Help me decide!

[DQ81]

I have a stock 2bbl 318 in my 73 Dart, it has a 8 1/4 rear (with stock ratio's) and a 904 trans.

Intended use is street, A lot of around town driving and the ocasional 1-2 hour highway cruise.

What should I put together to create the best street/Daily Dart (don't mistake daily for mild!)

I intend to put an Edelbrock 600cfm on all of this, or can I go bigger with a different cam?

Which intake of the following, I can get both cheap, the Edelbrock does cost 4x's the 360 though:

Elelbrock performer 4bbl intake

Stock 360 dual plane 4bbl intake (the Quadrajet type)


Cam options:

Stock 340 (in excellent condition) cam with new lifters 100,-

Edelbrock performer (all new) 160.-

Used 360 cam and lifters 120,-

The engine has hooker performance headers and a dual exhaust. I'm keeping the heads stock. I'll be running a 600cfm carb, bigger if possible but I think 600 should suffice.

What's the best option to improve spark btw? Mallory electronic ignition? I don't think an MSD setup is necessary for my application...

Looking forward to your ideas on this, I'd like to pick up the parts tomorrow and have it done by the weekend

 

[MopaR&D]

Don't go any bigger than 600 cfm, there's no reason you'd ever need more than that with a street 318. I'm kind of in the same boat, I'm building a street 318, but a little different than what you have in mind. First off I'm going with a pair of cleaned-up (and maybe ported) #302 318 heads, along with a used Edelbrock Performer intake off eBay (once I find one), a Lunati Voodoo 256/262 cam, stock exhaust manifolds (for cost and simplicity), and a Carter ThermoQuad carb (Mopar equivalent to the Quadrajet, used on many vehicles in the '70's and 80's with V8's). For ignition I already have in the car a Mallory HyFire 6A box and Mallory canister-type coil, with a stock replacement electronic distributor and all-new plugs (NGK V-power) and wires (MSD universal V8 8mm).

The Edelbrock intake is a better choice because it matches up better with the small-port 318 heads and is WAY lighter than the ~50 lb. iron 4-bbl intake. If the cam choices you listed are the only ones to choose from, I'd definitely go with the stock 340 cam.

 

[DQ81]

Don't go any bigger than 600 cfm, there's no reason you'd ever need more than that with a street 318. I'm kind of in the same boat, I'm building a street 318, but a little different than what you have in mind. First off I'm going with a pair of cleaned-up (and maybe ported) #302 318 heads, along with a used Edelbrock Performer intake off eBay (once I find one), a Lunati Voodoo 256/262 cam, stock exhaust manifolds (for cost and simplicity), and a Carter ThermoQuad carb (Mopar equivalent to the Quadrajet, used on many vehicles in the '70's and 80's with V8's). For ignition I already have in the car a Mallory HyFire 6A box and Mallory canister-type coil, with a stock replacement electronic distributor and all-new plugs (NGK V-power) and wires (MSD universal V8 8mm).

Sounds like some nice plans, I'm relativly new to tuning v8's and messing with cams, what does 256/262 refer to?

The Edelbrock intake is a better choice because it matches up better with the small-port 318 heads and is WAY lighter than the ~50 lb. iron 4-bbl intake. If the cam choices you listed are the only ones to choose from, I'd definitely go with the stock 340 cam.

Yeah I almost bought the 360 intake today for 25 bucks but man that thing is heavy! I'm pretty intent on the Edelbrock, I just needed a push over the edge.

So now the cam, why the 340 vs the edelbrock performer? What are the pro's and cons, I don't mind lumpy at all, I'm not looking for smooth per se, will the 340 give me more low end? I'm trying to keep the cam costs under 160 or so. If anyone can school me here please do! I know little about cams, I get what they do relative to valve clearance but....

BTW, I can pick up a Carter AFB 9625 (625cfm) carb, exact condition unkown, looks clean for 75 euro's. new Edelbrocks are 350+ euro's here and used about 150. What's so great about the Carter?

 

[Petzschler]

on the one hand you say "no need to go larger then 600cfm" then on the other you recomend goin with a 800cfm tq??? hmmmmm.
Most Engines that use a Vac. Sec. carb will only open the secondaries as much as it needs.
one other thing, the 50lb stock TQ intake with a 800cfm TQ will run rings around a Edelbrock perfomer intake w/ a 600cfm eddie carb.
as far as cams nothing wrong with the stock 340/360 4bbl cam. works with practically any cr and performance hop ups.
exhaust manifolds are nice, but a set of 1 1/2" to 1 5/8" headers with 42" primaries into a 3" collector will work wonders.
no need to get fancy pants on the ignition system either. the stock MP electronic pkg is more then adequate.
cheers.

 

[rumblefish360]

Elelbrock performer 4bbl intake and skip the used cams, if you like the 340 cam specs, which has a good report from others here for performing well, I'd get the updated version from MP.

on the one hand you say "no need to go larger then 600cfm" then on the other you recomend goin with a 800cfm tq??? hmmmmm.

