It depends, I could make 400hp scare the s..t out of you the first 60 ft.
340 Build help please.
- Thread starter Nkaiser81
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TT5.9mag
Two atmospheres are better than one
Well 400hp at 6000 rpm (the numbers thrown around in this thread) would be about 350lb/ft.
TT5.9mag
Two atmospheres are better than one
I rode a 400hp turbocharged hayabusa once. That definitely did the trick. That was new pair of shorts scary.It depends, I could make 400hp scare the s..t out of you the first 60 ft.
That’s so true! I told a buddy of mine that ran into a big sun of money and he asked me for some advice. When it came to the car, he wanted a Mustang, I said GREAT! What is your daily driver? He asked “What do you mean?”
I said to him,
“Look, great car, nice power, you’ll get bored with it and it’s power. You see what I do! Always hunting for more power, year after year, changing parts, because no matter how much I make the car faster, it’s boring by summers end. Get a low powered truck or SUV to bring crap home from Home Depot and save the hot rod for weekend car meets, over the road traveling, you’ll thank me in the long run.
He thanked me. No matter how much power you have, if your in it everyday for everything, it gets boring.
I said to him,
“Look, great car, nice power, you’ll get bored with it and it’s power. You see what I do! Always hunting for more power, year after year, changing parts, because no matter how much I make the car faster, it’s boring by summers end. Get a low powered truck or SUV to bring crap home from Home Depot and save the hot rod for weekend car meets, over the road traveling, you’ll thank me in the long run.
He thanked me. No matter how much power you have, if your in it everyday for everything, it gets boring.
Tq at peak hp is averagely 90% of peak tq so 350 tq should be 390 ish peak tq, 6000 rpm seems a little high to me and should be closer to 5700 rpm which would put peak tq over 400. There's no reason a decent built 340 can't get over 400 lbs/ft.
When 400 HP is the beginning of it all, yea! That can be scary.It depends, I could make 400hp scare the s..t out of you the first 60 ft.
I'd be more concerned with building more ave tq per cid than peak hp numbers, an average build range 1.15-1.25:1 tq:cid, which 1.25 + is a big difference over 1.15 -, 431tq vs 396tq, plus lowers were peak occurs for a given hp by hundreds of rpm probably 500+ rpm.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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To that I add that, for a streeter, torque off the line can easily exceed the tire/chassis ability to deal with it. In fact, it may be 40/50/60 mph before the chassis catches up.
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I know for a fact that my chassis cannot handle it. By it's trapspeed, my current combo 367 is making ~430 hp with a 230*@.008 cam... and the peak is around 5250, so as we all know, at 5250, torque equals horsepower. But at the torque-peak, it will be more, using @273s 95% estimate, that makes it about 450 ftlbs; somewhere near 3800, which, in Second gear for me, is 44mph. Hammer-down at 44mph results in instant tirespin with 295/50-15s.
The point is, what streeter needs 450 ftlbs?
I have a rule of thumb,
It goes like this;
If all you can fit on your car is 255s, then 255 crank hp is your target.
If you can install 325s, then 325hp should be your target.
Anything more, on the street, at WOT, is all of it going to tirespin, and bragging rights.
A stock rebuild lo-compression 360 with a 4bbl and headers, is already around 255 hp. Throw in a 220* cam and its pushing 275hp. Pop the compression up, and yur knocking on 300, a lil headwork gets you to 325, another couple of cam sizes is near 360
If yur replacing pistons anyway, it costs the same to rebuild from 255 to 300 maybe even 330, but headwork is where the money goes. So I get it, throw a 292([email protected]) cam into it and have at it.
But the 292 cam will not be happy with the stock convertor nor 3.23s, so right away yur looking at gears and a TC, and an 8.75 rear end if you don't already have one. mo-money,
and I well-remember, that the 292 cam was not all that much fun for me. even with a clutch; plus it drank fuel like a two-hump camel on fire. mo-money. It was only in there for one summer,
If I was to do it over, with a 360, I would top out at ~330 hp, which if an HFT, then a 218* cam, and 3.23s; the clutch is staying.
