Y2KZX12R

I'm surprised there hasn't been a post on this yet.... but the 821 ls-3 casting off of the 2010 camaro has a different intake port than the L-92 364 and 716 castings.

I found this by running our normal cnc port threw the 821 casting and it stuck out like a sore thumb. I'm going to digitize the new ls-3 port and directly compare the two different port models in master cam as well as flow test the new port and do a whole new velocity map and then evaluate the actual differences stock. Then we can develop a whole new cnc program based on this new port.

We (were not a sponsor so I wont post our company name) don't even specialize in the over saturated LS market we just do several dozen sets of these heads a year for other race shops around the country, so I'm shocked that no other cnc head porters have even noticed this yet?

I've tried to get to the bottom of this casting change. So far it appears that at some point in the last 4-5 recent part number changes for the bare LS-3 head, the intake ports were changed from the L-92 port.

Can anyone else shed some light on this as to when the port was actually changed?

GA95DCMSS

iTrader: (13)

The port on the LS3 heads, as I understand, have always been a smoother casting vs. the L92 heads. I may be thinking of the 823 and 364 castings for the L92, as I haven't seen the 821s yet. Pictures would definitely assist though.

irnwkrkev

How many cc's is your finished port? I'm wondering if most other companies take out enough material that the port difference isn't quite as noticeable. I know that AI mentioned something their 267cc port and casting differences effecting it.

Y2KZX12R

The difference is in the floor of the short turn. The ls-3 port is wider in that area. so the CSA is bigger and the air speed is slower. This helps keep the air attached, which is a problem on the L-92 heads.
Its something we addressed with our ls-3 ls-7 hybrid head which uses ls-3 heads and the ls-7 intake.