C5 Replacement Engine
10-11-2008, 11:36 PM
#1
Burning Brakes
Thread Starter
C5 Replacement Engine
Due to unforeseen circumstances, my '02 C5 may need a new powerplant. (I'm not sure about that yet...awaiting a professional diagnosis). So, in the mean time, I'm looking for some constructive comments on the direction I may have to take WRT engines.
The car's engine history: from factory LS1; then slightly mod'd w/ a cam, PP LS1 heads and LT headers; then replaced with a stroked LS6, which reused the PP LS1 heads and LT headers.
The car's use: a former daily driver, it's mainly a weekend car right now, with occasional trips (4-5 wknds/yr) to track days and HPDEs at places such as VIR, Summit Point (West VA), Sebring and Road America. FYI, the chassis now has a shade over 100K miles on it.
I was happy with the slightly mod'd OEM engine but replaced it three years and ~32K miles ago due to a previous problem (i.e., cracked block). It gave decent gas mileage compared to stock. My current stroked motor has been very streetable and has gobs more power (which has been great!), but gives a little less gas mileage.
The easy decision would be to drop in a crate LS6, but I've heard a crate LS2 works just as well.
I have no idea how easy or hard a crate LS3 would be to add into the car.
Of course, I could just have my stroked LS6 bored out to a 427 (if it's healthy enough to do so), but I don't know what that would do to my wallet and gas mileage.
A few small points--I'd like an engine warranty, I'd like to reuse my LT headers, I'd like to take it to track days and HPDEs it a few times a year and I'd like the option to use the 'Vette as a daily driver (which is what it started out to be.) An added plus would be to make it Sebring-proof (don't ask
).
So whattayathink? LS6/2/3 or further mod my current engine into a sleeved 427? Again, thanks for the constructive comments!
The car's engine history: from factory LS1; then slightly mod'd w/ a cam, PP LS1 heads and LT headers; then replaced with a stroked LS6, which reused the PP LS1 heads and LT headers.
The car's use: a former daily driver, it's mainly a weekend car right now, with occasional trips (4-5 wknds/yr) to track days and HPDEs at places such as VIR, Summit Point (West VA), Sebring and Road America. FYI, the chassis now has a shade over 100K miles on it.
I was happy with the slightly mod'd OEM engine but replaced it three years and ~32K miles ago due to a previous problem (i.e., cracked block). It gave decent gas mileage compared to stock. My current stroked motor has been very streetable and has gobs more power (which has been great!), but gives a little less gas mileage.
The easy decision would be to drop in a crate LS6, but I've heard a crate LS2 works just as well.
I have no idea how easy or hard a crate LS3 would be to add into the car.
Of course, I could just have my stroked LS6 bored out to a 427 (if it's healthy enough to do so), but I don't know what that would do to my wallet and gas mileage.
A few small points--I'd like an engine warranty, I'd like to reuse my LT headers, I'd like to take it to track days and HPDEs it a few times a year and I'd like the option to use the 'Vette as a daily driver (which is what it started out to be.) An added plus would be to make it Sebring-proof (don't ask
).So whattayathink? LS6/2/3 or further mod my current engine into a sleeved 427? Again, thanks for the constructive comments!
10-12-2008, 09:06 AM
#2
Team Owner
Member Since: Sep 2003
Location: Raleigh / Rolesville NC
Posts: 43,084
Likes: 0
Received 24 Likes
on
24 Posts
A few small points--I'd like an engine warranty, I'd like to reuse my LT headers, I'd like to take it to track days and HPDEs it a few times a year and I'd like the option to use the 'Vette as a daily driver (which is what it started out to be.) An added plus would be to make it Sebring-proof (don't ask
).So whattayathink? LS6/2/3 or further mod my current engine into a sleeved 427? Again, thanks for the constructive comments!
