[Subscribe to Daily Digest] |
 | [Main Performance Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: Sorry, I meant just piston RING set. nm. Posted by 900 Aero [Email]  (#425) [Profile/Gallery]
(more from 900 Aero) on Thu, 15 May 2008 09:38:07
In Reply to: Sorry, I meant just piston RING set. nm., Pat98, Thu, 15 May 2008 00:07:35 Members do not see ads below this line. - Help Keep This Site Online - Signup |
First of all ring end gap can be more than stock spec's as long as it's not way over spec. In other words .65mm (.0255") isn't really too much especially for a turbo application! Also your cylinder is probably a tiny bit smaller further down the bore which would of course lessen the end gap when the piston is in that area. The important thing is that the second ring has to have at least the same more end gap than the top otherwise pressure will be trapped between the 1st and 2nd rings causing them to flutter and therefore not seal as well as they could. Keith Black designed pistons that have a chamber machined in between the two so what pressure does get past the top ring will have a place to expand into. This is why a total seal 2nd ring is not the way to go! The reason the "OE" ring prices are so high is because their top ring is of a ductile material for a turbocharged engine which is as you said a chrome face. The 2nd ring doesn't have to be and isn't ductile as it's shielded from the heat by the top ring. The reason you'll find a set for $79 is because they are not suitable for a turbo charged engine even though they are a well made ring set (I know the manufacturer). There are lots of great suppliers out there that sell these particular inexpensive rings but they just don't realize that the material isn't right for a turbo application. Hastings has the same good rings that we used from Sealed Power for years when they were available that are a chrome faced ductile top with the right second ring design (it's called a reverse torsion twist if I remember correctly) and a good oil control ring. Dave
posted by 204.16.14...
, Mon, 19 May 2008 05:06:39, Thu, 15 May 2008 09:38:07 <-- Viewing This Message, Thu, 15 May 2008 13:47:52
, Fri, 16 May 2008 12:25:58, Sat, 17 May 2008 10:17:00
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
