Cometic MLS head gaskets
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Topic: Cometic MLS head gaskets
Posted By: brownspirit
Subject: Cometic MLS head gaskets
Date Posted: Dec/05/2018 at 7:40am
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Would like to know who is running these and if they are having good luck. I've got a fresh cast block/Indy Sr headed drag engine. It is around 14.5:1 comp. The engine was dynoed without incident and ran for 30 minutes and one awful pass at the track. After getting the car home I figured I would run the valves before pulling the rockers off and winterizing the car, There appeared to be a little water on the oil so I did a leakdown and found #3 was putting air in the radiator. Pulled the head and had it pressure tested and checked out at a reputable local shop and they said it looks perfect. I checked the deck surface out the best I could and it passes the feeler gauge test which is all I know to do, it looks freshly cut and smooth. The gasket has a small impefecrion on the lower left hand water jacket/fire ring area, which would appear to be the leak. I'm hoping it was some sort of fluke gasket issue, my plan is to clean everything up and reassemble, just wanted to make sure I shouldnt be thinking of something else while it's apart. Thanks, Andy. ------------- 69' BBB AMX 390/4-speed 69' s/crambler project 69’ International F210d Cummins/5+4 |
Replies:
Posted By: Lenni AMC
Date Posted: Dec/05/2018 at 9:08am
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I used them when I put the new engine together for my Gremlin I had the standard Felpro blue gaskets before. Haven´t had any problems with the Cometic Installed them dry with no copper spray or sealer on the gaskets ------------- AMC Gremlin w/401 6.212 @ 117.01 - 1/8 Mile 9.785 @ 133.11 - 1/4 Mile https://www.youtube.com/channel/UCikyNqrfpMB8VzLd910Hkhg https://rbjracing1.wixsite.com/website |
Posted By: PROSTOCKTOM
Date Posted: Dec/05/2018 at 9:21am
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Ask Kevin "Stickshifter" I am sure he has used every kind of gaskets known over the years. Since he has the same hardware as you he's one of a few here qualified to answer your question in that performance level. Tom
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Posted By: POS #1
Date Posted: Dec/05/2018 at 11:22am
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Hey Andy, when i first built the 407 iron block, sr heads. it kept blowing coolant... as it turned out the heads were not perfectly flat from INDY.... after i had the surface trued, no head gasket issue since... i have been using Rol gaskets...
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Posted By: pit crew
Date Posted: Dec/05/2018 at 11:26am
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My first impulse is to say it was more than likely a fluke. We have built several engines using the MLS gaskets and have encountered no problems so far. -------------  73 Hornet - 401EFI - THM400 - Twin Grip 20 |
Posted By: 343sharpstick
Date Posted: Dec/05/2018 at 1:38pm
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I use the Cometic MLS on everything I own from my 401 to motorcycles. |
Posted By: Red Devil
Date Posted: Dec/05/2018 at 1:42pm
| Do you have the extra head bolts? If not, might be worthwhile to add while it's apart. |
Posted By: DragRacingSpirit
Date Posted: Dec/05/2018 at 2:45pm
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The engine in my car is similar. Dome pistons and lots of compression. I could not hold a head gasket without the extra head bolts. With the extra head bolts and ROL gaskets I have never had a problem. I have never tried the cometic gaskets.
------------- Best 1/4 mile 8.99, 1/8 mile 5.71, 60 foot 1.27, no power adders |
Posted By: Rebel Machine
Date Posted: Dec/05/2018 at 3:58pm
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On my new engine we'll be using the MLS head gaskets. Engine builder told me it's important to machine the surface of the block mirror smooth. A standard decking like you'd do with the Fel-Pro gaskets isn't good enough. -Steve-
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Posted By: brownspirit
Date Posted: Dec/05/2018 at 4:05pm
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I do not have the extra headbolts. I would add them at this point given the opportunity, but the engine is still in the car. I will probably reassemble the way it is with a fresh gasket. I have a stock block, Im sure Kevin F has an Indy block and likely extra headbolts, so his setup is different, but Im happy to have anyone's opinion. Thanks, Andy ------------- 69' BBB AMX 390/4-speed 69' s/crambler project 69’ International F210d Cummins/5+4 |
Posted By: Red Devil
Date Posted: Dec/05/2018 at 4:25pm
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FWIW, I drilled & tapped for the extra head bolts for Indy SRs in an AMC block with the engine still in the car (didn't have access to a hoist at the time). I used a 90 deg. angle drill and the heads with drill bushings in the extra holes to guide the drill bit and tap. Drilled small pilot holes first with a small ID drill bushing then larger up to tap drill size and tapped by hand with a drill bushing to guide the tap to keep it square. Used a magnet to clean out any cuttings and flushed the block thoroughly. In hind sight, it would have been much easier to pull the engine. Some machinists may cringe, but it worked - just took extra care and time. Extra bolts weren't needed for my application, just did it because I could. Hope this helps,RD.
