Welcome, Guest. Please login or register.
September 26, 2017, 10:43:13 am

Login with username, password and session length
TRADER Feedback System
IS NOW AVAILABLE
* SBFTECH Membership Required *
433997 Posts in 37136 Topics by 9476 Members
Latest Member: joerberg
Search: Advanced search
Advertiser Inquiries
+ SBFTECH.com Experienced Small Block Ford Tech
|-+ General Tech
| |-+ General Tech
| | |-+ GT-40 head porting, a compilation with a bunch of pics and measurements
0 Members and 1 Guest are viewing this topic. « previous next »
Pages: 1 ... 3 4 [5] 6 Go Down Print
Author Topic: GT-40 head porting, a compilation with a bunch of pics and measurements  (Read 46842 times)
David Claflin
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 7862


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #60 on: October 18, 2013, 08:29:01 pm »

I took this out to the remote range and put it in this saw, cut it through in no time. I had never used this before, or seen how it works, but got figured out pretty quick. I was off a little on the first cut. I wanted to cut right through the center of the valve guides, but got a good cut that shows a lot to me.
The saw is something that supposedly came off of a large navy ship way back when. I took a video with the phone because I was so impressed with how nice it worked, and how brutally simple it's operation was.
Exhaust with part of the crossover port


* IMG_1237.JPG (3002.28 KB, 4000x3000 - viewed 576 times.)

* IMG_1240.JPG (2618.17 KB, 4000x3000 - viewed 536 times.)
Logged

1990 Red LX, 306, 75MM, ported gt40's, Holley SMII, accufab longtubes, 3" exhaust, 4.10's, 318RWHP/316RWTQ
1985 LTD LX 302, ported TW's, XE-264 cam, ported Holley SMII, 75MM-R TB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
David Claflin
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 7862


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #61 on: October 18, 2013, 08:30:48 pm »

one side of the intake


* IMG_1238.JPG (2511 KB, 4000x3000 - viewed 450 times.)

* IMG_1240.JPG (2618.17 KB, 4000x3000 - viewed 405 times.)
Logged

1990 Red LX, 306, 75MM, ported gt40's, Holley SMII, accufab longtubes, 3" exhaust, 4.10's, 318RWHP/316RWTQ
1985 LTD LX 302, ported TW's, XE-264 cam, ported Holley SMII, 75MM-R TB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
David Claflin
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 7862


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #62 on: October 18, 2013, 08:33:43 pm »

the head and where I made the cuts


* IMG_1241.JPG (2149.42 KB, 4000x3000 - viewed 364 times.)
Logged

1990 Red LX, 306, 75MM, ported gt40's, Holley SMII, accufab longtubes, 3" exhaust, 4.10's, 318RWHP/316RWTQ
1985 LTD LX 302, ported TW's, XE-264 cam, ported Holley SMII, 75MM-R TB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
David Claflin
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 7862


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #63 on: October 18, 2013, 08:34:56 pm »

The saw, and a video of it in action
http://www.youtube.com/watch?v=ach_78XI6yQ


* head saw.jpg (651.97 KB, 1600x1200 - viewed 294 times.)
Logged

1990 Red LX, 306, 75MM, ported gt40's, Holley SMII, accufab longtubes, 3" exhaust, 4.10's, 318RWHP/316RWTQ
1985 LTD LX 302, ported TW's, XE-264 cam, ported Holley SMII, 75MM-R TB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
David Claflin
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 7862


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #64 on: October 18, 2013, 08:37:39 pm »

What is the thinnest recommended to cut to on a cast iron exhaust port?
Logged

1990 Red LX, 306, 75MM, ported gt40's, Holley SMII, accufab longtubes, 3" exhaust, 4.10's, 318RWHP/316RWTQ
1985 LTD LX 302, ported TW's, XE-264 cam, ported Holley SMII, 75MM-R TB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
David Claflin
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 7862


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #65 on: October 19, 2013, 07:11:37 pm »

From what I've gathered .085 - .100 is about the thinnest recommended, guess it depends on what it will be used for and what you're willing to try to get away with. I know I'm probably close in a few spots on these, but from what I've learned, especially today I know I can port another pair and not worry about it at all.

Here's what Ray got on his bench for the intake, .100 increments.
94
157
192
218
228
240
244
245
245


Exhaust
90
125
153.5
178.9
188.07
189.69
188
192.71
190.7

These ports are now much more stable, and the intake is with nothing done to the port at all, only bowl, short turn and throat work. On the exhaust it's bowl, throat, short turn and cutting down that hump in the exhaust port.

Ray's still got the other pair of heads, he'll either send me the numbers or post them here. Special tip of the hat to Ray for helping me out with these and to all of the folks here who provided advice and suggestions.

 
Logged

1990 Red LX, 306, 75MM, ported gt40's, Holley SMII, accufab longtubes, 3" exhaust, 4.10's, 318RWHP/316RWTQ
1985 LTD LX 302, ported TW's, XE-264 cam, ported Holley SMII, 75MM-R TB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
Outlaw Bill
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 4756


Location: Canton, Michigan

« Reply #66 on: October 19, 2013, 07:20:48 pm »

Impressive, you are way better than my heads!.
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: 7862


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #67 on: October 19, 2013, 09:01:27 pm »

Thanks Bill , you're one of the guys that helped steer me to this point.

