View Single Post
911nut 911nut is offline
Metal Guru
911nut's Avatar
Join Date: May 2001
Location: Beverly Hills, Michigan
Posts: 2,524
Twin plugging is use on high compression N/A 911 engines because the piston dome cuts off half of the chamber, which retards the velocity of the flame front. The unburnt mixture on the other side of the dome then combusts in a uncontrolled manner which results in the pinging that can sometimes be heard.
As 125shifter stated, it stands to reason that the flat top pistons used in turbo motors have the same issues.
It's interesting that Porsche didn't use twin plugs on the 3.6 turbo engine. Could it be they didn't feel that the added complexity and expense were worth limited benefits?
Paul B.
'91 964 3.3 Turbo
Port matched, SC cams, K27/K29 turbo, Roush Performance custom headers w/Tial MV-S dual wastegates, Rarlyl8 muffler, LWFW, GT2 clutch & PP, BL wur, factory RS shifter, RS mounts, FVD timing mod, Big Reds, H&R Coilovers, ESB spring plates- 210 lb
Old 03-04-2008, 06:16 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #21 (permalink)