011 at 5:12pm
| I sprayed mine too with copper stuff. We have always used the Indian Head stuff which is really nasty sticky stuff in the past. My buddy nor I have ever blew a head gasket yet that we have sealed. |
Posted By: gregscram
Date Posted: Mar/07/2011 at 6:02pm
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I just installed the Fel Pro head gaskets on a 360 I'm building for my Javelin.It states right on the paper that has the part # on it to spray the block side only,and leave the blue side alone.I've been an automotove machinist/engine builder for 34 years.I have used copper coat on numerous builds and it does not hurt a thing as long as the gasket does not have a chemical already attached to it.What copper coat actually does is spread the heat out around any hot spots that can be created by imperfections on the gasket,block,head,and it helps let the gasket move uniformly with the head and block while torqing to avoid any "pinching" that may occur.
Greg ------------- Plenty of AMC Parts & Cars |
Posted By: 69 ambassador 390
Date Posted: Mar/07/2011 at 6:13pm
------------- Steve Brown Algonac, Mi. 69 Ambassador sst 390 84 Grand Wagoneer 69 Cougar XR7 65 Fairlaine 500XL 79 F-350 Super Camper Special |
Posted By: limachine
Date Posted: Jul/02/2011 at 7:25am
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Well, if anyone's still watching this page, need advice here. I just put a fresh 390 into my Machine, & I went to break in the cam last night, & as soon as I got a little temp into #2 header pipe, the head bolt under it started weeping coolant. I'm pretty sure when the 390 was assembled, no sealer was used on the bolts. I'm about to pop the header off & check this out, but man does this suck. My cruise for the 4th is in jeopardy here.
So you guys don't use sealer on the bolts?
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Posted By: limachine
Date Posted: Jul/02/2011 at 7:58am
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ok, well, just figured out why you don't need sealer on the bolts...checked another block & saw the hole doesn't go through into the jacket. Which means I've got a gasket sealing issue OR a crack. It wouldn't be so bad if the boss for the head bolt was cracked from a bolt that was too long, I (hope) just seal the threads & I'm good. But after I filled the coolant, I pressure tested it, & it was good overnight...not a drop! as soon as it got warm, poof.
I'm not postal yet, but the day is young.
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Posted By: 69 ambassador 390
Date Posted: Jul/02/2011 at 11:35am
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If it holds torque then just use some indian head sealer on the bolt and run it. no silicone or teflon containing stuff. the reason is if the sealer don't work, silicone or teflon will prevent the next step from working. If you still have a leak because of a crack in the lower bolt holes you can fix it with the head in place. You can use a solid style thread insert sealed with sleeve retainer liquid right through the offending head bolt hole. the repair will not be possible if you introduce any silicone or teflon into the damaged area. ------------- Steve Brown Algonac, Mi. 69 Ambassador sst 390 84 Grand Wagoneer 69 Cougar XR7 65 Fairlaine 500XL 79 F-350 Super Camper Special |
Posted By: gregscram
Date Posted: Jul/02/2011 at 5:11pm
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I use Permatex white teflon sealer on all my head bolts,no matter if they go into the water jacket or not.
Greg ------------- Plenty of AMC Parts & Cars |
Posted By: poormansMACHINE
Date Posted: Jul/02/2011 at 5:23pm
| How much does all this crap glopped on threads of head bolts affect the actual torque (clamping force)? |
Posted By: 69 ambassador 390
Date Posted: Jul/02/2011 at 8:46pm
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A lot. That is why ARP designed a special grey bolt prep so they can give you consistancy. All of their torques are based on this. ------------- Steve Brown Algonac, Mi. 69 Ambassador sst 390 84 Grand Wagoneer 69 Cougar XR7 65 Fairlaine 500XL 79 F-350 Super Camper Special |
Posted By: limachine
Date Posted: Jul/02/2011 at 10:50pm
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Very strange.
I did just that - permatex the bolt...BUT...
I did some exploratory surgery. Took the header & valve cover off, pulled the plugs. There was no coolant in the oil or in the cylinder. Pulled the offending bolt out & couldn't find any coolant in the hole, just the oil on the threads. There was a drop of coolant under the head of the bolt, but the shoulder was dry. Double checked the thread depth to make sure there wasn't something stuck in there, but that was ok. I gave the hole a swab with a q-tip, but no a-freeze. I was expecting the threaded boss to be cracked at the bottom, because when I got the car there was a 304 under the hood, & the 390 was in pieces. The block had a chain with 2 long bolts run into the head bolt holes, so that's what I was expecting. But I didn't see anything wrong.
I retorqed the head bolts (permatex on the one I pulled), & a few seconds after I fired it, I had the same seepage collecting around the bolt head, I even put a pressure gauge on the radiator to check for compression leaking into the jackets, thinking either a bad gasket or a pourous cylinder wall. But it stopped & dried up after a minute. So WTF???
The block was decked & bored, the heads were milled. I'm wondering if that causes a problem.
Otherwise it ran well. I broke in the cam, she stayed at 180, then I started tuning the carb & had problems with that. So tomorrow I swap out the carb & start over. If the leak comes back, I'll have to pull the head.
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Posted By: 69 ambassador 390
Date Posted: Jul/02/2011 at 11:10pm
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Maybe the head is cracked through the bolt hole. Not unknown to happen if somone in the past pulled it down uneven. If it pressure checks ok and runs ok then maybe throw some block sealer at it and forget it. I have several vehicls in my fleet with a new product called Blue Devil sealer and it seems to fix a really bad blown head gasket on ford triton engines as well as the cracked heads those engines develope. One has been running for almost a year with a gasket that used to squirt coolant out the side. The Blue Devil has no solids in it and should fix a little crack. Can't hurt. ------------- Steve Brown Algonac, Mi. 69 Ambassador sst 390 84 Grand Wagoneer 69 Cougar XR7 65 Fairlaine 500XL 79 F-350 Super Camper Special |
Posted By: limachine
Date Posted: Jul/02/2011 at 11:29pm
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Hey Thanks! I was debating on what to stick in there. There's clearly something going on & after spending all that time & money chasing parts & putting out fires, I don't want any more problems. Just want to get it out cruising again.
Rich
tried uploading a pic, didn't work. best I can do is a facebook link
http://www.facebook.com/#!/photo.php?fbid=240642462614187&set=a.103539586324476.7361.100000053061686&type=1&theater - http://www.facebook.com/#!/photo.php?fbid=240642462614187&set=a.103539586324476.7361.100000053061686&type=1&theater
 |
Posted By: limachine
Date Posted: Jul/02/2011 at 11:31pm
| http://www.facebook.com/photo.php?pid=1003541&l=136bbc4bd2&id=100000053061686 try this one instead |
Posted By: FuzzFace2
Date Posted: Jul/03/2011 at 10:05am
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Not everyone has FB so cam not look. I did not read all the paged to see what bolt you are finding the leak at but as someone pointed out the end blots can crack the head because the head when cased has a sharp edge where cracks like to start. When my street motor was out for detailing I took a grinder to round this edge.
Dave ---- ------------- TSM = Technical Service Manual 75 Gremlin X v8 for sale 70 Javelin 360/auto drag car 70 Javelin 360/T5 Street car |
Posted By: nda racer
Date Posted: Jul/03/2011 at 1:00pm
That's what I get posting the link into my browser.
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Posted By: limachine
Date Posted: Jul/04/2011 at 9:16am
| Hey thanks for posting it for me! Gonna try a different carb today, Rich |