PRC LS7 Small Bore Cylinder Heads Nears Production! 390cfm on a LS3 Bore!!
09-24-2011, 06:46 PM
#261
4.07 bore.
"We're working to get all the info added to the website, but basically they're going to flow much like our existing ports we've been putting in the GM castings, but with a good bit smaller runner (velocity!) We set them up so that they can use stock GM rockers, or any of the direct fit aftermarket rockers such as YellaTerra. Of course you still need the LS7 intake manifold or FAST 102mm LS7 manifold. We're also able to get better valve drop at the same chamber size, so you can run larger camshafts without cutting pistons. Of course that's not a concern for you though because we're going to have that aftermarket piston with reliefs in them. They require 4.065" bore or larger, which you have. "
I imagine this means it's the same port as their 265cc ls7 head, just squeezed into a tighter package, which makes perfect sense. In which case, flow numbers should be the same or very very close.
(the numbers on the right below)
"We're working to get all the info added to the website, but basically they're going to flow much like our existing ports we've been putting in the GM castings, but with a good bit smaller runner (velocity!) We set them up so that they can use stock GM rockers, or any of the direct fit aftermarket rockers such as YellaTerra. Of course you still need the LS7 intake manifold or FAST 102mm LS7 manifold. We're also able to get better valve drop at the same chamber size, so you can run larger camshafts without cutting pistons. Of course that's not a concern for you though because we're going to have that aftermarket piston with reliefs in them. They require 4.065" bore or larger, which you have. "
I imagine this means it's the same port as their 265cc ls7 head, just squeezed into a tighter package, which makes perfect sense. In which case, flow numbers should be the same or very very close.
(the numbers on the right below)
09-24-2011, 07:01 PM
#262
The ports are very very similar to the existing LS7 ports we've been using. There are very small differences in flow, but we're talking just a couple CFM at any lift point. We'll finish getting them on the website this coming week!
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Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
09-25-2011, 01:04 PM
#263
09-28-2011, 09:53 PM
#264
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I don't feel like reading though this whole thing again but are the exhaust ports the same as a normal LS7 head? I need to order headers for my car and im not sure if I should do with the normal style or the D ports...
10-27-2011, 11:45 AM
#268
They already are, you just dont know what you're looking for.
http://texas-speed.com/p-1236-prc-ls...cnc-heads.aspx
http://texas-speed.com/p-1236-prc-ls...cnc-heads.aspx
10-27-2011, 06:20 PM
#269
Small bore is misleading. The bore is standard. The valves just fit an ls3 bore with plenty of clearance. The bigger heads' valves are either too close, or hit the cyl wall.
More cnc problems (email), mine are supposedly going to be ready on monday now. We will see.
More cnc problems (email), mine are supposedly going to be ready on monday now. We will see.
11-03-2011, 01:16 AM
#272
Same part number as the ones I called and ordered for the LS3, so I"m assuming thats the case. I'll post more info on them when and if they ever actually show up. Lots of machining issues apparently, and now the valve seats had to be replaced... who knows. New and trial parts always have their kinks to work out, I just wish I had them here so I could put this damn motor together. Ordered 22 Sep. Everything else from TSP looks fantastic, so I expect these will too. Eventually.
11-03-2011, 08:46 AM
#273
The valve seats didn't need to be replaced Diet Coke, The exhaust seat has to be installed after the intake seats because they interclock. 
They are shipping today is the good news!
They are shipping today is the good news!
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Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
11-10-2011, 08:18 PM
#276
These are beautiful. Glad I waited. Take ls7 intake/hardware as its an LS7 port.
It's all here, assembly pics to come. BEHOLD! The first production set of TSP Small bore LS7 heads! Sheet metal intake comes tues. Assembly pictures to come.
:w00t: Assembly pictures to come. 58cc chamber as pictured. 265cc intake port. Check out my build thread for assembly pics tomorrow
It's all here, assembly pics to come. BEHOLD! The first production set of TSP Small bore LS7 heads! Sheet metal intake comes tues. Assembly pictures to come.
:w00t: Assembly pictures to come. 58cc chamber as pictured. 265cc intake port. Check out my build thread for assembly pics tomorrow
11-10-2011, 09:40 PM
#277
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Gorgeous, absolutely gorgeous.
What compression ratio will those 58cc chambers end up giving you with those domed (+3?) pistons?
Looking forward to some dyno sheets, but I know this is ALOT of work.
What compression ratio will those 58cc chambers end up giving you with those domed (+3?) pistons?
Looking forward to some dyno sheets, but I know this is ALOT of work.
