LS3 intake on cathedral heads?
11-18-2016, 03:48 PM
#1
Staging Lane
Thread Starter
iTrader: (7)
Join Date: Jul 2015
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
LS3 intake on cathedral heads? Keep in mind I'm an LS beginner.
I just picked up a set of CNC ported cathedral port heads from my local machine shop. I know the owner of the shop and trust him. He was selling these heads for a customer that was running them on a 6.0 and he has seen the heads on the engine. Owner did an LS3 head swap.
He says the guy also has an LS6 manifold so I tell him to let him know I'm interested. Manifold shows up at the shop and turns out it's an LS3 rect. port intake. The original owner of the engine claims this is the manifold that he was running. I checked the gasket imprints on the heads and they do appear to match the LS3 gaskets.
I didn't buy the intake. This sounds like a very bad idea to me. The lower part of the CNC ports closely match the LS3 profile, but it looks like there will be a lot of turbulence when the air hits the square shoulder of the upper part of the cathedral port which I would assume would kill a lot of flow.
Has anyone ever heard of this? I didn't know they would even bolt up.
I just picked up a set of CNC ported cathedral port heads from my local machine shop. I know the owner of the shop and trust him. He was selling these heads for a customer that was running them on a 6.0 and he has seen the heads on the engine. Owner did an LS3 head swap.
He says the guy also has an LS6 manifold so I tell him to let him know I'm interested. Manifold shows up at the shop and turns out it's an LS3 rect. port intake. The original owner of the engine claims this is the manifold that he was running. I checked the gasket imprints on the heads and they do appear to match the LS3 gaskets.
I didn't buy the intake. This sounds like a very bad idea to me. The lower part of the CNC ports closely match the LS3 profile, but it looks like there will be a lot of turbulence when the air hits the square shoulder of the upper part of the cathedral port which I would assume would kill a lot of flow.
Has anyone ever heard of this? I didn't know they would even bolt up.
11-20-2016, 08:54 AM
#3
Staging Lane
Thread Starter
iTrader: (7)
Join Date: Jul 2015
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
Just what I thought. It didn't make any sense that it would work right and I 've never seen anything in print or on the forums about it.
Word has it that the car the engine was in was fast and won a lot of races. I can't say for sure, but if that's true, it probably would have been a lot faster with the right intake.
Looks like I'm still looking for an LS6 manifold. Might have to go with a Dorman.
Word has it that the car the engine was in was fast and won a lot of races. I can't say for sure, but if that's true, it probably would have been a lot faster with the right intake.
Looks like I'm still looking for an LS6 manifold. Might have to go with a Dorman.
11-20-2016, 01:01 PM
#5
FormerVendor
iTrader: (1)
Join Date: Nov 2008
Location: Santa Ana, CA. USA
Posts: 2,157
Likes: 0
Received 17 Likes
on
17 Posts
Adapter Plate LS-3/LS-1 I spoke to the supplier of a "plate adapter" to go from LS-3 intake to LS-1 port.
My reason was to go from LS-1 to LS-3 port, not found.
Would you like more information ?
Lance, BTW this is a great idea. (LS-3/LS-1)
My reason was to go from LS-1 to LS-3 port, not found.
Would you like more information ?
Lance, BTW this is a great idea. (LS-3/LS-1)
11-20-2016, 01:20 PM
#6
Staging Lane
Thread Starter
iTrader: (7)
Join Date: Jul 2015
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
Sure, tell me all about it. I looked at some adapters, but thought they were mainly for blower conversions. Looking at the LS3 manifold, I can see that it would probably flow more due to port size. The transition from rect. to cathedral would be tricky.
Trending Topics
11-22-2016, 08:14 AM
#8
Staging Lane
Thread Starter
iTrader: (7)
Join Date: Jul 2015
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
Just bought an LS6 manifold. I looked at the BBK, but was concerned about the aluminum retaining heat on a street engine. The FAST's are out of my budget for now. Even the older ones. Also, I thought about a TBSS, but they were too tall to fit under the hood of the sports car I'm working on.
