jagman Posted March 8, 2005 Share Posted March 8, 2005 this is a pic of CJ,s cylinder head that we are currently repairing - the cause was a failed fuel regulator/ running lean thus overheating the plug to the point that the end came came off -leading to a few dents in piston crown,few scores in bore,ultimately exiting the exhaust valve chipping it and causing burnthrough --- just a warning to those who wanna run high boost without adequate fuelling and control of fuelling---(not CJ,s car he was just unlucky) I will post pics next week after head rework/port/polish if anyones interested ps if anyones going for larger valves i,d use ferrea in preference to crower far better finish,1 gram lighter(both lighter than stock)i dunno what the price diff is-just my opinion Quote Link to comment Share on other sites More sharing options...
dude Posted March 8, 2005 Share Posted March 8, 2005 I think you may want to check with Terry on the reg issue as it is apparently now on matts car i believe and working perfectly so i understand , if it was running iridium plugs at the time then bad fuel and DET would cause the same damage , i wouldnt put iridiums in my engine again if you paid me !!!! Dude Quote Link to comment Share on other sites More sharing options...
Timwildman Posted March 8, 2005 Share Posted March 8, 2005 Was there any turbo damage from the bits? Quote Link to comment Share on other sites More sharing options...
heckler Posted March 8, 2005 Share Posted March 8, 2005 I think you may want to check with Terry on the reg issue as it is apparently now on matts car i believe and working perfectly so i understand , if it was running iridium plugs at the time then bad fuel and DET would cause the same damage , i wouldnt put iridiums in my engine again if you paid me !!!! Dude Out of interest dude, what plugs do you use then? Quote Link to comment Share on other sites More sharing options...
jagman Posted March 8, 2005 Author Share Posted March 8, 2005 I guess iridium plugs are really costly!--not picking on fpr-he was just unlucky just highlighting the the importance of fuelling and excess heat due high boost-gotta keep those egts down Quote Link to comment Share on other sites More sharing options...
jagman Posted March 8, 2005 Author Share Posted March 8, 2005 turbo looks undamaged-every cloud.... Quote Link to comment Share on other sites More sharing options...
tbourner Posted March 8, 2005 Share Posted March 8, 2005 I'd better get an EGT gauge before the summer then!! Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted March 8, 2005 Share Posted March 8, 2005 Adam there was nothing wrong with CJ's FPR, we tested it and as Dude said it is on Matt's car. Also, look at the cylinder next to it...... Quote Link to comment Share on other sites More sharing options...
Miguel Posted March 8, 2005 Share Posted March 8, 2005 this is a pic of CJ,s cylinder head that we are currently repairing - the cause was a failed fuel regulator/ running lean thus overheating the plug to the point that the end came came off -leading to a few dents in piston crown,few scores in bore, not picking on fpr-he was just unlucky So whats the above then ??? Regulator was tested to be fine and is on another car . Have you got a shot of the entire head? From the looks of that shot there is no singh of DET . It just looks like Cyl 6 has got very hot and burnt out the valve as well as taking out the plugs , Ah the joy of Iridiums. May well be worth getting them injectors tested me thinks Quote Link to comment Share on other sites More sharing options...
absz Posted March 8, 2005 Share Posted March 8, 2005 Also, look at the cylinder next to it...... is that signs of unburnt fuel Quote Link to comment Share on other sites More sharing options...
jagman Posted March 8, 2005 Author Share Posted March 8, 2005 on collection of the car I was told it had previously had an fpr problem-dont shoot the messenger-the point of the post was to show the effects of incorrect fuelling-the head was/is as black as your hat-the car has had a good few starts and is currently hugely overfuelling-the other purpose of the post was to show folks what a ported/polished/flowed and matched head looks like and an insight into the reasoning behind the various techniques used by one of the top head guys in the country a good idea in a tech forum i thought Quote Link to comment Share on other sites More sharing options...
Miguel Posted March 8, 2005 Share Posted March 8, 2005 Defo ..will be good to see Quote Link to comment Share on other sites More sharing options...
absz Posted March 8, 2005 Share Posted March 8, 2005 it will be nice to see the follow up on a ported head. as i'm thinking of going down the same route. Quote Link to comment Share on other sites More sharing options...
CJ Posted March 8, 2005 Share Posted March 8, 2005 I hadn't used Iridium plugs for some time and had been running the NGK's. Now, I am not blaming any equipment for the damage caused but I do take exception to people pointing out that there was nothing wrong with the FPR. That is almost tantamount to calling me a liar - which I certainly am not. When the plug blew (prior to this latest incident) the FPR was not working correctly. It was holding pressure until I hit boost. It then stayed as it was and did not increase in proportion to the boost pressure. Dude can verify that these were the symptoms as I spoke to him on the phone whilst driving it and explained that the gauge was showing this. I changed over to a FSE and the pressure then showed as increasing thus taking away the chance of it being a duff gauge. I also took it to Matt at Oxford for him to check it out and he too confirmed that it was not working properly. Now, whether this was not working properly due to an incorrect fitting and therefore working OK when refitted, I do not know, but I do know that i was not making up a story. Quote Link to comment Share on other sites More sharing options...
