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Compression drop w/ replacement gasket on 318 #624245 02/25/10 06:45 PM 02/25/10 06:45 PM
Joined: Jul 2007 Posts: 1,682 Philadelphia R radar OP top fuel
radar OP top fuel R Joined: Jul 2007 Posts: 1,682 Philadelphia	I am rebuilding a 1967 318 motor. It has the closed chamber 904 casting heads with small valves and runners. I bought a Comp 268 (218* at .050 .454 lift) cam kit. The cam wants 9:1 cr and 3.55 gears. I have read about the replacement head gaskets all being thicker and bigger bore than the original equipment 318 steel shim. I already also bought a full felpro 318/273 gasket set with the blue head gasket. I'm assuming it is a 318 gasket set because of port sizes not bore size? Am I in for some machining? Heads/block decked? I don't want much more than a stock build if that matters. Super budget deal. Thanks

Re: Compression drop w/ replacement gasket on 318 [Re: radar] #624246 02/25/10 06:49 PM 02/25/10 06:49 PM
Joined: Oct 2003 Posts: 21,345 Marysville, O-H-I-O 70Cuda383 Too Many Posts
70Cuda383 Too Many Posts Joined: Oct 2003 Posts: 21,345 Marysville, O-H-I-O	Quote: I am rebuilding a 1967 318 motor. It has the closed chamber 904 casting heads with small valves and runners. I bought a Comp 268 (218* at .050 .454 lift) cam kit. The cam wants 9:1 cr and 3.55 gears. I have read about the replacement head gaskets all being thicker and bigger bore than the original equipment 318 steel shim. I already also bought a full felpro 318/273 gasket set with the blue head gasket. I'm assuming it is a 318 gasket set because of port sizes not bore size? Am I in for some machining? Heads/block decked? I don't want much more than a stock build if that matters. Super budget deal. Thanks yup, the blue gasket is probably around .030 thick compressed. to increase your compression, you WILL have to either A) mill the decks B) mill the heads C) install different pistons with taller Comp. height D) Any combination of the above. keep in mind that with milling the heads/decks, the intake side of heads might need touched so the intake still fits right, and you might need shorter pushrods. Photobucket sucks

Re: Compression drop w/ replacement gasket on 318 [Re: 70Cuda383] #624247 02/26/10 08:53 AM 02/26/10 08:53 AM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	Quote: Quote: I am rebuilding a 1967 318 motor. It has the closed chamber 904 casting heads with small valves and runners. I bought a Comp 268 (218* at .050 .454 lift) cam kit. The cam wants 9:1 cr and 3.55 gears. I have read about the replacement head gaskets all being thicker and bigger bore than the original equipment 318 steel shim. I already also bought a full felpro 318/273 gasket set with the blue head gasket. I'm assuming it is a 318 gasket set because of port sizes not bore size? Am I in for some machining? Heads/block decked? I don't want much more than a stock build if that matters. Super budget deal. Thanks yup, the blue gasket is probably around .030 thick compressed. to increase your compression, you WILL have to either A) mill the decks B) mill the heads C) install different pistons with taller Comp. height D) Any combination of the above. keep in mind that with milling the heads/decks, the intake side of heads might need touched so the intake still fits right, and you might need shorter pushrods. the fel pro gasket that comes in those kits isn't .030 thick, it's .054" thick compressed. easiest thing to do is buy the $40 Mr. gasket .028" thick compressed gasket. and it's actually the oil pan gasket that makes the 318/360 sets different. I can't remember if the rear main seal is the same or different between the motors, too...in all the complete gasket sets I've seen, they come with both sets of intake gaskets. 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: Compression drop w/ replacement gasket on 318 [Re: patrick] #624248 02/26/10 10:19 AM 02/26/10 10:19 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: buy the $40 Mr. gasket .028" thick compressed gasket. Patrick is it the same # for 318 and 360? and how thick are the oe metal gaskets that come out of there (80's 318) live every 24 hour block of time like it's your last day on earth

Re: Compression drop w/ replacement gasket on 318 [Re: RapidRobert] #624249 02/26/10 10:46 AM 02/26/10 10:46 AM
Joined: Nov 2005 Posts: 589 Fortworth TX M mod5v mopar
mod5v mopar M Joined: Nov 2005 Posts: 589 Fortworth TX	I did some resurch on this and the gasket u want is #1121G (Mr. Gasket}like Patrick said the fel-pro gasket is .053" thick.

