Spark Plugs and Ping, question |
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Spark Plugs and Ping, question |
jsayre914 |
Sep 30 2012, 04:18 PM
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#1
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Speed Up !!! Group: Members Posts: 3,188 Joined: 10-February 08 From: Timonium MD 21093 Member No.: 8,696 Region Association: MidAtlantic Region |
Engine is 2056 with Raby 9550 Cam and D-jet
I have the stock Bosch plugs with factory gap Running Pertronix with flamethrower coil Engine timing is dead on the nuts Valves adjusted 0 lash (chromoly with swivel feet) AFR is 12-13 on the freeway Fuel pressure is 30psi Car runs great and has a lot of power all the way up to the redline. Engine runs very cool, seems to be happy. I have noticed that on a longer drive pushing higher rpms for extended runs there is a tiny bit of pinging unless i push down or let off the throttle, it goes away. I know that any ping even a teeny tiny ping is bad. SO... I put Ultra Premium fuel instead of the midgrade and its still there. Keep in mind I might not hear it for a few days, but if I want to drive like I stole it for over an hour it can be heard. I would rather not retard the timing from spec, and I dont want octane booster. So I was reasearching plugs and found that some new plugs might do the trick. Question is do I want colder or hotter to cure my preignition. Is changing the plug my next step? A colder plug will help the preignition? Joseph (IMG:style_emoticons/default/beerchug.gif) |
brant |
Sep 30 2012, 06:20 PM
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#2
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914 Wizard Group: Members Posts: 11,622 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
12-13 at highway is pretty darn rich... thats WOT mixture.
I'm not sure that heat range in the plug will help with ping but maybe I don't know any better... when you say timing is dead on, what number is that for you? also I have found timing can very if a cheap or different timing light is used. I have one light that is crap and measure a different timing than another. so perhaps verifying timing with another light is not a bad idea too... your compression and temp. effect pre-ignition, so maybe lowering the combustion temp will help.. each different brand of spark plug uses a different system to designate hotter/colder. for example a bigger number means hotter in one brand and colder in another. |
jsayre914 |
Oct 1 2012, 09:56 AM
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#3
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Speed Up !!! Group: Members Posts: 3,188 Joined: 10-February 08 From: Timonium MD 21093 Member No.: 8,696 Region Association: MidAtlantic Region |
12-13 at highway is pretty darn rich... thats WOT mixture. I am driving 1 hour each way pretty much straight, with a lot of up and down hills. I am often @ WOT but when I am not it is closer to 14 QUOTE I'm not sure that heat range in the plug will help with ping but maybe I don't know any better... when you say timing is dead on, what number is that for you? 27 Degrees BTDC @3500 QUOTE also I have found timing can very if a cheap or different timing light is used. I have one light that is crap and measure a different timing than another. so perhaps verifying timing with another light is not a bad idea too... Will try another light to make sure, but my light is nice (IMG:style_emoticons/default/smile.gif) QUOTE your compression and temp. effect pre-ignition, so maybe lowering the combustion temp will help.. I didnt install the number gauge yet but My temps are AWESOME, even 1 hour of 80mph+ and flying past the other Porsches (IMG:style_emoticons/default/smile.gif) My gauge will stay on or just before the T in TEMP. Cht gauge will go in next week. QUOTE each different brand of spark plug uses a different system to designate hotter/colder. for example a bigger number means hotter in one brand and colder in another. So, if temps are cool and I still get pre ignition, AFR looks good, and running Premium gas, I need to retard the timing 1-2 Degrees. Or try a different plug while keeping the timing right on the nuts (IMG:style_emoticons/default/popcorn[1].gif) (IMG:style_emoticons/default/idea.gif) |
Black22 |
Oct 1 2012, 10:18 AM
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#4
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Senior Member Group: Members Posts: 886 Joined: 1-November 07 From: Creswell, OR Member No.: 8,290 Region Association: Pacific Northwest |
Pinging= Timing issue.
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