318 LA build

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solracmopar

solracmopar

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I'm currently building a 73 Swinger and using parts off my 72 4 door Valiant. The 318 was built bone stock about 4,000 miles ago and intended to run in the Valiant. Unfortunately I got T boned by a 90 year old geezer just weeks after rebuilding the front end.. Bright side is I finally bought a 2 door :)

My goal is to wake up my 318 without going too crazy. Can anyone suggest a good intake/carb set up and a mild cam that will run nicely with stock heads? I'm also looking for headers that will fit decently around my power steering box. Thanks in advance!!!
 

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Eddy performer intake,600 vac secondary holley with thin square to spread bore plate, a version of the crane 340 blueprint hyd cam=210*/220*@.050 .429/.444 lift on a 114cl , and install it 4* advanced.
works great to 6000 and some gear like minimum of 3.55 with optimal being around 3.91
some headers, multi spark cdi ignition, high initial timing [performance curve & all in by or about the 2200-2400rpm range, I would recommend [if auto] to get a 2500 stall convertor as well.
 
Good recommendations by 1wild&crazy. Best headers are TTI for fit with power steering though are quite expensive. Hooker and a few others make headers but I've heard a lot of guys complain they hang low and hit stuff on the road. No personal experience with them. Cheapest are Spitfire by Harold but many have had issues with him - best to send payment COD and then he seems to get them out faster. Laysons has a copy of Harold's header but last time I checked nearly twice the price. They are a shorty type header but fit good and flow well for a mild 318. That's what I'm running on my '65 Cuda 318 police motor (360 heads & 340 cam). 318 is a nice motor for a street A body. Keep us posted with your progress.
 
Thanks for the great response wild&crazy guy and rapom65!! When I'm shopping around for Eddy intake, do they make specific LA 318 size for the smaller port heads? Or do I shave the ports on the heads to compensate? I've heard of TTI headers but man they sound super expensive.. Think I'm gonna look into Harold's. My main concern is fit and obviously keeping that price range doable.. I have way too much left on the Swinger to finish..
 
 
I'm trying to do something similar, but after talking to BJR Racing (he's around these forums somewhere) I might have him do some work on a pair of "302" heads and use a Comp XE268H (20-223-3) cam, which is one of the larger ones that you can still use a stock converter with. I'm probably also going with a Performer or possibly the Weiand Action Plus (8007). I had already purchased a Holley 670 Street Avenger, so I'm going to use it and try to make it work.

I started out wanting to do just the carb, manifold, header, and exhaust deal, but the more I looked into it there isn't a great way to do that. The heads on these cars just apparently aren't all that great in stock condition.

Just my .02 though...I'm really new to all this, so I am sure you can get much better advice on here :)
 
You might want to ask about BJR racing,i believe a member here got "screwed" pretty good by him..that being said my buddy runs a 318 in his '70 dart nothing special just a 318 "smog" motor bottom-end .477/.480 cam, a set of "j" heads just basically rebuilt,a good dual-plane intake,carter 650 carb,dougs headers stock trans,and a set of 3.91's he's gone 13.75 not bad for what its got..
 
The problem with stock 318s, from a performance standpoint which gets worse the more performance you want to extract, is the lack of compression. These motors were built for mileage and long life not horse power. Standard 318 heads use small runners, valves, big-ish chambers and were combined with low compression pistons. Here are some options to consider:
302 heads have a great heart shaped and smaller combustion chamber (ups compression) but still utilize small runners and valves. To really make them flow you need bigger valves and lots of port work. Used are prone to cracking.
Any 360 head will have larger runners and valves (1.88 int & 1.60 exh). The combustion chamber is even bigger (lowers your compression even more). Going for 2.02 sized valves won't help as the low compression can't utilize the additional flow. You can mill the head and/or use thin head gaskets to up the compression a little. But too much milling requires the intake surface (on head or intake) to be cut to keep the intake seal and the ends where it seals to the block may need shaving also.
The answer to solve the problem is pistons to match the performance level (compression) you want to achieve and then match the carb, intake, cam, heads and headers to that level. The 318 can be built from a put-put to high rpm screamer. It's all determined by your wants and wallet.
Two nice running, cheaper, base street motor options:
Stock pistons: Keep 318 heads, matched intake (318 sized runners), 600ish carb (if Holley use Vac Sec), 340 type cam, headers of choice. If you can find uncracked 302 heads for cheap would help raise the compression.
Zero deck pistons: Here the world opens up. To stay low cost use stock 360 heads with 1.88 and 1.60 valves. Bargins on these are everywhere, I just picked up a set completely rebuilt, new stainless valves, new 340 springs for $300. Keeping the smaller valves keeps flow velocities up. 360 sized intake, 268 type cam, 600 - 670 cfm carb, and headers of choice. You can vary from there per your budget. Many will have all kinds of recommendations but these basic motors are good places to start.
 
