destroked motor?
TECH Resident
Joined: Jul 2003
Posts: 834
Likes: 0
From: Marysville, OH
Originally Posted by kumar75150
Obviously, you guys have not driven many cars and most of of you prolly havent heard of bikes. There is more to driving a car than 1/4 mile times.
FormerVendor
Joined: Nov 2001
Posts: 3,065
Likes: 6
From: Houston, Tx.
Kumar,
Unlike a lot of others on the board, I HAVE been around FAST cars and bikes and so am warning you that building what you are talking about is silly. You won't go any faster PERIOD. You'll go slower everywhere and anytime. You don't see fast street bikes either with small mini mee motors unless that's all your racing. Cubic inches aren't everything but they make it MUCH easier to make power. Who gives a crap how much rpm you're turning if your slower? Do you see F1 superbikes running smaller engines to turn more rpm or F1 cars? See any 2500 cc F1 engines? You never will unless they drop displacement back to that to slow them down again. They all run the largest engine they are possibly allowed and they do it for a reason. Road racers have even more of a reason than drag racers to run large engines and that's reliability. No one in road racing runs smaller engines than they can unless like in drag racing they get to take weight off of their car.
People turn rpm to make POWER not just to turn rpm. Anyone can do that, just make the engine smaller! With that logic why not build a 250 inch LS1 or just keep getting smaller until you have a full weight LS1 that makes less than a 100 hp at 20,000 rpm.
Unlike a lot of others on the board, I HAVE been around FAST cars and bikes and so am warning you that building what you are talking about is silly. You won't go any faster PERIOD. You'll go slower everywhere and anytime. You don't see fast street bikes either with small mini mee motors unless that's all your racing. Cubic inches aren't everything but they make it MUCH easier to make power. Who gives a crap how much rpm you're turning if your slower? Do you see F1 superbikes running smaller engines to turn more rpm or F1 cars? See any 2500 cc F1 engines? You never will unless they drop displacement back to that to slow them down again. They all run the largest engine they are possibly allowed and they do it for a reason. Road racers have even more of a reason than drag racers to run large engines and that's reliability. No one in road racing runs smaller engines than they can unless like in drag racing they get to take weight off of their car.
People turn rpm to make POWER not just to turn rpm. Anyone can do that, just make the engine smaller! With that logic why not build a 250 inch LS1 or just keep getting smaller until you have a full weight LS1 that makes less than a 100 hp at 20,000 rpm.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo FormerVendor
Joined: Nov 2001
Posts: 3,065
Likes: 6
From: Houston, Tx.
Just so that no one misunderstands me, I am not against rpm but it IS expensive and if you're getting it by making the engine smaller instead of the heads and intake better you are just not gonna be happy with the results in general.
Kumar please forgive me because I didn't mean any of the sarcastic stuff for you individually or anything since everyone brings this up every few months. I just don't believe in rpm for rpms sake.
Kumar please forgive me because I didn't mean any of the sarcastic stuff for you individually or anything since everyone brings this up every few months. I just don't believe in rpm for rpms sake.
TECH Addict
Joined: Nov 2001
Posts: 2,207
Likes: 0
From: College Station, Tx
Originally Posted by blk~2000~Z28
I agree with this statement. Just b/c it has smaller cubes does not mean you are sacrificing hp. Maybe sacrificing HP where "drag racers" need it but not where road racers or even some sick street racers would need it.
There really is no reason to destroke the motor, unless you just think it's fun or you are working under a cubic inch limit (as was pointed out earlier). You can get a big enough piston compression height on a stock stroke setup for anything the block can handle, and aside from that I don't think there are any other real world strength benefits from the destroking?
TECH Resident
Joined: Jul 2003
Posts: 834
Likes: 0
From: Marysville, OH
Originally Posted by ChrisB
Yes, you are sacrificing HP - even if you make the same peak hp you will have a much narrower powerband. What exactly do you mean - where "road racers" or "sick street racers" need it? Power is power, doesn't matter the rpm it comes at. If you have more of it (area under the curve) then you are better off, period.
TECH Resident
Joined: Jul 2003
Posts: 834
Likes: 0
From: Marysville, OH
Originally Posted by racer7088
With that logic why not build a 250 inch LS1 or just keep getting smaller until you have a full weight LS1 that makes less than a 100 hp at 20,000 rpm.
TECH Addict
Joined: Nov 2001
Posts: 2,207
Likes: 0
From: College Station, Tx
Originally Posted by blk~2000~Z28
You are assuming that the peak HP will be less. I do not think that will be the case. As stated he wanted a 4.125 bore with the 3.27 stroke which someone stated will be 350". With 4 more cubes and the possibility of more RPM's I think that there would be significant peak differences.
If you can keep your car at its peak HP range for most of the activity you will be doing,( i.e. top speed street racing or top speed oriented road racing) then what does power under the curve really matter if you are not spending anytime there.