Because the T-Q has tiniy primarys , it operates with very good throttle response. When the secondarys are called apon, the air door, being spring loaded opens as much as needed. Even if it opens all the way, later it cloes up since the engines needs die off.
A properly set up T-Q is serious, actually, a hard carb to beat.

Idles and drives around on primarys of approx. 200 cfm and has the abilty to open up to 800/850 cfm IF needed. And that is what the spring loaded door is all about.

The 600 cfm carb is just fine. And while it is even possible to tune in a larger 750, 800, 850 carb, it has a low end throttle response that slowly degrades as you get larger in size.
It is entirely possible to put a 850 ontop a bone stock 318 and drive it everywhere.

I'd rather shy away from the Iron T-Q intake for most street 318 engines. Again, it is entirely possible to use it and use it well.

The OE ignition system is just fine. An orange box is better, I prefur the Chrome box for anything I do.

 

[DQ81]

on the one hand you say "no need to go larger then 600cfm" then on the other you recomend goin with a 800cfm tq??? hmmmmm.
Most Engines that use a Vac. Sec. carb will only open the secondaries as much as it needs.
one other thing, the 50lb stock TQ intake with a 800cfm TQ will run rings around a Edelbrock perfomer intake w/ a 600cfm eddie carb.
as far as cams nothing wrong with the stock 340/360 4bbl cam. works with practically any cr and performance hop ups.
exhaust manifolds are nice, but a set of 1 1/2" to 1 5/8" headers with 42" primaries into a 3" collector will work wonders.
no need to get fancy pants on the ignition system either. the stock MP electronic pkg is more then adequate.
cheers.

All the abreviations leave me confused :toothy10:. I'm a newb, please be patient but also a tad more specific. I literally do not kow what you mean by TQ and cr... I'm not hip to all this jive turkey computer lingo ya dig?

Stock MP electronic, are you talking about a stock Mallory replacement distributor?

Nothing wrong with is good, can you back it up with specifics? I've read many times a stock 340 is great for a 318 for street use, but why? (i'm like a 5 year old sometimes, I like to know WHY) on that logic, if 340 is good, 360 is better?

 

[rumblefish360]

All the abreviations leave me confused :toothy10:. I'm a newb, please be patient but also a tad more specific. I literally do not kow what you mean by TQ and cr... I'm not hip to all this jive turkey computer lingo ya dig?

Stock MP electronic, are you talking about a stock Mallory replacement distributor?

Nothing wrong with is good, can you back it up with specifics? I've read many times a stock 340 is great for a 318 for street use, but why? (i'm like a 5 year old sometimes, I like to know WHY) on that logic, if 340 is good, 360 is better?

Allow me 360;

cr = compresion ratio
T-Q = Thermo Quad carb.
The stock distributor is an excellent part, no need for an aftermarket, though the Mallory is an excellent part.

 

[rumblefish360]

Nothing wrong with is good,

HUH!?

can you back it up with specifics? I've read many times a stock 340 is great for a 318 for street use, but why?

The 340 cam has larger duration specs and higher lifts.

on that logic, if 340 is good, 360 is better?

The 360's stock cam shaft is smaller, and the HP 360 cam shaft is the 340's cam.

 

[rumblefish360]

Off hand, I can not remember the exact 318 and 360 cam specs, but they will be very similar to

318, 252 .400 lift
360 260 .410 lift

the 340's cam specs look like 268/276 with mid to high 4's in lift.

 

[DQ81]

Thanks for stepping in there Rumblefish and thanks for being patient. I might just end up testing your patience by the end of this thread

A Thermo Quad carb works how exactly vs. what other types of carb... I thought there were Quadrajets and evenly distributed 4bbl's....

Is there a benefit to to a TQ (I"m learnin!) on a dualplane intake?

The 340 cam is used but ran perhaps 3k miles max, the lifters are new in the box. Still shy away?

MP= Mopar Performance? (I know, I know...how many stupid questions right?)

Partially I wan't an ignition upgrade for reliability, parts are hard to come by over here, I paid 25usd for a new rotor the other day...

If I go for the Mallory, any need for a higher voltage coil for street ap?

Again THANKS!

 

[DQ81]

Off hand, I can not remember the exact 318 and 360 cam specs, but they will be very similar to

318, 252 .400 lift
360 260 .410 lift

the 340's cam specs look like 268/276 with mid to high 4's in lift.

So the 340's cam has the highest lift which alows the valve stay open longer to let more air in which in turn raises compression which produces more powerfull combustion in the cylinder?

I'll look up an article on how cams work exactly instead of having you explain it to me piece by piece here. lol

 

[moper]

I'd go stock iron intake, stock hermoquad carb providing you KNOW it's good, otherwise run a 600 Edelbrock. you can get them used easily, or save cash and buy a new one. I would probably leave the ignition alone for now, but eventually buy an MP replacement. Last, I'd run the Summit smaller cam. I dont trust used cams, and I wouldnt run one for free unless I took it out of a running engine.

