Subject: extrude honing? Author: shogun (moderator) : member since March, 2004 : 16325 posts Posted on: 2005-03-06 05:06:04

Have copied these info from another board:

The cheapest I can get for a Extrude Hone intake manifold is $450 from Ireland engineering (http://www.bmw2002.com/).
-------------------------------------------

Been watching on the sidelines as two guys went at it over the extrude honing process. So, I decided to do a little investigating of my own. Found the extrude hone website and actually called them up to inquire about the process. The sales guy initially tried to sell me all the tea in China. He recommended that I not only have my manifold extrude honed, but, also have my head and exhaust manifold extrude honed. He recommended this due to the fact that increased air flow from the manifold would tend to lean out the mixture in the combustion chambers. At higher rpm's piston ring and valve damage could occur, as well as a loss of power.
The total process, I figured, with shipping, would run me almost $1500. I don't think its worth that, so I have come up with a solution. Go to the Snap On Guy and buy a set of bottle brushes that are use for honing brake or engine cylinder bores. They specifically have long necks for this purpose. Then coat the inside of your manifold with a mild rubbing compound and using a two speed drill, go nuts. The bottle brush will not distort the inside surface, as it is specifically used to remove carbon and rust. And all one would need to do is mildly manuver the drill and measure to the thousandth with a dial indicator when finished. And then move to your exhaust manifold and do the same thing. After viewing the extrude hone process on the site, I find it hard to believe that aluminum parts will not be damaged when placed under that much stress. These are just my opinions, and I do not wish to start a war with anyone. Feedback is encouraged.
----------
end of quote

Hope that helps

shogun >>E32 750iL<< 11/88
7 series Tech tips
http://tinyurl.com/3486c

• 3251c intake manifold cleaning - bmwken 2005-03-04 14:30:54 (884 views)
  • extrude honing? - shogun 2005-03-06 05:06:04 (828 views)