I have my 392 ordered, how much power will it make?

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NorthernSwede

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Ok, Here's the Specs. And yes I've thought them through quite a bit.

Block - 318
Heads - Stock 360 heads with smoothed ports, just smoothed not ported.
Intake - Edelbrock Performer
Pistons - Keith Black ICON Forged stroker pistons .030 over
Crank - MoparPerformance Heavy Duty cast crank
Camshaft - Int @ .050 = 203 Exh @ .050 = 219 Lift = .422Int/.462Exh
Ignition - Stock breaker Ignition
Exhaust - Stock 1966 A-body manifolds and 2" exhaust with x-pipe and no mufflers
Carburetor - Holley 650 DP
Compression Ratio - 9.2-1

As you might notice I'm going for high gas-speeds and big cubes for a lot of power right from the start.

Desktop Dyno gives me 277HP and 441Ftlbs

Best regards from Sweden
 
Couple things I would change--sorry. That camshaft, are you looking for a rap exhaust noise, if so ok but why not stay with 10 extra degrees max on the exhaust. A 214-214 or 214-224 would be a better choice.

Why no mufflers but 2 inch pipes? 2 1/4 would be a big help. Yeah maybe its hard or $ to get over there but 2 1/2 pipes are min over here.

Nothing wrong with running breaker points but a msd box firing off it would help but time. Trust me. I just ran breaker points for the last two weeks waiting for my msd dist from repair. Was a big difference having my 7al box firing the coil.

A msd E curve dist would be best and only 3 wires, like breaker points. Yeah, its $370 here and then wires but big improvement.

Why the dp carb with a small camshaft and exhaust pipes? A holley or my favorite Carter/ Edelbrock 750 carb I would pick. A bit down on power but like the camshaft, great driveablity.

So 750 Edelbrock, 2 1/4 or 2 1/2 exhaust pipes with high flow mufflers and a 214-224 camshaft will sound great and drive great and make about the same power.

Gear ratio, not sure. Any will work, even 2.73 but I pick 2.94 or 3.23.
 
NorthernSwede said:
Ok, Here's the Specs. And yes I've thought them through quite a bit.

Block - 318
Heads - Stock 360 heads with smoothed ports, just smoothed not ported.
Intake - Edelbrock Performer
Pistons - Keith Black ICON Forged stroker pistons .030 over
Crank - MoparPerformance Heavy Duty cast crank
Camshaft - Int @ .050 = 203 Exh @ .050 = 219 Lift = .422Int/.462Exh
Ignition - Stock breaker Ignition
Exhaust - Stock 1966 A-body manifolds and 2" exhaust with x-pipe and no mufflers
Carburetor - Holley 650 DP
Compression Ratio - 9.2-1

As you might notice I'm going for high gas-speeds and big cubes for a lot of power right from the start.

Desktop Dyno gives me 277HP and 441Ftlbs

Best regards from Sweden
Click to expand...

Camshaft...that thing will idle like a stocker in 390 cu inch engine ...something larger
Intake....Eddy Air Gag......the Performer be longs on a stocker..
Carb...Holley 750 DP....

power right from the start will come from the 4 inch stroke.......
 
Well the Performer RPM would allow the exhaust heat to be use. Some places need it. Maybe he wants to drive it most of the year. Not sure if Sweden gets much snow but it gets cold I believe.

I would not go with a dp carb unless you have 3.55 gears or better yet 4.10's. I take it gasoline is very expensive, maybe even a 650 Edelbrock carb would be best.

Maybe he wants it to idle like stock, no idea how things are there. Comps HE cams are good, the 260 will idle like stock with 214-214, the 214-224 will have an exhaust rap a bit.

Yeah I know, he could just build a 318 with 360 heads and rev it up and put a 230 cam and 4.10 gears and a 750 dp and maybe go faster but maybe the Swiss police would impound the car, lol.
 
Well the Performer RPM would allow the exhaust heat to be use. Some places need it. Maybe he wants to drive it most of the year. Not sure if Sweden gets much snow but it gets cold I believe. Personally I would go with a heavy cast iron 1969-70 340 with exhaust heat. Once seal tight it never leak or give you problems. Even in freezing weather but then my aluminum manifold never leaks either

I would not go with a dp carb unless you have 3.55 gears or better yet 4.10's. I take it gasoline is very expensive, maybe even a 650 Edelbrock carb would be best.

Maybe he wants it to idle like stock, no idea how things are there. Comps HE cams are good, the 260 will idle like stock with 214-214, the 214-224 will have an exhaust rap a bit.

