Could this idea work ? Did other guys did this ? 318 infos

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ValerianMagnum

ValerianMagnum

the little car that could
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Hi guys , putting the 69 valiant aside , ive changed my mind again and want to give my newly ratty 68 Fury 3 / 318 a chance...ive found a 340 intake in my storage and a 360 2bbl carb and adaptor... i really would like to run a dual exhaust system with the fury and good manifolds or even magnum manifolds / headers, im very inspired by little simple mods like 318willrun s pocket porting . I like the idea of running small ports and small valves and maybe even a 360 2bbl cam , or 340 cam to help the teener , **with dual exhaust , tuned carb , cold air system , electronic ignition , backfaced valves , windage tray and maybe 340 valves springs replacementi want a strong 318 but i want it to be a 2bbl , ** after all the views of the Mission impossible video on youtube and the intake porting i was wondering if a 360 2bbl holley 350 cfm ( 318 bbd is 275ishh ) and a better high rise 340/360 intake manifold could it be helpfull ( 318 heads would be gasket matched ) ?? I know a 4bbl would be better , but i like to think outside the box sometimes :)

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All good stuff, but I would concentrate on unshrouding the valves and a good 3 or 5 angle valve job before I did any pocket porting. I would also go with a small primary 4 barrel carb. Avs or thermoquad. Get good porting advise on David visards YouTube channel. I watched all the head porting vids and they are all relatable to mopar heads in some ways even if he is porting chevy or ford heads.
 
Thank you, on other opinions this 350 cfm carb could make me loose some low end torque as i read on other sites...my 1st idea was to be conversative and make the little 318 breathe a bit better with some better tiny flowing heads / better carb ( cfm ) and headers etc...i just didnt want to spend a ton of $$ on a 4bbl carb since i have 2x bbds and this one laying around
 
ValerianMagnum said:
Thank you, on other opinions this 350 cfm carb could make me loose some low end torque as i read on other sites...my 1st idea was to be conversative and make the little 318 breathe a bit better with some better tiny flowing heads / better carb ( cfm ) and headers etc...i just didnt want to spend a ton of $$ on a 4bbl carb since i have 2x bbds and this one laying around
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Are we talking part throttle or full throttle ?

On a full the throttle run what an engine makes under 2500 rpm really don't matter much you spend almost zero time there. Even half throttle makes 80% power of full with similar curve.

Look at the dyno run of the article on my post with cam and 4bbl there was about 50 tq gain at 3000 rpm, even at 2000 rpm which it didn't show I guarantee the modified was still making more, at least on par. It's good to be little conservative but power comes from air flow even down low, this idea you got to strangle your engine to make torque has never been shown on a dyno.

The idea on a street performance car where gearing and stall is gonna stock/mild side is to increase your powerband rpm range idle to 4500 rpm say to 5000-5500 rpm on top without moving to far away from idle where gearing and stall will be less than ideal. Which could be 100-150 ish hp gain
 
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look at these 400-425 hp 318 make about the same tq at 3000 rpm with more head cam etc..
even at 2000 rpm bet these engines are on par or better than the stock 2bbl 318, not saying don't build it your way but generally stock low power engine gonna make the least amount of torque all but maybe the lowest rpm's and probably not by much.

318 Small Block Build - How To - Hot Rod Magazine

Chrysler 318 Engine - Popular Hot Rodding Magazine

318 Engine Build - A Parts Book 400HP 318 - Mopar Muscle Magazine
 
Just clean up the bowls and get a good valve job. run your exhaust manifolds and run dual exhaust. Add a small cam and 340 valve springs. Use a 4 barrel carb with that 340 intake. No need to gasket match the head ports. Street Demon, AVS 2, any Edelbrock, Carter AFB or AVS. They just run better than 2 barrels.
 
Or if you wanna run a 2brl then put the 360 intake on and look into the holley 2 jet 500cfm out of a 2 barrel. fantastic out of the box carb. Have bought and ran many of them.
 
I have done a ton of reading around here and the consensus is that Teens run better with a 4 barrel. It would be fun to have a chassis dyno, a car with a stock teen, and a pile of parts and step by step see what each modification does. An adapter and 4 barrel first. An intake and 4 barrel next. May be the distributor curve next. Dual exhaust on stock manifolds. 340 manifolds after that. The next part could be tricky. Cam first or modified heads? A mild cam might need to be bigger if you have better heads and higher compression. See where I'm going here?
 
Even if i leave the stock 318 cam in there , i tought that it was maybe a good idea to put a 2bbl carb with a bit more cfm , ive seen the very big work of Charles ( man who ports stuff for D.Vizard ) and how restricted the 318 2bbl intake really is , here in my area in Montreal /Canada , nobody has 360 2bbl intakes , cant find 302 heads bla bla bla , lucky enough to find 318s and some cores or good parts once in a while , i was sure that putting a 2bbl carb ( with more flow ) was better than leave the 318's bbd there , i dont have much money to spend on a 700-800$ brand new 4bbl carb and intake nowadays. I wanted to experiment with what i had laying around and nlt braking the bank with a ratty 68 fury that needa love...
 
