F/A Tech
Well-Known Member
Where do I start for most bang for the buck. Dual exhaust .... Headers ....4 barrel intake and carb !!
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1971 Scamp stock 318
- Thread starter F/A Tech
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straightlinespeed
Sometimes I pretend to be normal
I've got a Edelbrock 1406 that Im no longer using that I'll give to you. It was passed onto me as a gift from another member and I upgraded to a AVS2. So I would like to pass it onto someone else. If your interested let me know. It ran great on my car, shouldnt need a thing, bolt on and go. I would say for intake look for an Edelbrock performer intake.
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You’re on the right track with a 4bbl intake and carb. Look for a dual plane intake, perhaps a Weiand Stealth as they are available new and are pretty good. If your budget is higher and you want an old school intake, look for an Edelbrock LD4B. If you go with headers, unless you want figment issues and issues banging them against curb ramps and speed bumps, best to find some 340 manifolds. Good headers exist but they are not cheap (TTI). Dual exhaust will help too. What gearing you have in the rear end and is it a sure grip?
dodge71demon
Well-Known Member
Been there done this way to many times I would say leave the 318 alone after tossing money at it doing adds and ends it may not perform the way you think it should. Save up your pennies and consider a 5.9 magnum with Fitech or Snipper throttle body EFI you would be amazed
F/A Tech
Well-Known Member
Thanks for the offer will see how we could get it to Canada.
Alaskan_TA
Well-Known Member
My 1970 318 does just fine with no modifications needed or wanted.
dodge71demon
Well-Known Member
good on you why mess with it I also have a stock 318 in a more door and it works great it does have dual exhaust
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Most bang for the buck......
to do what?
Most bang, to get off the line, is a 2800TC.
Most bang, after already moving at ~20 mph or so (depending on the rear gear), would be performance gears.
Most bang, for Part-Throttle operation, or fuel-mileage, would be more cylinder pressure.
Most bang for passing, would be the right second gear ratio.
The most bang for a downshift into first at ~32 mph, would be a combination of Stall and gear ratio.
Most bang for spinning tires off the line, would be Stall, gears, and a 4bbl, all three together.
Finally;
Most bang for second gear power after 3500rpm, THAT would be a cam.
In order for the bigger cam to work, the engine has to be able to process the additional air. That means, more air in = more air out. So you gotta consider the 4bbl,the headers, the dual free-flowing exhaust, fresh cold intake air, AND the heads; ALL as a set.
see note1
Start with;
Ignition timing,then
Stall,then
gears and SG.
Next; 4bbl, and free-flow muffler, both together, then
fresh cold air.
Next;Compression ratio,cam/kit,headers,and dual exhaust; all together; or
solid lifter cam/kit, headers and dual exhaust; all together
Note 1
The thing about cams is, with no other changes;
the next one size bigger (a size being ~7*) same type cam (hydraulic FT in this case) will, at the same LSA, bump the operating range up about 200 rpm, at the expense of the lower rpm losing power.. So if you bump your operating rpm up say 3 sizes from the current 240*, to say 262*, your power peak will want to move up from ~4200, to maybe ~4800. but your heads will be hard done-by to make any power up there.
In any case if you gain 600 rpm at the top, then you will also give it away at the bottom...
So 600 doesn't sound like a big deal right? Well with 2.76 rear gears, the power peak moves from say 46 mph to 53mph , and that's a lot. Depending on your actual power, that 7mph,could be 2,3 or maybe even 4 seconds.
At the bottom, each cam size will cost you about 200 rpm in stall,so if your teener was fine with an 1800 stall with the factory cam, then the 3-sizes bigger 262 cam, will want ~2400.
So, when you think about cams,you just gotta think about the whole air in/air out,combo. see note 2
The LA318 is stuck with a pitiful 8/1 NOMINAL Scr. And that means it could be less, even 7.6. . So when a cam is considered, you also have to think about a TC, and the final cylinder pressure, and the rear gears; all as a package.
If you don't, you will have just joined the club of thousands of unhappy 318 owners who all did the same thing.
note 2
Here's how it works;
the typical 7.8sCR-318LA might make 135 psi @sealevel with the factory 240*cam with an ICA of 48*.
The next bigger cam, with an Ica of 51.5, drops the pressure to 132
The second bigger cam will drop to 128
that's 7psi already!, or 5%.
But guys want to go straight to the 268/276, HFT 340 cam, with an Ica of 66*, and that drops the pressure into "Total Lazy-Dog"territory of 116psi/about a 15% pressure loss! Don't do that.