Thanks for the replies.
Thanks for the replies.
11-22-2016, 10:23 AM
#9
Keep in mind I'm an LS beginner.
I just picked up a set of CNC ported cathedral port heads from my local machine shop. I know the owner of the shop and trust him. He was selling these heads for a customer that was running them on a 6.0 and he has seen the heads on the engine. Owner did an LS3 head swap.
He says the guy also has an LS6 manifold so I tell him to let him know I'm interested. Manifold shows up at the shop and turns out it's an LS3 rect. port intake. The original owner of the engine claims this is the manifold that he was running. I checked the gasket imprints on the heads and they do appear to match the LS3 gaskets.
I didn't buy the intake. This sounds like a very bad idea to me. The lower part of the CNC ports closely match the LS3 profile, but it looks like there will be a lot of turbulence when the air hits the square shoulder of the upper part of the cathedral port which I would assume would kill a lot of flow.
Has anyone ever heard of this? I didn't know they would even bolt up.
I just picked up a set of CNC ported cathedral port heads from my local machine shop. I know the owner of the shop and trust him. He was selling these heads for a customer that was running them on a 6.0 and he has seen the heads on the engine. Owner did an LS3 head swap.
He says the guy also has an LS6 manifold so I tell him to let him know I'm interested. Manifold shows up at the shop and turns out it's an LS3 rect. port intake. The original owner of the engine claims this is the manifold that he was running. I checked the gasket imprints on the heads and they do appear to match the LS3 gaskets.
I didn't buy the intake. This sounds like a very bad idea to me. The lower part of the CNC ports closely match the LS3 profile, but it looks like there will be a lot of turbulence when the air hits the square shoulder of the upper part of the cathedral port which I would assume would kill a lot of flow.
Has anyone ever heard of this? I didn't know they would even bolt up.
11-22-2016, 08:10 PM
#11
Thanks for posting that pic it reveals quite a bit , surprising it appears to cover and be below the floor ! Do you have any pics of the LS3 intake and or part # . The part # location is drivers side between 3rd and 5th ports. Also those heads you have, I'm guessing they are 243 cnc ...... could you tell us what the port width is I'm guessing its around 1.10" to 1.12"
11-22-2016, 08:43 PM
#12
Staging Lane
Thread Starter
iTrader: (7)
Join Date: Jul 2015
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
I don't remember the intake part number and I didn't take any pictures, but it came up as an LS3 part number when I googled it. The manifold did not appear to have been modified.
The ports are approx. 1 1/8" wide. I did a rough comparison to a stock LS port and it appears that they are about 1/8" wider. The height is about the same as stock.
The CNC heads are 806 castings. I was looking for a set of 243's when I found these. My engine has the very early 337K castings. The CNC heads have titanium retainers, double springs and can take up to about .640 lift. I don't have much info on them as to who did the porting, but they have to better than what I had. I would have preferred a center bolt valve cover, though. I still need to CC the chambers to make sure I'm not cutting my CR.
My engine is a 5.7. As unbelievable as it sounds, this engine is practically new. I bought it out of an old unfinished project. Supposedly has only been test fired. I'm planning cam, PCV, and oiling upgrades as well as the heads.
The ports are approx. 1 1/8" wide. I did a rough comparison to a stock LS port and it appears that they are about 1/8" wider. The height is about the same as stock.
The CNC heads are 806 castings. I was looking for a set of 243's when I found these. My engine has the very early 337K castings. The CNC heads have titanium retainers, double springs and can take up to about .640 lift. I don't have much info on them as to who did the porting, but they have to better than what I had. I would have preferred a center bolt valve cover, though. I still need to CC the chambers to make sure I'm not cutting my CR.
My engine is a 5.7. As unbelievable as it sounds, this engine is practically new. I bought it out of an old unfinished project. Supposedly has only been test fired. I'm planning cam, PCV, and oiling upgrades as well as the heads.