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318 Build suggestions
- Thread starter C2ndLTpigeon
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2.02's fit fine on a stock 318 bore. Maybe you are thinking of a 273? I never over bore anything unless I have to, and then just enough to get straight, round bores. Had a friend running dirt track with a 318 with X heads, custom cam from somewhere in NC. Fastest car on the track in a sea of Chevies and Fords running 350 cu in.
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Blah Wha wha wha. No one "needs" to go out and get a POS 360. I have built all MOPAR small blocks for the street. I don't play with numbers. We built engines, ran them, and tried all kinds of combinations. We used what we had. All engines have their advantages and disadvantages. I personally love 273's and 340's. I love high rpm's. All MOPAR small blocks can be made to run very fast with a little thought and a little money. What do factory 360 heads cost anymore with everyone thinking they have to have aluminum heads? Once again you are answering a question no one asked. The poor guy even said it twice. Never would I consider a 360 for one of my cars. I had them, built them for others, sold them all, even a HP with a factory shot peened CFD crank and windage tray. Still have three 340's, four 273's, one 318 Magnum, two 383's, and one HP 440 that I will probably never use. That does not include any of my early Hemi's. Tell me again about being outclassed by a stupid 360 again... and I run a 273 and a 4 speed.
Dartswinger70
Well-Known Member
I dont doubt it, what was he running to get compression up domed pistons I mean when you say "318" i am thinking low comp, flat pistons, small combustion chambers small ports, if you mean the only thing 318 is the block, thats different. Thats also probably the only usuable thing about a "318" performance engine
I agree, and it seems to me that 318s are available,340s not so much. I have 340s and I have always felt that you start with the platform that will get you where you need to be. I was in tech school for automotive years ago, and a fellow student had a 6 cylinder Nova, talking about how hes putting a powerful small block in to make it a "sleeper" I said "you should start with a V 8 car to begin with to have that platform. Now youll need a trans and a rear to match the power out put. thats too much conversion work IMO. Its the same with the 318, if you need 340-360 heads, and machine work to get it there, why not start with the bigger engine? I have nothing against a 318, and i would use it as a base platform if that was all I had, and I am sure there are high comp pistons and all the same type parts that were /are available for the 340.
Dartswinger70
Well-Known Member
The 360 was a smog motor you can do the same with it that you would a 318 to get performance out of it, it is already bigger bore higher flowing heads, its the displacement of air that comes into play here. I mean if its heads machine work cam etc that you do with a 318,its the same effort for a 360 really and in the end you are displacing more air. this discussion could go on forever I suppose, and I am not beating down 318s, I just wouldn't think of starting a build with one, I have the 340s I suppose that is just where Im at. The 318 I have is totoally stock internals, stock heads, I ran it with 3.91 rear and 4 speed, it was fun, on the street but it was restricted breathing at high rpms, i dunno it just fell flat at a certain point. I suppose heads would have helped. The 273 was replaced with the 340 for a reason as the Hi Po small block. The engineers knew what they were doing.
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AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
- Joined
- Jan 19, 2014
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hang on fellas;
the OP clearly stated that he wanted a 340,
found them too pricey;
but is willing to break the bank for a 300hp 318.
I was responding to the issue from;
the cost of things,
the ease of assembly, and
the fact that a hi-compression 360 can totally waste a lo-compression 318 as to hiway economy,
and still make plenty of power, easily eclipsing 300hp.. using all stock major components; and in the process, the 360 makes enough torque to annihilate the tires.
The OP is in no hurry, and is exploring his options, already moving in the direction that will cost big money, for, in a 318, very little gain; surely a recipe for disappointment........
I am merely presenting a logical argument to the OP, for a bigger SBM, based on less money having to be spent, as, the OP has already stated wanting a bigger engine; and, of the SBMs, the 360 is the best place to stick his 318Whiplash cam (*2) into, which already has large-port heads, and adequate valve sizes to work with that cam. The additional 42 cubes will nicely replace the bottom-end torque, that the Whiplash sacrificed in the stock lo-C 318; and so, OP can re-use the stock convertor and 3.55s, albeit with a SureGrip required. OP already has all the add-ons to make the 360 with the 318 Whiplash, a great combo!
If it ends up too powerful for the chassis, and it will, well isn't that just too bad.....lol.
(*1) the 318whiplash, in a 360, with big-port heads and AG will want a shift rpm of more than 5000, and you can wring it out to 5500 all day, with the right valvesprings. Speaking of rpm, the 360 under my hood, with KB 107s, has been spinning to 7000Plus, since 1999.
(*2) Hughes says that the 318Whiplash (213/226/109+5)( and lifts of .480/[email protected]), works great in a 318, at "up to" 8.6Scr . OK, but there was no smoggerteen that was ever built to 8.6, so shame on Hughes for making you guess if it will work well in your STOCK lo-C teener. IMO Hughes is a lil slippery when it comes to camshaft specs.