Here it is with a 1 5/8" mac shorty header on it and the numbers with the pipe.

w/pipe
89
128
152
169
177
179
180
180
181


* gt40 with pipe picture.JPG (418.52 KB, 1296x968 - viewed 286 times.)
Logged

1990 Red LX, 306, 75MM, ported gt40's, Holley SMII, accufab longtubes, 3" exhaust, 4.10's, 318RWHP/316RWTQ
1985 LTD LX 302, ported TW's, XE-264 cam, ported Holley SMII, 75MM-R TB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
Outlaw Bill
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 4756


Location: Canton, Michigan

« Reply #68 on: October 19, 2013, 10:04:00 pm »

Your welcome. I will admit I flowed my heads on a 1020 which was very tight. I need to tune them up and see if I can hit 250 and 180-190.
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: 7862


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #69 on: October 21, 2013, 10:50:32 am »

Your welcome. I will admit I flowed my heads on a 1020 which was very tight. I need to tune them up and see if I can hit 250 and 180-190.
I didn't go as wide on the intake short turn as what Gerald said is possible, I had my little girl panties on..LOL!!
I think I got to 1.62 or thereabouts as measuring these is really subjective to me, he said he got to 1.75, but 1.80 is possible. On the other pair of heads I went to 1.68. We'll see how much difference that makes when he gets to those.

I sent the information on flow numbers to Buddy Rawls via PM on corral. Here's his response, got me wondering if I should have bought a 1 3/4 longtube along to compare it with the shorty.

"Wow, those number really caught me off guard.

To be honest, I have never seen exhaust numbers with a shorty fox body header. I would theorize that they would act similar to a stub pipe. Based on the numbers, I have to assume that the theory could possibly be valid.

Normally, when a typical ~30" header pipe with all the normal bends and such will peak in the 135 cfm region (give or take). A 1 3/4 set-up will typically peak out around 175 cfm. These are with the typical shock tower style headers with cramped quarters at the transition out of the head. The shorty, fox style header can often times have a better transition out of the head, not unlike a stub tube, and certainly somewhat similar in length.

Regardless, the numbers are what they are, and the comparison with 'old style' raised ported configuration should be a valid comparison.

Thanks for sharing the information. I cant wait to see the comparison.

Buddy Rawls "
Logged

1990 Red LX, 306, 75MM, ported gt40's, Holley SMII, accufab longtubes, 3" exhaust, 4.10's, 318RWHP/316RWTQ
1985 LTD LX 302, ported TW's, XE-264 cam, ported Holley SMII, 75MM-R TB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
David Claflin
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 7862


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #70 on: October 22, 2013, 08:42:35 am »

Ray sent me the info for the heads I called stage 1, sort of a tongue in cheek label, but it helped me keep it straight. These heads had the pinch opened up a little and then bowl and throat work done. Some work was done in the port, but only to keep the smallest part at the pinch. I found that when I opened it up at the pinch it made smallest part of the port close to the apex. The exhaust bowls were pretty much the same between this one and the first one, only thing I did on this was raise the roof a little. These were the heads that I cut down the valve guides, I don't know if that's why the flow dropped off compared to the other or not. I'll have retake the measurements on the short turn on this one compared to the first one and see if there was a difference somewhere.


* GT40 stage 1 intake flow.JPG (609.37 KB, 1296x968 - viewed 352 times.)

* GT40 stage 1 exhaust flow with header.JPG (657.23 KB, 1296x968 - viewed 311 times.)
Logged

1990 Red LX, 306, 75MM, ported gt40's, Holley SMII, accufab longtubes, 3" exhaust, 4.10's, 318RWHP/316RWTQ
1985 LTD LX 302, ported TW's, XE-264 cam, ported Holley SMII, 75MM-R TB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
Outlaw Bill
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 4756


Location: Canton, Michigan

« Reply #71 on: October 22, 2013, 04:31:09 pm »

Short turn and roof on the intake port.
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: 7862


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #72 on: October 26, 2013, 09:52:31 pm »

Got the info from Ray about the ones that have the most port work done to them. I still think the port with the least work to it flows the best. The exhaust here on this one had the shorty header on it too.


* GT40 stage 2 intake port flow.JPG (502.88 KB, 1296x968 - viewed 311 times.)

* GT40 stage 2 exhaust port flow with shorty header.JPG (574.53 KB, 1296x968 - viewed 300 times.)
Logged

1990 Red LX, 306, 75MM, ported gt40's, Holley SMII, accufab longtubes, 3" exhaust, 4.10's, 318RWHP/316RWTQ
1985 LTD LX 302, ported TW's, XE-264 cam, ported Holley SMII, 75MM-R TB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
David Claflin
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 7862


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #73 on: November 11, 2013, 09:08:52 pm »

Ray took the sectioned head and flowed it, before doing a valve job on it. I'm posting the original numbers again for reference only.

94
157
192
218
228
240
244
245
245

Flow numbers with a 45 degree backcut only
92
160
190
218
228
238
244
246
250

With the previously mentioned 45, and a 30 degree backcut
98
154
192
215
229
244
247
251
249
Logged

1990 Red LX, 306, 75MM, ported gt40's, Holley SMII, accufab longtubes, 3" exhaust, 4.10's, 318RWHP/316RWTQ
1985 LTD LX 302, ported TW's, XE-264 cam, ported Holley SMII, 75MM-R TB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
David Claflin
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 7862


Location: Redneck Riviera (Ft Walton Beach Florida)

« Reply #74 on: November 24, 2013, 12:45:43 pm »

I'm thinking I'll give this a whirl for blocking the EGR port in the one exhaust bowl, supposed to be good to 2,000 degrees.
http://www.acehardware.com/product/index.jsp?productId=1445566&cp=2568443.2568453.2627947.2627970.2627964
Logged

1990 Red LX, 306, 75MM, ported gt40's, Holley SMII, accufab longtubes, 3" exhaust, 4.10's, 318RWHP/316RWTQ
1985 LTD LX 302, ported TW's, XE-264 cam, ported Holley SMII, 75MM-R TB, MAC 1 3/4" longtubes, 4R70W, mach 1 brakes
1988 GT long term project
Pages: 1 ... 3 4 [5] 6 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