I have never used a 2-4 adapter. I would consider the “plenum” volume on that cast 4b intake and the lack of fuel feeding it.
I know it will run but it will probably bog.
If it runs right now I would experiment….since youre budget building I would install the 360 2 bl cam in no matter what! throw the 318 2 bl back on and the Carter.
Or… try your 340 4b intake with your 2 b adaptor and Holley.
Watch those holley 360/400 2 bls, the throtte body screws loosen themselves and you end up with a soggy carb. soak the carb in fuel to get the gaskets soaked then snug them up very little if needed.
Better to have a small leak on the carb than to have stripped one of the base screws( if it isnt already stripped from someone already over tightening). Common! They strip easily.
I put a 360 2 bl factory cam in a 78 318 with untouched 318 heads and a 360 2 bl truck intake and holley 2bl. It worked great and I noticed quite a difference without mods.
If you know how to work with carbs a used TQ can be your new favourite friend and will definitely still work with your 360 2 bl cam with minor adjustments.
Swap meets, moparfest, cruise nights, or someone in or near Montreal must have a used 4 bl for you for reasonable $!
Since you have the 2 b parts, try them in the meantime.
360 2 cam first if thats the best cam you have, It works if you dont dump too much fuel on it.
 
ValerianMagnum said:
Even if i leave the stock 318 cam in there , i tought that it was maybe a good idea to put a 2bbl carb with a bit more cfm , ive seen the very big work of Charles ( man who ports stuff for D.Vizard ) and how restricted the 318 2bbl intake really is , here in my area in Montreal /Canada , nobody has 360 2bbl intakes , cant find 302 heads bla bla bla , lucky enough to find 318s and some cores or good parts once in a while , i was sure that putting a 2bbl carb ( with more flow ) was better than leave the 318's bbd there , i dont have much money to spend on a 700-800$ brand new 4bbl carb and intake nowadays. I wanted to experiment with what i had laying around and nlt braking the bank with a ratty 68 fury that needa love...
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your plan will increase power just not a large amount like the 282 hp one I posted, I wasn't trying to discourage you just pointing out you don't have to worry about keeping mods super small or torque will suffer
 
You can find used 4 barrel carbs cheap
, you just have to look. Run your 2 barrel till you find one.
 
A bunch of cool "theory" that in the real world, is a waste of time. Consider that your larger 2 barrel, will decrease low speed velocity through the carburetor, compared to the stock 2 barrel, where as a small 4 barrel will have smaller primary's, for better low end response, and the secondarys provide the additional air flow for the upper rpms. The reason OEMS typically used 2 barrel carbs was strictly cost.
 
If you are really low budget keep the single exhaust and have a custom exhaust come off the Y with 2 1/2 pipe to a straight thru glass pack and out the back with a 2 1/4 tail pipe, like the 273 HiPo. If it is too loud just add a second 2 1/4 glass pack before the end of the tail pipe.
 
no matter what you run, you're going to be mismatched because of the 340 to the smaller 318 head. sure you can port match it up, but you're losing all that low end throttle response and probably giving up a fair amount of driveability with that set up-- especially with the 2bbl.

you could probably sell the 340 intake and use that dough to buy a small port weiand or performer and a used 4bbl and be way better off.

if you're trying to build on a beer budget, keep the intake. scoop up a used AFB or small holley with vacuum 2ndaries, snap in a 340 cam, massage the heads and match the valve springs and call it done.
 
Yes! Find something you aren't going to use and trade/sell for something you can. Kijiji.
Just looking at your adaptor.. will it accept the holley 2b carb?
I know those things are universal and maybe it is just the photo or me, but the 2 bll holes look too big and too small for holley 2 b.
Looks like Carter and mofoco 2 bl.
 
junkyardhero said:
no matter what you run, you're going to be mismatched because of the 340 to the smaller 318 head. sure you can port match it up, but you're losing all that low end throttle response and probably giving up a fair amount of driveability with that set up-- especially with the 2bbl.

you could probably sell the 340 intake and use that dough to buy a small port weiand or performer and a used 4bbl and be way better off.

if you're trying to build on a beer budget, keep the intake. scoop up a used AFB or small holley with vacuum 2ndaries, snap in a 340 cam, massage the heads and match the valve springs and call it done.
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i wouldn't worry about the port mismatch, is it ideal no but is gonna stop gains in power also no.
 
273 said:
i wouldn't worry about the port mismatch, is it ideal no but is gonna stop gains in power also no.
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fair point. and a gasket match would help alleviate most of the fuglyness.

i still think a 2V with the adapter on that manifold is just a exercise toward irrational thinking.
 
That is a Magnum intake manifold with the vertical mounting holes to the heads.
But I like that carb for your project, very reliable!
 
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