340 manifold on 318 problem? (pics inside) - Moparts Forums

Register Log In Moparts Forums Moparts Question and Answer 340 manifold on 318 problem? (pics inside)

Print Thread

340 manifold on 318 problem? (pics inside) #964472 04/02/11 04:28 PM 04/02/11 04:28 PM
Joined: Jan 2009 Posts: 124 Pittsburgh, PA B bigdaddywiz OP member
bigdaddywiz OP member B Joined: Jan 2009 Posts: 124 Pittsburgh, PA	today i'm finally getting around to finishing my winter project and decided to practice putting the manifold onto the heads so i dont screw up the gasket mating process. this may be common knowledge, but i noticed the manifold matches up port and bolt wise, but there is still surface showing where the 318 intake manifold covered that the 340 manifold leaves exposed. is this ok? also, the little bendy metal tabs (4 pairs total), do they need to be in the up position or down? it was recommended to me to NOT use the supplied front and rear gasket and just seal it up with some permatex "right stuff" sealant. remember, this is all new to me and figured this little project will teach me some engine work basics. thanks 6564447-0402011504edit.jpg (154 downloads) 73 Road Runner 09 Challenger R/T

Re: 340 manifold on 318 problem? (pics inside) [Re: bigdaddywiz] #964473 04/02/11 04:29 PM 04/02/11 04:29 PM
Joined: Jan 2009 Posts: 124 Pittsburgh, PA B bigdaddywiz OP member
bigdaddywiz OP member B Joined: Jan 2009 Posts: 124 Pittsburgh, PA	and the metal tabs... 6564448-0402011508.jpg (134 downloads) 73 Road Runner 09 Challenger R/T

Re: 340 manifold on 318 problem? (pics inside) [Re: bigdaddywiz] #964474 04/02/11 04:33 PM 04/02/11 04:33 PM
Joined: Jan 2003 Posts: 32,972 Grand Prairie,Texas stumpy I Win
stumpy I Win Joined: Jan 2003 Posts: 32,972 Grand Prairie,Texas	When you look at your intake gasket end pieces you will see where the metal tabs go. They help hold the gaskets in place.

Re: 340 manifold on 318 problem? (pics inside) [Re: stumpy] #964475 04/02/11 04:34 PM 04/02/11 04:34 PM
Joined: Jan 2009 Posts: 124 Pittsburgh, PA B bigdaddywiz OP member
bigdaddywiz OP member B Joined: Jan 2009 Posts: 124 Pittsburgh, PA	Quote: When you look at your intake gasket end pieces you will see where the metal tabs go. They help hold the gaskets in place. oh, ok...thanks! didnt even think of that...i thought those were for the front and rear gasket...duh! Last edited by bigdaddywiz; 04/02/11 04:35 PM. 73 Road Runner 09 Challenger R/T

Re: 340 manifold on 318 problem? (pics inside) [Re: bigdaddywiz] #964476 04/02/11 04:45 PM 04/02/11 04:45 PM
Joined: Jan 2008 Posts: 3,886 Lost and Spaced B bboogieart master
bboogieart master B Joined: Jan 2008 Posts: 3,886 Lost and Spaced	the 318 intake manifold covered that the 340 manifold leaves exposed. is this ok? Yep looks right from here. I have mechanical Aptitude. I can screw up anything.

Re: 340 manifold on 318 problem? (pics inside) [Re: bboogieart] #964477 04/02/11 04:51 PM 04/02/11 04:51 PM
Joined: Jan 2009 Posts: 124 Pittsburgh, PA B bigdaddywiz OP member
bigdaddywiz OP member B Joined: Jan 2009 Posts: 124 Pittsburgh, PA	Quote: the 318 intake manifold covered that the 340 manifold leaves exposed. is this ok? Yep looks right from here. thanks for the response thats the 340 intake in the picture...sorry if i wasnt clear in my original post, but the 340 intake is leaving it more exposed than the 318 intake did. 73 Road Runner 09 Challenger R/T