CJ Posted March 8, 2005 Share Posted March 8, 2005 is that signs of unburnt fuel What would that indicate? Running far too rich? Quote Link to comment Share on other sites More sharing options...
Miguel Posted March 8, 2005 Share Posted March 8, 2005 No one is calling you a liar CJ or infact that you are making it up at all... All that is being said is that it has now been tested and is now working And running on another car ..just one of them things Like you say it could have been a number of things. I like you take offence to things being said that until proven stands no ground. I replaced anyway without even questioning as I would do for anyone else . I then get them tested and if it works it works ..no reflection on the customer. In heinsight if the FPR was to blame at the time it would have gone lean on ALL the cyl not just one . You can see from Jagmans shots that Cyl 5 shows overfueling BUT cyl 6 has been running very lean for some time this I would blame that to an injector not doing its job. Burnt out valves on high boost is quite a comon problem and yours is not the 1st car I have seen with this problem . Quote Link to comment Share on other sites More sharing options...
CJ Posted March 8, 2005 Share Posted March 8, 2005 Thanks for the reply Mig. So, looking at that head, would people say that I may have a problem with the injector? I guess the sensible thing would be for me to get them cleaned and flow tested. Quote Link to comment Share on other sites More sharing options...
b_have Posted March 8, 2005 Share Posted March 8, 2005 I had a similar problem with HKS plugs a few years ago, a failed AVCR allowed 2.2 bar boost with hybrids. This was a huge but momentery boost spike which caused the ultra thin electrode to break (I think due to the ressonance of the det) causing damage to bore/piston/ex valve and wiped out the turbo. When stripped, there was NO visible evidence of det, the $20 plug virtually destroyed the engine. Have had many years of dyno experience with racing two stroke engines and found the same problems with this type of plug when exposed to det. So where does the blame lye? The plugs are fine if the engine is running correct afr's and timing BUT have a misshap ( blocked fuel filter/failing fuel pump or injector/overboost etc) and these type of plugs ARE the weak link. Since then, i have always used NGK coppers at about £15 a SET and change them every 6000 miles. Quote Link to comment Share on other sites More sharing options...
Miguel Posted March 8, 2005 Share Posted March 8, 2005 Yes I would defo get all the injectors tested and cleaned as they should have been before fitting them anyway. It only takes 1 injector to be down on the rest and it will lean the Cyl that its on everytime. And if you want to see what Irriduims, under fueling and DET can do have a gander at this . Quote Link to comment Share on other sites More sharing options...
Ian C Posted March 8, 2005 Share Posted March 8, 2005 Looks like a gammy injector to me as well I kept up with your initial probs when the fuel regulator didn't appear to be upping the pressure in line with boost, seems like shitty luck to get a dodgy injector straight after - the worst problems are multiple-point-of-failure ones... Did you get your injectors cleaned and tested before fitting them CJ? -Ian PS I just refitted my nice Denso IKs, don't make me worry about them taking the engine out Quote Link to comment Share on other sites More sharing options...
CJ Posted March 8, 2005 Share Posted March 8, 2005 Did you get your injectors cleaned and tested before fitting them CJ? -Ian : Yes, prior to fitting I had them cleaned and flow tested by CW. Quote Link to comment Share on other sites More sharing options...
Guest slow dog Posted March 8, 2005 Share Posted March 8, 2005 dont worry mate thanks for the info its nice to see some of us are still getting our hands dirty. i had the same thing over oxys big end shells on how it aint gonna last and you need a new crank blah blah blah!!!!!!!!!!!!!!!! oxys car has not missed a beat since the work and runs very well. its been 5 months and he has done alot of hard miles. keep it up mate if you dont wanna postup any more pics please send them to my e mail as i am very interested in on how cjs car goes Quote Link to comment Share on other sites More sharing options...
Ian C Posted March 8, 2005 Share Posted March 8, 2005 Then you took every precaution I use CW for injector stuff as well. I can't think why one would have blocked so quickly, maybe it just failed...? Are all the other combustion chamber roofs black like #5? -Ian Quote Link to comment Share on other sites More sharing options...
Miguel Posted March 8, 2005 Share Posted March 8, 2005 Love the Slowdog. Class. Quote Link to comment Share on other sites More sharing options...
CJ Posted March 8, 2005 Share Posted March 8, 2005 Then you took every precaution I use CW for injector stuff as well. I can't think why one would have blocked so quickly, maybe it just failed...? -Ian Sods law eh? Are all the other combustion chamber roofs black like #5? -Ian I am not sure - maybe Adam can answer that? Quote Link to comment Share on other sites More sharing options...
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