need some opinions. looking to build a new engine for my truck and cant decide on what size. want to stay low block as i have a few 230 casting 400's and a date coded 400 for it.(would use it if i went just a 400) this is a street driven truck but looking for some good power without going totally broke on fuel. i cant see a 470 being that much worse on fuel than a 400, correct?

so what would you guys build? i would like to use my stealth heads and rpm intake for the build. this thing will never go to the track (too slow) and will see all highway miles. hyd cam, big torque low rpm would be great


any opinions would be appreciated.

Id shoot for the 451. Massive torque and lighter than a 440. Probably the best bang for the buck there is. Fuel mileage wouldnt be much of an option with any of these engines, however increasing torque will increase driveability. It seems to me also that it would take a pretty decent set of heads to feed 470 cubes even though 451 cubes wouldnt be to far from that reality either. Good luck with whichever you choose...

Its hard to build the 400 to get good compression (and therfore economy). Besides, it kinda defeats the purpose of building a BB and winding up with SB displacement and torque.

I'd build the 451 or 470. The heads and intake you have should work fine with either. The 470 giving more torque and perhaps a bit worse mileage all else being equal.

Andy F has a nice writeup on the 470 in the archives. It works really well with BBC rod journal and 6.7" BBC rod. That combo can sometimes use a shelf stock 451 piston.

The 470 is a great low deck motor. Everything fits in there just fine without costing a ton. Piston is tall enough that you can put a dish in it for pump gas. Use a Performer RPM intake and you'll have a great motor but a Performer will also work ok I guess. Keep the cam small, run 10:1 compression and an Edelbrock 800 carb and it will be a killer street motor for your truck.

470...I actually like it over a 493, you might can still get the Mopar-width 6.76 rods from Brandon (if he still makes them)

I don't understand why those rods are not more popular.....easy to make a 470 cube 400 or 440 and even a 422" B motor 400 by offset grinding the 3.375" crank to 3.51".

yup.. a 470 is a KILLER engine that can make some seriously SICK horsepower.

I did the 451cid back in the early '90s and just broke it two years ago. When I built the engine, there were no inexpensive crank and rods, and not many places to get pistons. The crank was a stock 440 crank machined to fit the 400 block, stock reconditioned 440 rods, and custom dished Ross Pistons.

Now days there are alot of stroker kits avaliable at affordable prices. The 451 has a good rod ratio (same rod length and stroke as a 440, with a larger bore and shorter/lighter pistons) and a decent compression height piston. The 470 uses shorter chevy rods, but the compression height is slightly more. The 470 would be good for a truck engine. It should make lots of torque. The 500 stroker kit with 440 length rods uses a really short piston. Good for racing, but for the street the short piston may reduce the life of the rings?

In my world if big is good then BIGGER is better.

thanks alot guys for the opinions. did some looking and it seems a stock 400 piston isnt too popular for sure.

thinking i will do the stroker deal, i have everything but the rotating assy so its not huge $$$

my buddy swears by the 470-472 400. He's been doing them for years.

You might already have your answer but in the spirit of sharing here is my . My good friend Karl Lindgren aka Maximum Entropy, built a 471 for me last year. Using a 440 Source stroker kit with a 1.67 rod ratio, Eddy Rpm heads, Eddy Rpm intake, Hughes 579/256 solid lifter cam installed 105* cl, with 1.5 roller rockers, KB forged flat top pistons, Smith Bros. 3/8 X .083 wall pushrods etc. etc. Happy motor. Great fuel mileage too....uhuh, uhuh. Great lookin' truck by the way.

I say go as big as you can afford!

Really your mpg is going to be bad worse or worst with those motors if all else stays the same. The way the bigger motor could get better mpg is gear it down more. Calculate out how many rpm at 60 and cut it in 1/2 since you only suck in air every other revolution then multiply it times the displacement, this will tell you how much air your engine will displace per mile. You can change the rpm or the displacement to be equal to any of the other combos of gears and displacements.

1 Example 400 / 2 X 3000 rpm = 600,000 cubic inches per mile

2 Example 500 /2 X 2400 rpm = 600,000 cubic inches per mile

If you have a 400 running 3000 @ 60mph and are happy with the mpg build a 500 and gear it to turn 2400 to keep the same efficency. Plus you will get more tq and a little more fun when you rev it to 6000

You are still gonna get about the same miledge with either, and in my experiance the bigger motors turnning slower even displaceing the same amount over time will get better mpg. Velocity in the ports is about the same but the bigger ones just seem to run more eficent. Consider the freight train as a perfect example, pistons bigger than 5 gallon buckets and they run 300 rpm and pull a mile long load of coal and get incredible mpg (or is it gpm ) relative to there size. Or mabey down to earth more think about an excursion weighing 5 times what a geo metro weighs with probably 3 times the frontal area and almost 6 times the displacement gets better miledge than if you drove 5 geo metros the same distance and it is way faster than a geo.

In my opinion get the biggest motor you can and gear it up to get the efficency you want. You will reach a point of diminishing returns when you motor spins low enough to get about 10inches vacume at cruise and the bigger engine will do this at a lower rpm than the little motor.

Mine is a 451.

Here's a 505 i helped sort out for a buddy.....very basic build that would be perfect for your truck. The same numbers could be made with a 470 i'm sure.

The rundown :

SD intake, Proform 950, 10:1 compression, stock stealth heads, Engle K60 custom grind 112* lsa, stock non-adjustable rockers, hv oilpump, windage tray, hemi repro pan. Idles smooth and makes gobs of torque.


Ron

Stock appearing motor on the stand

The car it's going into : 69 Charger R/T with ps, pb, 727 and 3.23's

The new bullet should liven things up a bit compared to the old 383

So, 509hp and 592lbft, all under 5K and THROUGH HP MANIFOLDS?

That may just be the perfect stealth bullet for my Sport Fury...



Clair