stroke vs bore
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stroke vs bore
ok i might be fully wrong about all this but help me out.. This might be really noobish so please keep the flaming down and teach me....
Currently I have an LT1 inside of my converted 95 T/a (the one in my sig)
anyhoo to compete my conversion I'd like to swap in an LSx. I have a bare short block (LS6) and i'm looking for a rolling assem. right now. I'm thinking about using Mahle parts... What side bore is my LS6?
Also they have a 454 stroker kits and others
what are the pro's and con's of stroking? What is more effiective just boring or stroking? which is more fuel effiecent and which will produce more power?
Currently I have an LT1 inside of my converted 95 T/a (the one in my sig)
anyhoo to compete my conversion I'd like to swap in an LSx. I have a bare short block (LS6) and i'm looking for a rolling assem. right now. I'm thinking about using Mahle parts... What side bore is my LS6?
Also they have a 454 stroker kits and others
what are the pro's and con's of stroking? What is more effiective just boring or stroking? which is more fuel effiecent and which will produce more power?
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Cubes are cubes. The power will come from displacement. Fuel economy
will suffer accordingly.
You would benefit more from boring however. That will allow for more flexibility
in head/chamber work.
IE: Unshrouding valves will improve flow
Going too long on the stroke is said to limit upper RPM potential, but I haven't
really heard of street engines suffering from stroking.
will suffer accordingly.
You would benefit more from boring however. That will allow for more flexibility
in head/chamber work.
IE: Unshrouding valves will improve flow
Going too long on the stroke is said to limit upper RPM potential, but I haven't
really heard of street engines suffering from stroking.
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A recent tech article in Popular Hot Rodding tested the HP (bore) vs TQ (stroke) debate. The testing was very comprehensive, and every effort was made to minimize variables. I was shocked at the results, as I had always bought into the idea that strokers make superior TQ. The tests proved otherwise. The long and the short of it; TQ is a function of displacement.
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The largest PRACTICAL LS1 displacement increases I've read about involve carefully grinding the bottom of the cylinder liners to allow the installation of a 4.250 crank in an LS1 block. This will yield 406 ci. I've also read about machined-out and re-sleeved (4.125 bore) LS1 blocks using a 4.000 stroke, which will produce a 427 ci LS1-based engine. There may be ways to get even more displacement from an LS1 block, but I haven't read about them.
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Obviously if you aren't limited to an engine size you'd want the biggest bore and the biggest stroke possible, but that isn't always the case.
The big bore/short stroke is prefered in race engines because the engine builders want to get everything out of the induction system possible, so they run the biggest bore allowed by the block. Then they put the maximum amount of stroke they can to make sure they are at the max CID they are allowed to run.
Then of course it's who has the best induction system and who can keep the engine together at some of the big RPM levels a race engine sees. And of course there is so much more than that, but those are the very basics.
In a street engine you don't really want to turn a bunch of RPM because the stress put on the engine due to RPM increases exponentially.
The big bore/short stroke is prefered in race engines because the engine builders want to get everything out of the induction system possible, so they run the biggest bore allowed by the block. Then they put the maximum amount of stroke they can to make sure they are at the max CID they are allowed to run.
Then of course it's who has the best induction system and who can keep the engine together at some of the big RPM levels a race engine sees. And of course there is so much more than that, but those are the very basics.
In a street engine you don't really want to turn a bunch of RPM because the stress put on the engine due to RPM increases exponentially.
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#8
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Originally Posted by bichin95redta
The largest PRACTICAL LS1 displacement increases I've read about involve carefully grinding the bottom of the cylinder liners to allow the installation of a 4.250 crank in an LS1 block. This will yield 406 ci. I've also read about machined-out and re-sleeved (4.125 bore) LS1 blocks using a 4.000 stroke, which will produce a 427 ci LS1-based engine. There may be ways to get even more displacement from an LS1 block, but I haven't read about them.
largest off the shelf crank i know of is 4.125 stroke which is 395ci with the stock bore. there's really not enough deck height in the ls1 to run really long stroke. MTI used a darton sleeved bored out to 4.160 and a custom 4.185 stroke for there 455ci packages.
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Adding bore to an LS6 block will require big $$ and increase risk of failure. If 388" or 395" isn't enough, I'd sell the block and start with a 6.0 block and go to 408" A good 388 package will give you a fat torque curve with a minimum of 450 ft-lbs over a nice range and peak HP in the high 400s, if not 500 RWHP. Throw on a 100 shot for when you need a little extra kick.
I think Fastech built a 395 that reved to almost 7k and put down 500 RWHP
I think Fastech built a 395 that reved to almost 7k and put down 500 RWHP
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"largest off the shelf crank i know of is 4.125 stroke which is 395ci with the stock bore"
Custom billet steel cranks are available in strokes up to 4.250". One supplier of this size stroker crank is LA Enterprises. So, yes, as far as off-the-shelf cranks go, you are right; 4.125 strokers (Lunati, Scat, etc.) are the largest.
Also, billet cranks are a good bit more pricey than a forged crank.
Custom billet steel cranks are available in strokes up to 4.250". One supplier of this size stroker crank is LA Enterprises. So, yes, as far as off-the-shelf cranks go, you are right; 4.125 strokers (Lunati, Scat, etc.) are the largest.
Also, billet cranks are a good bit more pricey than a forged crank.