 one cure for small chamber syndrome, something I whipped up |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
| brer |
 Jan 18 2008, 11:08 AM
Post
#1
|
|
Advanced Member  Group: Members Posts: 2,555 Joined: 10-March 05 From: san diego Member No.: 3,736 Region Association: None  |
I'm working on a head program for guy here in SD. He had a similar problem I believe a member here had, and that was his chambers were too small for his 2056cc engine. (edited, he's using a 71mm crank and 96mm slugs)
Facing large barrel shimming, which he didn't want, I worked this up for him. perfect 60cc chambers, his non 2.0L heads will now install with a .045 shim , he has a zero deck, giving (I believe) a 8.5:1 compression ratio. This method of modifying heads results in perfectly matched chambers (and ports for him), so when he gets them back they will technically be blueprinted to within .001". not a 2.0L head granted, but thats sometin else and this is within his budget. Attached image(s) 
|
   |
 
|
  |
Replies
| brer |
Feb 22 2008, 11:41 PM
Post
#2
|
|
Advanced Member Group: Members Posts: 2,555 Joined: 10-March 05 From: san diego Member No.: 3,736 Region Association: None |
I've been playing with video and thought I'd post this of the head machining. Better than TV in person, but on video? not so sure.
After the seats were installed in these heads, and in most, there was a fairly uneven lip where the seat was proud or recessed into the chamber floor. The initial roughing of the chamber looked nice, but still hadn't cut deep enough to totally clean the chamber floor, leaving areas of the orginal chamber showing. So after the seats where installed I zeroed the table and ran the program again on both heads one after the other. By running both on the same talble and setup sequentially, without adjusting the height between the heads it was possible to see how different the chambers on this matched set of heads was. One removed a good .020" more from the base of the chamber while the other just kissed it, worrying to watch! After both chambers were finished with the final passes and all the seats were then totally flush with the chamber floors they were moved to the next station and bored and surfaced. It was only during the surfacing that it was possible to see that the chambers were no where near identical. Both heads cleaned up to exactly the same depth when surfacing while there was that frightening .020" difference in the floor of the chambers. In the end these ended up exactly the same without a doubt, and the seats are flushed and should make an easy valve job. sorry for the SHAKY VIDEO but the camera is the size of a pack of smokes. Attached image(s) 
|
|
|
|
Posts in this topic
brer one cure for small chamber syndrome Jan 18 2008, 11:08 AM
Jake Raby Looks like that chamber would have interesting que... Jan 18 2008, 12:02 PM brer I figured someone would have seen the design befor... Jan 18 2008, 12:22 PM Jake Raby
I consider that a perfect chamber volume for a w... Jan 18 2008, 12:25 PM Phoenix 914-6GT I just thought that people who have small chamber ... Jan 18 2008, 12:56 PM
lotus_65
I just thought that people who have small chamber... Feb 23 2008, 08:11 AM brer 44x38 valves. Jan 18 2008, 03:14 PM brer 2 revisions later, this is how they look... Jan 23 2008, 11:28 PM sean_v8_914 ...major wood..oh wait, thats metal. Jan 24 2008, 12:33 PM brer i'll bring it along to your gig sean.
open th... Jan 24 2008, 01:31 PM 2-OH! brer:
With that much meat removed, and the histor... Jan 24 2008, 02:02 PM brer
brer:
With that much meat removed, and the histo... Jan 24 2008, 02:57 PM brer Since jake mentioned it, and out of curiosity I ca... Jan 28 2008, 09:55 PM Jake Raby And the spark plugs are .100" closer to the c... Jan 28 2008, 10:13 PM brer forgive me for repeating things other people tell ... Jan 28 2008, 10:27 PM alpha434 Lol.
Your machinist. Who is he? Feb 23 2008, 08:21 AM brer Hi Alpha. :wavebye:
I built the models, I bui... Feb 23 2008, 10:20 AM brer I hope you're laughing at the jokes and not my... Feb 23 2008, 10:45 AM brer I should give kudos to this special tool Don makes... Feb 23 2008, 03:17 PM Jake Raby That tool is in my box too... Its made by the guys... Feb 23 2008, 06:56 PM |
2 User(s) are reading this topic (2 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 11th May 2025 - 02:10 AM |
Invision Power Board
v9.1.4 © 2025 IPS, Inc.