They all say it ain't so bad, but I tell you. it sucks/ don't do it.
Happy HotRodding
to do what?
Most bang, to get off the line, is a 2800TC.
Most bang, after already moving at ~20 mph or so (depending on the rear gear), would be performance gears.
Most bang, for Part-Throttle operation, or fuel-mileage, would be more cylinder pressure.
Most bang for passing, would be the right second gear ratio.
The most bang for a downshift into first at ~32 mph, would be a combination of Stall and gear ratio.
Most bang for spinning tires off the line, would be Stall, gears, and a 4bbl, all three together.
Finally;
Most bang for second gear power after 3500rpm, THAT would be a cam.
In order for the bigger cam to work, the engine has to be able to process the additional air. That means, more air in = more air out. So you gotta consider the 4bbl,the headers, the dual free-flowing exhaust, fresh cold intake air, AND the heads; ALL as a set.
see note1
Start with;
Ignition timing,then
Stall,then
gears and SG.
Next; 4bbl, and free-flow muffler, both together, then
fresh cold air.
Next;Compression ratio,cam/kit,headers,and dual exhaust; all together; or
solid lifter cam/kit, headers and dual exhaust; all together
Note 1
The thing about cams is, with no other changes;
the next one size bigger (a size being ~7*) same type cam (hydraulic FT in this case) will, at the same LSA, bump the operating range up about 200 rpm, at the expense of the lower rpm losing power.. So if you bump your operating rpm up say 3 sizes from the current 240*, to say 262*, your power peak will want to move up from ~4200, to maybe ~4800. but your heads will be hard done-by to make any power up there.
In any case if you gain 600 rpm at the top, then you will also give it away at the bottom...
So 600 doesn't sound like a big deal right? Well with 2.76 rear gears, the power peak moves from say 46 mph to 53mph , and that's a lot. Depending on your actual power, that 7mph,could be 2,3 or maybe even 4 seconds.
At the bottom, each cam size will cost you about 200 rpm in stall,so if your teener was fine with an 1800 stall with the factory cam, then the 3-sizes bigger 262 cam, will want ~2400.
So, when you think about cams,you just gotta think about the whole air in/air out,combo. see note 2
The LA318 is stuck with a pitiful 8/1 NOMINAL Scr. And that means it could be less, even 7.6. . So when a cam is considered, you also have to think about a TC, and the final cylinder pressure, and the rear gears; all as a package.
If you don't, you will have just joined the club of thousands of unhappy 318 owners who all did the same thing.
note 2
Here's how it works;
the typical 7.8sCR-318LA might make 135 psi @sealevel with the factory 240*cam with an ICA of 48*.
The next bigger cam, with an Ica of 51.5, drops the pressure to 132
The second bigger cam will drop to 128
that's 7psi already!, or 5%.
But guys want to go straight to the 268/276, HFT 340 cam, with an Ica of 66*, and that drops the pressure into "Total Lazy-Dog"territory of 116psi/about a 15% pressure loss! Don't do that.
They all say it ain't so bad, but I tell you. it sucks/ don't do it.
Happy HotRodding
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Johnny Dart
Well-Known Member
Ede Performer intake.
Ede 600cfm carb.
340 HiPo exhaust manifolds.
Dual exhaust, H pipe, hi flow mufflers of your choice.
Mopar Performance electronic ign.
318 I had back in the day. It was a "Peg Leg Tire Roaster".
Ede 600cfm carb.
340 HiPo exhaust manifolds.
Dual exhaust, H pipe, hi flow mufflers of your choice.
Mopar Performance electronic ign.
318 I had back in the day. It was a "Peg Leg Tire Roaster".
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AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
- Joined
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What;
no cam, no stall,no gears? lol
Was that a smogger-teen @8.0 Nominal Scr?
Just asking, not tryng to start anything....
Johnny Dart
Well-Known Member
No, it was the original 318 in my 70 Dart. All stock bottom end. Original 2.73 gear. Day 2 bolt on goodies.
Those were 9:1 I believe. Better than nothing and no big cam to take compression away.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
- Joined
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I had a 70
Bought it in late summer of 70 with 11,000 miles on it.
She was a 340/4-spd/3.55s
From there to fall of 75 I bought her a lotta lotta tires,lol.
70 Was a good year.
PantherPink it was
Bought it in late summer of 70 with 11,000 miles on it.
She was a 340/4-spd/3.55s
From there to fall of 75 I bought her a lotta lotta tires,lol.
