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Can thermactor passages be drilled...

  • Thread starter Thread starter Bigstang1
  • Start date Start date Dec 18, 2003
B

Bigstang1

Founding Member
Aug 28, 2002
415
0
16
Massachusettes
Dec 18, 2003
#1
  • Dec 18, 2003
  • #1
Can thermactor air pump passages in gt40p heads be drilled and tapped by an ordinary machine shop? Or does it have to be an automotive machinse shop? I have a friend with a machine shop and was just wondering before i ask him thanks
 

tmoss

Gettin Wired
Founding Member
Jun 28, 2001
7,153
32
128
Saint Louis, MO
Dec 19, 2003
#2
  • Dec 19, 2003
  • #2
I would think any machine shop that is good could do it.
 

BlackFox5.0

Founding Member
Aug 7, 2000
3,514
1
0
Massachusetts
Dec 19, 2003
#3
  • Dec 19, 2003
  • #3
Yeah, don't worry about it, i don't have any problems without EGR I still pass emissions
 

Lxpony

Founding Member
Mar 30, 2001
355
0
17
central mass
Dec 19, 2003
#4
  • Dec 19, 2003
  • #4
hey, I just got GT40P heads- can someone tell me what the rear of the heads should look like if they are emissoins legal?

my heads have the cap in the rears on both--
 

BlackFox5.0

Founding Member
Aug 7, 2000
3,514
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0
Massachusetts
Dec 19, 2003
#5
  • Dec 19, 2003
  • #5
P's do not have EGR if they are P's then you can't tell....

If they are GT40s, then you should have a hole in the back of the head, and a hole at the end of the insides of the exhuast ports....which is what this thread is about
 

Lxpony

Founding Member
Mar 30, 2001
355
0
17
central mass
Dec 19, 2003
#6
  • Dec 19, 2003
  • #6
no actually this head is about GT40P heads isnt it?
 

BlackFox5.0

Founding Member
Aug 7, 2000
3,514
1
0
Massachusetts
Dec 19, 2003
#7
  • Dec 19, 2003
  • #7
yes, I was referring to the thermactor holes in the exhuast ports, which is what Bigstang1 is asking if he can drill his own
 

tmoss

Gettin Wired
Founding Member
Jun 28, 2001
7,153
32
128
Saint Louis, MO
Dec 19, 2003
#8
  • Dec 19, 2003
  • #8
I have P heads with thermactor holes - but they were drilled in there and tapped.
 
B

Bigstang1

Founding Member
Aug 28, 2002
415
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Massachusettes
Dec 20, 2003
#9
  • Dec 20, 2003
  • #9
Arite i will ask him soon if he can drill them but i will need to know where to drill to. There is just one tapped hole in the back of the head that goes to the rear exaust port only? if somone could explain that would be excellent. thanks
 

tmoss

Gettin Wired
Founding Member
Jun 28, 2001
7,153
32
128
Saint Louis, MO
Dec 20, 2003
#10
  • Dec 20, 2003
  • #10
the hole goes all the way through the head - that is the channel that the bumps in the ehaust port feeds in each exhaust runner. A good machinist will know what to do.
 

MustangPunk302

Founding Member
Sep 11, 2002
1,051
0
36
West Michigan
Dec 20, 2003
#11
  • Dec 20, 2003
  • #11
Alright I think some people are getting confused. He is asking about the exhaust gas passage for the Smog pump system. (themactor system) Any decent machine shop should be able to drill the themactor passage since GT-40P's do not come with the thermactor hole drilled (if the casting itself allows this). The EGR system is different then the Themactor system though both deal with exhuast gas and emission controls. The EGR passges are present in most GT-40P heads (I believe later castings do not have it), if you look in the number 2 and 6 exhaust ports you can see the egr passages which go through the head and into the intake. Both the EGR passages and Thermactor holes can be drilled if the castings allow which I'm sure they will.

I have a question regaurding the EGR passages, what is the best way to fill them? Since I plan on deletling the EGR system and using non-egr intakes I figure fill the passages in the head to, do they hurt flow much? Thanks.
 
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