10-13-2008, 12:42 PM
#5
Pro
Member Since: Jan 2006
Location: Alexandria Northern Virginia
Posts: 643
Likes: 0
Received 1 Like
on
1 Post
Hey stranger! Back state-side?
If you need a new home for that old motor, I may know of a good one...
Have a pickup truck...
BTW, I would suggest LS7 if you can swing it. That crate motor is a beast. LS2 would be my second choice if it were me. I don't see your car ever getting Bloomington Gold award for stock class anyway!
Cassidy
If you need a new home for that old motor, I may know of a good one...
Have a pickup truck...BTW, I would suggest LS7 if you can swing it. That crate motor is a beast. LS2 would be my second choice if it were me. I don't see your car ever getting Bloomington Gold award for stock class anyway!
Cassidy
10-17-2008, 03:17 PM
#6
Burning Brakes
Thread Starter
Hey stranger! Back state-side?
If you need a new home for that old motor, I may know of a good one... Have a pickup truck...
BTW, I would suggest LS7 if you can swing it. That crate motor is a beast. LS2 would be my second choice if it were me. I don't see your car ever getting Bloomington Gold award for stock class anyway!
Cassidy
If you need a new home for that old motor, I may know of a good one...
Have a pickup truck...BTW, I would suggest LS7 if you can swing it. That crate motor is a beast. LS2 would be my second choice if it were me. I don't see your car ever getting Bloomington Gold award for stock class anyway!
Cassidy
10-17-2008, 03:37 PM
#8
Melting Slicks
If you have that money to spend for no gain in hp and only so you can say you have a LS7, then sure. I would rather rock the LSX for less...
10-17-2008, 03:58 PM
#9
Burning Brakes
Thread Starter
I appreciate the continuing suggestions! 
A continuing desire is reliability. A reemphasized factor this time 'round is a warranty.
Thus, I think I'm dropping considerations for turning what I have into a 427 (i.e., further mod'd from the stock set-up it once was.) It's either going to be repair what I have (within financial reason) or go the crate route.
A continuing desire is reliability. A reemphasized factor this time 'round is a warranty.
Thus, I think I'm dropping considerations for turning what I have into a 427 (i.e., further mod'd from the stock set-up it once was.) It's either going to be repair what I have (within financial reason) or go the crate route.
Last edited by kedvesh; 10-17-2008 at 04:00 PM. Reason: clarification
10-17-2008, 06:50 PM
#10
Team Owner
Member Since: Sep 2003
Location: Raleigh / Rolesville NC
Posts: 43,084
Likes: 0
Received 24 Likes
on
24 Posts
I appreciate the continuing suggestions!
A continuing desire is reliability. A reemphasized factor this time 'round is a warranty.
Thus, I think I'm dropping considerations for turning what I have into a 427 (i.e., further mod'd from the stock set-up it once was.) It's either going to be repair what I have (within financial reason) or go the crate route.
A continuing desire is reliability. A reemphasized factor this time 'round is a warranty.
Thus, I think I'm dropping considerations for turning what I have into a 427 (i.e., further mod'd from the stock set-up it once was.) It's either going to be repair what I have (within financial reason) or go the crate route.
:
10-18-2008, 12:13 AM
#12
Burning Brakes
Thread Starter
Curiosity kills the cat (or so I've heard). 
If you mean me as the original poster, here's the short version.
My mod'd LS6 experienced high crankcase pressure, which then forced oil out of the dipstick tube, which over the short time this was happening, caused a low oil level in the pan, which when in a turn at a high rate of speed, caused the oil pickup to suck air, which caused abnormally low oil pressure in the engine, which who knows what happened next. My #5 cylinder now shows only 50 pounds of compression and I have to arrange to open up the engine to see what may actually be the issue.
Some people say I should forget about this engine and get a new one. Others say to fix it. Still others say a combination of actions resulting in the selling of this 'Vette and the purchase of a new C6 coupe or Z06.
The saga continues.
If you mean me as the original poster, here's the short version.
