Keith, Your carb might not be tuned correctly for the added load of 'driving' instead of the dyno run. I would suggest getting a Gunson Colortune (clear spark plug) and put it in No.1 cylinder and tune the engine for all RPMs with it (and remove when done tuning). Then go for a drive. IF you still have ping, try installing a simple water injection setup ... should help A LOT with ping. http://website.lineone.net/~da.cushman/misc/mannject.html - Water Injection from Down Under http://www.kuratrading.com/PDF/WaterInj.pdf - PDF downloadable version Sincerely, Greg Taylor :) <>< And the testimony is this, that God has given us eternal life, and this life is in His Son. He who has the Son has the life; he who does not have the Son of God does not have the life. - 1 John 5:11-12 --- On Tue, 6/24/08, Keith Evenson <epd@xxxxxxxxxxxx> wrote: From: Keith Evenson <epd@xxxxxxxxxxxx> Subject: [Amc-list] detonation To: AMC/Rambler@xxxxxxxxxxxxxxxx, owners@xxxxxxxxxxxxxxxx, "drivers and fans." <amc-list@xxxxxxxxxxxx> Date: Tuesday, June 24, 2008, 12:14 PM So this is the deal. As some of you may remember, I just had my 390 rebuilt and it dyno'd best with the timing at about 36 degrees adv. at 2500 rpm. Since I got it in the car I have been having some detonation issues. I was running 92 oct. (which is what I used at the dyno) and in the car it runs great but when I put it under some load it has what I am calling detonation. I have lower the timing a bit to about 34 degrees and I have used the NOS brand octane boost. Still getting the detonation. Yesterday I went to the local airport and put in 6 gal of 100 octane with the rest of the tank filled with 92. I am still getting the noise but it is not as bad. So should I go to a 50/50 mix or try lowering the timing more or is there something else anyone can suggest? I have run it with the vacuum advance disconnected and still getting it. I have this great new motor and I can only run it about 1/2 to 3/4 throttle so I want to DRIVE my car not just put around in it. HELP! Thanks, Keith Evenson -------------- next part -------------- An HTML attachment was scrubbed... URL: http://splatter.wps.com/pipermail/amc-list/attachments/20080624/b2b9f8fe/attachment.htm _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list -------------- next part -------------- An HTML attachment was scrubbed... URL: http://splatter.wps.com/pipermail/amc-list/attachments/20080624/67e34e73/attachment.htm _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list