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Hi Guys,

I've been lurking for a little bit. I bought a '22 R/T A8. No ups, extras really. I've been a motor head for a long time. Owned a motorcylce, drove my dad's '67 Firebird 326 V8, suffice it to say, I love cars, and engines in particular. Having said that, when I was growing up in the ahem, mid 80's early 90's the popular thing to do in order to just generate more HP was to bore out the cylinders for more displacement an then adjust the stroke of the piston, as needed. Obviously you're pulling the motor and tearing it down to the core and altering it in a very unchangeable way, but hell, you're getting a bigger engine where it counts, if you do it right.
Do they do this to modern HEMI engines, specifically the 5.7? Or is the 'bore and stroke' best left to the dustbin of hot rodding history?
Here is a pic of Phyllis, I live in that big city in Illinois. Although, now she had rock guards front and back on.
Wheel Tire Car Vehicle Window

Eric
 

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Going bigger bore should be easy. That in itself isn’t worth it though. It does look like they make strokes kits that get you to about 397 cubic inches for about $2000. A cam and maybe some ported heads and exhaust headers will get you probably 500 hp, but your talking about some money to make that happen.
 

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Politically correct.
'09 SRT 440 HEMI
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12,007 Posts
I have a 440ci.block in my '09. So yes, it's still done. There are quite a few reputable hemi speed shops around the country that can do this for you. To do it right though costs money.
 

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2015 R/T 5.7L A8
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Welcome from South Carolina! :)

For the end finished product money that would actually cost you, plus tossing your 2022 warranty out the window, you should just consider supercharging it. You have quite a few options out there available to you, Magnuson, Whipple, Ken Bell, Edlebrock, and Pro-Charger types plus, turbos. The minimum gains with those is usually 100hp and can go to 150hp+, just something to think about.
 

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2011 SXT Pw7 Bright White Challenger
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3,518 Posts
Bore and Stroke alone wont work anymore you have to unlock your PCM and doing that Voids the Warranty.
Even a Tune will Void it about all you can do is Cat Back Exhaust for Rumble and a Hellcat lower Air Box with Air Filter.
Not really gonna release any HP but will sound good and wont void the Warranty.

2nd Fun thing you can do is install a Banks Pedal Monster will wake up the Throttle Response and it wont harm the Car.
 

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welcome from south florida. +1 on everything posted so far. anything done will void the warranty. even the exhaust, ask me how i know that. drive it as is, enjoy the car, learn the car. there are a lot of us who grew up in the 80's, some of us in the 70's (ahem). all of what was used to be done pretty much can't nowadays. no swapping engine into the base models. easy horsepower doesn't exist. read some of the posts here and see what the other members have done, what worked, what didn't. it is the old adage once again, you want to go fast, how much do you have?
 

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2020 Dodge Challenger Hellraisin Scat Pack
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There is no replacement for displacement.

And....

Speed costs money. How fast do you want to go?

Have no idea of how much displacement can be had from a 5.7l engine via a larger bore and longer stroke.

If you want to dig into this further this book might be of some value to you:

New Hemi Engines, 2003 to present, How to build Max performance…

Larry Shepard.

Published by CarTech, Inc. cartechbooks.com

softbound

ISBN 978-1-61325-357-1, 146 pages

An alternative to making the engine larger -- which essentially just means it can pump more air and burn more fuel and generate more power -- is to supercharge the engine.

I owned a 2006 GTO with a 6.0l V8 that produced 400hp. Then I owned a Porsche Turbo with a 3.6l flat 6 engine with two turbos and the engine produced 420hp. No way was it possible to bore/stroke that 3.6l engine to 6.0l. But with the presence of turbo chargers it produced a bit more HP than a 6.0l N/A engine.

'course, lets not forget the 6.2l engine in my Hellcat produced 707hp, over 200hp more than the GTO 6.0l engine. (Way over as I believe it takes something like 75hp to spin the supercharger at WOT.)

Back to your 5.7l engine: As long as the boost is kept reasonable the risk to the engine is (probably) minimal. 'course, it depends upon how you drive. If you have your foot in the engine every chance...

And I would hazard a guess that to increase the displacement of a 5.7l engine vs. supercharging it (but leaving the internals stock) would be about equal in cost.

Last but not least I have to mention if you want more HP one way is to buy a more powerful car to begin with. Rather than speed oodles of money on your 5.7l engine consider moving to a Scat Pack and its 6.4l 485hp engine. Plus it comes with a factory warranty.
 

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2014 Boosted 392 Stroker Shaker
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I would never consider boring a Hemi, but stroking it is another matter entirely...
 
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