Re: Compression drop w/ replacement gasket on 318 [Re: mod5v] #624250 02/26/10 10:56 AM 02/26/10 10:56 AM
Joined: Nov 2004 Posts: 892 USA K krw71ragtop super stock
krw71ragtop super stock K Joined: Nov 2004 Posts: 892 USA	The last batch of Felpro's I measured were .054"-.057" thick. I purchased the Mopar set #P4120094 from Mancini and are advertised at .024-.028" compressed.

Re: Compression drop w/ replacement gasket on 318 [Re: RapidRobert] #624251 02/26/10 11:48 AM 02/26/10 11:48 AM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	Quote: Quote: buy the $40 Mr. gasket .028" thick compressed gasket. Patrick is it the same # for 318 and 360? and how thick are the oe metal gaskets that come out of there (80's 318) yes, same part. it's a 4.14" bore head gasket. the slight amount of crevice volume isn't going to be a big deal... my '86 76k mile 318 had a composite head gasket that was ~.040" thick OEM... Quote: The last batch of Felpro's I measured were .054"-.057" thick. I purchased the Mopar set #P4120094 from Mancini and are advertised at .024-.028" compressed. if the MP ones you bought are white, then it's a repackaged Mr. gasket gasket set. 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: Compression drop w/ replacement gasket on 318 [Re: patrick] #624252 02/26/10 01:47 PM 02/26/10 01:47 PM
Joined: Jul 2007 Posts: 1,682 Philadelphia R radar OP top fuel
radar OP top fuel R Joined: Jul 2007 Posts: 1,682 Philadelphia	I looked around. Mancini has the .028 gasket for $40 but is says out of stock or something on the webstore. Summit only showed an $80 SCE copper gasket which is .021. Jegs has a mr gasket #720-1135 which is listed to compress to .018 to .020. I'm going to order a set of the thin mr. gaskets. Especially because they're only $20 at Jegs! Anything to watch out for? I'm going to assume head and deck surfaces need to be dead flat and smooth? Are these prone to blowing easy? Do I need copper spray for them? Thanks for all the replies Im sure this topic is beaten to death a couple times a year but parts availability changes so I really appreciate it kevin

Re: Compression drop w/ replacement gasket on 318 [Re: radar] #624253 02/26/10 02:05 PM 02/26/10 02:05 PM
Joined: Nov 2005 Posts: 589 Fortworth TX M mod5v mopar
mod5v mopar M Joined: Nov 2005 Posts: 589 Fortworth TX	AHHH!!! I think the #720-1135 are for a big block!! May not work so good on a 318

Re: Compression drop w/ replacement gasket on 318 [Re: mod5v] #624254 02/26/10 03:14 PM 02/26/10 03:14 PM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	http://www.mr-gasket.com/CatalogsList.aspx PN 1121 is what I used....I bought a set from summit in june. don't know why they're not listed anymore... edit: jegs and amazon have them http://www.jegs.com/i/Mr.%20Gasket/720/1121/10002/-1?CT=999 http://www.amazon.com/Mr-Gasket-1121-Cylinder-Head/dp/B000CMF09M Last edited by patrick; 02/26/10 03:56 PM. 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: Compression drop w/ replacement gasket on 318 [Re: patrick] #624255 02/26/10 04:14 PM 02/26/10 04:14 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: yes, same part. it's a 4.14" bore head gasket. the slight amount of crevice volume isn't going to be a big deal...my '86 76k mile 318 had a composite head gasket that was ~.040" thick OEM.... thank you Patrick. I didn't know that my 83 318 might have a thick gasket (I was assuming thin steel). 302 heads and thinner ones should make a seat of the pants difference live every 24 hour block of time like it's your last day on earth

Re: Compression drop w/ replacement gasket on 318 [Re: RapidRobert] #624256 02/26/10 07:24 PM 02/26/10 07:24 PM
Joined: Jul 2007 Posts: 1,682 Philadelphia R radar OP top fuel
radar OP top fuel R Joined: Jul 2007 Posts: 1,682 Philadelphia	Thanks fellas- I almost bought the big block set! Nobody I can find has the thin Mr Gasket ones. They seem to be discontinued. I had turned up reports of 'national backorder' on moparts search engine but I guess it's really over for this p/n. I haven't inspected the heads yet. If they turn out to be nice and flat I will just suck it up and shell out $86 for SCE Gaskets p/n 069152 the .021 copper ones. Thanks again and if anybody has any other ideas I probably won't be buying the gaskets for a few weeks anyway.

Re: Compression drop w/ replacement gasket on 318 [Re: radar] #624257 02/26/10 08:47 PM 02/26/10 08:47 PM
Joined: May 2003 Posts: 1,200 fort worth,tx T txterry2 super gas
txterry2 super gas T Joined: May 2003 Posts: 1,200 fort worth,tx	Google 1121 mr.gasket.Found 3 sites that had them within 5 minutes,one was amazon.

