Engine Dyno - Destroked 6.0 333ci, TFS 255 LS3's, 12.5:1, 620HP, 8000RPM
07-30-2014, 11:19 PM
#21
Thanks Martin! I really liked the looks of these lobes as well, and they seem to work great.
The intake runners are 3.93" ² at the plenum. I forgot what the plenum area is, I'll have to measure it up again. The runners are about 4.5" from plenum to cylinder head. This intake is actually one we just had sitting on the shelf, not spec'd for this deal, but it works. I'd definitely like to make a new one for it, but that's a ways down the list for now.
It turned out good for a decently budget built boost engine. After seeing what it did, it really makes me want to optimize it for NA, there's more power to be had in this same basic combo with slight changes here and there for sure. But this one will do for now, 25psi blowing through it will wake it up a bit
Oh and I'll post up some graphs tomorrow, they are on the work PC.
The intake runners are 3.93" ² at the plenum. I forgot what the plenum area is, I'll have to measure it up again. The runners are about 4.5" from plenum to cylinder head. This intake is actually one we just had sitting on the shelf, not spec'd for this deal, but it works. I'd definitely like to make a new one for it, but that's a ways down the list for now.
It turned out good for a decently budget built boost engine. After seeing what it did, it really makes me want to optimize it for NA, there's more power to be had in this same basic combo with slight changes here and there for sure. But this one will do for now, 25psi blowing through it will wake it up a bit
Oh and I'll post up some graphs tomorrow, they are on the work PC.
07-31-2014, 10:15 AM
#22
Thanks Martin! I really liked the looks of these lobes as well, and they seem to work great.
The intake runners are 3.93" ² at the plenum. I forgot what the plenum area is, I'll have to measure it up again. The runners are about 4.5" from plenum to cylinder head. This intake is actually one we just had sitting on the shelf, not spec'd for this deal, but it works. I'd definitely like to make a new one for it, but that's a ways down the list for now.
It turned out good for a decently budget built boost engine. After seeing what it did, it really makes me want to optimize it for NA, there's more power to be had in this same basic combo with slight changes here and there for sure. But this one will do for now, 25psi blowing through it will wake it up a bit
Oh and I'll post up some graphs tomorrow, they are on the work PC.
The intake runners are 3.93" ² at the plenum. I forgot what the plenum area is, I'll have to measure it up again. The runners are about 4.5" from plenum to cylinder head. This intake is actually one we just had sitting on the shelf, not spec'd for this deal, but it works. I'd definitely like to make a new one for it, but that's a ways down the list for now.
It turned out good for a decently budget built boost engine. After seeing what it did, it really makes me want to optimize it for NA, there's more power to be had in this same basic combo with slight changes here and there for sure. But this one will do for now, 25psi blowing through it will wake it up a bit
Oh and I'll post up some graphs tomorrow, they are on the work PC.
Very nice Jakson, I'm impressed with everything that you do.
07-31-2014, 07:18 PM
#23
Staging Lane
Join Date: Feb 2013
Location: Miami, FL
Posts: 55
Likes: 0
Received 0 Likes
on
0 Posts
Sick, always loved short-stroke setups, especially for boost. Not so useful on the street but I've wanted to do a 4.8 crank in a 6.0 block just to see what happens and what kind of rpms you can turn out of it.
07-31-2014, 10:56 PM
#24
Here's a graph of the curve. Sorry for the crappy quality, and excel graph but its all I have for now. The lighter line curve is last years setup with the stock LS3 intake, vs the red/blue curve is the new setup. To see the new setup with the sheetmetal stronger down low against the old setup with the plastic intake is cool. I never drove the car with the plastic intake, but I'm sure it would have been much better down low over the sheetmetal intake. It would have been nice to see the old engine with the sheetmetal too, but oh well. This combo is going to pull pretty hard up top, no doubt about that!
08-01-2014, 03:17 PM
#29
No class rules, just something different.