Yeah I know, he could just build a 318 with 360 heads and rev it up and put a 230 cam and 4.10 gears and a 750 dp and maybe go faster but maybe the Swiss police would impound the car, lol.
 
well...I have my glasses on and his post says Performer.....NOT Performer RPM...


yes..given he is in Sweden...the Performer RPM would be better then the Air Gap...

I keep forgetting that is actually gets cold some places in the world.
 
This engine is going in a truck, right?

The stock 66 manifolds and 2" exhaust will limit this setup far more than the intake or cam will. Airflow=horsepower, and you won't have much of either. The desktop dyno is probably pretty close.

Why a DP carb on such a mild build? Might be OK with a 4 speed.
 
Well, the exhaust is really no probs, I can just as easily get it to 2,5" since it's not built yet, the parts have yet to arrive and my father sells exhausts so no biggie. About the '66 manifolds, well that's all I can afford at the moment, probably custom headers coming up later. I drive 3.23 in the rear and an 1800stall on the 904. And yes it gets down to -35Celsius here in the winter... 'bout the DP, well I might just as well run the 650VacSec I have in the garage.

Anyhow, all the intake air will come from a scoop sucking from the front of the windshield where there's overpressure. So cool air is not a prob really.

And about the 750, the desktop dyno gives me like 5 horses and 5 FTlbs more from a 750...
 
I have those same manifolds and while they are nasty restrictive, I have to say that cam is a terrible choice. I think if you run it that way it will be all done before 4K rpm. Prob closer to 3800 really. You're making big stroke and not letting it work for you. I would go at least another 25° at .050 and get the valves open at least a real .470 at the retainer. I think my first choice might be the 60403 Lunati, with a second of the XE268. I know you want conservative and you must have the split pattern with those manifolds... But it's an air pump. You have to get the air and fuel in to make any power. Those cams will get you up past 5Krpm anyway and at least another 40hp. I also believe the carb is too small. You've gone a litle past "conservative" into "so small the non adjustable passages are out of spec for the engine". I'd recommend at least the 670 Street Avenger VS. That is about 110cfm bigger than that 650DP or VS and calibrated properly for that size engine.
 
Well, I don't say that you're wrong about the manifolds, I'm well aware of the problems they will cause, but then again that's an wasy thing to upgrade later. About the camshaft, I still think you are wrong, though Desktop Dyno isn't perfect I have still to find it way of course and just to use it as an example it shows a loss of almost 40ftlbs if I were to add 25more at .050. And only a gain of 20 horses... And to quote a man that probably knows a bit 'bout what he's saying, Carrol Shelby himself "Horsepower sells cars and torque wins races." And about the carb... Dyno gives me 433ftlbs with a 400cfm carb and 444ftlbs with a 750 carb... Believe me when I say that it's far worse to over-carb an engine then to use a small one. just look at a chevy 454 truck engine. I haven't measured them but I would not be suprised to find the intake ports smaller in one of those than in a stock 340... Air speed is the key to torque, I have no fun with horses at 6000rpm. 430ftlbs at 2000rpm sound exiting though!
 
sorry, English is not my native language? Do you have another word for center line? The lobe separation is 110 degrees if that's what you're after?
 
Northern, I respect your ideas, and those you're quoting. However the fact that the dyno program only shows a gain of 11 pound feet when the carb size is almost doubled should be a good indicator of how inaccurate it is. The more "non standard" your build, the further the programs are because they use average figures to compute the result. This would be why I have little faith in them other than showing trends, which in the carbs' cases the trend is bigger makes more power. As long as your happy with the result, nothing else really matters.
 
It's 390 sumthun inches, throw a 700 holley dp on it, truck or not, thats what I would do.

BUT if you are gonna choke the exhaust with lil stock manifolds then 'not much' use in upping the carb cfm more than what you have, I don't think it will make less though...

that cam is good for a truck that has to pass smog

but you want mileage ...and that you'll have.
 
do yourself a favor and get the rpm intake, some headers, electronic ignition, taylored curve 'doubt the dyno program accounts for that', and a lil port work on the exhaust side.

the heads 'bone stock' are good for 390-400'ish hp 'cfm wise', the exhaust work would only help this situation with the focus of torque and that cam...jmo
 
70aarcuda said:
well...I have my glasses on and his post says Performer.....NOT Performer RPM...


yes..given he is in Sweden...the Performer RPM would be better then the Air Gap...

