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[QUOTE=z0sicktanner;19836412]Not gonna share all my info but i posted pretty good bit of info on this over the years..low lift numbers don't mean **** to me when i can do this in 1500 ft d/a over an over...
Your yellow Z? Heads, cam, compression, fuel? In 1500' that's killer mph with a 1.6...
Is anyone ever measured how big HP difference there is between 370cfm heads and 400cfm heads? LS7 heads flows pretty damn good stock so i've been thinking how much power i gain when i spend many many nights porting and polishing them... Obviously there is big diccerence in cathedral heads when there is nearly 100cfm gains.
Is anyone ever measured how big HP difference there is between 370cfm heads and 400cfm heads? LS7 heads flows pretty damn good stock so i've been thinking how much power i gain when i spend many many nights porting and polishing them... Obviously there is big diccerence in cathedral heads when there is nearly 100cfm gains.
I believe 20-30rw is the norm, and more cam, more gain.
Z06sicktanner - would you say a lot of the gains are not just in the intake port but working the exhaust port which on an LS7 head is a little weak from the factory. What flow numbers are you getting out of the exhaust ports with or without a tube. I see you have 99 cc exhaust port what are they like 92 cc from factory?
I've also wondered how to how to improve LS7 exhaust port. Its a D-shaped so maybe making it round shaped?
Keeping the floor flat would be an advantage on the exhaust side. I think the improvements will be a valve job ,opening the throat to 90-91%, re working the bowl and guide, and just carrying that clean up throughout the port to increase overall volume. The exhaust is so weak in comparison, it seems you almost can't mess it up lol...
Well here is my finished exhaust port. What do you think?
Looks good from here. Most important thing imo, what's the throat measure, just below the valve job, where the seat meets the head material. I wouldn't go anymore than 91% of the valve size. I would think the LS7 head isn't super sensitive to that measurement on the exhaust side like other heads may be, so may not be very critical here, but I am a nobody... Lol.
Been porting the ls7 heads since 06 and I can tell you a few things about that swirl vein..
all the testing I've done was with die, the ls7 port will go turbulent at high lift.
Once this happens the air is being sucked back up the short side. also the wing seems to help with flow numbers but once die is injected into the port the truth shows its self. on all high lift cams its better to have them removed here is a cathedal heads with the wing same thing you see here the ls7 is doing then a picture of how I port them for big cam cars or fi. did this to my own car and eveyone has gained trap speed its helped for me...an after testing a set of AI heads on my own car with the vein removed been doing this way since.
The wing isn't why the port backs up, and there is no relevance to the wing vs valve lift.
The wing isn't why the port backs up, and there is no relevance to the wing vs valve lift.
First do you port heads? if not don't reply. I'll give you a list that says otherwise... Darin Morgan, Greg Good Chad lively Gavin at SPS did until he sold to AI. Phil at AI, LME Mast and a few others...but you port them they way you want..makes no diff to me...this is why i've stopped posting in over 2 years.. an will be my last...because of people like you...
My BES ported LS7 heads have the wing taken out but the port floor has a heavy amount of taper to it. Don't know how it compares to a factory port. I assume is slows down the air by the cylinder wall and tries to speed it up towards the center of the bore but I don't know. I haven't run these but I've heard good things. They're ~285cc. You can see witness of where the wing was but it is pretty much entirely gone.
02-16-2018, 08:32 AM
