Welcome, Guest. Please login or register.
October 22, 2018, 03:50:32 pm

Login with username, password and session length
Director PLEASE!!!!
Add your location information to your personal profile. Thanx!
435267 Posts in 37272 Topics by 9537 Members
Latest Member: Mgabski
Search: Advanced search
Advertiser Inquiries
+ My Community
|-+ Grass Roots Tech
| |-+ Grass Roots Cylinder Heads
| | |-+ Porting and Flow testing GT40 heads
0 Members and 1 Guest are viewing this topic. « previous next »
Pages: 1 ... 8 9 [10] Go Down Print
Author Topic: Porting and Flow testing GT40 heads  (Read 93441 times)
Outlaw Bill
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 4760


Location: Canton, Michigan

« Reply #135 on: April 02, 2013, 06:51:00 pm »

The exhaust ports are tough. They like to sign off early at .500 lift. The short turn is the 100%  key to the exhaust port to work. My exhaust port only flows 160cfm(no pipe) at .500 lift then rolls over after that, its all in the short turn.
On the one I did the exhaust went to 180 @ .400 and then tapered off to 168 @ .700. I was hoping there was more to be had there because the bowl looks like it should be a little bigger on the one side, but I don't want to hit water with it.
Yeah I need to widen and lay back the short turn more. No time to mess with them though.
Logged

www.TeamZmotorsports.net

TeamZmotorsports 25.2 outlaw drag radial stock suspension 1991 Mustang
Thank You to the following for their help
TeamZmotorsports
Marcella Manifolds
Schoneck Composite
Ultimate Converter Concepts


"Stupid is as stupid does", "You can't fix stupid"
"Common sense is not common"
David Claflin
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 7907


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #136 on: April 02, 2013, 09:42:34 pm »

Yeah I need to widen and lay back the short turn more. No time to mess with them though.
Same here, but I really need one of those electronic things that measures the port wall, that way I can know how much material is left there.
Logged

1990 Red LX, 306, 80MM, ported gt40's, ported explorer upper accufab longtubes, 3" exhaust, 4.30's, 336/331
1985 LTD LX 347, 205 11R's, TFS-R, 90MMTB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
coulterracn
6 Banger
**
Offline Offline

Posts: 65


Location: Pascagoula, MS (Gulf Coast)

« Reply #137 on: April 05, 2013, 04:59:22 pm »

It's been awhile since I've read the entire thread and can't remember if anyone talked about port velocities. While we had David's head on the bench I checked port speed at the center of short side radius, it was in the 500+ range. Is there enough material in the port walls to widen this area to help reduce port velocity?

I think overall the head has good potential. Would have liked to enlarge the exhaust bowl and reground the exhaust valve seat. My fault this didn't happen, I got distracted.

Ray
Logged
Pages: 1 ... 8 9 [10] Go Up Print 
« previous next »
Jump to:  



Powered by MySQL Powered by PHP Valid XHTML 1.0! Valid CSS!
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines



408 Stroker