Home port/polish Explorer U/L + GT-40 irons.

Falcons Talon · 08-25-2003, 08:51 AM

I finally scored a set of gt-40 irons off of a 94 cobra for a great price. I already have the Explorer intakes, and now I have to get started on some home porting and polishing. I do have a few questions.

First, I have an electic drill. Is this the kit that I want to use for the work port/polish bits, or should I get a dremel and a similar kit? If I get a dremel, is the 35,000 rpm variable speed the one I want or can I gat away with a single speed?

Second, Is there a definitive guide on home porting/polishing. I already did the search and found some info on cleaning out all the flashing, opening/smoothing out the exhaust port, gasket matching, and not polishing the intake runners because of turbulence needed...

Third, did anyone feel like they were about to "screw the pooch" when working on their first port/polish job? I've been putting it off because I'm a little afraid that I'll mess something up, but I don't trust anyone else to work on the stuff. I don't want to just bolt and go to have to come back later to squeeze evey last ounce out of it.

Thanks guys.

Falcons Talon · 08-25-2003, 09:01 AM

In fear of derailing this thread, please don't give me this advice.

How to port/polish an Audi.

88workcar · 08-25-2003, 05:28 PM

I have ported a few sets. Results were great. I also have a GT-40 iron head, totaly ported and big valves. You want it? The other was trashed in a bad way.

Coupe50h · 08-26-2003, 12:54 AM

The guys at the machine shop told me you cant go real deep on gt-40's cuz of water passages, if i were you i would just clean up the intake side, and cut out a good amount on the exhaust and polish smooth).
my intake was hogged out, carved on the upper inlet, and opened up the lower pretty good, on the lower part of the runners they made a swirl rough polish for turbulence.
I would recomend a 3 angle valve job also.

red82gt · 08-26-2003, 01:21 AM

Don't mess with the floor of the port and don't mess with the short turn radius, these are the most critical areas to avoid screwing up on. Fox lake found a ton of flow out of my heads and the car dynoed at 288.7 rwhp @6000 and 313 ft/lbs of torque at 3800rpm last friday. This is on a stock 302 short block and with only 8.75:1 compression (damn 65 cc combustion chambers

)

Coupe50h · 08-26-2003, 03:41 AM

red82, i have the same problem with my heads....low compression (good for blower)

....but i heard different about the 'floor' especially the intake floor because that is where your flow turbulence is....but oh well...im no expert.....

88workcar · 08-26-2003, 06:37 AM

Well the one head I have left is ported quite well, very professional. One of the big badass shops acually ported the ones I have. The car they came off of had a WR1087, and a big hit of spray. It ran 10s.

tmoss · 08-26-2003, 07:25 AM

Don't fret about working on the floor or short side radius - the short side of the head and the intake and lower intake runner roof where it turns into the lower are actually where you'll find some more flow. Just don't get carried away.

I have a bunch of ported intakes out there - stock lower and Cobra style lowers - on Stangnet,Corral,50Tech and maybe one or two from this site. Rather than buy all those rolls, I'd suggest buying a couple of "double cut" carbide burs for both the heads and intake. If you don't use much pressure on the bits the bite soft and don't take a bunch of metal out. Just take your time - you got plenty of that - go to:

www.carbidebur.com

get one "Flame (SH)" and one "Taper (SL)" bit in a 3/8" diameter.

go to www.veryuseful.com/mustang/tech/engine

and download my basic instructions on porting an intake. Taking measurements with the tools I recommend will keep you from breaking through of the runners.

red82gt · 08-26-2003, 11:00 PM

For a rookie, the floor probably isn't too bad, but the short side radius can give you a dead port if you don't understand airflow and take too much out of it
Coupe5oh, I've been playing with the idea of a blow thru turbo or supercharger, was leaning towards the turbo but they are so finicky and it's a lot easier to just buy the paxton kit than to have to fabricate all the turbo plumbing. Oh well, maybe I'll just bottle it.

tmoss · 08-27-2003, 04:59 PM

It is usually better to let a pro do porting, but the stocl lower is so ripe for improvement it would be hard to screw up. If you use a good internal snap guage or internal calipers set combined with an exxternal caliper set to keep track of wall thickness and aim to equalize the runner cross section (internal runner size), it's hard to go too wrong - unless you get carried away and do not measure as you go - follow my instructions and you should be OK.

08-25-2003, 08:51 AM	#1
Falcons Talon T.P.M. President Join Date: May 2002 Location: Brownsville Posts: 265	Home port/polish Explorer U/L + GT-40 irons. I finally scored a set of gt-40 irons off of a 94 cobra for a great price. I already have the Explorer intakes, and now I have to get started on some home porting and polishing. I do have a few questions. First, I have an electic drill. Is this the kit that I want to use for the work port/polish bits, or should I get a dremel and a similar kit? If I get a dremel, is the 35,000 rpm variable speed the one I want or can I gat away with a single speed? Second, Is there a definitive guide on home porting/polishing. I already did the search and found some info on cleaning out all the flashing, opening/smoothing out the exhaust port, gasket matching, and not polishing the intake runners because of turbulence needed... Third, did anyone feel like they were about to "screw the pooch" when working on their first port/polish job? I've been putting it off because I'm a little afraid that I'll mess something up, but I don't trust anyone else to work on the stuff. I don't want to just bolt and go to have to come back later to squeeze evey last ounce out of it. Thanks guys. __________________

08-25-2003, 09:01 AM	#2
Falcons Talon T.P.M. President Join Date: May 2002 Location: Brownsville Posts: 265	In fear of derailing this thread, please don't give me this advice. How to port/polish an Audi. __________________

08-25-2003, 05:28 PM	#3
88workcar Registered Member Join Date: Oct 1999 Location: Pierre Part, La. U.S.A. Posts: 1,850	I have ported a few sets. Results were great. I also have a GT-40 iron head, totaly ported and big valves. You want it? The other was trashed in a bad way. __________________ 88workcar 1988 Mustang LX 342. 417rwhp @ 6800. 28 X 10 ET Drag, 4.30s, 10.69 @ 126.43 1.42 60ft. 11.13 @ 127.7 on BFGs 1.72 60ft Rice Hater # 42 To be old and wise, You must first be young and stupid I'm somewhere in tthe middle.

