"LS2" with 317 Heads?
Thread Starter
On The Tree
Joined: Nov 2012
Posts: 145
Likes: 0
From: Bel Air, MD
"LS2" with 317 Heads? I recently purchased a 2000 C5 vette which the previous owner had swapped (what he said was) a LS2 into the car. I was looking around under the hood the other day and noticed it has 317 heads.
I know they are basically the same as the 243 heads that came on LS2s but with a larger combustion chamber that lowers compression. These are the same heads that are on the LQ4 in my truck.
I know it is a gen IV block because he had to move the knock sensors, and I am pretty sure its still an aluminum block but I never actually checked. My question to you guys is what motor do you think I actually have? As far as I know 317s only came on the Gen III 6.0L truck motors (LQ4 and LQ9), but maybe there is something else? My only other though is maybe he swapped the heads but I don't know why anyone would swap to lower CR. I am going to try and get the serial number off the block casting at some point also. Thanks for any input.
I know they are basically the same as the 243 heads that came on LS2s but with a larger combustion chamber that lowers compression. These are the same heads that are on the LQ4 in my truck.
I know it is a gen IV block because he had to move the knock sensors, and I am pretty sure its still an aluminum block but I never actually checked. My question to you guys is what motor do you think I actually have? As far as I know 317s only came on the Gen III 6.0L truck motors (LQ4 and LQ9), but maybe there is something else? My only other though is maybe he swapped the heads but I don't know why anyone would swap to lower CR. I am going to try and get the serial number off the block casting at some point also. Thanks for any input.
Thread Starter
On The Tree
Joined: Nov 2012
Posts: 145
Likes: 0
From: Bel Air, MD
The guy I bought it from owned a shop and it was done by his guys. He said he has a few LS crazy techs that talked him into doing it. I emailed the guy I bought it from to see if he can dig up the VIN from the vehicle the motor came out of.
Do you actually know what was done to the 317 heads? Some people use those as they can be welded and actually achieve smaller combustion chambers without much milling, so he could've done that.
Or he had some high dollar heads on there before that he swapped out for some cheapos right before selling the car as those fit the bill.
Or he had some high dollar heads on there before that he swapped out for some cheapos right before selling the car as those fit the bill.
Thread Starter
On The Tree
Joined: Nov 2012
Posts: 145
Likes: 0
From: Bel Air, MD
Do you actually know what was done to the 317 heads? Some people use those as they can be welded and actually achieve smaller combustion chambers without much milling, so he could've done that.
Or he had some high dollar heads on there before that he swapped out for some cheapos right before selling the car as those fit the bill.
Or he had some high dollar heads on there before that he swapped out for some cheapos right before selling the car as those fit the bill.
Just from talking to him I wouldn't think he would swap the heads just to sell the car, or really even have better heads on before. Mostly because he said he used the car primarily just for driving around with his wife. lol
Trending Topics
Thread Starter
On The Tree
Joined: Nov 2012
Posts: 145
Likes: 0
From: Bel Air, MD
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
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
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote
Thread Starter
On The Tree
Joined: Nov 2012
Posts: 145
Likes: 0
From: Bel Air, MD
The guy I bought the car from included the motor he took out, said it is fine. I have yet to thoroughly check it out but he did keep it for a few years so I can't really see someone storing a motor for that long that is shot...
If the old motor is actually good, it would make absolutely no sense to switch to a LQ4 or LQ9 for the same/reduction in HP and an extra 80-90 pounds over the front end. So either the guy is dense or something else weird is going on
If the old motor is actually good, it would make absolutely no sense to switch to a LQ4 or LQ9 for the same/reduction in HP and an extra 80-90 pounds over the front end. So either the guy is dense or something else weird is going on
But at the same time some people are just under the impression more cubes = drastically more power which is not the case.
Thread Starter
On The Tree
Joined: Nov 2012
Posts: 145
Likes: 0
From: Bel Air, MD
I agree with that. Unless those heads are highly worked over it makes even less sense to swap those onto a ls2 shortblock as the loss of compression would lower power negating the entire point of the swap. Especially when you factor in the swap parts to go gen IV and the need for a tune (which may or may not be done).