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Posted By: Coloradoamx
Date Posted: Dec/05/2018 at 5:52pm
| MLS gaskets are very good, Cometic especially, however, if you have over 13:1 compression, you are asking for trouble without the extra headbolts. |
Posted By: amx600rr
Date Posted: Dec/05/2018 at 8:06pm
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I do not have experience with MLS gaskets. At 14.5 compression I believe You will need the copper head gasket and o-ringed block. I have used FlatOut Group Rubber Coated Copper gaskets on my o-ringed 401 w/ iron 502-2 heads. |
Posted By: Grey Ghost
Date Posted: Dec/06/2018 at 9:46pm
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I HAVE THE SR HEADS WITH 13.5 COMPRESSION AND THE EXTRA HEADBOLTS AND I USE SCE ICS TITAN COPPER GASKETS, THEY HAVE THE O-RING BUILT IN HAVE NOT HAD A HEAD GASKET ISSUE FOR AT LEAST 7 YEARS AND I WAS TOLD THEY ARE REUSABLE ------------- Lets go racing! |
Posted By: DragRacingSpirit
Date Posted: Dec/07/2018 at 1:07pm
At one
point Kevin was running with an oem iron block with the older Indy head castings. When
he got his Indy aluminum block he drilled it for both the std Indy
castings and the CNC300 castings. I hope he doesn't mind reposting this pic. It was on this forum somewhere. I had to save it :) The bottom row of bolts is for the CNC castings the holes above that that he filled in with a threaded aluminum stud and machined flat is for the std casting. So He is set to use either casting that he wishes.  ------------- Best 1/4 mile 8.99, 1/8 mile 5.71, 60 foot 1.27, no power adders |
brownspirit wrote:Posted By: i6cj7
Date Posted: Dec/22/2018 at 11:01pm
| would head studs help sealing if one didn't get the extra head bolt holes drilled? |
Posted By: Lenni AMC
Date Posted: Dec/23/2018 at 3:40am
Yes ------------- AMC Gremlin w/401 6.212 @ 117.01 - 1/8 Mile 9.785 @ 133.11 - 1/4 Mile https://www.youtube.com/channel/UCikyNqrfpMB8VzLd910Hkhg https://rbjracing1.wixsite.com/website |
Posted By: amx390ssc
Date Posted: Dec/27/2018 at 9:51am
| A second Yes for head studs!!! |
Posted By: i6cj7
Date Posted: Dec/27/2018 at 10:54am
too bad I didn't get the latest edelbrock heads that have the head bolt area machined down for header clearance when using studs . 
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Posted By: pfordamx
Date Posted: Jan/21/2019 at 11:00pm
| we have had nightmares with headgaskets 15.1 418 with indy srs went through 3 sets of cometics on a brand new engine would always pressurize the coolant system with load has yet to make a full pass. although i don't believe the gaskets are the issue the last time our engine was apart it was noted that the center water jackets in the indy heads are huge and actually going within the compression ring where the head was pushing the gasket wasn't compressed because it was in the water jacket. we had the center water jackets on both heads tig welded and built up and heads surface and now they should actually clamp the gasket. its not back together yet to prove if this worked or not but it should be soon and its going on a dyno to find out if its fixed. |
Posted By: DragRacingSpirit
Date Posted: Jan/22/2019 at 11:45am
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The best head gasket I have used for my application, though I don't have at much compression as your engine is the ROL HG31190HT if you can still find a set. But like I said i dont have 15.1 compression, only 13.5:1. To get the ROL HT gaskets to hold at this compresion level all I had to do is install the extra head bolts on my SR heads, drill the block and used a gasket punch on the ROL head gaskets to match the extra holes. Never had a problem in years running this combination of iron block and SR heads. ------------- Best 1/4 mile 8.99, 1/8 mile 5.71, 60 foot 1.27, no power adders |
Posted By: brownspirit
Date Posted: Jun/04/2019 at 7:11am
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Well, I dusted off this project to get it back together. I re-examined all the components and found the issue, the coolant port on the lower front corner of the number 3 cylinder is cast too large compromising the gasket. I can’t believe I didn’t see it before, but it is very clear at this point. I’m told to match a set of felpro gaskets up and see if they will seal. If that’s a no go I will need to tig it up and resurface the head. Has anyone encountered this with the Indy SRs before? Andy ------------- 69' BBB AMX 390/4-speed 69' s/crambler project 69’ International F210d Cummins/5+4 |
Posted By: PROSTOCKTOM
Date Posted: Jun/04/2019 at 8:05am
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Posted: 22/Jan/2019 at 1:00amPosted By: brownspirit
Date Posted: Jun/04/2019 at 9:02am
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Haha, how did I miss that in my very own thread!