Ima guessing your cranking pressure, in your sub 8.0Scr 1973 smoggerteen, is around maybe 145, so while it might be true that this cam works with 8.6, 145psi is about what a stock teener would put out in Indio. Read, lo-rpm pussyfied. OOps I mean soft.
The 360,will accept a lil more Scr; maybe something like 9.4/1, which is an easy build for a 360 with stock iron heads, and KB107s. That Whiplash cam has enough extraction duration, and a small enough overlap period, that it has the potential, at the right Scr, to make pretty good hiway gas-mileage. I mean, as to extraction and overlap, it's nearly identical to that of the 223/230/110Hughes, the one I used , to make 32mpgUSg. If anything, it's a lil better. You will, of course, not get close to that with 3.55s, geared 65=2900@ zero-slip, perhaps 3000 or more, on the tach; I was geared 85=2100 using a manual trans and overdrive.
(3) BTW, Biden has already stated that he is gonna raise the price of gas exponentially. So being able to run 87 gas and getting great fuel mileage, IMO, is sorta crucial to actually being able to drive the car, in the coming years. Biden and/or his party, is/are never gonna get voted out; they are here to stay. In the very near future, he is hoping to rid America of people, never mind gas-burning cars. In this scenario, a small cam 360 makes the most sense....
to me anyway.
I can't speak for the rest of you big-balled 300hp, 318 boosters.
In case you have forgotten,
here is a recap of some of the things that OP has said;
To be clear; I am not a 318 hater,
having had many many of them, in my 52plus years of driving. Almost all of our DDs have been 318cars. We have almost always been a two or three car family; one 318 car for me, a slanty-car for the wife, and a 340 or 360 bruiser for me to take out my frustrations on. With the occasional "other" car hanging around.
Btw
I would rather have a 340 shortblock with a 318 top and cam, than a 318 short with a 340 top and cam. It's really really hard to say no to the low-rpm torque increase.
As a streeter, yur only gonna pass thru the power peak once at WOT, possibly twice, and the first time don't count cuz the tires are melting. With 3.55s, the second time comes at around 65/70 mph........... Whereas the rest of the time, the engine will be lumbering along at 3000rpm or less..... probably closer to 2000, so.......... I mean, what good is 300hp at 5000, if the engine is sucked-out at 2000.............. On the street, you have a choice; 1) build the engine to have some honest torque, or 2) yur gonna need a hi-stall and near 4.xx series gears, AND an overdrive. I've done it both ways.
At 3600 pounds, I prefer a 360. That would be 10 pounds per cubic inch, a number hard to find fault with. My 1970 Swinger340 back in 1970, was 9.79 with me in it. It was slow; posting 98 in the qtr, versus 93 in the Eighth, for my Barracuda........
My 367 is nothing special, being built nearly the same as that 1970 340. The Scr is a true 10.95 compared to an advertised 10.5 for the 340. My cam is a 230/237/110 compared to the 340 being 228/236/114. Both were 4-speeds, had 4bbls, but my 367 has headers and full-length 3" duals. Yeah my 367 has OOTB Eddies on it so what.
The car posted that 93mph@3467 pounds, being shifted at 7000, well past the powerpeak of around 5100,lol. All in all, the advantage is just the headers, the free-flowing exhaust, and the 27 cubes. And the Barracuda was even a lil heavier than the Swinger.
They say that the 1970 340 made a tic over 300hp with headers and a good tune-up. Do you really wanna put that gas-hog 340 cam into your 318? And bump it's compression to 10.5, and make maybe 280hp; when the 360 in the same trim might make 320hp? In terms of dollars, is the cost of the 360 core worth 40 hp? Or a 5.9M? or even a 5.2M
Nah, "I like my 318", is the mantra.
Ok fine, there can be no argument against liking your 318. You like what you like, I get that. I don't like short,fat,black-haired girls. That doesn't make me a hater of short,fat,black-haired girls. If a short, fat, black-haired girl was the last girl on Earth, I would love her 17 children's worth. At least.
People throw the word "hate" out on everything, sorta like they brandish "racism".
the OP clearly stated that he wanted a 340,
found them too pricey;
but is willing to break the bank for a 300hp 318.
I was responding to the issue from;
the cost of things,
the ease of assembly, and
the fact that a hi-compression 360 can totally waste a lo-compression 318 as to hiway economy,
and still make plenty of power, easily eclipsing 300hp.. using all stock major components; and in the process, the 360 makes enough torque to annihilate the tires.
The OP is in no hurry, and is exploring his options, already moving in the direction that will cost big money, for, in a 318, very little gain; surely a recipe for disappointment........
