anyone ever do the whole destroking thing in the LSx engines?
11-09-2006, 06:34 PM
#21
It is possible to build a 328" LSX motor using a 6.0L block, late 4.8L crank and rods with all stock parts. The deck heights work out, and the CR works out using the 4.8/5.3 heads. 6.0L heads may work if the LQ9 flat top pistons are used, but I never checked the CR. You end up with a (real) long rod motor; rod ratio something like 1.9 or 2.0 if I remember correctly. I was looking to do this build until I came across a real nice '01 LS1 for very reasonable money. In my particular case, I was looking to lower the low RPM torque. This 328 has nearly identical bore/stroke to the GEN I 327.
I don't think the orignal poster was looking for a which is better discussion.
Andy1
I don't think the orignal poster was looking for a which is better discussion.
Andy1
11-10-2006, 08:55 AM
#22
FormerVendor
Kurt,
I think it's cool deal but just meant that even you guys wouldn't build that same deal with unlimited engine size rules on purpose and try and race people with much larger turbo engines if you weren't getting some kind of break in weight etc. People seem to think they are gaining some kind of crazy "advantage" by destroking and they aren't besides being able to run a stronger piston possibly which I do on really crazy stuff sometimes too. I have built many 3.900 stroke turbos on really crazy stuff just to get more ring land real estate because I had to on those deals but not because I wanted to destroke.
Even NHRA PS which people talk about as another class that "destrokes" their engines are only going faster from the bigger bore NOT the shorter stroke. If they could run their stroke way back up they'd be much faster even still but it's not allowed since it is an obvious advantage.
I think it's cool deal but just meant that even you guys wouldn't build that same deal with unlimited engine size rules on purpose and try and race people with much larger turbo engines if you weren't getting some kind of break in weight etc. People seem to think they are gaining some kind of crazy "advantage" by destroking and they aren't besides being able to run a stronger piston possibly which I do on really crazy stuff sometimes too. I have built many 3.900 stroke turbos on really crazy stuff just to get more ring land real estate because I had to on those deals but not because I wanted to destroke.
Even NHRA PS which people talk about as another class that "destrokes" their engines are only going faster from the bigger bore NOT the shorter stroke. If they could run their stroke way back up they'd be much faster even still but it's not allowed since it is an obvious advantage.
Originally Posted by 427
We do build slightly bigger engines for most of our racecars (402 mostly). The 352 of mine was built for racing in the Tech series with a 360ci limit. It would be very competetive in its current form in many local races running against open competition turbo cars. It still is the fastest/quickest LS based engine in a quarter mile, although I can't believe it still is.
Kurt
Kurt
11-10-2006, 08:56 AM
#23
FormerVendor
Andy,
Yes you can certainly do that type of combo and it all fits great. The compression is what is harder to get with lower cubes though so you need to watch that.
Yes you can certainly do that type of combo and it all fits great. The compression is what is harder to get with lower cubes though so you need to watch that.
Originally Posted by Andy1
It is possible to build a 328" LSX motor using a 6.0L block, late 4.8L crank and rods with all stock parts. The deck heights work out, and the CR works out using the 4.8/5.3 heads. 6.0L heads may work if the LQ9 flat top pistons are used, but I never checked the CR. You end up with a (real) long rod motor; rod ratio something like 1.9 or 2.0 if I remember correctly. I was looking to do this build until I came across a real nice '01 LS1 for very reasonable money. In my particular case, I was looking to lower the low RPM torque. This 328 has nearly identical bore/stroke to the GEN I 327.
I don't think the orignal poster was looking for a which is better discussion.
Andy1
I don't think the orignal poster was looking for a which is better discussion.
Andy1
11-10-2006, 11:30 AM
#24
Originally Posted by racer7088
Andy,
Yes you can certainly do that type of combo and it all fits great. The compression is what is harder to get with lower cubes though so you need to watch that.
Yes you can certainly do that type of combo and it all fits great. The compression is what is harder to get with lower cubes though so you need to watch that.
By recollection, the CR comes out to ~ 9.6:1 when using the 4.8/5.3 heads, so it's pretty close to start with. One would of course want to measure and map out everything if they choose to build this type of hybrid.
One motivation is that the truck motor pull-outs are very cheap. A 4.8L LR4 complete, with low miles, is about $750. Then, prep a 6.0L block and you're on your way. Within all of that, are several levels of build sophistication that can be persued if you choose, so it appears to be a pretty friendly situation.
