Today, dollar for dollar, is the 318 faster than the 340 ???

would you agree ?

  • yep, the 318 wins if buying and building for under 3k

    Votes: 48 41.7%
  • Nope, the 340 always has and always will beat the 318

    Votes: 57 49.6%
  • Actually, never thought about it like this... Good Point !

    Votes: 10 8.7%

  • Total voters
    115
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I need to find another one of those 380hp crate motor cams. For another project I have going on
 
I never built anything with a 2.76 gear that would perform up to my liking .
Well, you seem one dimensional.... as in how fast can I pass through the 1/4 mile. I like that also, but I don't like all my car rides to end in a mere few seconds. We venture out for hours.. and sometimes days. We just got back, by the way...
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I need to find another one of those 380hp crate motor cams. For another project I have going on


It’s just a cam and intake on a truck long block 5.9l, air gap and a 230 .500” ish cam should get ya close.
 
Yeah thanks I'm a stickler so I'm looking for a mopar performance cam. But you are correct hipotek and a few others have a cam that is close to the same specs
 
Yeah thanks I'm a stickler so I'm looking for a mopar performance cam. But you are correct hipotek and a few others have a cam that is close to the same specs

Or cut guide for more lift, more cams to choose from.
 
True but stock magnum heads don't need anymore lift than .500 or so. Alot of wasted valve motion anything over .500 or so
 
Well, you seem one dimensional.... as in how fast can I pass through the 1/4 mile. I like that also, but I don't like all my car rides to end in a mere few seconds. We venture out for hours.. and sometimes days. We just got back, by the way...
View attachment 1715781337

That’s a cool car, even with the two extra doors. I could cruise that from coast to coast and enjoy doing it.
 
That’s a cool car, even with the two extra doors. I could cruise that from coast to coast and enjoy doing it.
I would have too, back in the day. I'd rather jump in my wife's Durango RT for the road trips these days.
 
True but stock magnum heads don't need anymore lift than .500 or so. Alot of wasted valve motion anything over .500 or so


True don’t know if I’m right or not but always felt going a bit over your gonna spend more average time in the top 90% of the flow like if you have peak flow of 200 cfms @ .500” lift and around 180 cfms @ both .480” and .520” a .520” or so would give more average flow plus you go through the peak twice, could be wrong.
 
This the engine I got the 380hp 5.9l Magnum which dyno 409hp at peak and only varies 14hp from 5000-6000 rpm, but under this torque doesn't take over, when your under 5000 rpm torque is not now the power your using it's whatever hp @ rpm your at during your acceleration aka 230hp @ 3000 rpm, 333 hp @ 4000 rpm, 396 @ 5000 rpm, 409 @ 5400 rpm thats what moving your at those rpm's. If your engine is geared so you spend almost no time main powerband 4000-6000 rpm and spends more time in the 3000-4000 rpm range it's gonna act more like a 333 hp engine instead of a 409 hp one.


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What I get from what your saying, Is say a street car is idle-5000 rpm you want to peak in the 5000 rpm area. So since rpm is fixed There's only one main way to increase NA hp which is torque and Torque is mainly a product of displacement which is where the saying Torque is King, No replacement for displacement etc.. so yes a well put together 318 and 340 in these rpm ranges peaking at the same rpm the 340 will have a stronger hp and torque curve through the whole power band.
But still whatever part of the rpm range your talking about off idle low mid high well over peak power etc.. it's hp moving, accelerating towing crusin etc.. your vehicle which is the combed effort torque and rpm, torque is one powerstroke and hp is all of them added up per minute aka rpm.

But If were building to the same hp then the power "hp" curve could be the same but the rpm's will be different, cause everyone goes on about static displacement aka non running engine 318 340 etc.. but a running engine displacement is dynamic and we measure it in cfm's and a 318 needs more rpm to displace the same amount of air maybe 0-800 rpm more depending how well built and yes a 318 will need more gear and stall etc.. but doesn't automatically make it a race car now depending on what power level were talking about.


I’m lost on this. It doesn’t really matter what the rpm is. Torque is always what it is at whatever rpm you chose. To increase the horsepower at any given rpm you chose, you have to increase the torque.
 
UTAwesome has a TECH page where he has spent a lot of time flowing and Dyno testing a 5.9 with CRACKED stock heads. He's only getting 397 HP out of a slightly modified 5.9..... 397 HP At the rear Wheels of a 4X4 Ram, not crank

UTAWESOME PERFORMANCE
 
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How many street driven high 11 second 318’s do you see? I haven’t seen many. Apparently the 400 HP 318 is the new 500 HP 350 chevy. You make make it sound like a rebuilt core will make 400. Ain’t no way. Have you ever built a 400 HP anything.

They can do 400HP, but it's not gonna be anywhere near as easy as it will be with a 360. Now....a 325 honest HP, you can do pretty easily and is enough power for a reasonably quick street car if it's a light A body. In fact, I'd go so far as to say it'd fare well in most street battles with the right gearing. Problem is most guys are too pussified to use the gear it would take.
 
Ok, more details.... 1970 318 short block; 650 Brawler carb, under .500 lift cam (that's right, under), eddy heads, RPM air gap intake, Crane gold rockers, 3200 stall and 4.30's. He was in and won my small block race I did two years in a row, using the deduction chart.


Very cool. He ain't a puss and knows how to gear a small cube motor.
 
Is this 318 thing limited to LA motors? What if I put 3K into a poly and mop the floor with all yall yahoos?
 
Does anyone grind decent poly cams anymore?

Oh hell yeah. Camcraft will, Scheinder will and there's one other company that specializes in them. Ken Heard at Oregon of course will, too.
 
Oh cool! I have a couple 4bbl intakes and a 2-4 intake for the 318 poly. Those motors make strong torque
 
Oh cool! I have a couple 4bbl intakes and a 2-4 intake for the 318 poly. Those motors make strong torque

Chit....I tell you what I would do. The 360 crank is a direct drop in I think with the exception of the main journal size.....so that means the 4" arm will slap right in it. ....and several have been built. That Gary Pavolich dude is the poly guru and has done it. MEGA stump puller with ported heads and big valves.

Read all about it.

Building a Polyspherical (Poly or Polyhead) 318 Mopar Race Motor
 
Sounds like a good combo. Now if I remember correctly? Poly heads will bolt onto a la block and vice versa but the poly heads have to have a poly cam and la heads have to use la cam. And if memory serves correct the poly oils through the pushrods
 
Sounds like a good combo. Now if I remember correctly? Poly heads will bolt onto a la block and vice versa but the poly heads have to have a poly cam and la heads have to use la cam. And if memory serves correct the poly oils through the pushrods

No, I am almost 100% positive the Poly heads will work off an LA camshaft as long as the pushrods are correct. I see no reason why they wouldn't. Valve arrangement and firing order are the same.....of course with the exception the valves are splayed on the poly. Unless I'm missing something, I cannot think of any reason why the LA camshaft would not work in that situation. I think they are each block specific. I could be mistaken, but I think that's right.

@Bighead440 might know. He's pretty sharp on that stuff.
 
I don't know.....after a quick search, it appears the heads will not interchange.
 
I think you may be right about having to use the poly camshaft, too. Hell, just build the poly and bee did wif all dat, yo. lol
 
I don't know.....after a quick search, it appears the heads will not interchange.
.
I think the poly heads have 2 water passage holes about an inch in diameter that you have to plug up to go LA.
Just put the 340 4 inch stroker crank with 360 Pistons that would be 4 inch Pistons in the poly block. The 318 poly can be bored to 4 inchs without a problem
 
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