But if a 340, I'd want a lil more low-rpm torque with that clutch, so I'll trade some advertised duration away and get a Solid lifter cam.
A hot streeter, does not mean a detuned race car. Build your car for it's intended purpose and whatever you get at the track .... is what you get.
My 360 combo has run three cams;
292/292/108 which was 250/[email protected]
270/276/110 which was 223/[email protected]
276/286/110 which was 230/[email protected]
Guess which combo was the favorite... HYUP the lil 223* was; All the torque I could ask for, fuel-thrifty, and still went 106 @12.9. I drove that thing everywhere all the time.
and yes; Major tirespin at WOT.
By it's trapspeed of 106, the Wallace pegs it at ~335hp. Super-fun car.
Diesel1276
Active Member
Havent read all threads but I have 73 block built to 68 specs. Usual balanced blue printed. 68 4 speed cam used 360 unleaded head 340 valve sizes hi po springs etc factory rockers. Cost me $7000 in 94. No dyno and yet to break it in. Built it with my dad so its in the garage cuz i found a 426 street wedge after and went big block. Point is expect now to pay but you can save money building it yourself. My money was in parts and machining. I found a 69 GTS i may be able to buy needs an engine. So i have the 340. Ill prolly get 6 pack in put it in. I dont know about boredom for me old cars are everything. Nostalgia, my dad, time travel, coolness factor, smell of fuel. You get the picture. I hope you get it done. I have a 71 Charger that my wedge is going in. 4 speed ramcharger hood all the goodies. Its a grand spaulding tribute. Had this idea since 91 hearing my dad talk about mr norm. Took awhile with career and family but its coming. Promise I wont get bored! Mopar or no car.
If I had a dollar for every thread I've read in the last 10-years where someone want lots of horsepower, but doesn't want to spend much money I would be a millionaire.
With the cost of parts today if you want a true 400 HP small block from 340" your going to spend some "Budget Breaking" money. No way around it.
Tom
junkyardhero
Well-Known Member
budget build is kind of a nebulous term. what's your budget? $500? $5000? $10 and a burrito?
no matter the coin involved it's going to come down to: compression, heads that breathe, and a cam that works with everything else. selection of the right components that work properly together as a system is key here.
how bad off your engine is to start with is a deciding factor in the initial selection of components. there's a massive dollar difference between getting away with just freshening it up and needing a crank/rods/heads, etx.
no matter the coin involved it's going to come down to: compression, heads that breathe, and a cam that works with everything else. selection of the right components that work properly together as a system is key here.
how bad off your engine is to start with is a deciding factor in the initial selection of components. there's a massive dollar difference between getting away with just freshening it up and needing a crank/rods/heads, etx.
The easy and cheap ish hp is what a basic cam 4bbl headers will get you then above that dollars per hp keeps increasing goes up.
stock 68 to 71 340 legit 10.5 to 1 xe224@50 480 comp cam headers air gap 750dp 150 shot easy 400 hp pretty cheap
Rat Bastid
Dunamis Metron
For true.
The way I see each long block has a general amount of hp sitting and waiting to be unlocked with basic cam 4bbl and headers, Eg. a low cr long block is somewhat limited by what cam you can use especially if it's a mainly street car, take a low cr 318 250-300 hp with most cams people would use, low cr 340/360 325-375hp with the average cams etc... that's why people love LS and Hemi's a lot of untap power waiting for basic hot rodding.
I think nowaday's $ 10,000 for a moderate
It's still going to cost 10 grand to build a reliable one.
15,000 we're starting to get into real horsepower. starting. lol
That depends on if one has a actual reasonable budget, and how much work you are capable of or plan to do yourself. If you have a good core engine already, 400 hp with a 340 isn't exactly setting the bar too high.
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