Forgot to add you will have to match the converter and rear gear to optimize more power. After 30 years of dinking around with cars and motorcycles the most important thing I've learned is to match ALL the pieces parts to what you've modified. Any badly miss-matched component could completely unravel all you efforts not to mention waste a butt load of coin.
 
stroked 340 said:
You might want to ask about BJR racing,i believe a member here got "screwed" pretty good by him..that being said my buddy runs a 318 in his '70 dart nothing special just a 318 "smog" motor bottom-end .477/.480 cam, a set of "j" heads just basically rebuilt,a good dual-plane intake,carter 650 carb,dougs headers stock trans,and a set of 3.91's he's gone 13.75 not bad for what its got..
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Yeah, so I've since read the thread/problem you are referring to and am DEFINITELY having second thoughts on this.

That being said, does anyone know a good Mopar guy near Louisville, KY? :)
 
Just thought Id mention the magnum head as another cheap way to bump comp. It's runners are inbetween the 360 and 318 ports so it matches up nicely for a power build 318 head. You can expect around 400 hp with stock pistons and a .480 ish cam without port work.

There are fans of the 302 head who claim it can make more power than the magnum on a 318. Might be true might not be,but you will have to do a TON of porting.

Magnum main disadvantage is that you need a magnum intake or drill your heads to accept la intakes. It needs magnum specific head bolts as well. Needs oil thru pushrods and lifers but not a big deal there. Most aftermarket cams already have oil thru lifters as the amc lifter is the same as the sb mopar but has oiling hole for rockers,so companies just make one lifter for both brands.
 
solracmopar said:
I'm currently building a 73 Swinger and using parts off my 72 4 door Valiant. The 318 was built bone stock about 4,000 miles ago and intended to run in the Valiant. Unfortunately I got T boned by a 90 year old geezer just weeks after rebuilding the front end.. Bright side is I finally bought a 2 door :)

My goal is to wake up my 318 without going too crazy. Can anyone suggest a good intake/carb set up and a mild cam that will run nicely with stock heads? I'm also looking for headers that will fit decently around my power steering box. Thanks in advance!!!
Click to expand...

I have a 318 .30 ova with 360 heads. Cam sounds like a RV type cam. Doesn't have much chop...Enuff that though people ask is it a 340 when it starts an runs. Street Dominator intake. Speed Demon 650. Full Msd ignition. Hedmann headers. 2500 stall Torqure converter... That being said. It's a good combo to work with. I've had that combo goin on six years now. Chirp tires goin to second that's wit 3:23 gears. I do plan to run the Hughes Whiplash Cam. Check they website a guy has a video wit one installed. Talked to a tech and he say they are designed for low compression chrysler engines. Gave him my combo and he says that cam will waken it up. Plus it has one NASTY :-D idle.. I do plan to put some 3:73 gears in. I NEVA took it down the track so I ain ga lie an fudge numbers on what it runs but it's good enuff for the street.....Just thought I give a suggestion since I have a 318....
 
625 Carter AFB
Edelbrock LD4B (Pre Performer intake, the performer is excellent as well)
Crane cam @ 218/228-.454/.480 CL-112 (Comp has a very comparable cam)
Hooker headers into a Jegs 2-1/2 exhaust
3.21 sure grip equiped rear on 225/70/14 t

This combo ran 15.14 @ 89 pmh at ATCO untuned on a cold day this time of year.
A good tune up/timing of the combo added a real good performance improvment but I never toook it to the track to see. I'm confident it would have ran in the 14's. VERY much so.
 
Thanks for all the input. My original plan was to run a set of late model Magnum heads, Edy RPM intake, 650cfm carb, 218/228 cam and doing the longer push rods etc Magnum set up..

Rublefish I appreciate your accurate numbers and think thats the route I'm going to take for now. Basically a mild 318 but more than the bone stock set up I'm running now.

Later down the road when the entire car is back together and I start driving it.. I might pick up a late model 360 and build that as a proper performance engine. Just want to add that this is an AWESOME site with people who actually care about Mopar.
 
So your just gonna run the stock small port heads? I like this idea better than using 360 heads. Just keep the cam smallish .450 or so lift and have fun! Should have snappy throttle and lots of torque down low.Keep the power band of the cam under 5000 as the stock heads will run out of breath around there anyways.
 
Needaresto Well said. I ran across the finish line at the 1/4 mile around 5300 or so. Launch dependent. Spinning tires was an issue depending on launch RPM. Though I was still accelerating well, I know I didn't have much left in it. But pull it did.