------------- 69' BBB AMX 390/4-speed 69' s/crambler project 69’ International F210d Cummins/5+4 |
Posted By: POS #1
Date Posted: Jun/04/2019 at 11:18am
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when i 1st got my SR's.. i also had head gasket issues... in my case, turned out it took. .015 to get my heads Flat, and that was the issue i had personally. |
Posted By: brownspirit
Date Posted: Jun/23/2019 at 6:24pm
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Well, disappointment strikes again. I guess the extra head bolts are mandatory. The engine builder I used has remained adamant that I don’t need them but that seems to be BS. What is the best way to approach this? I assume I just have the machine shop drill 3/8” holes where INDY has them? My local machine shop has done this to a few amc engines but typically with steel heads and one with HLR heads. Can I do this with quality results in the car? Any advice is appreciated. Andy ------------- 69' BBB AMX 390/4-speed 69' s/crambler project 69’ International F210d Cummins/5+4 |
Posted By: PROSTOCKTOM
Date Posted: Jun/23/2019 at 11:59pm
Tom
------------- Molnar Technologies Full Service Dealer - Crankshafts & Connecting Rods 1969 AMC Rambler Rouge Race Car 1974 AMC Hornet Hatchback, Wally Booth Outlaw Nostalgic Pro Stock Race Car Project |
Posted By: brownspirit
Date Posted: Jun/24/2019 at 7:41am
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So that’s a no? Haha, I honestly can say at this point I don’t care. If the motor blows up I’d probably be relieved, I could either start over on a new engine or sell the car as a roller. This thing has been a disappointment from day one, for someone with time this it’s probably not much of an issue, but I just don’t have it. I spent a lot money and put my faith in the notion that someone who has a great deal of experience was going to do what needed to be done. I didn’t cheap out, I actually brought up adding the additional bolts and was assured that with studs and modern MLS gaskets everything would be happy. If the motor comes out I’d probably like to send it to someone competent to fix it. For something this seemingly basic to this type of build to be overlooked is odd and has me questioning everything. I find it hard to believe this wasn’t an issue on the dyno, Im willing to give people the benefit of the doubt, but this combined with a handful of other things has made it obvious this is a lack knowledge or an intent to deceive. Thanks for all the advise, I appreciate it. Andy ------------- 69' BBB AMX 390/4-speed 69' s/crambler project 69’ International F210d Cummins/5+4 |
Posted By: Red Devil
Date Posted: Jun/24/2019 at 10:58am
I'd say yes, but takes extra care and time. If you're not confident in doing it, pull the engine and send to the machine shop.
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Posted By: i6cj7
Date Posted: Jun/24/2019 at 11:01am
| What's it cost for a machine shop to do the extra bolt holes in an aluminum head and block? |
Posted By: brownspirit
Date Posted: Jun/24/2019 at 11:49am
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I’d say $500 to have a machine shop do it in the process of an engine build at the most. Personally the money is not important to me. It’s nothing compared to the headaches and bs I’ve had with this engine. I’ve never been screwed this bad before, I’ve wasted a year on getting head gaskets to seal on this turd. Now it should come out, again, be torn down, machined by a second machine shop who likely wants nothing to do with an engine someone else built. I think RD is probably right, and I feel like I should be able to do it, but I just can’t get over that fact that I’m in this position. At this point I don’t think there is much to lose. Andy ------------- 69' BBB AMX 390/4-speed 69' s/crambler project 69’ International F210d Cummins/5+4 |
Posted By: DragRacingSpirit
Date Posted: Jun/24/2019 at 12:43pm
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You can do it yourself pretty easily. My Indy heads had the location marks on the casting so they were easy to locate. Put the head in a milling machine, get it squared and straight and drill it through. Also, I didn't use 3/8 studs I actually used 5/16 and it worked just fine. Make sure and cut a spot face for the hardened flat washer so it is flush and square in the casting. After the head casting is machined put the head onto the block and use drill guides in the castings hole to mark the spot on the block. Start small and work you way up slowly and carefully. The main thing is to get is square with the deck. It really isn't that hard to do. If you are careful you can do it without tearing the whole engine down but it needs to be out of the car imo. ------------- Best 1/4 mile 8.99, 1/8 mile 5.71, 60 foot 1.27, no power adders |
Posted By: DragRacingSpirit