I'm not sure exactly what "top speed street racing" consists of, so can't comment on that - but yeah, if peak hp is the same and you stay at peak hp then then the destroked car wouldn't be any slower. It would be just as fast. But then you would be turning 8000 rpm vs. say 6000 rpm. Which motor do you think will last longer?
Who ever said a 4.125" bore and a 3.27" stroke was smaller than a stock LS1? I think that this particular combo would be way better than a stock cube and stroke LS1.
You are entirely missing the point - you are comparing bore vs. stroke while keeping the cubic inches the same. Comparing a stock motor to a built 4.125" bore motor. But for the $$$$ you could have much more than stock cubic inches - the point is by going with the smaller crank you are giving up cubic inches, everything else being equal.
TECH Resident
Joined: Jul 2003
Posts: 834
Likes: 0
From: Marysville, OH
I totally agree that a 400+ motor is the only logical way to go for the price, but price was never mentioned here. If the style of racing was limited to 350" then a destroked all bore 350" would have an advantage over over engines b/c of the higher rpm potential. I agree that comparing the peak hp of a 400+ cu in motor and the one in question you would arrive at roughly the same value. I can not argue with the fact that that this way is backward logic but if seeing the brighter side of 8000 rpm gives you a rush then so be it.
As far as top speed street racing, I basically mean side by side as fast as you can go and who ever is willing to hold it there the longest. I have never been a fan drag racing so running down the freeway at top speed is what I meant.
As far as top speed street racing, I basically mean side by side as fast as you can go and who ever is willing to hold it there the longest. I have never been a fan drag racing so running down the freeway at top speed is what I meant.
TECH Addict
Joined: Jul 2002
Posts: 2,261
Likes: 0
Originally Posted by ChrisB
Why compare it to a stock displacement motor? For the $$$ you are going to spend you could have a 380-430" motor. If you are limited to 350 cubic inches, then yeah, I would probably go for as big of a bore as possible - but we aren't limited to 350 cubic inches.
What exactly is "top speed oriented road racing", and how does it differ from say, a normal SCCA Road Race? Because in a typical event like that you are going to be going through a wide mph range, and if you have to shift to keep your car in a 1000rpm band you are going to be going slower than if you can just stay in gear and power through a 3000 rpm band.
I'm not sure exactly what "top speed street racing" consists of, so can't comment on that - but yeah, if peak hp is the same and you stay at peak hp then then the destroked car wouldn't be any slower. It would be just as fast. But then you would be turning 8000 rpm vs. say 6000 rpm. Which motor do you think will last longer?
[/b]
You are entirely missing the point - you are comparing bore vs. stroke while keeping the cubic inches the same. Comparing a stock motor to a built 4.125" bore motor. But for the $$$$ you could have much more than stock cubic inches - the point is by going with the smaller crank you are giving up cubic inches, everything else being equal.
What exactly is "top speed oriented road racing", and how does it differ from say, a normal SCCA Road Race? Because in a typical event like that you are going to be going through a wide mph range, and if you have to shift to keep your car in a 1000rpm band you are going to be going slower than if you can just stay in gear and power through a 3000 rpm band.
I'm not sure exactly what "top speed street racing" consists of, so can't comment on that - but yeah, if peak hp is the same and you stay at peak hp then then the destroked car wouldn't be any slower. It would be just as fast. But then you would be turning 8000 rpm vs. say 6000 rpm. Which motor do you think will last longer?
[/b]
You are entirely missing the point - you are comparing bore vs. stroke while keeping the cubic inches the same. Comparing a stock motor to a built 4.125" bore motor. But for the $$$$ you could have much more than stock cubic inches - the point is by going with the smaller crank you are giving up cubic inches, everything else being equal.
joel
TECH Addict
Joined: Nov 2001
Posts: 2,207
Likes: 0
From: College Station, Tx
Originally Posted by blk~2000~Z28
I totally agree that a 400+ motor is the only logical way to go for the price, but price was never mentioned here.
So it's not just the de-stroking that gives more rpm, it's a reduction in piston speed that allows for a higher rpm while maintaining sane piston speeds - but you still need to alter the rest of the car to achieve that higher rpm.
If the style of racing was limited to 350" then a destroked all bore 350" would have an advantage over over engines b/c of the higher rpm potential. I[...] if seeing the brighter side of 8000 rpm gives you a rush then so be it.