I am merely presenting a logical argument to the OP, for a bigger SBM, based on less money having to be spent, as, the OP has already stated wanting a bigger engine; and, of the SBMs, the 360 is the best place to stick his 318Whiplash cam (*2) into, which already has large-port heads, and adequate valve sizes to work with that cam. The additional 42 cubes will nicely replace the bottom-end torque, that the Whiplash sacrificed in the stock lo-C 318; and so, OP can re-use the stock convertor and 3.55s, albeit with a SureGrip required. OP already has all the add-ons to make the 360 with the 318 Whiplash, a great combo!
If it ends up too powerful for the chassis, and it will, well isn't that just too bad.....lol.
(*1) the 318whiplash, in a 360, with big-port heads and AG will want a shift rpm of more than 5000, and you can wring it out to 5500 all day, with the right valvesprings. Speaking of rpm, the 360 under my hood, with KB 107s, has been spinning to 7000Plus, since 1999.
(*2) Hughes says that the 318Whiplash (213/226/109+5)( and lifts of .480/[email protected]), works great in a 318, at "up to" 8.6Scr . OK, but there was no smoggerteen that was ever built to 8.6, so shame on Hughes for making you guess if it will work well in your STOCK lo-C teener. IMO Hughes is a lil slippery when it comes to camshaft specs.
Ima guessing your cranking pressure, in your sub 8.0Scr 1973 smoggerteen, is around maybe 145, so while it might be true that this cam works with 8.6, 145psi is about what a stock teener would put out in Indio. Read, lo-rpm pussyfied. OOps I mean soft.
The 360,will accept a lil more Scr; maybe something like 9.4/1, which is an easy build for a 360 with stock iron heads, and KB107s. That Whiplash cam has enough extraction duration, and a small enough overlap period, that it has the potential, at the right Scr, to make pretty good hiway gas-mileage. I mean, as to extraction and overlap, it's nearly identical to that of the 223/230/110Hughes, the one I used , to make 32mpgUSg. If anything, it's a lil better. You will, of course, not get close to that with 3.55s, geared 65=2900@ zero-slip, perhaps 3000 or more, on the tach; I was geared 85=2100 using a manual trans and overdrive.
(3) BTW, Biden has already stated that he is gonna raise the price of gas exponentially. So being able to run 87 gas and getting great fuel mileage, IMO, is sorta crucial to actually being able to drive the car, in the coming years. Biden and/or his party, is/are never gonna get voted out; they are here to stay. In the very near future, he is hoping to rid America of people, never mind gas-burning cars. In this scenario, a small cam 360 makes the most sense....
to me anyway.
I can't speak for the rest of you big-balled 300hp, 318 boosters.
In case you have forgotten,
here is a recap of some of the things that OP has said;
To be clear; I am not a 318 hater,
having had many many of them, in my 52plus years of driving. Almost all of our DDs have been 318cars. We have almost always been a two or three car family; one 318 car for me, a slanty-car for the wife, and a 340 or 360 bruiser for me to take out my frustrations on. With the occasional "other" car hanging around.
Btw
I would rather have a 340 shortblock with a 318 top and cam, than a 318 short with a 340 top and cam. It's really really hard to say no to the low-rpm torque increase.
As a streeter, yur only gonna pass thru the power peak once at WOT, possibly twice, and the first time don't count cuz the tires are melting. With 3.55s, the second time comes at around 65/70 mph........... Whereas the rest of the time, the engine will be lumbering along at 3000rpm or less..... probably closer to 2000, so.......... I mean, what good is 300hp at 5000, if the engine is sucked-out at 2000.............. On the street, you have a choice; 1) build the engine to have some honest torque, or 2) yur gonna need a hi-stall and near 4.xx series gears, AND an overdrive. I've done it both ways.
At 3600 pounds, I prefer a 360. That would be 10 pounds per cubic inch, a number hard to find fault with. My 1970 Swinger340 back in 1970, was 9.79 with me in it. It was slow; posting 98 in the qtr, versus 93 in the Eighth, for my Barracuda........
My 367 is nothing special, being built nearly the same as that 1970 340. The Scr is a true 10.95 compared to an advertised 10.5 for the 340. My cam is a 230/237/110 compared to the 340 being 228/236/114. Both were 4-speeds, had 4bbls, but my 367 has headers and full-length 3" duals. Yeah my 367 has OOTB Eddies on it so what.
The car posted that 93mph@3467 pounds, being shifted at 7000, well past the powerpeak of around 5100,lol. All in all, the advantage is just the headers, the free-flowing exhaust, and the 27 cubes. And the Barracuda was even a lil heavier than the Swinger.
They say that the 1970 340 made a tic over 300hp with headers and a good tune-up. Do you really wanna put that gas-hog 340 cam into your 318? And bump it's compression to 10.5, and make maybe 280hp; when the 360 in the same trim might make 320hp? In terms of dollars, is the cost of the 360 core worth 40 hp? Or a 5.9M? or even a 5.2M
Nah, "I like my 318", is the mantra.
Ok fine, there can be no argument against liking your 318. You like what you like, I get that. I don't like short,fat,black-haired girls. That doesn't make me a hater of short,fat,black-haired girls. If a short, fat, black-haired girl was the last girl on Earth, I would love her 17 children's worth. At least.