My mod'd LS6 experienced high crankcase pressure, which then forced oil out of the dipstick tube, which over the short time this was happening, caused a low oil level in the pan, which when in a turn at a high rate of speed, caused the oil pickup to suck air, which caused abnormally low oil pressure in the engine, which who knows what happened next. My #5 cylinder now shows only 50 pounds of compression and I have to arrange to open up the engine to see what may actually be the issue.
Some people say I should forget about this engine and get a new one. Others say to fix it. Still others say a combination of actions resulting in the selling of this 'Vette and the purchase of a new C6 coupe or Z06.
The saga continues.
10-18-2008, 05:08 AM
#13
Race Director
Curiosity kills the cat (or so I've heard).
If you mean me as the original poster, here's the short version.
My mod'd LS6 experienced high crankcase pressure, which then forced oil out of the dipstick tube, which over the short time this was happening, caused a low oil level in the pan, which when in a turn at a high rate of speed, caused the oil pickup to suck air, which caused abnormally low oil pressure in the engine, which who knows what happened next. My #5 cylinder now shows only 50 pounds of compression and I have to arrange to open up the engine to see what may actually be the issue.
Some people say I should forget about this engine and get a new one. Others say to fix it. Still others say a combination of actions resulting in the selling of this 'Vette and the purchase of a new C6 coupe or Z06.
The saga continues.
If you mean me as the original poster, here's the short version.
My mod'd LS6 experienced high crankcase pressure, which then forced oil out of the dipstick tube, which over the short time this was happening, caused a low oil level in the pan, which when in a turn at a high rate of speed, caused the oil pickup to suck air, which caused abnormally low oil pressure in the engine, which who knows what happened next. My #5 cylinder now shows only 50 pounds of compression and I have to arrange to open up the engine to see what may actually be the issue.
Some people say I should forget about this engine and get a new one. Others say to fix it. Still others say a combination of actions resulting in the selling of this 'Vette and the purchase of a new C6 coupe or Z06.
The saga continues.
IMO The C6Z is a supirior car and if you can swing the coin you wont be disappointed... I have some track time over at Roebling Road in a C6Z and was amazed!!! I liked it better than the 997 - 911 C4S I drove the sessions before!
10-18-2008, 07:21 AM
#14
Burning Brakes
Thread Starter
FYI, and based on my experience, the track that would define whether a car--any car--survives the rigors of a high-speed event or not is Sebring. It eats cars/engines/components for breakfast, lunch and then spits them out for dinner.
10-18-2008, 08:10 AM
#16
Team Owner
Member Since: Sep 2003
Location: Raleigh / Rolesville NC
Posts: 43,084
Likes: 0
Received 24 Likes
on
24 Posts
SO an accu-sump and oil cooler are a must.
Dry sump is better but more expesive
Plus frequent oil changes. Every two or three events. Use heavier oil
M1 5-w50, Redline 40wt racing oil or something simular.
For one or two events a year the stock 5-w30 is just fine. But if you consistantly doing events, you need oil that can take the heat and abuse.
Next
transmission and diff coolers
next better coolant. ie water, 10% dex and two bottles of water wetter, keep that radiator cleaned out
or a bigger radiator which is preferred.
Most LS1, LS6 and LS2 motors blow do to poor oiling and poor cooling. around the #7 or #8 cylinders
The C6Z06 needs the new LPE oil tank and even the AER oil pan. 2009 Z06s are already equipped with better dry sump system.
Next are brakes: Brake cooling, much better brake pads and fresh DOT 4 brake fluid. ( there are no double duty, street and track brake pads)
Good Luck
I have 24K hard 3000 to redline miles on my LS1 converted to a LS6 engine ( 243 heads and small cam) The BEST mods I have done to my car are the accu-sump, oil cooler and transmission cooler.
Last edited by AU N EGL; 10-18-2008 at 08:14 AM.
