PDA

View Full Version : 3.1 Exhaust Flanges

BigRandCarFan_5
11-24-2007, 08:46 PM
Hey everyone.
I'm curious if anyone knows what the shape of the exhaust ports on the 3.1L V6 from a 95 GA are? And what the dimensions are?
I'd like to know as I'm going to be undertaking a custom header project for my welding class in College, and I'd like to know so I can plan ahead for all eventualities.
Thanxs for your help eveyone.
TA^Guy
11-24-2007, 10:07 PM
If they are the same as 3400 heads I can get you a photo and information tomorrow.
BigRandCarFan_5
11-25-2007, 09:11 AM
I'm not sure if they're the same or not. I have a friend who says that a 3100 can use headers for a 3400 because the ports are the same.
But in some pictures I've seen of 3100 stock exhuast manifolds, the ports actually look for one reason or another, sextagonal(7 sided shape).
I have a feeling they are the same shape as a 3400, but I just wanted to check with everyone else to see if they knew.
But if you could get pictures of both 3100 and 3400 exhust flanges and ports, that'd be very much appreciated TA^Guy.
Thanxs for your help, again I really appreciate it.
DomestikDemon
11-25-2007, 11:16 AM
The 3400 has a somewhat "D" shaped port....I think the OBD II 3100 are the same, but Im not sure
Big Joe
11-25-2007, 11:28 AM
I'm not sure if they're the same or not. I have a friend who says that a 3100 can use headers for a 3400 because the ports are the same.


You can use 3400 headers, but they will fit the engine and not the car. You will have firewall clearance issues with the 3400 headers. There was a guy on 60degreev6.com that was selling flanges. This was a while ago I don't know if he still is. IIRC they are D shaped ports like said above.
Korbendallas68
11-25-2007, 04:25 PM
The 3400 has a somewhat "D" shaped port....I think the OBD II 3100 are the same, but Im not sure

No such thing as a ODBII 3100 (Though I understand what you meant). 1996 had OBDII controlled 3100, but still had the smaller ports.

The 3100 changed in '00 to larger ports which are the same size as the 3400's.
TA^Guy
11-25-2007, 05:30 PM
Took my kids out shopping today, came home and made a big dinner. If I can step out in teh freezing cold in a it to take a few photos I will.