Solracmopar; No problem. I figured the description would help point away for ya. If there was a want/need for more or less, the adjustments would be easy and small. Oh! by the way, the converter was stone stock.
And yea, most people here are really good about things. I really like this crew here. Lots of excellent people. Indeed! this place does rock!
 
solracmopar said:
When I'm shopping around for Eddy intake, do they make specific LA 318 size for the smaller port heads?
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The Performer is a small port intake, the Performer RPM and Air Gap are the larger port heads. There is a small port Weiand manifold in production as well, but I can't recall the model designation.

IMO, the carb may be too large unless it has an air valve controlled secondary.
 
I'll tell you what I did to my daily driven cop car. It was a 1983 Plymouth Caravelle,same as a Fury. Had a 4 bbl 318,904 and 2:94 gears witrh 245/60 15 all the way round.

The 318 was a typical low compression 4bbl with 360 heads,so around 7.5:1. It had a good cloyes double roller timing chain,hv oil pump a small Isky cam around .450 ish and an 800 cfm tq.I also custom made a fresh air intake. That made a huge difference.

The car was a dog off the line due to heavy car, low comp,gears and a narrow centerline cam (108) but the mid range from 3000 to 5000 was glorius fun! It also had quite a bit of highway power.
 
needsaresto said:
Just thought Id mention the magnum head as another cheap way to bump comp. It's runners are inbetween the 360 and 318 ports so it matches up nicely for a power build 318 head. You can expect around 400 hp with stock pistons and a .480 ish cam without port work.

There are fans of the 302 head who claim it can make more power than the magnum on a 318. Might be true might not be,but you will have to do a TON of porting.

Magnum main disadvantage is that you need a magnum intake or drill your heads to accept la intakes. It needs magnum specific head bolts as well. Needs oil thru pushrods and lifers but not a big deal there. Most aftermarket cams already have oil thru lifters as the amc lifter is the same as the sb mopar but has oiling hole for rockers,so companies just make one lifter for both brands.
Click to expand...
Thanks to Resto for mentioning the magnum heads - totally boned the dog and forgot them.
 
more money than they are worth, the port volume is far more than the 124cc stock 318 had, might just hurt the bottom end if you can't tune, and then they crack...
 
needsaresto said:
Just thought Id mention the magnum head as another cheap way to bump comp. It's runners are inbetween the 360 and 318 ports so it matches up nicely for a power build 318 head. You can expect around 400 hp with stock pistons and a .480 ish cam without port work.

There are fans of the 302 head who claim it can make more power than the magnum on a 318. Might be true might not be,but you will have to do a TON of porting.

Magnum main disadvantage is that you need a magnum intake or drill your heads to accept la intakes. It needs magnum specific head bolts as well. Needs oil thru pushrods and lifers but not a big deal there. Most aftermarket cams already have oil thru lifters as the amc lifter is the same as the sb mopar but has oiling hole for rockers,so companies just make one lifter for both brands.
Click to expand...

best thing is magnum heads are plentiful and cheap in junkyards, and you can get head bolts, rockers, valve covers with them for around $50 each, an edelbrock air gap, or chinese knock off crosswind, intake and set of mopar performance adapter pushrods, (just make sure the lifters you get with your cam have the oil through provision) SOME heads are cracked not all, there are plenty of magnum powered vehicles out there still running fine

http://www.dippy.org/forum2/index.php/topic,295.0.html

http://www.moparmusclemagazine.com/techarticles/mopp_0409_318_engine_build/index.html
 
1wild&crazyguy said:
more money than they are worth, the port volume is far more than the 124cc stock 318 had, might just hurt the bottom end if you can't tune, and then they crack...
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.

Then again theres the eq magnums as well.


Your opinion has been noted,lol.

There are some here who do not like the magnum.

I for one cant argue with cheap chev price roller rockers,and a boost to 9:1! They make great street heads and the nice thing is they'll make 400h.p on your 318 with no porting.Magnums also produce a very flat and fat torque curve

All heads crack eventually. Id run em without fear myself. I still have my pair here and a 360 waiting for them. Some good porting on the magnums and I think 450 hp is not hard to achieve.
 
The engine builder I was talking to seemed confident with the Magnum set up. Trouble with pulling heads out of a junk yard is you never know how much work they'll need..

Rumblefish, I think I'm going to keep things simple to start. Re: the cam, is it imperative that it gets degreed in at install? Also, when you ran those hooker headers, did you have any issues with fit around power steering pump / idler arm? The engine builder seems hot on those TTI's but damn they is expensive!!
 
All headers suck except Dougs and tti's. I'd go with tti's!

A cam that small dosen't need to be degreed in but it would help.
 
I've never heard of Dougs.. Do they fit as good as the TTI's claim to fit? They seem a lil bit cheaper at Summit.. Thanks again!
 
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