Ebay/OBX style header install w/plenty of PICS (LONG, but detailed)
Jun 21, 2010 | 05:23 PM
#161
sure they "should" be, but their not... Headers are made out of tubing and not pipe. Tubing is measured by the OD and Pipe is measured by the ID. Sure it would be nice for them to be measured and advertised by the ID since that is where all the flow is but it just makes things even more confusing. Especially for anyone working in an industry that deals with OD's and ID's day in and day out.
Whether they are supposed to be or not, every Gen3/4 LSx header that has come through thsi shop has been measured OD....I just now verified this on Pacesetter, Kooks, ARH, and Dynatech headers to be sure. The only ones that varied slightly were the TSP coated headers and Pacesetters due the slight extra thickness of the coating....the stainless headers were all spot on by the OD. AND....Not only do the primaries measure correctly by the OD, so do the collectors! 
Jun 21, 2010 | 07:47 PM
#162
Thread Starter
11 Second Club
iTrader: (42)
Joined: Nov 2005
Posts: 1,643
Likes: 4
From: Baltimore, MD.
As for the whole ID vs. OD debate going on, all I can tell you is that I measured and passed along the true INSIDE diameter measurement, strictly for informational purposes in this thread. I guess if we are supposed to go by OUTSIDE diameters on header tubes, than these are 1-3/4".
Jun 21, 2010 | 07:55 PM
#163
Thread Starter
11 Second Club
iTrader: (42)
Joined: Nov 2005
Posts: 1,643
Likes: 4
From: Baltimore, MD.
But just for the record, and to clarify MY actual inside diameter measurement...
The Ebay seller advertises these headers as 1-3/4" INSIDE DIAMETER, as per their auction picture, which is NOT correct...
The Ebay seller advertises these headers as 1-3/4" INSIDE DIAMETER, as per their auction picture, which is NOT correct...
Jun 21, 2010 | 08:06 PM
#164
Jun 21, 2010 | 10:22 PM
#166
Has anyone else had a sealing problem around the collectors? I'm getting a loud annoying tick coming from the collector area, but I don't feel any leaks or see any black marks. How tight did yall get that donut gasket? I have about 1/4 inch all the way around the flange.
Jun 22, 2010 | 05:57 AM
#168
Has anyone else had a sealing problem around the collectors? I'm getting a loud annoying tick coming from the collector area, but I don't feel any leaks or see any black marks. How tight did yall get that donut gasket? I have about 1/4 inch all the way around the flange.
Yes, i had my Summit 3'' cat back installed, bolted right up.
Jun 22, 2010 | 08:20 AM
#169
Has anyone else had a sealing problem around the collectors? I'm getting a loud annoying tick coming from the collector area, but I don't feel any leaks or see any black marks. How tight did yall get that donut gasket? I have about 1/4 inch all the way around the flange.
These bolted right up to the exact same location as my stock exhaust. I didn't have to move or redo my aftermarket setup. I am having a sealing problem at the ball and cup joint or whatever it's called. I am just going to cut the section out and put in an electric cutout.
Jun 22, 2010 | 09:33 AM
#170
Does his add say ID? Or is it just that drawing? The average consumer wouldnt flinch at that drawing and would just assume it means the primary is 1.75", without giving that much attention to ID vs OD measurements. If they drew that line up on the primary a few inches after the flange, they'd just get a ton of calls asking what size they were and what the drawing meant (I say this from experience, they'd call about that one).