Twin-plug /4 motors...(pictures) |
|
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. |
|
Twin-plug /4 motors...(pictures) |
Mueller |
Jul 30 2003, 10:48 AM
Post
#1
|
914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None |
This is a Type I head, but it'll give you an idea for the 914 /4 motors.
Paul Guard, of Guard Transmission (maker of bitch'n parts for Porsche transmissions) loaned me this head to get an idea on how to twin-plug my motor. The secondary plug is a 10mm motocycle plug. A modified distributor cap from a Nissan 4 cyl truck engine is adapted to fit on the stock /4 distributor...the rotor is from Nissan as well. I have the drawings for this modification somewhere in my garage (IMG:style_emoticons/default/smile.gif) Using an aftermarket distributorless ignition would be ideal, but for cost savings, the above will work. There is a company that'll machine these heads for about 300 dollars or so (they do this for aircraft...not for performance, but for redundancy (saftey)) The sockets in the head are to give you an idea of the angles. Attached image(s) |
aufaber |
Jul 31 2003, 12:49 PM
Post
#2
|
Member Group: Members Posts: 190 Joined: 7-April 03 From: Huntington Beach, CA Member No.: 525 |
QUOTE(J P Stein @ Jul 30 2003, 09:33 AM) Not to be redundant, but....Mueller is talking airplanes which have 2 seperate ignition systems....magnetos, me thinks. The down side of twin plugs & high compression is if one plug fails and the other keeps on firing, detonation will occur, you may not notice and keep on truckin'. At some point, you will notice the hole in your piston, tho. Hey Rich, maybe I'm off here, but what would twin plugging have to do with detonation? Detonation is cused by lean or overly hot conditions in the cylinder the air fuel mixture to ignite at teh wrong time, right? Wouldn't an extra plug actualy make this worse since youy have another thin piece of metal to over heat and preignite the mixture? As I understadn it the reason you twin plug is if you are going to run very high compression or boost pressures where your plug gaps must be very small to fire at all. Plus you gives you a more complete burn on in the right part of the downward run of the piston. |
Lo-Fi Version | Time is now: 2nd June 2024 - 04:04 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |