What is needed for a street motor 455 500hp then 600hp?

Keep in mind that as the power goes up your drivabilty will go down. But there are many opinions on good drivabilty. Larry hit on what I tried to say earlier. Very good flowing heads, smaller cam, and better street manners with more horsepower. Especially for your power brakes. John

 

Greater avg piston speed via stroke as well as displacement bring back driveability as do deeper gears and better matched top ends.

 

My pick for Pistons would be JE as the can be fitted with only .003" wall clearance which saves the rings from getting bounced around during the transistion from cold to normal running temps, not to mention no cold pistion rattle!

 

Do what Jim says. He's really good at this stuff.

 

Wow. This is A lot to take in. I need to rethink a few of my choices on this build. Cam and intake mainly, but would cbc ported heads be overkill without sufficient cam? Would a good porting with decent cam like the ta 290 94h with my combo give me solid low end torque and solid 500 hp motor? I don't want a pig cruising around, but would like some decent hp numbers in this beast. Lol

 

If the $10K budget is just for the engine and not for the whole car then you can do a 482 BBB with good pistons and rods with slightly ported TA Stage 2 SE heads topped of with an Edelbrock dual plane using TA roller rockers and a custom ground roller cam to more take advantage of higher lift flow while keeping the duration @ .050" on the conservative side like JW said. Get the 1.65:1 rockers if they make 1.7:1(not sure if this ratio is made?) that would be even better to help slam the valve open more in the meat of where the port flows to fill the cylinders.

You don't need the highest level porting either so the heads flow at max where the cam will never take the valve! When you get the valve job done have the intakes back cut 30* to help low lift flow as well.

Doing the above should hit your goals and beyond no problem to propel that land barge, I would guess 550 + HP with close to 600 ft lbs! Do all the assembly yourself and you'll fall below your budget :TU:.(unless the cost of beer is in it :laugh






Derek

 

You also do know it's not all in how much power you make, but it's just as important to how you used it. Why are you leaning towards the 700r4, is it just for overdrive.

700,s have a very steep first gear, over 3. Th400 are just under 2.5. The overdrive ratio is also .7, couple that with the torque converter clutch and your 2.93 gears at 55 and 60 this thing will down way below 2000 at those speeds. We did a sbc build in a 52 chevy had 425 hp 383, 700r4, 373, and at 65 mph it was barely cliping 2000 rpm.

My point here is that trans will not live behind our motors long without a lot of work, but a stk 400 dual feed, with a 36 element sprag, and a good shift kit will, I know alot of ppl don't use then but I like a gear vendors overdrive unit. It can be applied in any gear, not just at the end. So you can Taylor you rpms at all speeds. Heck if you wanted it basicly turns a 3 speed into a 6 speed( though not really needed but you could)

I would also look to run a little more gear ratio, it will help get thing moving easier. Your selection for trans and gear will be like have a 2.0 final gear when applied. If my math is right at 55 mph you will be about 1400rpm. This will lug so bad on ever hill and want to down shift like crazy. But a set of 3.73, with the 400 and gear venders puts you about 2000. Still good rpm but not lugging. And at 70 mph be aboUT 2500rpm.

The way your car will get moving with 3.73 compared to 2.93 will feel like an extra 150hp. To back up facts here. In college we took a buddies stk 5.0 stang, had 3.2s gear u believe, ran 15.0s in the quarter, after only swapping gears to 4.10 it ran 14.0s. That's alot of differance, even if you were to 4.10 rear, that would be 2800 at 70. Now I would not recommend going that far, but that is still less rpm than it would turn with a 3 speed an 3.42 gears. All my numbers were calculated on the 27.5 tire previously mentioned.

It's just food for though, but you say you have have 10k to spend. The gear venders is 2600, a set of gear installed if you can't do it is about 750 for gears, bearing, and labor, a good build 400 with those 2 mods should be about 1000, a good, conveter built for your car 650. That's 5000. That leaves you 5000 for your motor.

Unless you just wanted the bragging rights of says I have 600hp, build an easy 500 which is much more daily driver friendly and cheaper and put the rest of the money into getting the drive train spot on and working for you.

 

Another issue with the 700, is I don't know if the made a case that will bolt directly to our motor. I think you would have the same issue with the 4l80e, plus it takes another controler plus sensor adding up to close to another thousand over the price of trans and conveter. But the 4l80e is literally a th400 with overdrive. All buy a few of the major inside parts swap with the 400 ditectly.

 

A little clarification on airflow issues for an engine like this.

Before we go there, we must understand this concept.

Horsepower is a mathematical term to describe the amount of work that can be done. I has two factors- force and time.

Torque is the force, rpm is the time.

The mathematical equation is torque x rpm /5252 = HP

So, for instance, lets take a 455 Buick that makes 500 ft lbs at a peak of 3200 rpm

Here's the math.. 500x3500/5252= 304.6 HP... the motor is making 304 HP at 3200 rpm. So what you say? Watch what happens when we move that same 500 ft lbs to 5200 rpm

500x5200/5252= 495 HP Almost a 200 HP gain, by not making more torque, just making it at a higher rpm.

So that is what all engine builders do, to make HP. Raise the torque peak.

I am over-simplifying things here, we certainly do more than just raise the torque peak, but that's outside of the reason for writing this post.

I want you to understand that a 550 ft lbs engine at 3800 rpm, is much better for your application than one that makes that 550 at 1000 rpm higher. And those are realistic numbers for a performance BBB.

The two biggest factors are intake type and camshaft specs.