Date Posted: Jun/24/2019 at 12:46pm
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Also, I understand how you feel from reading your posts that you are really frustrated right now and I am not cutting on you at all, but if you would listened to advice from people that have been there and done that your issues would have been long behind you and you would be having fun going down the track. ------------- Best 1/4 mile 8.99, 1/8 mile 5.71, 60 foot 1.27, no power adders |
Posted By: brownspirit
Date Posted: Jun/24/2019 at 2:17pm
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No sweat man, I appreciate all the comments and looking back your right. I just can’t get over the fact that the guy who built this engine has been racing and building these engines for close to 50 years. I didn’t just hatch up this anti-extra head bolt scheme myself, a well respected builder made the call. I can’t even bring myself to call him again because I will be sent into a tailspin if he says again that I don’t need the extra headbolts. He has remained adamant that they are unnecessary and even told me to try a set of fle-pro gaskets. It probably doesn’t seem like a big hurdle to some guys, but I don’t have the time to be be pulling the engine every couple months and hope that it’s fixed, go to the track and be disappointed again. I’m I crazy for feeling like I got f-ucked, cause I absolutely feel that way. Andy ------------- 69' BBB AMX 390/4-speed 69' s/crambler project 69’ International F210d Cummins/5+4 |
Posted By: brownspirit
Date Posted: Jun/24/2019 at 2:36pm
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But moving forward, why 5/16” as opposed to 3/8”, where you concerned about the amount of material there. Do you remember how deep you went with them? Also, there is a special punch that can be used to modify the MLS gaskets without any concern of creating an issue? It looks like a fairly thick piece of stainless (???). If I had a milling machine in my garage I probably wouldn’t be crying on the internet about doing the modification. I will need to bring them to the local machine shop and have the holes drilled and washer surfaces cut. Thanks again, Andy’s ------------- 69' BBB AMX 390/4-speed 69' s/crambler project 69’ International F210d Cummins/5+4 |
Posted By: DragRacingSpirit
Date Posted: Jun/24/2019 at 3:08pm
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I had the hardened 5/16 arp studs, machine washers and 12 point nuts that were laying around intended for a Buick build that never got used. So I used them. I will double check on that though, it's been awhile. I'm thinking they were 5/16 but I could be remembering wrong and they could be 3/8 ? When you drill the block deck you will drill through into the water jacket. When it goes through you know that you are deep enough. I don't think you will be able to use a gasket punch on a MLS gasket ?? If they are steel shim gasket you might be able to cut them with a laser, a water jet machine or a mill bit.
------------- Best 1/4 mile 8.99, 1/8 mile 5.71, 60 foot 1.27, no power adders |
Posted By: pfordamx
Date Posted: Jul/02/2019 at 10:04pm
| ours is currently out of the car to get extra head bolts and oringed if it doesn't make passes this time i don't know what else to try. but our experience over the past year do what ever it takes to get it done. |
Posted By: brownspirit
Date Posted: Jul/04/2019 at 7:11pm
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I’m sorry to hear your issue hasn’t been resolved either. I hope you can get it squared away quickly, personally, I just want this thing out of my garage at this point. Andy ------------- 69' BBB AMX 390/4-speed 69' s/crambler project 69’ International F210d Cummins/5+4 |
Posted By: tsanchez
Date Posted: Jul/05/2019 at 6:50pm
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On mine I had better luck with the fel pro gasket, the cometics seeped just a tad, I also have the extra head bolts, 3/8th ------------- http://s192.photobucket.com/user/antonsan/media/jav1_zps87a70dce.jpg.html" rel="nofollow"> 
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Posted By: pfordamx
Date Posted: Jul/07/2019 at 11:25pm
| seeping out of the motor doesn't really bother me its when it fills the cylinder that its an issue. |
Posted By: brownspirit
Date Posted: Jul/08/2019 at 6:17am
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I couldn’t agree more. Andy ------------- 69' BBB AMX 390/4-speed 69' s/crambler project 69’ International F210d Cummins/5+4 |
Posted By: tsanchez
Date Posted: Jul/11/2019 at 10:38am
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Mine did seap into the engine, ruined a few cylinders ------------- http://s192.photobucket.com/user/antonsan/media/jav1_zps87a70dce.jpg.html" rel="nofollow">
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