I keep forgetting that is actually gets cold some places in the world.
Click to expand...

haha yea i hear ya
 
NS do you have actual head flow numbers your using in the Desktop Dyno program or are you just picking from the menu? I ask because I can guarantee you if you don't have the actual air flow numbers YOUR heads produce you might as well throw it all out the window because it isn't going to be right.

Also let me ask you this. When you put in a bigger cam (which you definitely need) and your program shows it losing torque, at what rpm are you seeing that torque loss? If it's down low (1000-2000 rpm) remember this, your only at low rpm for a second or two at most. After that your in the mid range so you have to look at the mid numbers as well. I totally agree with the others that say you need a bigger cam. I can't imagine that one doing much past 3500 rpm. Kinda like a fat guy running a race trying to breath through a straw.

I am nothing to dispute anything Carroll Shelby says but I do know one thing. You have to get all that torque hooked up. You can have an engine that makes 600 ft. lbs. of torque at 1000 rpm and it won't touch a engine making 400 ft. lbs. of torque at 2000 rpm if the big dog doesn't hook up good.

Just my thoughts.
 
I would throw that desktop dyno in the trash, ha ha.

Believe us, going from a 400 cfm carb to a 750 cfm carb is more than a few hp. But with that cam you picked a 750 cfm isn't really needed.

It still be a 390 and not a 318, you give those 4 bangers Saab cars a run but watch out for the turbos, they will make you want a larger cam and carb.

Only thing is, my hot 340 car gets 8 mpg, @ $3.00 US a gallon its ok for short runs. If yours got 8 mpg you likely could not afford to drive it.
 
Oh yeah and about that statement "it's far worse to over carb and engine than to under carb it". I can't agree. I have installed carbs several times that according to everyone's calculator is too big (sometimes way-way too big) for the engine yet after I tune it they run just fine. Right now my Cuda is a great example. Mild built 360 (home ported iron heads, cam=234 at .050", headers and Air-gap intake) has a 850 Holley on it and runs fantastic. I installed it just to test the carb as I have plans on using it on my new 408 I'm building. I figured if there was anything wrong with it it's better to let something happen to the old engine than the new engine. Funny thing is it's the best running carb I've had on the 360 and I've tried several on it, 670 Holley Avenger, 750 Holley vac. sec, standard 750 Holley double pump, 750HP double pumper, 770 Holley Avenger, 625 Carter AVS, and now the 850 Holley. When I say it runs the best I mean it's the fastest and yet it has throttle response just as good as any of the others. It is worse on fuel mileage though.
 
fishy68 said:
Oh yeah and about that statement "it's far worse to over carb and engine than to under carb it". I can't agree. I have installed carbs several times that according to everyone's calculator is too big (sometimes way-way too big) for the engine yet after I tune it they run just fine. Right now my Cuda is a great example. Mild built 360 (home ported iron heads, cam=234 at .050", headers and Air-gap intake) has a 850 Holley on it and runs fantastic. I installed it just to test the carb as I have plans on using it on my new 408 I'm building. I figured if there was anything wrong with it it's better to let something happen to the old engine than the new engine. Funny thing is it's the best running carb I've had on the 360 and I've tried several on it, 670 Holley Avenger, 750 Holley vac. sec, standard 750 Holley double pump, 750HP double pumper, 770 Holley Avenger, 625 Carter AVS, and now the 850 Holley. When I say it runs the best I mean it's the fastest and yet it has throttle response just as good as any of the others. It is worse on fuel mileage though.
Click to expand...

Agree with what you said ^^^^^....I know this isn't a Mopar, but I fitted a 350 Holley 2 barrel ,list# 4778, to a 1.6lt Holden Gemini, had a fair wack of a cam, p&p head, fully balanced.....blah blah blah....and it went like stink, was driveable...sounded just like a bridge-port rotary at idle.....throw you back in the seat at 160kmh in 5th.
Anyway, there's over carbing and there's over carbing.....as mentioned before.
 