People throw the word "hate" out on everything, sorta like they brandish "racism".
ChargedDart75
Well-Known Member
I had to lol
No idea what else he was running in his 318. I used to give him stuff for his race car. He did his own work. You guys still miss the point. You do not need a 340 or 360 to go fast with a MOPAR small block. The only thing basically different between a 318 short block and a 340 is piston diameter. A 340 bore is .13 of an inch larger. Do you really think that makes any difference? I hate to tell you but if you take 360 heads, cam, intake, carb, and distributor from a 340 and put them on a 273, 318, or 360 they all run pretty much the same, except for the rpm where the hp peaks. Maybe just a tad slower in the quarter for the smaller engines, not much though.
C2ndLTpigeon
Mopar or no Car!
So what your saying is a 360 with stock heads, some taller pistons with the 318 whiplash cam would be a good combo? It would be nice since I can reuse alot of my components which saves me some money.
I might also change the transmission to a 727, but think I should maybe go with a slight stall in the converter.
I do plan on keeping the 3.55 Gears but would like to throw in a suregrip.
Dartswinger70
Well-Known Member
Yes, but you are talking about a modified 318, adding parts that a 340 comes with stock. I believe what you are saying as it makes sense you could work 340 parts and specs into a 318, I am saying you are putting alot of effort into turning a 318 into a 340 when all you had to do is start with a 340 or A 360.It comes down to economics really I wouldn't spend that $$$ on a 318 if I really wanted a 340. I would fork over the cash for a 340 and start with that as a build, that or a 360. The thousandths of an inch in the bore does matter because it is displacement and air flow, the blocks can only safely be punched out so big, each bit of airflow through each cylinder adds up. It has been a long time standard that with a small block you want a 4 inch bore, you cant get there with a 318. I know its semantics but to each their own. Tis is almost like arguing 883-1200 in the Sportster world
Yes, but you are talking about a modified 318, adding parts that a 340 comes with stock. I believe what you are saying as it makes sense you could work 340 parts and specs into a 318, I am saying you are putting alot of effort into turning a 318 into a 340 when all you had to do is start with a 340 or A 360.It comes down to economics really I wouldn't spend that $$$ on a 318 if I really wanted a 340. I would fork over the cash for a 340 and start with that as a build, that or a 360. The thousandths of an inch in the bore does matter because it is displacement and air flow, the blocks can only safely be punched out so big, each bit of airflow through each cylinder adds up. It has been a long time standard that with a small block you want a 4 inch bore, you cant get there with a 318. I know its semantics but to each their own. Tis is almost like arguing 883-1200 in the Sportster world
I never cared for standards. I disprove them every day of my life. A 4 inch bore means nothing. My 273, with a 1.88 intake 340 top end and cam, ran the same as AJ's 340 in the quarter mile with Early A factory exhaust manifolds and 2" duals back in the day. If I had a good 318, I for surely would not trade for a 360. Heck I didn't trade a 273 for one, and I had 360's laying around. I would never bore any block more than just enough to clean up the bores. That is not where you make power. As for AJ's 360, how much money is in that thing. 11:1 compression and Edelbrock heads? I don't need any of that either. Trying to put that up against a low compression 318, what a comparison...
Dartswinger70
Well-Known Member
AJs build and yours ,it sounds like two different engines for two different uses are you drag racing your 318? I am in the middle of a 340 build that I am trying to keep "as stock as possible" as far as cam, heads ,compression...I want it to run on pump gas and not over heat in traffic etc. The point with my 340 is, it had all the good stuff stock. A gasket set is all I would need basically... I believe it is possible to have a 273 in a 65 barracuda that moves that car scary quick...but that is a street car. Take that car to the strip and try to compete, and eventually out will come the 273 and in would go a race worked 340-360. it would come to that naturally I believe the 318 would only get the car to a certain bracket and it would stop there. However I am not up with the times and do not know what is out there as far as 318 internals for racing engines. I am fairly certain the heads would have to go , the stock 318 heads. Just my thoughts and I could be wrong. I figure the truth is 318s are drying up, and 340s have all but dried up, they definitely aren't cheap, and figure the things you have to know, what years did they go low comp, what valves are in what heads, internal vs external balance etc. I'm not sure 318s have that issue is there an external balance 318LA engine? Keep in mind I always talk in terms of LA I am not all that familiar with the magnum, I know a little about them but never owned one. I like the roller cam setup in the magnum though that makes sense to me, and i wish it was in the LA
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Dartswinger70
Well-Known Member
After reading AJs post and then referring back to the OP's post I conclude that :
the OP wants a 340 (why wouldn't he they are the holy grail always have been even when I was a young man, not that I am old but getting there , I was in diapers when my 70 swinger 340 was new...)
he mentioned UTG ok ,there's the culprit. Has anyone seen Uncle Tony get the performance he stated he would out of Bottle rocket yet? or is he still working on shaving weight from that B body? I am familiar with his 318 bottle rocket project but don't buy the numbers he's talking... wasn't he saying 10s? is that 1/8 mile?
if so he may be able to do it but I was actually thinking "10s in a B body with a 318? in the 1/4? I wanna see it..."