Low rpm torque engines want dual plane intakes and relatively small camshafts.

AS far as full out ported alum heads, while they will always help, the big gains in airflow are often at higher valve lifts, that you will never get to with a small duration cam. Physical limitations in ramp speed will only allow so tall a lobe, with a given duration. So in the 226 duration range at .050 a "high lift" cam is going to be in the .525 lift range with stock rockers, the "low lift" version is going to be in the .480 range... so who cares if the head flows great at .600+.

In my experience, Either TA SE or Edelbrock heads with just a mild cleanup are enough airflow for the engine you should be building. You will get much more usable power spending that porting money on a hydraulic roller cam setup. In the heads, you need what I call the "easy air" that you get with mild bowl reshaping and chamber work. And that certainly does not cost $1000+ for porting.

I suggest the TA heads because quite frankly, while the E heads flow nice, and have good potential, they are a PITA to get them set up right, due to the rocker offset issue. Also because after you take your new E heads apart to clearnace the guides properly, and re-do the valve job, they cost about the same as the TA heads. Further, there are a lot of rumblings these days with what is going on with Edelbrock financially, I have heard of no issues so far with the products, but it's something to be aware of. Even if Mike T steps off a curb tomorrow, and gets hit by a bus, I am sure someone will step up for TA Performance, so I would consider them a more "stable" business to buy expensive parts from right now.

And you don't need full out roller rockers, 430 rockers with a mild roller cam will hold up fine. Or go with the TA rockers, the Buick shaft rockers are superior to the stud SBC stuff that the E heads have, and you will be investing in a lifetime of trouble free valvetrain performance.

I am just trying to impress on you that with your car, and gearing selection, the smoothest running, most efficient at low rpm engine is going to be the fastest one in that car, from a standing start, and the most enjoyable to drive. Leave the HP numbers for the bench racers to brag about..

I build an engine combo called the "Super Stage 1", that uses my 470 shortblock, has TA alum heads, headers, a small hydraulic roller cam, and a dual plane intake. That engine produces just shy of 500 HP, but feels really snappy off idle, even in a 4000 lbs GS. I have a similar version in a 4700 lbs 71 Centurian, and both of those cars, even with stock converters, are a real joy to drive around town. Great off idle performance, and they will still set you back in the seat to 5500 rpm.

Dennis Manner, a longtime Powertrain Engineer for Buick, and the one man most responsible for the factory performance stuff, summed up this conversation well when he said...

"Customers drive torque, they buy Horsepower".

 

Does this have an 8.2 or 9.3. I show both were options and if the 8.2 I know thete are few options for the bop 8.2. I just sold a 3.91 set

 

A 70 Electra had no option for an 8.2 rear. It only came with a 66-70 Buick only 9 3/8" rear.

 

Jim is right full size Buicks could be had with the 8.2 if they were equipped with a small block. I think only the Lesabre was available with a 350.

 

That's right. Unlike the Electra in 70, you could get a LeSabre with a 350 cid. It came with a Buick 8.2 rear. But if you bought a LeSabre 455 you got the 455 cid engine which mandated you also got a 9 3/8" rear.

 

Since Molnar makes the 2.00" journal stroker rod for $585, would there be any problems using the 494 cu inch engine on the street especially since it would never see over 5500 rpm?
Autotec would be willing to move the wrist pin and change the size to .990" on their piston to match.
This would move the peak torque much lower and the torque band would be extremely wide.

http://molnarrods.com/buick-big-block-connecting-rods

 

Paul,

Yes it will produce more torque, but cost/benefit ratio is poor. Your talking maybe 5-15 ft lbs. with just a 1/4 inch stroker.

Only when we go to the aftermarket cranks and 4.400+ strokes do we see considerable power differences.

Buick engineering found that out in the early 70's, they built a 525ci test mule and put it in a 72 Electra. Dennis Manner Drove it from Flint MI to his folks place in Duluth MN for Christmas that year. He reported to me that it was a torque monster. But too expensive, and with the pressures on lower emissions and fuel ecomony coming, the brass never followed up on the project.

A billet crank is $4400 balanced from Crower, so that's way out of his budget.

Cost/Benefit ratio... NOT GOOD

That is true of any of the strokers, which is why I didn't recommend my 470 or 482 combos. Those are all about combos of parts suited for different purposes, and the right dimensions, at an economical price, more than about making more power.

He has a set of fresh stock rods, might as well use them, they will work fine, for the engine he should be building.

JW

 

Swapping gears in my car will be more of a headache then any gain I would get imho. With the posi and deep gears makes it a great road car. My reasoning for using a bigger cam is that around here (central nebraska) 70% of driving is highway. In the cities the acceleration will be less then it could be under light acceleration with the torque curve, but by my understanding the 2000 lockup rpm is low for the cam which should help offset the limited tire size I can fit on the car. That would help from smoking the tires when accelerating from a stop unless I put the hammer down. My thinking is using the weight and gearing as a way to keep the power in check under normal driving. Only letting it go like king Kong under hard power applications. Is that a realistic goal?

 

Thanks Jim for your reply.
I forgot that he already has a set of prepped stock rods.
Interesting about the 525ci test mule.

I didn't expect any additional torque or HP with the increase in displacement. Just a wider power band.
It has been my experience that increasing the displacement while keeping the same induction and exhaust system lowers the engine's VE, moves the peak torque to a lower rpm and widens the power band with very little increase in peak TQ or HP as a result.
The discussion concerning gear change prompted my response as a way to increase low end torque.

Paul