Well of course, but as I said earlier, overcarbing in worse than under... I did not say that big carbs is bad. But a to big carb will give you slow airspeeds at low and mid rpm until you get the revs up high enough to get enough vacuum to suck big enough amounts of fuel and air to get the airspeed in those big holes up. Well sure those japsturboshitcars will outrun me on the highway, no doubt. My brother has a 600horse toyota supra and I'm well aware that he will outrun me like nothing. But then again he outruns pretty much everything around here... Back to the carb, just for an example, how do you think the stock 318 ran with the 650DP that was on it when I bought it? Don't think that'd have run better with a 400cfm? And one person who totally agrees with me is Larry Schreib, author of "Mopar Performance"... And Rune Westbom, who singlehandedly built a working miniature Merlin V12 for his RC plane... Then I mean singlehandedly.. Crank, Camshaft, Rods, Pistons, Block, Heads... All of it... I think I have some heavy names on my side in this argument. You think that it will have a narrow powerband. Well as I said I don't reckon that Dyno is right but it gives a hint of the truth anyway and according to it, if I were to get some headers made it'll produce 470ftlbs @ 2000rpm and 300ftlbs @ 5000rpm... Not that narrow... And 'bout the horses 295hp @ 3500rpm and 276 @ 5000rpm... Not that narrow either. And this thing will litterally be able to pull down a building in idle, pretty neat... With the heads ported a bit too I'm thinking in the 235-240 range it'll be a beast.
 
Power requires airflow and you're choking it with those choices.

But if you know better, then spend your money and prove everyone wrong
 
I'm not stupid. Take apart a 454 chevy truck engine and tell me how big the intake ports are... How often do you touch 5000rpm with a bloody truck eh? It's red marked at 4500rpm on the dash... I want power between 0 and 4000rpm nothing more, and to big ports, carbs, cams and so on will put me way, way over that... I have a car that does 65mph at 2000rpm... That's the bloody speed limit?! On top of that I drive 2000km PER WEEK on AVARAGE.... I don't need 700 horses at 7000rpm... I need 600Nm at 3000rpm.... I'm well aware that your arguments are valid AND CORRECT if I were building for HP and fast laptimes. The simple question was how much power the bloody thing would make and if anyone had any ideas to improve MY concept, not how to build an engine for a fancy "Idrivemycar1/8mileayearcar". I'm sorry for loosing my temper but I feel pretty damn attacked right now and I fail to see why some of you are to narrow-minded to see that I dont want a car with .750 lift and 400 horses at 8000rpm...
Thank you, all of you for your advice and tips, I really, really appreciate the suggestions, even those that did not answer my questions because they are good solid advice anyhow.

Once again, I'm sorry for loosing my temper but I really felt like I was beeing called an idiot without proper arguments to back the assumption. I have built 480 horses out of 2.0liters so yes, I know how to make horses. But as I said, I don't want them at 8000rpm...
 
Easy Norther. You asked how it will do on a public forum. I also have a truck that has seen the high side of 3500 rpm once in the last 4 years. I tow locally, I plow, it runs thru the woods at my farm ,etc. It has a 750cfm carb on the 360 in it. What desktop dyno and I think you are missing is the relationship between the non-adjustable pars of a carb, and how the engine runs. That 454 with the huge ports had a Quadrajet on it that flowed at least 750cfm. And it has a shorter stoke IIRC than your 392. Stroke makes the air move faster, faster air will quickly move out of the range of small air bleeds and emulsion passages, not to mention the ability to get a good idle quality and transition off idle. You can run a Briggs and Stratton carb for all I care. It will run. Hopefully it does what you want. I never go full throttle in my truck. I'd be amazed if it ever gets to open the secondaries. But it has the XE256 cam and a 750 carb on it because at the rpms I DO use it at, I want real power. Placing faith in a software program designed to average a lot of technical variables to come to an answer and then getting hreated when experienced people give opnions you asked for is a waste of yours and our time. You were not being called an idiot. (least not by me I don't think) You were being corrected because you asked what I/we thought would be holding your engine back. Nothing personal unless you make it such. Have fun.
 
Moper, I really did not mean you our any of the serious answering people here to take offence, you are really gold worth when dealing with these engines! And yes I agree to 100% that I would actually gain both torque and Horses on upping the carb size to 750 or even 800. I do not base my assumptions on the software, I just use it to give a hint of what I'm trying to tell you. I have had several seriously over carbed engines, for example a stock 318 with a 650DP, a stock 1.8 liter volvo engine with dual weber-45s. they ran like **** basically. And then again I've had a couple of heavily under-carbed engines, they have generally been running quite well except for the fact that they stop revving long before they should. But adding more cfm on the carb means more fuel per mile. About the camshaft, is this the cam you're talking about? http://www.summitracing.com/parts/CCA-20-221-3/
And I sincerely did not mean that you people are wrong, I just don't think I'm that way off either. And as stated before, I will, without doubt, be changing to headers and ported heads as soon as my economy allows it.
 
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