P.S. I Partly blame Uncle Tony for driving the price of 318s up...
just kidding Uncle Tony but you know what I mean... I guess slants are next...
the OP wants a 340 (why wouldn't he they are the holy grail always have been even when I was a young man, not that I am old but getting there , I was in diapers when my 70 swinger 340 was new...)
he mentioned UTG ok ,there's the culprit. Has anyone seen Uncle Tony get the performance he stated he would out of Bottle rocket yet? or is he still working on shaving weight from that B body? I am familiar with his 318 bottle rocket project but don't buy the numbers he's talking... wasn't he saying 10s? is that 1/8 mile?
if so he may be able to do it but I was actually thinking "10s in a B body with a 318? in the 1/4? I wanna see it..."
P.S. I Partly blame Uncle Tony for driving the price of 318s up...
just kidding Uncle Tony but you know what I mean... I guess slants are next...
rigger3006
Well-Known Member
yep, he shows up, i start scrolling, sounds like charlie browns teacher!
rigger3006
Well-Known Member
the roller cam 318s with 302 heads the 80s were rated somewhere in the low 9s for compression were they not?
Those were great engines.
SEE! The 318 hater spends a ton of time furtherly proving his Hatred of the 318!
SEE! The 318 hater spends a ton of time furtherly proving his Hatred of the 318!
you caint fix stupid.
rigger3006
Well-Known Member
yep, still have one in garage,plus 3 360s, that 318 took everything i threw at it
Dartswinger70
Well-Known Member
That's magnum 318 or 5.2 right?
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
- Joined
- Jan 19, 2014
- Messages
- 25,874
- Reaction score
- 13,184
Ok
I've been thinking it over
if you really want to spend your money on a 318
and with the parameters as already stated ( see *1 below),then;
>the first thing you will need to do is get some airflow going at rpm, >and the second thing is get the Effective Pressure up.and
>the third will be in the tune.
(*1)
>so the first thing you have to do is decide if the 3.55s are gonna do it for you; because, 65=3000@4% slip with 26.7" tires .
>This is gonna set the tone for the rest of the build, because the next thing to do is to choose the rpm of operation to work together with those 3.55s.
Here's what I mean; with 3.55s, and your TF904 (2.45-1.45-1.00)
your self-imposed rpm limit of 5000, brings the following;First gear tops out at 40 mph and second at 67mph. These are good numbers. To shift at 5000, the power peak can be at 4700, so, I doubt this will get you 300hp. But you installed a "?" after 300, so lets forget about the 300, and concentrate on "good performing",on "pumpgas".
> So, having set the powerpeak at say 4800, we can now look to the cam as to intake duration. In this case, I'd be looking at [email protected].
> to get the power with that small a cam, and limited to 5000rpm, you are gonna need a very specific head and a lotta pressure, more than IMO, iron can supply. You're not gonna touch 300hp at 155/160 psi. Yur gonna need 185 or more, and that pressure dictates alloy heads, and the .039 FelPro head-gaskets. So now we have the second piece of data 8.8cc for the gasket, and the third; 185or more psi
> So now, lets choose fuel economy. How important is this to you? Ok so IMO, because I believe that the price of gas is gonna skyrocket in the coming months, I'm gonna go with "very important". And so we come to the cam's extraction cycle and overlap. In an effort to make power at 5000, with headers, that cam is gonna need a generous amount of overlap. Normally we can't get away with that, but cruising at 60@2780rpm, we can. So I'm gonna set the max to 50*overlap, because I already got 32mpg with that number, even at 2100. Next is extraction. We're gonna need to maximize this to, IMO, greater than 114*
> so now we can begin to build a cam spec. So far we have intake of [email protected], 50* overlap, and 114 extraction.I already know that I want a minimum TC stall of 2800, so, I can chose a tighter than "normal " LSA, so I'm going with 108. And I know I will need a solid lifter profile, so I can control the exact opening and closing points of the valves, so I can control the pressure. So that [email protected] is gonna become about 258 @.006/.008, we'll finalize that later.
> because our heads will be fantastic, and because we have headers, and because we will have plenty of pressure, and because I want more than 114* of extraction; I'm gonna choose a tight split of 6*, so that makes the exhaust duration to be about 264*. I now have everything I need to generate a cam profile. And I get;
258/264/108+1/45* overlap/56*Ica/124* compression/119*power.
>Bam! now we have an Ica. But look, the extraction is a huge 119*, and overlap is only 45*, so it has the potential to make fantastic fuel economy; the stock 318 cam has 20*overlap and 122* extraction.