Re: Compression drop w/ replacement gasket on 318 [Re: krw71ragtop] #624258 02/26/10 09:07 PM 02/26/10 09:07 PM
Joined: Jan 2008 Posts: 2,233 ILLINOIS V volaredon top fuel
volaredon top fuel V Joined: Jan 2008 Posts: 2,233 ILLINOIS	Quote: The last batch of Felpro's I measured were .054"-.057" thick. I purchased the Mopar set #P4120094 from Mancini and are advertised at .024-.028" compressed. I got these P-number thin ones, thru the local dealer when I put the EQ heads onto my LA 318 a year ago; I have a Magnum 318 in the machine shop as we speak I will be trying to get another set when that engine gets back here.

Re: Compression drop w/ replacement gasket on 318 [Re: volaredon] #624259 02/26/10 11:24 PM 02/26/10 11:24 PM
Joined: Jul 2007 Posts: 1,682 Philadelphia R radar OP top fuel
radar OP top fuel R Joined: Jul 2007 Posts: 1,682 Philadelphia	I just ordered a set off amazon. Ended up being around $50 shipped. Thanks I didn't think to look there. Jegs has the p/n but it says call service rep to order. The service rep told me it's a discontinued part. I was starting to have flashbacks to a couple years ago when everybody had 1"+ torsion bars listed for like $150 and none in stock. I ended up spending big bucks for just suspension bars. Now they're on sale for around $150. Go figure. Anyway, thanks everybody for all the help and hopefully this thread can help the next poor sucker with his replacement gasket problem.

Re: Compression drop w/ replacement gasket on 318 [Re: radar] #624260 03/03/10 11:08 AM 03/03/10 11:08 AM
Joined: Jun 2008 Posts: 1,822 Colorado D denfireguy top fuel
denfireguy top fuel D Joined: Jun 2008 Posts: 1,822 Colorado	I just ordered set off of Amazon as well. It appears that this part is discontinued. If you want a thin gasket, might be best to order one now. Somehow I wonder if there ever will be any made again. Craig 2014 Ram 1500 Laramie, 73 Cuda Previous mopars: 62 Valiant, 65 Fury III, 68 Fury III, 72 Satellite, 74 Satellite, 89 Acclaim, 98 Caravan, 2003 Durango Only previous Non-Mopar: Schwinn Tornado

Re: Compression drop w/ replacement gasket on 318 [Re: radar] #2236833 01/18/17 05:30 PM 01/18/17 05:30 PM
Joined: May 2004 Posts: 4,920 Joplin, MO USA Robbins master
Robbins master Joined: May 2004 Posts: 4,920 Joplin, MO USA	Didn't FelPro used to make a steel shim factory style head gaskets? Whether this is a good idea or not...but my dad would spray paint those gaskets with silver paint....my cousin sprays them with copper coat to help them seal. Last edited by Robbins; 01/18/17 06:37 PM. Moparlee

Re: Compression drop w/ replacement gasket on 318 [Re: radar] #2237229 01/19/17 01:29 PM 01/19/17 01:29 PM
Joined: Nov 2004 Posts: 2,495 Oregon City, OR Baxter61 top fuel
Baxter61 top fuel Joined: Nov 2004 Posts: 2,495 Oregon City, OR

Re: Compression drop w/ replacement gasket on 318 [Re: Baxter61] #2237279 01/19/17 02:57 PM 01/19/17 02:57 PM
Joined: Jun 2008 Posts: 1,822 Colorado D denfireguy top fuel
denfireguy top fuel D Joined: Jun 2008 Posts: 1,822 Colorado	First, this is a 7 year old thread that has been resurrected from the dead. And things have changed a bit. The Mr Gasket 1121G (.028 compresses) that was disappearing then is back in stock at Summit and many other vendors. Guess it was just a seasonal shortfall. Craig 2014 Ram 1500 Laramie, 73 Cuda Previous mopars: 62 Valiant, 65 Fury III, 68 Fury III, 72 Satellite, 74 Satellite, 89 Acclaim, 98 Caravan, 2003 Durango Only previous Non-Mopar: Schwinn Tornado

Re: Compression drop w/ replacement gasket on 318 [Re: radar] #2237320 01/19/17 04:42 PM 01/19/17 04:42 PM
Joined: Jan 2003 Posts: 1,232 Chicago, IL P PLUM_72 pro stock
PLUM_72 pro stock P Joined: Jan 2003 Posts: 1,232 Chicago, IL	Cometic has a 4.04 bore gasket for the small block with a 0.027" compressed thickness. The trouble there is they are about $80 each. 1972 Dodge Challenger

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