Generation III External Engine LS1 | LS6 | Bolt-Ons | Intakes | Exhaust | Ignition | Accessories
Sponsored by:
Sponsored by:

Header 'flange' flatness?

Thread Tools
 
Search this Thread
 
Old 10-16-2002, 01:14 PM
  #1  
TECH Apprentice
Thread Starter
 
J'sRamAir's Avatar
 
Join Date: Nov 2001
Location: Lexington, SC
Posts: 350
Likes: 0
Received 0 Likes on 0 Posts

Default Header 'flange' flatness?

I sent out my MAC headers to get ceramic coated ($135 total including shipping both ways through Speed, Inc., FYI) and when I got them back I decided to check and see how flat the flanges were. I failed to check the flanges before I sent them off so I don't know if they were already like this or they got dinged during shipping. I'm not sure of the techincal name, but I'm calling them flanges. I'm talking about the part of the headers that bolts directly to the engine. Anyway, I placed a 12" steel ruler against the flanges and it looks like there is about a .075" gap in one place and about .030"-.040" in other places (eyeballing here). .075" seems waay too much to me. I figure these flanges will conform a little to the heads once you bolt them down, but I don't think they will conform THAT much. Do these flanges need to be perfectly flat or is there a tolerance of some amount? I know a guy that does machine work on a lot of car parts so I may be able to get them perfectly flat, but I wanted to get some opinions here first. Thanks guys.
Old 10-16-2002, 10:29 PM
  #2  
wrencher
iTrader: (2)
 
wrencher's Avatar
 
Join Date: Aug 2002
Location: Chicagoland
Posts: 4,762
Likes: 0
Received 0 Likes on 0 Posts

Default Re: Header 'flange' flatness?

If they are not flat I would have it done. I had a prob on my BBC & ended up getting new headers. They were off alot more though like .150ish.
Old 10-18-2002, 12:55 AM
  #3  
TECH Apprentice
Thread Starter
 
J'sRamAir's Avatar
 
Join Date: Nov 2001
Location: Lexington, SC
Posts: 350
Likes: 0
Received 0 Likes on 0 Posts

Default Re: Header 'flange' flatness?

Surely someone else has an opinion on this?
Old 10-18-2002, 06:39 AM
  #4  
TECH Enthusiast
 
01 SS Jay's Avatar
 
Join Date: Nov 2001
Location: Richmond, Va
Posts: 543
Likes: 0
Received 0 Likes on 0 Posts

Default Re: Header 'flange' flatness?

I cant imagine .075 causing a problem, especially after tighten it down.. I suppose what it boils down to is get them fixed so you dont have to worry about it, or put them on and possibly have to take them off and spend the cash anyway. How much spare time do you have?
Old 10-18-2002, 10:01 AM
  #5  
TECH Junkie
 
GeorgeC's Avatar
 
Join Date: Nov 2001
Location: Melbourne, FL
Posts: 3,987
Likes: 0
Received 0 Likes on 0 Posts

Default Re: Header 'flange' flatness?

You shouldn't have a problem. Once you get the headers in place and start to tighten them down, everything should fall into place. Sure, it would be more desireable for the flanges to be perfectly flat, but they usually aren't. There is enough flexibility in the header tubes themselves to take up the ~.075" gap you're talking about.
Old 10-18-2002, 10:43 AM
  #6  
TECH Junkie
iTrader: (3)
 
11 Bravo's Avatar
 
Join Date: Nov 2001
Location: Republic of Texas
Posts: 3,078
Likes: 0
Received 1 Like on 1 Post

Default Re: Header 'flange' flatness?

Dude, you've had those Macs for 9 months, get those bad boys on <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> Did you have them Jet Hot coated?
Old 10-19-2002, 12:57 AM
  #7  
TECH Apprentice
Thread Starter
 
J'sRamAir's Avatar
 
Join Date: Nov 2001
Location: Lexington, SC
Posts: 350
Likes: 0
Received 0 Likes on 0 Posts

Default Re: Header 'flange' flatness?

I know that the header bolts aren't tightened down very much (11lb/ft on one pass 18lb/ft on the next) and I guess that just didn't seem like enough torque to straighten them out. Of course once they heat up some they may bend a little. The worst bend is right on the end of the flange (last cylinder on drivers side)...I wasn't sure if that would make things worse or not. I'd really rather not have them machined since they are already coated, but I don't want to have to take them back off if I have a leak. Oh well, I'll make a decision somehow. Maybe I'll try to straighten them out myself.

Mike: I'm slow ain't I! I've been buying lots of other parts which is why I don't have these on yet. I'm going to try to get them on next weekend. I didn't send them to Jet-Hot, but they were ceramic coated. They look nice!



Quick Reply: Header 'flange' flatness?



All times are GMT -5. The time now is 11:55 AM.