70 Was a good year.
PantherPink it was
4 barrel, headers and a hot ignition curve will have you a tire melting fun street car.
The first thing to do is dual exhaust to let it breathe...
then 4 bbl intake and carb....
Replace the old timing chain with a good double roller, the stock 318 timing chain is junk...
dodge71demon
Well-Known Member
straightlinespeed
Sometimes I pretend to be normal
Well thats simple, I'll ship it to you. I'll send you a conversation and we can go from there.
DartGTDan
'71 Dart GT Fan
I added 2 1/4" dual exhaust (using the factory 318 manifolds & FlowMaster 40s), Edelbrock LD4B intake & 1406 carb, Lokar throttle & "kickdown" cables, Mopar Performance electronic ignition, and a Cloyes double roller timing chain & gear set to my 100,000+ mile 318, automatic transmission (A904), 3.23:1 sure-grip 8 3/4" rear end '71 Dart GT.
It's not a race car, but a fun ice cream parlor cruiser. Last summer our group made an approximate 1,000 mile road trip to St. Ignace (in Michigan's upper peninsula) for their annual car show.
Picture was taken on the north side of the Mackinac Bridge
Perfect. And it probably gets darned near 20 mph/ hwy.
Because the OP, quoted below is looking to have fun with his ride. Why even bother replying with what you said.
You should just move along, NOTHING here for YOU to see. Since your not helping....
Yep. Duals first because you will need them anyway. TTI makes hook ups to almost any manifold combination or header if you choose. 4 barrel and intake next. A stock Teen likes 500-600 cfm. Edelbrock, Holley, or even a old Thermoquad are good choices with a intake to match. Keep it simple. Electric chokes work well.
Electronic ignition is a plus. A Mopar kit or Pertronix are good choices. Don't forget to recurve the advance. @halifaxhops is a expert here and can fix you up.
MrJLR
Built, not bought
For the engine itself I’d say cam Something like comp cam 255 maybe a 265 deh would be the biggest power gain for the $$$ but not much point adding without at least 4bbl and duals upgrade too, headers are a good mod too but not necessarily at this level.
Out side the engine Gears “Rear gear and or 2.74 1st gear tranny and stall.
Out side the engine Gears “Rear gear and or 2.74 1st gear tranny and stall.
Wyrmrider
Well-Known Member
what aj said
timing chain and water pump if needed
no worthless high ratio rockers- what a waste of money
but cold air ( with hot stove if up north or anywhere with low speed driving)
ignition curve, electronic ignition, sprial core wires, extended tip plugs like champ LY series, brass terminals in the cap
exhaust- just duals or larger single for now, free flow cat for the $$$ headers and 340 exhaust nohelp unless you are going to rev more than stock
check out magnum and jeep exhaust manifolds there are several choices
transgo tf2 reprogramming kit adj bands atf+ 4
dual plane intake and TQ is best but other with small primaries work
250-256 cam from jones, lunati, howards designed for mopar lifter -or 248 MP but too expensive to buy new
not comp or summit (what aj said) 262-268 too ig and comp 256 does not have much area eventhough duration is ok it costs power
do a compression test first- bad compression score some better heads, (302, magnum, used aluminumrebuild and swap but think of that $200 pick a part 360 magnum-
when you upgrade the plugs to ones that were developed to fix problems with misfires with early 70s oemextended gap plugs
there is a reason for the change
timing chain and water pump if needed
no worthless high ratio rockers- what a waste of money
but cold air ( with hot stove if up north or anywhere with low speed driving)
ignition curve, electronic ignition, sprial core wires, extended tip plugs like champ LY series, brass terminals in the cap
exhaust- just duals or larger single for now, free flow cat for the $$$ headers and 340 exhaust nohelp unless you are going to rev more than stock
check out magnum and jeep exhaust manifolds there are several choices
transgo tf2 reprogramming kit adj bands atf+ 4
dual plane intake and TQ is best but other with small primaries work
250-256 cam from jones, lunati, howards designed for mopar lifter -or 248 MP but too expensive to buy new
not comp or summit (what aj said) 262-268 too ig and comp 256 does not have much area eventhough duration is ok it costs power
do a compression test first- bad compression score some better heads, (302, magnum, used aluminumrebuild and swap but think of that $200 pick a part 360 magnum-
when you upgrade the plugs to ones that were developed to fix problems with misfires with early 70s oemextended gap plugs
there is a reason for the change
-
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