> With the Ica known, we can now generate, using the Wallace Calculator, the Scr/Dcr numbers, and get an idea of how much fun this engine will be, looking at the VP. I'm gonna jump the pressure up to 185, because I know with a tight-Q and alloy heads, you will be able to run 87E10 at full load/full timing. And since Indio is near sealevel, that's what I'm gonna input. So here's what the Wallace says
Static compression ratio of ................... 10.5:1.
Ica of 56*/sealevel
Effective stroke is 2.74 inches.
Your dynamic compression ratio is ................ 8.85:1 .
Your dynamic cranking pressure is ............... 186.51 PSI.
V/P (Volume to Pressure Index) is ................ 149.
BadBoom!
VP of 149 puts you solidly into the funzone, so I am downgrading the TC to stock, or use what ever you have. You can upgrade later if you feel the need.
> now, all we have to do is build your 318LA up to 10.5Scr, which at .020 o/s, will require 69.36cc.
The gasket was earlier selected at 8.8cc, so that leaves 60.56 for the total of head plus piston. So lets use a 58cc closed chamber alloy design, leaving 2.56cc NET for the piston plus deck clearance.. This design calls for no more than .050 less .039= .011 deck clearance, and up to .028 less .039= .011 pop-up , but has to end at NET 2.56cc, sounds pretty easy.
You could try this with an .028 gasket, allowing up to .022 deck clearance, and maybe save the cost of decking, BUT, I have not had long-term success at 185psi with those; the one-time I used them, they blew the fire-ring into the valley. Of course this will change the NET volume so you would have to re-calculate.
If you can't get a flat-top piston with a high enough cd to get you up to the minimum .012 deck height, then you will need to either lower the decks (I don't like doing that), or get a piston with a dome or step or a reverse dome step-D cup, whatever it takes. At 185psi, you can't afford detonation.
> in a nutshell this build will satisfy your every dream.
You can use the stock crank and rods.
But you will need some way to adjust the lash on your solid-lifter cam. This doesn't need to be fancy with the modest 5000 rpm shift speed. You can use the 273 stuff, or IMO, even just adjustable pushrods, if you can find some adjustable with the intake still installed.
You can use everything else that you already own; namely the TC/3.55s and bolt-ons, and all your current support-works should be fine. And she's an easy to tune combo.
> of course it is highly unlikely that you will find an off-the-shelf cam as detailed. Not to panic, you have lots of pressure to burn, so you could use a fast-rate hydro of similar .050 numbers, and readjust your Scr as may be required, to try to maintain the minimum 185psi spec. Yes you could even go back to iron heads and 165psi; but then you will need to pull the Scr back to 9.5.... which reduces the V/P to 131, still a bit better than the stock 318, but really a ho-hum number; Say goodbye to roasting both tires. To get the bottom-end back, you will need that 2800TC now. Also, at V/P of 131, your fuel-mileage is slipping away. And at 165psi, you will need best pumpgas. If you drive 10,000 miles a year like I used to, the fuelcost difference between 87 and 91, is gonna rapidly eat up the equivalent cost of alloy versus iron heads.
Do you need alloy heads?
At this power level no; not for power gains. But it allows you to run the pressure, to make big-engine, down-low torque, and to make decent fuel economy, so you will want to put the miles on it instead of complaining how expensive it is to drive..
As to VP, for comparison, the 340 of 1970 had a VP of 131, and NOBODY I know, ever bragged about how much torque the 340 had. So we know that 131 is nothing to brag about, lol. The 440M made about 137, and out of the gate, they never impressed me either. But 149 is a real ripper.
Furthermore, alloy heads will, by virtue of their assumed to be better flowing ports, OOTB, will be worth about one cam-size at peak power, so there is that,lol, getting you closer to 300hp.......
>So there you go; power with economy and a chitload of torque, not usually all mentioned in the same sentence, concerning a 318.
> BTW, if you find some traction, hang the heck on, cuz when she spits the driveshaft out on the 1-2 shift with those puny 7260 joints, things get a lil crazy; hope the back one lets go first. VP of 149 tends to break stuff. Don't even think about peg-legging that 8.25, the spiders will not take it for long either seizing on the crosspin, or simply shattering on the shift. Order your "posi", and your driveshaft loop .....today. In your camsearch, PM @Wyrmrider, to get the skinny on fat .200lift cams.
Now, I leave the task of choosing the components in the hands of my very capable fellow FABO members, who like to paint me a 318hater.
Happy HotRodding
I've been thinking it over
if you really want to spend your money on a 318
and with the parameters as already stated ( see *1 below),then;
>the first thing you will need to do is get some airflow going at rpm, >and the second thing is get the Effective Pressure up.and
>the third will be in the tune.
(*1)
>so the first thing you have to do is decide if the 3.55s are gonna do it for you; because, 65=3000@4% slip with 26.7" tires .
