 one cure for small chamber syndrome, something I whipped up |
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| brer |
 Jan 18 2008, 11:08 AM
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#1
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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) 
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| 2-OH! |
Jan 24 2008, 02:02 PM
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#2
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Senior Member Group: Members Posts: 552 Joined: 17-October 03 From: Santa Clarita, Kalifornication Member No.: 1,253 |
brer:
With that much meat removed, and the history of cracking around the spark plug holes, how do you think that configuration will hold up...Particularly if you open up the valve sizes... Also, will that much removed, how will it effect the valve/rocker geometry...It would appear that the valve stems will clear the other side of the guide by quite a bit more... 2-OH! |
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| brer |
Jan 24 2008, 02:57 PM
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#3
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Advanced Member Group: Members Posts: 2,555 Joined: 10-March 05 From: san diego Member No.: 3,736 Region Association: None |
QUOTE(2-OH! @ Jan 24 2008, 12:02 PM)  brer: With that much meat removed, and the history of cracking around the spark plug holes, how do you think that configuration will hold up...Particularly if you open up the valve sizes... Also, will that much removed, how will it effect the valve/rocker geometry...It would appear that the valve stems will clear the other side of the guide by quite a bit more... 2-OH! Spark plug depth on these heads hasn't changed, only the angle of deviation either side of the plug hole. These 1.7L heads are not as prone to cracking due to the fact that there is more material around the plug to act as a heat sink... this head still has a large bulk of alloy, more than a 2L, around that hole. The flat area of the chamber had less than .003" removed so your valve height will remain identical to stock... depending on the valve job you put on it of course, so rocker geometry with not change any more than a regular head rebuild which is nearly nothing. This head gains cc's by pushing down along the lower edge (similar to the 2.0), opening up several millimeters next to each valve and bowing back at the plug. more prone to cracking than a 2.0 head? Don and I discussed that and he feels this will not alter its lifespan much in relation to its performance. whats important is factoring the cost of a cherry set of 1.7 cores in relation to the performance gains. (IMG:style_emoticons/default/shades.gif) |
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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 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 brer I've been playing with video and thought I... Feb 22 2008, 11:41 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 |
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