Andy1
11-10-2006, 12:43 PM
#25
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I think its a cool idea, a 4.125 Bore and a 3.2" stroke makes roughly a 346. Spin it to 9000 with a hardcore solid roller cam. Could be fun!
Not sure how practical it is, or why someone would do it, but it would be cool to see..
Not sure how practical it is, or why someone would do it, but it would be cool to see..
11-11-2006, 01:24 AM
#26
FormerVendor
You might be able to use a small dome to get back up the 11 to 1 most people seem to prefer on LS1tech.
Originally Posted by Andy1
Eric,
By recollection, the CR comes out to ~ 9.6:1 when using the 4.8/5.3 heads, so it's pretty close to start with. One would of course want to measure and map out everything if they choose to build this type of hybrid.
One motivation is that the truck motor pull-outs are very cheap. A 4.8L LR4 complete, with low miles, is about $750. Then, prep a 6.0L block and you're on your way. Within all of that, are several levels of build sophistication that can be persued if you choose, so it appears to be a pretty friendly situation.
Andy1
By recollection, the CR comes out to ~ 9.6:1 when using the 4.8/5.3 heads, so it's pretty close to start with. One would of course want to measure and map out everything if they choose to build this type of hybrid.
One motivation is that the truck motor pull-outs are very cheap. A 4.8L LR4 complete, with low miles, is about $750. Then, prep a 6.0L block and you're on your way. Within all of that, are several levels of build sophistication that can be persued if you choose, so it appears to be a pretty friendly situation.
Andy1
11-11-2006, 11:47 AM
#27
Originally Posted by WS6TransAm01
I think its a cool idea, a 4.125 Bore and a 3.2" stroke makes roughly a 346. Spin it to 9000 with a hardcore solid roller cam. Could be fun!
Not sure how practical it is, or why someone would do it, but it would be cool to see..
Not sure how practical it is, or why someone would do it, but it would be cool to see..
11-11-2006, 07:22 PM
#28
Originally Posted by Andy1
It is possible to build a 328" LSX motor using a 6.0L block, late 4.8L crank and rods with all stock parts. The deck heights work out, and the CR works out using the 4.8/5.3 heads. 6.0L heads may work if the LQ9 flat top pistons are used, but I never checked the CR. You end up with a (real) long rod motor; rod ratio something like 1.9 or 2.0 if I remember correctly. I was looking to do this build until I came across a real nice '01 LS1 for very reasonable money. In my particular case, I was looking to lower the low RPM torque. This 328 has nearly identical bore/stroke to the GEN I 327.
I don't think the orignal poster was looking for a which is better discussion.
Andy1
I don't think the orignal poster was looking for a which is better discussion.
Andy1
11-14-2006, 11:48 AM
#29
Originally Posted by 67RSCamaroVette
that would be a killer engine for my '67 that originally came with a 327.. a quick revving, high RPM engine would be lots of fun in a lightweight car. I cant help but crack a smile when I hit 5500 and keep it floored. I cant imagine 9000rpm.
11-14-2006, 04:26 PM
#30
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Originally Posted by Asmodeus
With a good valvetrain you can spin a 427 LS7 to 8k pretty easy, no need to destroke and make more power.
11-14-2006, 04:31 PM
#31
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Oh one other thing I forgot to mention is if you destroke a motor, it should help durability at high rpm's. That is because you are moving the piston less distance, less wear on the those parts down low and less piston rock, but you have the trade off of lost low end power. Just a thought for everyone to ponder.
11-14-2006, 05:06 PM
#32
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It shouldn't be RPM's that kill motors, but piston speed. I could see how destroking and increasing the bore of a turbo engine, to come out with about the same displacement that you started with, would be a huge advantage.
11-14-2006, 05:45 PM
#33
FormerVendor
Originally Posted by Louie83
It shouldn't be RPM's that kill motors, but piston speed. I could see how destroking and increasing the bore of a turbo engine, to come out with about the same displacement that you started with, would be a huge advantage.
A NASCAR Nextel cup engine doesn't turn incredible piston speed and several LS1 street engines turn as much in piston speed but will not last any 500 miles at 9000+ rpm. RPM kills parts fast whereas pistons speed has little to do with parts getting torn up fast.
A 2 inch stroke 12000 rpm engine will not last 1/8 as long as a 4 inch stroke 6000 rpm engine.
