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9,000 RPM

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Old Jun 3, 2007 | 03:48 PM
  #1  
Rook6's Avatar
Rook6
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Default 9,000 RPM

I know high redlines require valvetrain work, but what exactly should I be looking for? In the theoretical stage of my engine build I've decided that I wide powerband over a large rev range and a high redline would work better for me than a stroker. So I think I'll de-stroke for less dwell time, and bore/re-sleeve the block 30 or 40 over.

Also, would 2v or 4v heads be more responsive at high RPM? I'm not looking so much for peak power, as powerband characteristics are what I'm after.

I'm wondering if I could even run a supercharger at 9k rpm...
Old Jun 3, 2007 | 05:14 PM
  #2  
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Default RE: 9,000 RPM

What are you going to be using the car for exactly? If it will be a street car, that high of a powerband will be usless on the street. If you have a powerband that peaks at 9K, you probably wont start making decent power until 4-5k.

To build an engine that would support that redline, you would have to forge everything, completely blueprint and balance the rotating assembly, strengthen all the valvetrain components and thats just a start.

From what ive seen, the 4v will out perform the 2v every time at any rpm. Its all about airflow in and out of the engine, and the 4v flows MUCH better.

I dont know about the supercharger. I would guess if you could find one that would support that high of rpm i dont see why you couldnt run one.
Old Jun 3, 2007 | 06:29 PM
  #3  
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Default RE: 9,000 RPM

I guess I should have explained more. I want the car to have alot of rev range as it's objective, besides being a daily driver, is navigating road courses. It doesn't need to peak that high, just rev that high. I discovered on the Blue Ridge Parkway that having alot of rev band to work with makes things alot easier.

Do you know what the weight difference between 4v heads and 2v heads is like? I'm trying to keep the balance I've got going right now.
Old Jun 3, 2007 | 07:35 PM
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Default RE: 9,000 RPM

Reving beyond peak power (by more than a few hundred rpm) will do nothing but wear things out MUCH faster. ON the road course you should try finding a gear ratios, both in the rear and in the trans itself that suits your needs. I mean why spend thounsands of extra dollars when you don't need to.
Old Jun 3, 2007 | 07:57 PM
  #5  
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Default RE: 9,000 RPM

ORIGINAL: Rook6

I know high redlines require valvetrain work, but what exactly should I be looking for? In the theoretical stage of my engine build I've decided that I wide powerband over a large rev range and a high redline would work better for me than a stroker. So I think I'll de-stroke for less dwell time, and bore/re-sleeve the block 30 or 40 over.

Also, would 2v or 4v heads be more responsive at high RPM? I'm not looking so much for peak power, as powerband characteristics are what I'm after.

I'm wondering if I could even run a supercharger at 9k rpm...
It would be cheaper to buy a motor already done based on the questions your asking you have no clue inwhat is involved.You are going waste a lot off money trying to figure out how.Most motors above 7500 are N/A motors.

Thanks Matt
Old Jun 3, 2007 | 08:05 PM
  #6  
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Default RE: 9,000 RPM

The motor is in a theoretical stage, besides the parts I've already aquired....and having no clue is usually why people do things like research , which costs no money.

EDIT: I realize the above is pretty vague lol. Basically what I'm saying is I'm just figuring out the pros/cons of several courses of action so I can make a more educated decision. Heh, to put it this way, the -only- thing I'm certain about is that it'll have an aluminum block, forged internals, and a 6-Speed behind it....possibley supercharged. I still need to decide big bore/stroker, SOHC/DOHC, powerband characteristics, rev range, and gearing. I'm havin' a ball, in the process, though.
Old Jun 4, 2007 | 12:49 AM
  #7  
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Default RE: 9,000 RPM

If it's a street driven vehicle, realistically you're looking at about 2,000-6,000rpm range to make good broad usable power across a wide range. A car setup to make power out to 9k rpm is gonna have a power range of about 5,000-9,000 or there abouts. Everything has to come together as a package, an rpm range for street use, gears matched to the engine's rpm range etc. If you think you're going to build an engine that revs from 2,000-9,000rpm you're wrong. You can't extend the range the engine revs when it makes power, only move the rev range up or down the rpm band. That's one of the differences between race cars and street cars, street cars rev at lower rpm'sthan race cars. You can easily build a sub 6k rpm car with a supercharger that has way more power than you can use on the street effectively, and an engine that revs out to 9k rpm won't last long
Old Jun 4, 2007 | 02:29 AM
  #8  
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Default RE: 9,000 RPM

Even a potent 2k-6k range is difficult to build...usually you'll need a lot of cubes to get that kind of range. With a 4.6L, 3k-6k is more reasonable, as would 3.5k-6.5k. Even though the 4.6L does make decent torque below 3k, it isn't real happy down there.
Old Jun 5, 2007 | 10:52 PM
  #9  
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Default RE: 9,000 RPM

Hmm, very interesting. Thanks for all that info, dudes.

Another question for ya....I'd like to destroke and bore out the block to reduce piston dwell time and side loading. Is there any reason I wouldn't want to do that?
Old Jun 5, 2007 | 11:34 PM
  #10  
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Default RE: 9,000 RPM

seems like you want a import. something that you rev's alot higher and makes power at a different range. if you are wanting to get into the course racing thing maybe you have the wrong car for what you want to do. there are cars you can buy that already have what you want without all the headaches involved.



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