redneckK20

Like the title says, does anyone think its possible to get 600 ft lbs of torque out of a pump gas friendly 496 bbc? The 427 in my truck spun a rod bearing and im looking into my next build.. i want a good all around motor with good torque for crawling and towing. thanks in advance!

therewolf

Hi redneckK20

Welcome to the Chevy Forums.

Nice K20. A man after my own heart.

While the new 6.0 puts out 340HP+ stock, you're going to be needing gears to match that type of work. A 600ft./ lb torque rat engine, while probably a little insanely priced, is do-able. The question is, do you want to visit the gas pump twice a day? And be stuck using premium gas?

What's your differential ratio now? I suggest a balance between raw power and proper gearing may be in order.

Do a thread search of the username "mudmaniac". He's probably done more muddin' than any 10 of us combined.

A compromise which would give you power in the clutch,and reasonable gas mileage would be a newer small-block, for fuel economy, a CAI for revs, and possibly a higher differential gear ratio.

desrtrat

600 ft/tq your going to need 800+ hp at the crank. will not be pump gas friendly by any means, unless you go FI with a mild cam, or build a twin turbo diesel..

happy trails..

redneckK20

you dont need 800+ hp to get 600 lb ft of torque.. if i was going with a race motor with a big cam, crazy flowing heads, etc. i would... i think a 454 stroked to 496 with say, 10.0 to 1 compression, with a good low velocity flowing head and a custom ground cam could definitely clear 550ft lbs or so..

think of the factory vortec 454's in the late 90's.. they had relatively low compression, decent heads, choked by the TBI setup and they still made 290hp, 410 lb ft of torque.. with a bump in cubes and compression, with an rv style cam, i think its doable.

therewolf

How much HP were you getting out of your old mill?

Building High HP sounds good now, but once it's done, you'll be sweating bullets every time you go below half a tank.

What's your gear ratio now? Possibly new diff gears to match a more economical engine will be preferable. The best of both worlds, as gas goes from 2.75 a gallon to who knows what next?

JK23112

It would probably be cost-prohibitive to do it, but a diesel swap might work. Getting 600+ lb/feet of torque is possible with a diesel engine that only generates about 300 to 325 horsepower. The Ford (International) Powerstroke in the F-Series, GM (Isuzu) Duramax in the Silverado HD and the Dodge (Cummins) Ram are all pretty much capable of hitting those figures.

With a big-block gasser, pulling 450 hp and close to 600 lb/ft is definitely possible; but you better have a lot of stock in the oil companies and equip your truck with dual tanks! Building something like a "monster" Rat block (upwards of 454 cubic inches) for your truck will set you back a few ducats - and you are going to get about 7 or 8 miles to the gallon on a good day.


A finely-tuned turbodiesel will nearly double that figure and cost you a lot less in fuel; even though diesel fuel costs more per gallon than does unleaded gasoline.

Good luck with it!

mudmaniac

I agree with you, I'm no engine builder but I think a mild cam, bore and stroke will get you there. I get 450 lbs out of my 383 with TBI, but I do need to run 93

redneckK20

old mill at 440 cubes (427 bored .060)(10.5-11 to 1 comp) probably pushed out 450+ lb ft peak. it ran minimum 91 octane.

turbodiesel is not an option.. im not made of money lol...

truck got a best of 10 mpg in town anyways, fuel consumption doesnt bother me too much.. if i get actualy radial tires and an NV4500 like i want, it wouldnt do too bad.

its got a 3.42 ratio right now, and on 36 inch tires is WAY tall but with no overdrive, its kind of nice on the highway. with 33" radials, with about 1800lbs of firewood in the back it got 14 mpg at 70 mph. if i do end up with an NV4500, ill probably go with 4.10's.

maxxman04

even with stock bore, it's very doable. flat top pistons, rv cam, maybe find a donor vortec big block for the intake. a mild supercharger isn't unreasonable. the nv manual not a bad option, switching to 4.10's, or even 3.73's, with improve towing ability greatly.

years ago, ol friend and i built a 454. '77 4 bolt out of motorhome, bored .030 over, 268 cam. oval port heads, aluminum intake, speed demon 850 carb, hei with upgraded module, coil, msd box, 10mm wires, .005" over stock gap on plugs. roller rockers, quiet gear drive. it would run 89 octane just fine all day long. dyno pull on stand showed 475hp (roughly) 525 torque. we shopped alot for parts (ebay, summit, swap meets) but ended up with only $3500 into entire motor, including original cost of motor. i think with a slightly larger cam, port job to heads, full roller cam, quality fuel injection system, 550+hp, with over 600 torque is pretty easy. tho i will say, the big block we built, in a 1991 burb, pulled a 29' camp trailer over hills with more than plenty of power.