08-26-2003, 01:21 AM	#5
red82gt Sober voice of Reason Join Date: Nov 1998 Location: Kelowna, B.C., Canada Posts: 1,514	Don't mess with the floor of the port and don't mess with the short turn radius, these are the most critical areas to avoid screwing up on. Fox lake found a ton of flow out of my heads and the car dynoed at 288.7 rwhp @6000 and 313 ft/lbs of torque at 3800rpm last friday. This is on a stock 302 short block and with only 8.75:1 compression (damn 65 cc combustion chambers ) __________________ 393W: AFR 205's, hydraulic roller, TKO600.

08-26-2003, 03:41 AM	#6
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	red82, i have the same problem with my heads....low compression (good for blower)....but i heard different about the 'floor' especially the intake floor because that is where your flow turbulence is....but oh well...im no expert..... __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

08-26-2003, 12:54 AM	#4
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	The guys at the machine shop told me you cant go real deep on gt-40's cuz of water passages, if i were you i would just clean up the intake side, and cut out a good amount on the exhaust and polish smooth). my intake was hogged out, carved on the upper inlet, and opened up the lower pretty good, on the lower part of the runners they made a swirl rough polish for turbulence. I would recomend a 3 angle valve job also.

08-26-2003, 06:37 AM	#7
88workcar Registered Member Join Date: Oct 1999 Location: Pierre Part, La. U.S.A. Posts: 1,850	Well the one head I have left is ported quite well, very professional. One of the big badass shops acually ported the ones I have. The car they came off of had a WR1087, and a big hit of spray. It ran 10s. __________________ 88workcar 1988 Mustang LX 342. 417rwhp @ 6800. 28 X 10 ET Drag, 4.30s, 10.69 @ 126.43 1.42 60ft. 11.13 @ 127.7 on BFGs 1.72 60ft Rice Hater # 42 To be old and wise, You must first be young and stupid I'm somewhere in tthe middle.

08-26-2003, 07:25 AM	#8
tmoss Registered Member Join Date: Mar 2003 Location: Saint Louis, MO Posts: 634	Don't fret about working on the floor or short side radius - the short side of the head and the intake and lower intake runner roof where it turns into the lower are actually where you'll find some more flow. Just don't get carried away. I have a bunch of ported intakes out there - stock lower and Cobra style lowers - on Stangnet,Corral,50Tech and maybe one or two from this site. Rather than buy all those rolls, I'd suggest buying a couple of "double cut" carbide burs for both the heads and intake. If you don't use much pressure on the bits the bite soft and don't take a bunch of metal out. Just take your time - you got plenty of that - go to: www.carbidebur.com get one "Flame (SH)" and one "Taper (SL)" bit in a 3/8" diameter. go to www.veryuseful.com/mustang/tech/engine and download my basic instructions on porting an intake. Taking measurements with the tools I recommend will keep you from breaking through of the runners. __________________ Tom (Torque) Moss 88Gt 5spd Vert, FLowmaster Catbacks, stock cam advanced 4° @ 108.5° ICL, NMRA prepped GT40P heads 1.85/1.55 valves and 1.7 rockers, MAC P headers Jet-Hot coated, 97 Exlporer intake (ported lower), TB and injectors. 277RWHP/330RWTQ (SAE). http://www.fastlanecars.com/

08-26-2003, 11:00 PM	#9
red82gt Sober voice of Reason Join Date: Nov 1998 Location: Kelowna, B.C., Canada Posts: 1,514	For a rookie, the floor probably isn't too bad, but the short side radius can give you a dead port if you don't understand airflow and take too much out of it Coupe5oh, I've been playing with the idea of a blow thru turbo or supercharger, was leaning towards the turbo but they are so finicky and it's a lot easier to just buy the paxton kit than to have to fabricate all the turbo plumbing. Oh well, maybe I'll just bottle it. __________________ 393W: AFR 205's, hydraulic roller, TKO600.

08-27-2003, 04:59 PM	#10
tmoss Registered Member Join Date: Mar 2003 Location: Saint Louis, MO Posts: 634	It is usually better to let a pro do porting, but the stocl lower is so ripe for improvement it would be hard to screw up. If you use a good internal snap guage or internal calipers set combined with an exxternal caliper set to keep track of wall thickness and aim to equalize the runner cross section (internal runner size), it's hard to go too wrong - unless you get carried away and do not measure as you go - follow my instructions and you should be OK. __________________ Tom (Torque) Moss 88Gt 5spd Vert, FLowmaster Catbacks, stock cam advanced 4° @ 108.5° ICL, NMRA prepped GT40P heads 1.85/1.55 valves and 1.7 rockers, MAC P headers Jet-Hot coated, 97 Exlporer intake (ported lower), TB and injectors. 277RWHP/330RWTQ (SAE). http://www.fastlanecars.com/

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