Re: 340 manifold on 318 problem? (pics inside) [Re: bboogieart] #964478 04/02/11 05:01 PM 04/02/11 05:01 PM
Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska	Actually you want those "horseshoe" opening on each side to b open for heat to not affect or b wicked off to the adjacent ports. I would suggest you use a wide carefully placed swath of silicone (clear is barely noticeable) at each end instead of the supplied gaskets as they in a lot of cases are a bit too thick & can hold the intake up a bit causing one of the front manifold water ports to leak after a period of time. If so let it sit up overnight then fire it up & if not at least mockup & see how thick of end gaskets you were given & go from there. Some of those cork gaskets are real thick. Dont know if you have done any milling that would ch your heights. Prob overkill (I'm like that) but never hurts to check live every 24 hour block of time like it's your last day on earth

Re: 340 manifold on 318 problem? (pics inside) [Re: bboogieart] #964479 04/02/11 05:22 PM 04/02/11 05:22 PM
Joined: Jul 2003 Posts: 6,167 Maryland GO_Fish master
GO_Fish master Joined: Jul 2003 Posts: 6,167 Maryland	Quote: the 318 intake manifold covered that the 340 manifold leaves exposed. is this ok? Yep looks right from here. If you still have the 318 intake, lay it next to the 340 intake. I think you will find that they both are almost identical shape in that area. I think what you are seeing is where the old intake gasket lay against the head. Some brands of gasket (cardboard fiber type for example) covered a much larger area than just the sealing surface. And then everything got painted afterward, and the gasket sticking out was not so noticeable. Scott B. "I'm a self-made man... I started with nothing, and I still have most of it!" 68 360 rusty B'cuda 'vert (GO Fish)13.59@ 98.72 mph 69 340 GTS stock 14.18@ 95.60 mph 01 5.9L Ram 1500 Quad Cab 4x4 01 3.5L 300M 16.23@ 86.97 mph

Re: 340 manifold on 318 problem? (pics inside) [Re: GO_Fish] #964480 04/02/11 05:26 PM 04/02/11 05:26 PM
Joined: Jan 2009 Posts: 124 Pittsburgh, PA B bigdaddywiz OP member
bigdaddywiz OP member B Joined: Jan 2009 Posts: 124 Pittsburgh, PA	Quote: Quote: the 318 intake manifold covered that the 340 manifold leaves exposed. is this ok? Yep looks right from here. If you still have the 318 intake, lay it next to the 340 intake. I think you will find that they both are almost identical shape in that area. I think what you are seeing is where the old intake gasket lay against the head. Some brands of gasket (cardboard fiber type for example) covered a much larger area than just the sealing surface. And then everything got painted afterward, and the gasket sticking out was not so noticeable. now that you say that, i think that is what i'm seeing...its been 2 months since i took it apart and i couldnt remember exactly how it looked. thanks everyone! 73 Road Runner 09 Challenger R/T

Re: 340 manifold on 318 problem? (pics inside) [Re: bigdaddywiz] #964481 04/02/11 09:44 PM 04/02/11 09:44 PM
Joined: Mar 2003 Posts: 5,193 NEW JERSEY AARCONV master
AARCONV master Joined: Mar 2003 Posts: 5,193 NEW JERSEY	the fel pro gasket will cover the horseshoe part also

Re: 340 manifold on 318 problem? (pics inside) [Re: bigdaddywiz] #964482 04/02/11 09:47 PM 04/02/11 09:47 PM
Joined: Aug 2003 Posts: 12,291 Kent, Wa 340SHORTY Truck Nut
340SHORTY Truck Nut Joined: Aug 2003 Posts: 12,291 Kent, Wa	you do relize that there is a large port size difference between a 318 and a 340/360 ? I am truckless..

Re: 340 manifold on 318 problem? (pics inside) [Re: AARCONV] #964483 04/02/11 09:51 PM 04/02/11 09:51 PM
Joined: Jan 2003 Posts: 25,200 Upper Midwest M MoparforLife Too Many Posts
MoparforLife Too Many Posts M Joined: Jan 2003 Posts: 25,200 Upper Midwest	Quote: the fel pro gasket will cover the horseshoe part also You don't want this covered. It is to keep a cooler air flow dam between to hot exhaust valve castings. It is designed to be open. Over heated valve seats = cracked valve seats.

