tDR Posted July 4, 2007 Share Posted July 4, 2007 You should have gone for a colder plug. Use NGK BKR7E's gapped at 0.9mm for your application. BCPR7ES are fine too but marginally longer than the ISO fitment so not EXACTLY same length plug as OEM. Again you can gap them at 0.9mm for your application. 0.7mm is too extreme IMO and if you need to gap down to that level to avoid misfires I'd suggest you look elsewhere for the problem - duff coilpack etc. If you were using a 6 heat range plug it means its more likely to ignite prematurely when faced with the higher cylinder head / combustion temperatures associated with running raised boost. This is itself could damage the plug. Suggest fitting new plugs and seeing how it runs, if still problems then compression and / or leakdown test. EDIT - Use ONLY super unleaded / Optimax when running increased boost! You're asking for trouble otherwise. Cheers, Brian. Quote Link to comment Share on other sites More sharing options...
Armin Posted July 4, 2007 Share Posted July 4, 2007 This thing happend to me today.. my supra is broken my boost was 1,2bar and the RR was a bit over 2", greddy bcc, dp 3" exhaust and a walbro gss341, plugs were ngkbcpr7es.. the plugs on no 5 and 6 cyl had their top burned off.. and now ha have none compression on those two cylinders. This sucks! any ideas? melted down pistons? burnt valves? The car runs fine on 4cyp and no wierd smoke or anything comes out of the exhaust pipes.. read again.. Quote Link to comment Share on other sites More sharing options...
Guest moosebuster1st Posted July 7, 2007 Share Posted July 7, 2007 Hi Armin, Sorry to hear mate, it was not good for me, my head is off at the moment, the end of the plug basically tried to get out the cylinder through the exhaust valve and erm it didn't make it, I will post some pics soon to show you the damage. You need to find someone who knows what they are doing to fix this for you, I was lucky in that my only damage is to the valve, I am still amazed the turbo's didn't get it or for that matter the rest of the engine....I have had the head skimmed 9 thou and I live in hope that all will work when it goes back together, I would suggest that you do not run the car anymore in case there is debris still in the engine.... Quote Link to comment Share on other sites More sharing options...
Armin Posted July 7, 2007 Share Posted July 7, 2007 sounds nice, i hope that i haven´t got more damage than that. Quote Link to comment Share on other sites More sharing options...
Armin Posted July 10, 2007 Share Posted July 10, 2007 Lyfte av toppen idag och kunde konstatera att det var ett ras modell BIGSIZE! Bilderna säger nog en del.. ps: topplockspackningen är 3lagers stål. ds. http://medlem.spray.se/arminracerx/Supra/3.%20Ras+Godis/KODAK%20025%20(Small).jpg http://medlem.spray.se/arminracerx/Supra/3.%20Ras+Godis/KODAK%20027%20(Small).jpg http://medlem.spray.se/arminracerx/Supra/3.%20Ras+Godis/KODAK%20030%20(Small).jpg http://medlem.spray.se/arminracerx/Supra/3.%20Ras+Godis/KODAK%20031%20(Small).jpg http://medlem.spray.se/arminracerx/Supra/3.%20Ras+Godis/KODAK%20028%20(Small).jpg I got some problems, it was worst than i thought. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 11, 2007 Share Posted July 11, 2007 Nasty Quote Link to comment Share on other sites More sharing options...
Jake Posted July 11, 2007 Share Posted July 11, 2007 http://medlem.spray.se/arminracerx/Supra/3.%20Ras+Godis/KODAK%20031%20(Small).jpg Blimey! I've never seen damage like that before! Quote Link to comment Share on other sites More sharing options...
Armin Posted July 11, 2007 Share Posted July 11, 2007 yep.. oits as nasty as it gets, total engine rebuild and i have to get the head welded and skimmed. Quote Link to comment Share on other sites More sharing options...
Ric Posted July 11, 2007 Share Posted July 11, 2007 yep.. oits as nasty as it gets, total engine rebuild and i have to get the head welded and skimmed. erm Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted July 11, 2007 Share Posted July 11, 2007 You are going to repair it? Why not just get a new/second hand head? Quote Link to comment Share on other sites More sharing options...
Armin Posted July 11, 2007 Share Posted July 11, 2007 the price is one good reason, a friend of my is an expert on welding heads, he is a dragracing ceneberty here in scandenavia and runs 1200hp+ in a 4cyl volvo engine, the man knows his shiet You are going to repair it? Why not just get a new/second hand head? Quote Link to comment Share on other sites More sharing options...
Kranz Posted July 11, 2007 Share Posted July 11, 2007 Glad to hear you are getting a professional to weld the head. It may need heat treating after welding or it'll probably crack in the weld area. Just for everyone's information a hot plug has a long insulator projection so the tip runs hotter in a given engine than a colder plug with a shorter insulator projection. Cold plugs being shorter from the tip of the central electrode to the body of the plug conduct heat away quicker, so run cooler. A plug that is too cold will not burn off deposits from the tips and will foul, causing misfire. A plug that is too hot will get so hot the incoming fuel/air mix will fire before the spark ignites it, causing sporadic burning (pre-ignition) in the cylinder & lengthening the time the spark plug is exposed to the flame & heat. this in turn heats the tip up more, causing even earlier pre-ignition, causing an even hotter plug tip.......... Until the tip melts off Too cold a plug is much better than too hot, for this reason! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 12, 2007 Share Posted July 12, 2007 the price is one good reason, a friend of my is an expert on welding heads, he is a dragracing ceneberty here in scandenavia and runs 1200hp+ in a 4cyl volvo engine, the man knows his shiet I am in to my Volvo engines, tell me more about this 1200 BHP 4 cylinder please I'd just buy a used head, welding will soften it, and probably distort it enough to nee the cam journals line boring and honing. A used head won't cost much... Quote Link to comment Share on other sites More sharing options...
b_have Posted July 12, 2007 Share Posted July 12, 2007 Often seems the case that #5 suffers more from det. I guess those using Motec/AEM could pull a little more timing on the prone cylinder? Quote Link to comment Share on other sites More sharing options...
Stevie Boy Posted July 12, 2007 Share Posted July 12, 2007 Arn't the NGK BKR6EP-11 just a NGK BKR6EP with stock gap set to 1.1mm? Dunno where I got that from, Alex is te best man to ask bout plugs. Hopefully rings and cylinder wall hasn't sustained any damage/scoring, could add quite a bit to cost of repair than just head off. Quote Link to comment Share on other sites More sharing options...
Armin Posted July 12, 2007 Share Posted July 12, 2007 the cylinders have some scratches but after a ,020 bore it will be fine. This volvo im talking about is a 16v engine has ran 7,62 288kmh 1/4mile. He had the engine mapped today with Ethanol, the think broke the freakin dyno Quote Link to comment Share on other sites More sharing options...
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