Extrude hone - to do or not?
 

Interested in hearing any comments on the topic from people with experience with it.
Thanks much
Tad

Are you running carbs or FI?

FI here, and also interested in it.

extrude hone
 

FI
thanks

From what I've read, you need to get some feedback on who's doing it. Some parts have been mauled, while others do a great job with it.

I was told not to do it for a carbed engine.

I'm considering doing my 930 intake when I go to EFI, from what I understand it helps equalize the flow to each cylinder. I think the benefit depends a lot on the original design of the intake. The guys from TurboKraft are members of this board and post in the 930 forum, they may be able to offer some insight.

http://www.turbokraft.com/catalog/im...an_Extrude.jpg

It always seemed like a lot of money that could be better spent somewhere else. If you've done everything else then sure, go for it.

MO is all the early euro intakes (FI) were sand cast aluminum (cheap) but hard to control internal runner size/volume because most were cast as two pieces then mated. Looked pretty good from the outside but inside I've seen mis-matched joints and rough casting seams.

If you are looking to improve performance overall, then this would be a great addition as the process mostly equalizes runner volume, which even in a mild street motor makes a big difference in tuning

The Carcraft articles mentioned a rough surface in a carb'd intake creates tubulence and improves mixture.
Not sure what the trade-offs would be, or if that limits overall flow: aka the golf ball therory.

Port matching/beveling with a grinder would probably be a good first step, or manifolds designed for desired operational rpm range.

I think some of it depends on where you want to make power. A rough surface is supposed to be better to low end torque whereas a polished surface is good for high RPM HP. The surface of the runners after extrude honing isn't perfectly smooth as the abrasive putty they use is pretty aggressive.

The idea has always struck me as gimmicky. ...somehow a blob of grit is supposed to magically make a better pathway than what the engineers (and their testing & computational fluid dynamics) came up with.


That is, simply opening up the tube might sound smart (for some) but really, there is more involved with efficient intake than just a high flow number.

I had my 88 3.2 Extrude Honed. Also had other stuff done(motor rebuild) so it is hard to tell
if just that alone made a difference. I had EBS flow match and rebuild injectors, Steve Wong
Chip, Fabspeed Pre Muf and dual out muffler.This with the rebuild has been a very good motor,
runs great and the one thing I have noticed most is that is runs cool, I mean temp needle stays
about mid point all the time, AND I live in Louisiana with 100 degree temps with 95 percent humidity all summer.Don't know if that means anything,but I like it !

to do or not...
 

Thanks for all your input, much appreciated.
Cheers