TECH Enthusiast
Joined: Mar 2003
Posts: 698
Likes: 0
From: PA
while on the subject of RPMS...
the new ls7 motor for the corvette will spin to 8k from the factory no problem gm says..this is the 6.0l 500hp motor, by the way.
u have to know GM knew that RPMs was one of the things sort of missing from the ls-blocks.
u can have a high displacement engine making 1000 ft pounds and it redlines at 4k rpm, but if u have a motor making 600ft pounds and it revs to say...8500 rpm, the torque monster has no advantage in power at all. more usable RPMs are always good.
u have to know that an s2000 that would redline at 7k rpm would not get 240hp out of that 2.0l inline 4.
the new ls7 motor for the corvette will spin to 8k from the factory no problem gm says..this is the 6.0l 500hp motor, by the way.
u have to know GM knew that RPMs was one of the things sort of missing from the ls-blocks.
u can have a high displacement engine making 1000 ft pounds and it redlines at 4k rpm, but if u have a motor making 600ft pounds and it revs to say...8500 rpm, the torque monster has no advantage in power at all. more usable RPMs are always good.
u have to know that an s2000 that would redline at 7k rpm would not get 240hp out of that 2.0l inline 4.
Teching In
Joined: Jun 2002
Posts: 3
Likes: 0
From: Houston, TX
Originally Posted by kumar75150
With light/expensive valvetrain components, couldnt you spin one of these motors over 9000rpm?
Strokers are good for the track but on the street I'd rather have a high revving motor that makes crazy hp up top. Torque down low just spins the tires on the street.
Strokers are good for the track but on the street I'd rather have a high revving motor that makes crazy hp up top. Torque down low just spins the tires on the street.
Ooh, my first post. 
On The Tree
Joined: Jul 2002
Posts: 179
Likes: 0
From: Texas
Originally Posted by Excal
while on the subject of RPMS...
the new ls7 motor for the corvette will spin to 8k from the factory no problem gm says..this is the 6.0l 500hp motor, by the way.
u have to know GM knew that RPMs was one of the things sort of missing from the ls-blocks.
u can have a high displacement engine making 1000 ft pounds and it redlines at 4k rpm, but if u have a motor making 600ft pounds and it revs to say...8500 rpm, the torque monster has no advantage in power at all. more usable RPMs are always good.
u have to know that an s2000 that would redline at 7k rpm would not get 240hp out of that 2.0l inline 4.
the new ls7 motor for the corvette will spin to 8k from the factory no problem gm says..this is the 6.0l 500hp motor, by the way.
u have to know GM knew that RPMs was one of the things sort of missing from the ls-blocks.
u can have a high displacement engine making 1000 ft pounds and it redlines at 4k rpm, but if u have a motor making 600ft pounds and it revs to say...8500 rpm, the torque monster has no advantage in power at all. more usable RPMs are always good.
u have to know that an s2000 that would redline at 7k rpm would not get 240hp out of that 2.0l inline 4.
How many people have tried this on an LS motor to know that it will not do any good?
Why would GM have gone to great lengths to make the ZR1 the high revver that it is. I think the general idea of the ZR1 was to trade off some low end torque in favor of an extended powerband and more top end needed to compete with the other supercars of the time. Sure it had 4 valve heads to help it breathe better, but I am sure a well ported set of LS6 heads could keep up with, if not outperform them. Here it is 8 years later and it seems that no one believes that todays technology can expand the envelope on that concept even further without having to mortgage your house? Why not have a motor that revs to 8 or 9K? I know of atleast one LS6 motor spinning to 8K with a solid roller cam. How many are spinning well into the sevens with stock blocks? If you look at the import side of performamce, the rule is max efficiency through high revving well breathing motors over 90 hp per liter in many cases. As someone pointed out earlier, our mustang bretheren have been exploring this concept for years. Add a turbo to the mix and you have a very versatile motor with a huge amounts of power "under the curve", an unbelievably long, broad, flat, useable curve. And the money issue is not relative, because anyone who is willing to build a very serious motor is not looking for a bang for the buck project (and stroker motors are not exacly cheap). Anyway, that's my 2 cents.
Why would GM have gone to great lengths to make the ZR1 the high revver that it is. I think the general idea of the ZR1 was to trade off some low end torque in favor of an extended powerband and more top end needed to compete with the other supercars of the time. Sure it had 4 valve heads to help it breathe better, but I am sure a well ported set of LS6 heads could keep up with, if not outperform them. Here it is 8 years later and it seems that no one believes that todays technology can expand the envelope on that concept even further without having to mortgage your house? Why not have a motor that revs to 8 or 9K? I know of atleast one LS6 motor spinning to 8K with a solid roller cam. How many are spinning well into the sevens with stock blocks? If you look at the import side of performamce, the rule is max efficiency through high revving well breathing motors over 90 hp per liter in many cases. As someone pointed out earlier, our mustang bretheren have been exploring this concept for years. Add a turbo to the mix and you have a very versatile motor with a huge amounts of power "under the curve", an unbelievably long, broad, flat, useable curve. And the money issue is not relative, because anyone who is willing to build a very serious motor is not looking for a bang for the buck project (and stroker motors are not exacly cheap). Anyway, that's my 2 cents.