>This is gonna set the tone for the rest of the build, because the next thing to do is to choose the rpm of operation to work together with those 3.55s.
Here's what I mean; with 3.55s, and your TF904 (2.45-1.45-1.00)
your self-imposed rpm limit of 5000, brings the following;First gear tops out at 40 mph and second at 67mph. These are good numbers. To shift at 5000, the power peak can be at 4700, so, I doubt this will get you 300hp. But you installed a "?" after 300, so lets forget about the 300, and concentrate on "good performing",on "pumpgas".
> So, having set the powerpeak at say 4800, we can now look to the cam as to intake duration. In this case, I'd be looking at [email protected].
> to get the power with that small a cam, and limited to 5000rpm, you are gonna need a very specific head and a lotta pressure, more than IMO, iron can supply. You're not gonna touch 300hp at 155/160 psi. Yur gonna need 185 or more, and that pressure dictates alloy heads, and the .039 FelPro head-gaskets. So now we have the second piece of data 8.8cc for the gasket, and the third; 185or more psi
> So now, lets choose fuel economy. How important is this to you? Ok so IMO, because I believe that the price of gas is gonna skyrocket in the coming months, I'm gonna go with "very important". And so we come to the cam's extraction cycle and overlap. In an effort to make power at 5000, with headers, that cam is gonna need a generous amount of overlap. Normally we can't get away with that, but cruising at 60@2780rpm, we can. So I'm gonna set the max to 50*overlap, because I already got 32mpg with that number, even at 2100. Next is extraction. We're gonna need to maximize this to, IMO, greater than 114*
> so now we can begin to build a cam spec. So far we have intake of [email protected], 50* overlap, and 114 extraction.I already know that I want a minimum TC stall of 2800, so, I can chose a tighter than "normal " LSA, so I'm going with 108. And I know I will need a solid lifter profile, so I can control the exact opening and closing points of the valves, so I can control the pressure. So that [email protected] is gonna become about 258 @.006/.008, we'll finalize that later.
> because our heads will be fantastic, and because we have headers, and because we will have plenty of pressure, and because I want more than 114* of extraction; I'm gonna choose a tight split of 6*, so that makes the exhaust duration to be about 264*. I now have everything I need to generate a cam profile. And I get;
258/264/108+1/45* overlap/56*Ica/124* compression/119*power.
>Bam! now we have an Ica. But look, the extraction is a huge 119*, and overlap is only 45*, so it has the potential to make fantastic fuel economy; the stock 318 cam has 20*overlap and 122* extraction.
> With the Ica known, we can now generate, using the Wallace Calculator, the Scr/Dcr numbers, and get an idea of how much fun this engine will be, looking at the VP. I'm gonna jump the pressure up to 185, because I know with a tight-Q and alloy heads, you will be able to run 87E10 at full load/full timing. And since Indio is near sealevel, that's what I'm gonna input. So here's what the Wallace says
Static compression ratio of ................... 10.5:1.
Ica of 56*/sealevel
Effective stroke is 2.74 inches.
Your dynamic compression ratio is ................ 8.85:1 .
Your dynamic cranking pressure is ............... 186.51 PSI.
V/P (Volume to Pressure Index) is ................ 149.
BadBoom!
VP of 149 puts you solidly into the funzone, so I am downgrading the TC to stock, or use what ever you have. You can upgrade later if you feel the need.
> now, all we have to do is build your 318LA up to 10.5Scr, which at .020 o/s, will require 69.36cc.
The gasket was earlier selected at 8.8cc, so that leaves 60.56 for the total of head plus piston. So lets use a 58cc closed chamber alloy design, leaving 2.56cc NET for the piston plus deck clearance.. This design calls for no more than .050 less .039= .011 deck clearance, and up to .028 less .039= .011 pop-up , but has to end at NET 2.56cc, sounds pretty easy.
You could try this with an .028 gasket, allowing up to .022 deck clearance, and maybe save the cost of decking, BUT, I have not had long-term success at 185psi with those; the one-time I used them, they blew the fire-ring into the valley. Of course this will change the NET volume so you would have to re-calculate.
If you can't get a flat-top piston with a high enough cd to get you up to the minimum .012 deck height, then you will need to either lower the decks (I don't like doing that), or get a piston with a dome or step or a reverse dome step-D cup, whatever it takes. At 185psi, you can't afford detonation.
> in a nutshell this build will satisfy your every dream.
You can use the stock crank and rods.
But you will need some way to adjust the lash on your solid-lifter cam. This doesn't need to be fancy with the modest 5000 rpm shift speed. You can use the 273 stuff, or IMO, even just adjustable pushrods, if you can find some adjustable with the intake still installed.
You can use everything else that you already own; namely the TC/3.55s and bolt-ons, and all your current support-works should be fine. And she's an easy to tune combo.
