Hi guys , im on a extremely poor budget for my 318 fury
, bought a new 9905 600cfm edelbrock with an adaptor to convert the 2bbl to a 4bbl , i have tons of magnum manifolds laying around , i want to clean and port the intak and heads...but a big BUT ***** i want to order a cam , AND its like 700$ canadian for a cam kit , is there any cheaper way to have a good 450-480ishh cam and to run with a stockishh 318 and not spend a ton on springs -retainers / , special pushrods bla bla bla , of you guys have a cheap recipe and part numbers i would really appreciate it , i saved a bit but its for the whole car , i cant spend 1 or 2k on the 318 to updrage it neither : * 1st LA for me , always ran rollerized magnums
" or you guys have a cheaper recipe?"
Now, I'm not gonna tell you how to spend yur hard-earned savings.
First I'm gonna tell what yur gonna be most excited about when you drive it. Then Ima gonna tell you why this is so. Then I'll tell you what I would do and have already done, and finally, I'm gonna say;
Whatever you chose to do
Happy HotRodding.
Ok so;
I'm assuming you're looking for a lil more grunt off the line. If that is true then; IMO, you need a new plan. One that involves a higher than stock stall and deeper rear gears.
First Part;
1) Barring supercharging, the single most effective modification you can do to an auto trans car, to get off-the-line grunt, is a higher-stall convertor; and
2) the second most effective mod is deeper rear gears. and
3) The THIRD is a 4bbl on a 4bbl intake which usually necessitates a free-flowing exhaust system.
Second Part;
Here is how this works:
As to #3
the 4 bbl will not add even ONE horsepower until the Two bbl chokes, which is gonna be around 2800 or a lil higher. With 2.76 gears and 205/70-15 tires at 26.3 tall and 82.6inches of rollout, 2800 will be 32mph @ zero-slip, say 27.5@15% slip. So unless you can get the tires spinning, the 4bbl, for all it's noisome fury, does nothing to very little until 27.5 mph
........... at which time, it starts adding..... about ONE or two-at-most horsepower per 100rpm, until it hits about 4000 to 4400. With a 4bbl on a stock factory 2bbl intake, IDK what to expect, but IMO it's a waste of time.
Lets recap; with no changes except the 4bbl on a 4bbl intake; under 27.5 mph you get zero hp increase. By 4000 perhaps 20hp, but 4000=39mph.
Whoot-whoot!
As for #2
Gears multiply your engine torque, actually whatever torque makes it thru the transmission. With a 904/727, the ratios are 2.45-1.45-1.00; so in first gear, the trans is multiplying the engine torque by 2.45..
Lets say your un-modified engine is stalling at 2000, and at WOT, is putting out 160 big fat ft-pounds. (BTW;That comes to 60hp, jus saying).
Out the axles with 2.76 gears this comes to 160 x 2.45 x 2.76=1080 ftlbs to be shared by two tires. Assuming a GVW of 3800 pounds, this comes to a paltry 1080/3800=
.285ft lbs per pound of car;and that is soooooo sad.
Ok so lets put 3.91s in the back. 160 x 2.45 x 3.91=1533 ftlbs and
1533/3800=
.40 ftlbs per pound of car. This is an increase of ~42%, and it comes right from ZERO mph; yahoo!
As to #1
Going back to the 160ftlbs at 2000rpm. Lets say you install a 2800TC and it really stalls there, and at 2800 your engine is up to 200 ftlbs (jus saying), and (BTW 200@2800 is now 107hp, already an increase of 107/60=, plus 78%! ) Going back to the 2.76s, this comes to
200 x 2.45 x 2.76= 1352 ftlbs, and 1352/3800=
.356 ftlbs per pound of car, an increase of .356/.285= about 25% and it begins right at ZERO mph.
Ok lets install those 3.91s again to go with the 2800TC. I get 200 x 2.45 x 3.91=1916 ftlbs to the rear axles and 1916/3800=
.504 ftlbs per pound of car. From the beginning of this story, this is .504/.285=
an increase of 77% at zero mph versus .....the 4bbl at 0% at zero mph.
Which would you rather have?
Dare I say this is a no-brainer?
Ok but I get it, 3.91s are a bit high for cruising, and you might want to dial it back a bit, say 65=2750 tops. This will require, a gear of 3.23 for 65=2764@3% slip. Ok so then, still at 2800 and 82.6roll-out, I get
200 x 2.45 x 3.23=1583 ftlbs and 1583/3800=
.4165 ftlbs per pound of car, which is still .4165/.285=plus 46% over the starting position.
Ok so I flogged that to death.
Lets talk money.
