320ci 320 natrually aspirated h.p. Possible???

[rapidride2]

Is it possible to get around or about 320 horsepower from a natrually aspirated, pump gas, streetable 320ci (or bored larger)straight 8?

I am looking for ideas for a 52' 320 build in the future. Eventually it will be in front of a th-700r4/200r4 trans. It will have to be streetable.
Is this far fetched? or possible?

Feel free to share any real world experiences. Thanks, Matt.

[BigRivy]

Anything is possible. You're going to need a heavily modified head and a lot of cash! With an emphasis on the cash part. A lot of fabrication and custom parts are in your future. Horsepower is a function of RPM, you are going to have to wind your 320 to get those horsepower figures and to use it you are going to have to gear for it. High engine speed equals short engine life and high fuel consumption, = less streetability. Look back through the posts in this section for the "Alleycat" and the " Anything new from the straight 8 hotrodders" threads and read them. You can do a lot to increase the performance of the straight 8. It will respond to the same modifications that any engine responds to, regardless of make or model. It really ain't rocket science. Read up on building high performance engines and just adapt what they do to your engine. 320 horsepower is a big jump, close to doubling the stock rating, it's gonna take some work. Oh, and don't forget the money!

[presten]

Look at Ebay under Buick intake manifold and check out the 4 carb custom intake manifold. A good start on building your engine.

[rapidride2]

I realize the potential of high performance engines. However i am totally new to the straight 8's. I have a somewhat mild 540 chevrolet that put down 815h.p. Of course i realize that there is tons of r&d and aftermarket support for the venerable big block chevy.

I realize the lack of (if any) r&d and aftermarket support for the straight 8. I'm also aware of the long rod effect going on. Heck it's a walk in the park to get a buick, olds , pontiac or cadillac to get 1h.p (OR ALOT MORE) per c.i. these days all while being very streetable.
Thats why i specifically ask about the 1 h.p. for 1 c.i. on the normally aspirated straight 8.

Maybe i should rephrase my question,,,
How much h.p. are people getting with say a freshly rebuilt 320 ci with a milled and ported head. A reground or howards type cam, 9:1 compression, custom headers and a "tuned" intake manifold with possibly multiple carbs. I understand that is vague but it will still give me an idea of what to expect. Thanks, Matt.

[39CENT]

A 320 inch Buick straight 8 with the stock head, or even ported would be hard pressed to get 1hp per in. However a west coast Buick rodder has recently attained a 12.5 sec,109 mph dragstrip time in a street legal 38 Buick Century coupe [blown] gg. It has been reportedly dynoed at about 400hp. I personally seen it turn 105. A blower is probably the best way to go for power on the straight 8,s.

[alleycat]

Is a h.p./inch possiable out of a str8 Buick? I think so. In fact, I think it has already been done. By some of the "old" racers that post here from time to time and some of the guys that are building str8's now, that are scattered around the country and post here as well. Trouble is, is that nobody has bolted one of these engines to a dyno and made a pull or two. The only dyno test I've seen dates from the 40's, I think, and it's really bad. The torque line (no curve!) stays above the h.p. line and the pull is done at about 4400 rpm! Furthermore, virtually every engine build in every car mag for the last 30+ years is devoted to big high rpm power. This can alter one's perception on how to build a engine. On the other hand it makes it simple: make everything big, the power will follow. But that does not mean that these build-ups are not valuable. Take a look at this months "Engine Masters" mag. It takes apart the 2nd place engine. Look at the intake, look at the torque curve. It's telling you something.

H.p. is a function of rpm. How fast do you want to spin this engine? Torque on the other hand, is a function of piston area, compression, and cylinder fill. 9 to 1 comp is good but if there is only 25% cylinder fill the dynamic comp might actually be about4 to 1. The 320 is a high rod ratio engine, making everything big may work, it also may make for a engine somewhat hard to live with.

So, the trick is: use every trick you can think of to enhance low rpm cylinder fill. Offset piston pins, roller cam, long tube step headers, long runner (dual quad?) intake, ram air, and don't forget to lighten parts. Cut off the piston skirts, work over the rods, and that 110+lb crank! Drill it out! The problem to all this is: you will get to do almost all of it yourself. The engine builder guys really don't want to monkey with this stuff. Will it make power? You betcha. alleycat