New vortecs..to port or not?
#1
Member
Thread Starter
Join Date: Dec 2003
Location: Houston,Tx
Posts: 157
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1985 Camaro Z28
Engine: 350 carb
Transmission: TH-700-R4
New vortecs..to port or not?
I will be getting a set of new vortec heads from summit...the GMPP ones. I will also be getting roller rockers, and springs to accomadate a 480 lift cam easily...now i know u have to machine the valve guides or some crap like that to get the springs in...and should i have them ported or not??? what would be better? Also, what companies do Porting work in the Houston area???
#2
Supreme Member
iTrader: (1)
Join Date: Aug 1999
Location: Rowlett, TX
Posts: 2,842
Likes: 0
Received 5 Likes
on
5 Posts
Car: 1988 GTA
Engine: 5.0 TPI
Transmission: T5
Axle/Gears: 9 Bolt, 3.45
What engine is this going on? Will it be a high rpm engine, or a more streetable low-mid rpm engine? For a street car I would go with either no or mild porting. If you're shooting for high revving power, then I would port them. Other factors affect this though, like intake, cam, etc.
#3
Member
Thread Starter
Join Date: Dec 2003
Location: Houston,Tx
Posts: 157
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1985 Camaro Z28
Engine: 350 carb
Transmission: TH-700-R4
It is for a 350 carb motor...street, everyday driver....but want about 340-350 to the wheels...what would be good? no porting? edelbrock intake and comp xtreme cam with 480lift...
#4
Supreme Member
iTrader: (1)
Join Date: Aug 1999
Location: Rowlett, TX
Posts: 2,842
Likes: 0
Received 5 Likes
on
5 Posts
Car: 1988 GTA
Engine: 5.0 TPI
Transmission: T5
Axle/Gears: 9 Bolt, 3.45
For street driving, torque is key, not just horsepower. Porting the heads a little would be good, just mostly to even out casting imperfections. But no need to have tons of airflow through them, because the engine doesnt really need it. I would go with a dual plane intake, probably a performer rpm or equivalent. Choosing a cam is a little tricky, but something that works in the idle to around 5500 range would be good. HP is meaningless if you dont make your peak power until 6000 rpm. You'll be slow as hell off the line, and winding out gears all day long. I would focus on low to midrange torque for a street car.
#5
Supreme Member
Join Date: Jan 2002
Location: Valley of the Sun
Posts: 3,852
Likes: 0
Received 0 Likes
on
0 Posts
Car: 82 Z28
Engine: Al LT1 headed LG4 305
Transmission: TH350
Axle/Gears: 3.73 posi with spacer
I wouldn't port GM vortecs, they can't flow much more (+5cfm) nd you will most likely hurt flow(-25cfm)!
#6
Supreme Member
try them as is. you won't get 350 at the rear wheels
more like 370-400 at the crank.
more like 370-400 at the crank.
Thread
Thread Starter
Forum
Replies
Last Post