 

[green1]

manifold-ld4b

 

[rumblefish360]

Thanks for stepping in there Rumblefish and thanks for being patient. I might just end up testing your patience by the end of this thread

No problem, 360z28 could have answered these as well just sa easy. I think he was in another thread at that moment.
patience? I have enuff most times. But your best bet is a book or two. After reading the books, you'll have more questions, but not so newbie questions.
Look for "How to rebuild my small block mopar" and "How to hotrod my small block mopar" The factory has books as well. There good to get.
The Chassis book and an engine book on the size engine (And style) you have.

A Thermo Quad carb works how exactly vs. what other types of carb... I thought there were Quadrajets and evenly distributed 4bbl's....

Same as anyother carb. The T-Q has a spring loaded secondary door that allows you add or subtract tention for quicker or slower opening rates of the secondary door. The secondary door is above the butterflies.
The Carter AVS and Edelbrock Thunder AVS (Very similar carbs) also has this feature.
The AFB from Carter or Edelbrock have a weighted door.

The Holleys have a different design, but function in a sinilar way. Then theres Holley that have no secondary vacuum systems, these are called double pump carbs and are excellent for very high performance cars and race cars.

Is there a benefit to to a TQ (I"m learnin!) on a dualplane intake?

Well, that actually depends on what were looking to do. In general, a street or mild performance engine will like a spreadbore carb on top of a dual plane intake. This combo is very driver freindly and offers good all around performance.

However, there is nothing wrong with a squarebore carb on a square bore intake. Identical results could be found. Alot has to do with keeping a balance in the engine , car and driver.

The 340 cam is used but ran perhaps 3k miles max, the lifters are new in the box. Still shy away?

I made my statement quite clear, do what you want.

MP= Mopar Performance? (I know, I know...how many stupid questions right?)

YES, MoPar Performance, --- (NO)

Partially I wan't an ignition upgrade for reliability, parts are hard to come by over here, I paid 25usd for a new rotor the other day...

If you paid that much for a rotor, go back and get your money and punch the seller in the face, hard, break his nose twice, He deserves it for chargeing you that much.

I have not gotten one in a while, but I think I paid a total of a $1.79 for the rotor.

If I go for the Mallory, any need for a higher voltage coil for street ap?

All you really need is an upgraded MP box, and IMO (In My Opinion) and I like the Chrome box. Use with the proper ballast resister. Your good to go.
Though a MSD set up is really nice and can help with low RPM power and mileage.

Again THANKS!

No problem, we all here to help.

Green, that is not a manifold listed and he is across the pond and then some.

Good advise Moper.

 

[Petzschler]

rumblefish360...
thats some pretty sound advice considering your a FABO Moderator! LOL!
cheers

 

[rumblefish360]

LOL, Thanks 360z28, you aint to bad yourself. :-D

 

[MopaR&D]

Just an FYI, the 340 was a much higher-performance engine than the 360 was, so even though the 360 was bigger, it wasn't faster. Now, that does NOT mean you can't build a fast 360, it just means that from the factory 360's were usually set up to be truck engines.

As far as cams, the 256/262 refers to the advertised duration of the cam. That particular cam is the second mildest in Lunati's Voodoo line of hydraulic flat-tappet cams. That particular cam is a bit better than the stock 340 cam because it has a little more lift but less duration and overlap; this translates to more torque in the lower and mid-ranges, but no loss in top-end power. With a little more extreme build you could go with the 262/268 or maybe even the 268/274 cams, but those would kill a little of the low-end torque you need with a "small" engine like the 318 unless you increased the compression.

 

[rumblefish360]

A good way to compare cams is with the duration at .050 numbers.
The biggest performance killer on the 360 was the low compresion and the regular low duration cam. When they came with the 340's cam, it still sufered from low compresion.

The factory offered a E-58 (360) engine as a performance option. It came with the 340 cam as well as a double roller timing chain and windage tray.

 

[DQ81]

Thanks guys,

Anyone have experience with Melling cams?

The stage II cam near the specs of a stock 340 with a slightly shorter duration...

 

[DQ81]

Rumblefish

I can get my hands on a Thermoquad 9008s, from what I've found it's a 1975 CA emissions model with some ports to plug etc. applicable on a 400 cui engine...that stumps me slightly.

It's cheap and rebuilt off a running 360 motor, I can get a dual plane stock 360 intake to bolt it too, sound like a good poor mans matchup?

Any idea how many cfm's the primary's are and all combined?

If I went this route I'd be done for 50 bucks...

or should I hold out on a Holley 750 w/ Edelbrock intake I can get for 250,-

It's up to me I know but what kind of performance difference are we talking with stock heads, hooker headers and the 340 cam I'm dropping in...is it worth? Use remains regular driver, street machine.