But at the same time some people are just under the impression more cubes = drastically more power which is not the case.
But at the same time some people are just under the impression more cubes = drastically more power which is not the case.
https://ls1tech.com/forums/pcm-diagn...low-input.html
Tough call on how to advise you to proceed.
If it were me and my budget allowed I would be looking into getting some CNC ported 243s then pull the 317 heads and see what's up with them. Once you know what you have you could sell them and install the 243s before taking it to be tuned.
Is it cammed at all?
If it were me and my budget allowed I would be looking into getting some CNC ported 243s then pull the 317 heads and see what's up with them. Once you know what you have you could sell them and install the 243s before taking it to be tuned.
Is it cammed at all?
Thread Starter
On The Tree
Joined: Nov 2012
Posts: 145
Likes: 0
From: Bel Air, MD
Tough call on how to advise you to proceed.
If it were me and my budget allowed I would be looking into getting some CNC ported 243s then pull the 317 heads and see what's up with them. Once you know what you have you could sell them and install the 243s before taking it to be tuned.
Is it cammed at all?
If it were me and my budget allowed I would be looking into getting some CNC ported 243s then pull the 317 heads and see what's up with them. Once you know what you have you could sell them and install the 243s before taking it to be tuned.
Is it cammed at all?
Depending on what I find I might just go that route. At least swapping heads on a vette with the motor in the car is easier then the 4th gens.
My geuss is the old motor was hurt and he performed a cheap 6.0 swap which is probably a lq9. U can pull the numbers on the front of block near the head and find the year of it. Only difference between a lq9 and ls2 is weight, compression, and cost. I say swap a cam and run it!!
Thread Starter
On The Tree
Joined: Nov 2012
Posts: 145
Likes: 0
From: Bel Air, MD
My geuss is the old motor was hurt and he performed a cheap 6.0 swap which is probably a lq9. U can pull the numbers on the front of block near the head and find the year of it. Only difference between a lq9 and ls2 is weight, compression, and cost. I say swap a cam and run it!!
Do you have a picture of where the number is on the front of the block? I was only aware of a block serial number on the back against the firewall
Personally I would prefer not to have the extra 100lbs on the nose of a Corvette as it's detrimental to handling.
If it turns out to be iron I would look at either rebuilding the aluminum engine you got with the car and swapping it back in with some power goodies or selling both engines for some other aluminum block crate engine.
Depends on OP's goals, budget, and how he intends to use the car what is best for him.
If it turns out to be iron I would look at either rebuilding the aluminum engine you got with the car and swapping it back in with some power goodies or selling both engines for some other aluminum block crate engine.
Depends on OP's goals, budget, and how he intends to use the car what is best for him.
Personally I would prefer not to have the extra 100lbs on the nose of a Corvette as it's detrimental to handling.
If it turns out to be iron I would look at either rebuilding the aluminum engine you got with the car and swapping it back in with some power goodies or selling both engines for some other aluminum block crate engine.
Depends on OP's goals, budget, and how he intends to use the car what is best for him.
If it turns out to be iron I would look at either rebuilding the aluminum engine you got with the car and swapping it back in with some power goodies or selling both engines for some other aluminum block crate engine.
Depends on OP's goals, budget, and how he intends to use the car what is best for him.
. Not to mention reduce resale if you ever sell it. Thread Starter
On The Tree
Joined: Nov 2012
Posts: 145
Likes: 0
From: Bel Air, MD
Personally I would prefer not to have the extra 100lbs on the nose of a Corvette as it's detrimental to handling.
If it turns out to be iron I would look at either rebuilding the aluminum engine you got with the car and swapping it back in with some power goodies or selling both engines for some other aluminum block crate engine.
Depends on OP's goals, budget, and how he intends to use the car what is best for him.
If it turns out to be iron I would look at either rebuilding the aluminum engine you got with the car and swapping it back in with some power goodies or selling both engines for some other aluminum block crate engine.
Depends on OP's goals, budget, and how he intends to use the car what is best for him.
I eventually want to do autocross every now and then and maybe some road course events, so handling will be a concern.