I needed a new engine and had a pile of 6.0 parts, a set of used forged pistons, everything but a crank and rods. At the time my buddy Nate at OGG and I were also coming up with a plan for a turbo kit to keep the stock rad and AC, so turbo packaging was a concern. The first tentative plan for a turbo was going to be a pt7675 (ended up finding and going with a PT8847 later though). I knew I was going to use the 6.0 block with LS3 heads. I thought a 370 would be a bit too much for the 7675, and not be very efficient at 1000+. I thought it would be fun to throw a 4.8 crank in it, be better suited for the turbo, and be able to spin it up a little higher for fun. Also help get the torque down, and move the peak torque up to help keep the 4 bolt heads on when I crank it up, and it would be a stronger crankshaft stock for stock; 4.8L vs 5.3L+ as well . So I went on Ebay and picked up a $30 4.8L crank, then bought 6.300" rods. I would say it makes just the same, if not better power as a similar 370 would. The less torque doesn't bother me at all, just helps with traction and helps keep the 6 speed together a bit longer! The old setup with the larger cam and less compression was a bit of a dog down low out of boost, and slower into boost with the pt88. That was just not a great combination overall, but still fun, it pulled real hard from 5-8k! The new setup will be much better overall.
I needed a new engine and had a pile of 6.0 parts, a set of used forged pistons, everything but a crank and rods. At the time my buddy Nate at OGG and I were also coming up with a plan for a turbo kit to keep the stock rad and AC, so turbo packaging was a concern. The first tentative plan for a turbo was going to be a pt7675 (ended up finding and going with a PT8847 later though). I knew I was going to use the 6.0 block with LS3 heads. I thought a 370 would be a bit too much for the 7675, and not be very efficient at 1000+. I thought it would be fun to throw a 4.8 crank in it, be better suited for the turbo, and be able to spin it up a little higher for fun. Also help get the torque down, and move the peak torque up to help keep the 4 bolt heads on when I crank it up, and it would be a stronger crankshaft stock for stock; 4.8L vs 5.3L+ as well . So I went on Ebay and picked up a $30 4.8L crank, then bought 6.300" rods. I would say it makes just the same, if not better power as a similar 370 would. The less torque doesn't bother me at all, just helps with traction and helps keep the 6 speed together a bit longer! The old setup with the larger cam and less compression was a bit of a dog down low out of boost, and slower into boost with the pt88. That was just not a great combination overall, but still fun, it pulled real hard from 5-8k! The new setup will be much better overall.
Last edited by Jakson; 08-01-2014 at 03:36 PM.
08-05-2014, 05:09 PM
#30
Teching In
Join Date: Aug 2014
Location: Toms River, NJ
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
I've been very curious to see how these destroked 6 liters would react, I was thinking about building an all motor one with T-56 behind it to have some fun with.
08-29-2014, 10:55 AM
#34
What do you attribute the flatter and much higher torque curve to from 3500-5500?
Also the torque not falling off above 6000rpm?
Partially attributed to the higher compression?
Incredible how much more power the motor makes above 6000rpm!
How much is that new sheetmetal intake approx?
Also the torque not falling off above 6000rpm?
Partially attributed to the higher compression?
Incredible how much more power the motor makes above 6000rpm!
How much is that new sheetmetal intake approx?
04-06-2015, 03:56 AM
#35
Staging Lane
A unique engine designed around used parts already laying around. Gangster as ****. I like.
Are you concerned about valve float at 8,000RPM with boost, or are the QXI lobes that good?
Are you concerned about valve float at 8,000RPM with boost, or are the QXI lobes that good?
04-06-2015, 04:46 AM
#36
TECH Veteran
However why the reverse split on the lift on the cam ?
04-07-2015, 11:55 AM
#37
No issues there.
Added exhaust lift over intake lift is normally just a by-product of the same lobe family being used for intake and exhaust. 90% of the time as you go up in duration, the lobe lift goes up as well. So if you have a traditional split cam that has a larger exhaust lobe than intake using the same lobe family, there is a good chance the exhaust lobe will have more lobe lift.
When you use lobe profiles that are specifically designed for intake and exhaust usage, usually the exhaust profiles will have less lobe lift.
It all depends on what the cam designer is trying to achieve with the lift envelope and the profile of the lift/duration curve. Sometimes using the same lobe family for intake and exhaust is what is wanted. Sometimes it's better to use a specialized lobe profile for both intake and exhaust.
07-24-2015, 07:18 AM
#40
TECH Apprentice
Join Date: Apr 2002
Location: Hickory, NC
Posts: 373
Likes: 0
Received 0 Likes
on
0 Posts
. 