Re: 340 manifold on 318 problem? (pics inside) [Re: 340SHORTY] #964484 04/02/11 10:02 PM 04/02/11 10:02 PM
Joined: Feb 2003 Posts: 8,020 Pangaea B5 Bee master
B5 Bee master Joined: Feb 2003 Posts: 8,020 Pangaea	Quote: you do relize that there is a large port size difference between a 318 and a 340/360 ? The factory used a 360 intake on the 318s with 318 heads. There's a Mopar racer that ran one in Stock. His engine builder said it would never be fast with the mismatch ports. His 'never will be fast' combo set the record in T/SA at the first points meet he went to, qualified #1 and won the Gatornationals, runner up'ed the Summernats and won a Div 2 race.

Re: 340 manifold on 318 problem? (pics inside) [Re: B5 Bee] #964485 04/03/11 02:07 AM 04/03/11 02:07 AM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova Banned. Forever.
69L78Nova Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	The factory used 360 intakes on 318s with 360 heads..... 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

Re: 340 manifold on 318 problem? (pics inside) [Re: 69L78Nova] #964486 04/03/11 02:19 AM 04/03/11 02:19 AM
Joined: Feb 2007 Posts: 1,025 Las Vegas, NV dodgeboy11 super stock
dodgeboy11 super stock Joined: Feb 2007 Posts: 1,025 Las Vegas, NV	Put a little sillycone around the water passages and down to the china walls before you install the gaskets to the heads. Before you do ANY of that, set the intake on with the gaskets to see how thick a bead of silicone you'll need to lay on those china walls. This way you don't use too much or too little. After you tighten up the intake bolts, wipe off the excess sealer with a rag before it sets up. Doing this you can also push the sealer into the gap (in case you're worried it's there's not an adequate amount in there) while wiping away the excess. Makes it look a little nicer.

Re: 340 manifold on 318 problem? (pics inside) [Re: bigdaddywiz] #964487 04/03/11 12:32 PM 04/03/11 12:32 PM
Joined: Sep 2003 Posts: 314 North East Missouri E express enthusiast
express enthusiast E Joined: Sep 2003 Posts: 314 North East Missouri	Quote: Quote: When you look at your intake gasket end pieces you will see where the metal tabs go. They help hold the gaskets in place. oh, ok...thanks! didnt even think of that...i thought those were for the front and rear gasket...duh! These are for the front & rear foam or cork seals,but you are not using them so just silicone them down. cny25421@centurytel.net 70 Duster Turbo Charged 79 Lil Red Express Bonded Locksmith

Re: 340 manifold on 318 problem? (pics inside) [Re: 340SHORTY] #964488 04/03/11 03:07 PM 04/03/11 03:07 PM
Joined: Sep 2007 Posts: 14,889 up yours Supercuda About to go away
Supercuda About to go away Joined: Sep 2007 Posts: 14,889 up yours	Quote: you do relize that there is a large port size difference between a 318 and a 340/360 ? So? If it's a factory 4bbl 318 then it has 360 heads, no port mismatch. If it's a factory 2bbl then the heads are the problem, not the port mismatch. A 4bbl on a 318, regardless of the port mismatch is an improvement over the 2bbl, period. They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.

Re: 340 manifold on 318 problem? (pics inside) [Re: Supercuda] #964489 04/03/11 03:19 PM 04/03/11 03:19 PM
Joined: Jan 2003 Posts: 25,200 Upper Midwest M MoparforLife Too Many Posts
MoparforLife Too Many Posts M Joined: Jan 2003 Posts: 25,200 Upper Midwest	Done it several times with no complaints. Vast improvement over the 2 barrel 318.

Re: 340 manifold on 318 problem? (pics inside) [Re: 69L78Nova] #964490 04/03/11 03:22 PM 04/03/11 03:22 PM
Joined: Feb 2003 Posts: 8,020 Pangaea B5 Bee master
B5 Bee master Joined: Feb 2003 Posts: 8,020 Pangaea	Quote: The factory used 360 intakes on 318s with 360 heads..... That's true, most 318-4 had 360 heads, but they also used 360 intakes on 318s with 318 heads. The 360 head 318 motor has a higher NHRA HP factor. He ran the small head because it had the most favorable HP factor. It didn't last long, NHRA added HP to the small head 318-4 by the end of that year which moved his car up a class from T/SA to R/SA (there is no S/SA).

Moderated by Al_Alguire, Hotwheelsjr, moparts, not_a_charger, RangerDan440, tboomer

Hop To

Powered by UBB.threads™ PHP Forum Software 7.7.1