So far, I bought you a 2800 stall and 3.23gears, and yur gonna need a Suregrip. You are gonna install the TC, so no cost there. You should have an 8.75 under that C-body, so somebody is gonna practically give you a complete 3.23 chunk, with a reconditioned clutch-type, and a matching yoke to what you got under there now, for about the cost of a new LSD...... and all you gotta do is swap it in. You can do both jobs in say less than 6 hours, if you have never done it before.
How much have you spent?
IDK, I haven't got a clue about pricing, but guessing a lot less than $2000C, unless you chunk is coming from Australia, lol.
While the trans is down, you can freshen it, add a TF-II kit to it, and a deep pan, and flush the lines, and forget about it. So now yur into it for a weekend. And you still have enough cash left over for a good used 4bbl intake, and a tune-up. And just maybe a cobbled up dual exhaust.
Third Part;
So, to recap, my order of parts installation would be;
1) convertor
2) gears, unless you already have 3.23s and need to keep the Rs down for the hiway. If no hiway then, up to 4.10s for city with stock stall or 3.73s with the 2800
3) an LSD
4) a 4bbl carb, AND a 2-plane 4bbl intake, fresh cold air, and a new tune
5) a free-flowing exhaust, headers optional
6) forget the cam, I say
7) If you just cannot forget the cam then
8) Ok then about now, after all the other listed mods are done, you can think about a modest cam
Why forget the cam?
Two reasons at least;
1) any cam you install with a later closing intake valve, will cause the cylinder pressure to decrease, which will cause the low-rpm torque to decrease, which will usually be disappointing to say the least. and
2) installing a longer period cam always always always makes it's power at a higher rpm, and not always gives you much in the midrange, and, with no other changes, will almost always give up low-rpm power to get that top-end power. Furthermore;
If the LSA has simultaneously been decreased with the new cam selection, the powerband will usually also have been decreased. You can get away with this, if you have a hi-stall and gears, because those will help the car to motor thru the handicap, which will still be there, just not felt as much.
3) those 2bbl heads will not support much of a power increase, and without headers, the overlap period is entirely nullified, which is from where most of the power increase comes from..
Ok I got one for ya; installing a long-period cam in an engine with tiny ports and log manifolds; is like making a peanutbutter and jelly sandwich..... without any jelly, and only half the peanutbutter, and nothing to wash it down with. The sandwich is gonna go down hard and leave a bad after-taste. $700 for a cam, netting just ~15/20hp at 4800, and losing a bunch of torque down low, is gonna do about the same. Forget the cam, I say
4) 4800 with 2.76s is about 50mph, still in First gear. Forget the cam.
5) once the cylinder pressure falls below about 135psi, the engine is rapidly getting lazy. A strong engine will have over 150psi. By 160 it needs special attention to be paid to the fuel. By 165psi it needs best pumpgas, and usually a delayed power-timing. If you want to run more than 165 psi, yur gonna need to be a freeking genius or if a DA like me, just switch to alloy heads and run her up to 185/190 psi, but yur gonna need to pay attention to the chosen gasket and the surface prep, so it stays where you put it.
6) as far as cams go;
a) cams come in about 7* steps; the stocker is a 240/248/112. The next step up is a 248, then a 256, then 262, then 268 and so on.
b) Each step, when accompanied by appropriate changes will push the power up about 200rpm and steal about 100 off the bottom to get it.
That 200rpm is worth more as your engine power creeps up in efficiency.
c) when yur heads choke, so does the power
d) getting the air into the engine is always the problem, and the hotter the air is, the harder the job gets to be. Having outside ambient air at ~72* being rammed into the airhorn, versus heated underhood air at say 250/300degres, well, I don't have a formula for that, but it don't take genius to see the problem.
And Finally, as promised;
Whatever you chose to do
Happy HotRodding.
BTW, I once had a 71 Monaco with a tired old oil-burning 360 in it . So I sorta know what yur thinking.
I replaced that pig with a freshened lo-compression 318 bottom end from out of a 73 Dart.
I did not install a TC nor gears. I did install a complete 340top end on her including the cam. With 2.94s this combo was a complete and utter disaster ......... until the Rs got up. But as you can imagine, 4000 in first gear did not come until .....41(Forty-One) mph, and this is where the march of power
began, the peak did not occur until closer to 5500/56 mph. In Second gear, 4000 was 76 mph, so I got a big fat bonus of a useless passing gear. And to add insult to injury, the cruise rpm was 65=2400, and that 340 cam drank gasoline like two Russians on a drunk.
But I gotta tell ya, that 340 cam, in the 318, idled with almost exactly the same sound as it had in the 340, lol. And the ThermoQuad roar was just nasty!
I think I get you.
BTW, That car is long gone, but, I still have that engine, now rebuilt back to stock, except for a smallport 4 bbl INTAKE under that same TQ. She's a darling lil engine that loves a 2800, ANY gears, and including an overdrive.
As always
Happy HotRodding