> of course it is highly unlikely that you will find an off-the-shelf cam as detailed. Not to panic, you have lots of pressure to burn, so you could use a fast-rate hydro of similar .050 numbers, and readjust your Scr as may be required, to try to maintain the minimum 185psi spec. Yes you could even go back to iron heads and 165psi; but then you will need to pull the Scr back to 9.5.... which reduces the V/P to 131, still a bit better than the stock 318, but really a ho-hum number; Say goodbye to roasting both tires. To get the bottom-end back, you will need that 2800TC now. Also, at V/P of 131, your fuel-mileage is slipping away. And at 165psi, you will need best pumpgas. If you drive 10,000 miles a year like I used to, the fuelcost difference between 87 and 91, is gonna rapidly eat up the equivalent cost of alloy versus iron heads.
Do you need alloy heads?
At this power level no; not for power gains. But it allows you to run the pressure, to make big-engine, down-low torque, and to make decent fuel economy, so you will want to put the miles on it instead of complaining how expensive it is to drive..
As to VP, for comparison, the 340 of 1970 had a VP of 131, and NOBODY I know, ever bragged about how much torque the 340 had. So we know that 131 is nothing to brag about, lol. The 440M made about 137, and out of the gate, they never impressed me either. But 149 is a real ripper.
Furthermore, alloy heads will, by virtue of their assumed to be better flowing ports, OOTB, will be worth about one cam-size at peak power, so there is that,lol, getting you closer to 300hp.......
>So there you go; power with economy and a chitload of torque, not usually all mentioned in the same sentence, concerning a 318.
> BTW, if you find some traction, hang the heck on, cuz when she spits the driveshaft out on the 1-2 shift with those puny 7260 joints, things get a lil crazy; hope the back one lets go first. VP of 149 tends to break stuff. Don't even think about peg-legging that 8.25, the spiders will not take it for long either seizing on the crosspin, or simply shattering on the shift. Order your "posi", and your driveshaft loop .....today. In your camsearch, PM @Wyrmrider, to get the skinny on fat .200lift cams.
Now, I leave the task of choosing the components in the hands of my very capable fellow FABO members, who like to paint me a 318hater.
Happy HotRodding
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AJs build and yours ,it sounds like two different engines for two different uses are you drag racing your 318? I am in the middle of a 340 build that I am trying to keep "as stock as possible" as far as cam, heads ,compression...I want it to run on pump gas and not over heat in traffic etc. The point with my 340 is, it had all the good stuff stock. A gasket set is all I would need basically... I believe it is possible to have a 273 in a 65 barracuda that moves that car scary quick...but that is a street car. Take that car to the strip and try to compete, and eventually out will come the 273 and in would go a race worked 340-360. it would come to that naturally I believe the 318 would only get the car to a certain bracket and it would stop there. However I am not up with the times and do not know what is out there as far as 318 internals for racing engines. I am fairly certain the heads would have to go , the stock 318 heads. Just my thoughts and I could be wrong. I figure the truth is 318s are drying up, and 340s have all but dried up, they definitely aren't cheap, and figure the things you have to know, what years did they go low comp, what valves are in what heads, internal vs external balance etc. I'm not sure 318s have that issue is there an external balance 318LA engine? Keep in mind I always talk in terms of LA I am not all that familiar with the magnum, I know a little about them but never owned one. I like the roller cam setup in the magnum though that makes sense to me, and i wish it was in the LA
Na, 273's were always fast. Like the 340 the High Performance 273 had all the good stuff and unencumbered by emissions considerations. The only problem with 273's is you have to wind them up too high once you go past J heads. I feel that 7,000 rpm, 6,500 on the safe side, is the top limit using stock internals and valve train. 340's were always the best, but it was because they got all the good stuff, from compression to good heads and really too much to list. Not the "magic" 4 in bore. Not the few extra cubic inches. But the whole high performance package. I remember 340 guys buying Holley carbs, Edelbrock intakes and in the end they ran about the same as stock. What did us poor boys do to get 340 performance? Start with a 318. They were all internally balanced, including the Magnum 5.2. Get the heads off a 360, same 340 ports, the intake valves were a bit smaller, but they still flowed great, clean up the bowls under the valve head, milled the heads .040 and intake side .038, 340 or similar cam, 340 intake and carb, 340 exhaust manifolds, dual exhaust, quick curve distributor, windage tray, high pressure oil pump spring and you were just about there. The same works for 273's and 360's also. We are talking the 70's here. I did it all the time for people. I never had the time or money to race my only car. My friends raced Super Stock and Stock Class. They helped me sort out the BS from magazines and knuckle heads, to what it really takes to run fast. It is not as much as one would think. I know what it takes to have a dedicated drag car, and I have finally realized, that is not what I want. My 273 was not stock, never was, and was a test mule for just about anything that sounded good to me. It was and is crazy fast.
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rigger3006
Well-Known Member
KISS,we all know what that means, headers,dual exhaust,340 cam,any dual plane, 600-650 carb,a good tune and any 318 will be happy
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