ktm Posted May 18, 2008 Share Posted May 18, 2008 No photos this time as the wife is out of the country with the digital camera, but those of us familiar with this issue know the skinny. I lost my third head gasket at #6, with #5 showing signs of detonation as well. The two water jackets on the driver's side of #6 were both compromised and the gasket was deformed towards the drivers side as well. This one came as a surprise as my AFRs are dead nuts on (12:1 from 10 psi on, 12.5 from 0 to 10 psi) and my timing is not aggressive. However, I believe that it is the California 91 craptane that is responsible. I just can not run the standard timing on California 91. I am running 24 degrees at 15 psi on a stock L28ET bottom end. I am now running meth injection and that has helped considerably. I will pull 3 degrees of timing on #5 and #6 on my primary map as well as my fail safe map at 15 psi. On a few positive notes, I can now pull the head in 1 hour and 15 minutes. I also ordered one of Justin's flanges and plenum bases and will port match the head and ceramic coat my downpipe. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted May 18, 2008 Administrators Share Posted May 18, 2008 Hi Bo, Whats your cooling system like? Quote Link to comment Share on other sites More sharing options...
ktm Posted May 18, 2008 Author Share Posted May 18, 2008 Ron, it's a 3 core brass radiator with Flex-a-lite 210 (dual) fans. I am running 100 % distilled water with Redline's Water Wetter. Cooling has not been an issue lately. At cruise the fans are off; when idling at a stop light they will cycle on and off as they should. I say lately as I had an issue about a month ago where the fans were constantly running, even when cruising. Turns out it was a bad thermostat. I know exactly when I popped the gasket (this past Thursday). Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted May 18, 2008 Share Posted May 18, 2008 Having worked in the oil and gas industry as well as several gas stations when I was in high school I have to tell you that just cause the pump says 91 octane doesn't mean thats whats in the tank. At the bulk plant, chevron, shell, 66, etc. trucks would come get plain ol low grade and take it to their stations. Many, Many times at the stations we either couldn't get high octane gas (100 back then and 93 later on, now 91) or the delivery driver would put the wrong gas in the wrong tank. During the gas crunch back in the '70s we used to put regular in the super tank and nobody knew the difference! So, if your tuning for good gas, you'd better be sure what your getting in the tank! Quote Link to comment Share on other sites More sharing options...
z-ya Posted May 18, 2008 Share Posted May 18, 2008 I think it's the gas too. What are you using for ignition? I'd back your timing off more under boost. I run 23-24deg at 12psi on 93 octane east coast gas. I'd try 20 deg @ 15psi to start. If you have access to a dyno, and the shop has a set of audio headphones that let you listen to the knock sensor, do some runs and listen carefully. Another option is to get a knock sensor in there to back off the timing automatically. Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted May 18, 2008 Share Posted May 18, 2008 Having worked in the oil and gas industry as well as several gas stations when I was in high school I have to tell you that just cause the pump says 91 octane doesn't mean thats whats in the tank. At the bulk plant, chevron, shell, 66, etc. trucks would come get plain ol low grade and take it to their stations. Many, Many times at the stations we either couldn't get high octane gas (100 back then and 93 later on, now 91) or the delivery driver would put the wrong gas in the wrong tank. During the gas crunch back in the '70s we used to put regular in the super tank and nobody knew the difference! So, if your tuning for good gas, you'd better be sure what your getting in the tank! Hmmmm so if your engine got damaged from improper fuel grade being pumped, would you be able to sue the oil company for charging you for a low grade gass when you pumped premium, and due to this, caused your car to go poof? Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted May 18, 2008 Share Posted May 18, 2008 Pretty sure the gas station would be responsible. Lots of cars with stock superchargers and turbos require premium to not ping. If they mix them up or lie it would be their fault. A friend of mine owns a gas station, and water got into his diesel somehow, and he had to pay for repairs and cleaning for all the rigs that got his tainted gas. Should be the same in the case of fibbing about premium. Quote Link to comment Share on other sites More sharing options...
ktm Posted May 19, 2008 Author Share Posted May 19, 2008 z-ya, I am using the LS-1 coil-on-plugs in a fully sequential configuration. I was at 20 degrees at 15 psi and slowly worked my way up. The detonation is only occuring on cylinders #5 and #6 which are known to run hotter than the rest. Cylinders 1 through 4 showed no signs of detonation. I also have a 24x12x3 FMIC as well and my IATs hover right around 100 degrees F. Now that I am running methanol 100% of the time I should no longer have an issue. This last head gasket was run on a combination of 91, a 50/50 mix of 91 and 100, and 91 plus 100% meth. I was working the bugs out of my meth injection setup (not tuned for it yet, just trying to get the PWM and fail safe switching working correctly) and occassionally Wolf would switch maps (a grounding issue with my pressure sender and settings in Wolf as well) to my fail safe map which was identical to my normal map (for the time being). On my fail safe map I am only on 91 octane so I would hear it ping. In the end my luck ran out, but it was not due to overly aggressive tuning but rather tuning for the wrong quality of gas. This is a good lesson for folks who drive their cars from out of state into California. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 19, 2008 Share Posted May 19, 2008 Having worked in the oil and gas industry as well as several gas stations when I was in high school I have to tell you that just cause the pump says 91 octane doesn't mean thats whats in the tank. At the bulk plant, chevron, shell, 66, etc. trucks would come get plain ol low grade and take it to their stations. Many, Many times at the stations we either couldn't get high octane gas (100 back then and 93 later on, now 91) or the delivery driver would put the wrong gas in the wrong tank. During the gas crunch back in the '70s we used to put regular in the super tank and nobody knew the difference! So, if your tuning for good gas, you'd better be sure what your getting in the tank! I made the same point a few years ago. Why is there not an octane police! It's robbery. My WRX is highly sensitive to octane. It dramatically pulls timing if I get a bad tank of gas and it happens very often. There is a flaw in the early WRX ecu that pulls timing for knock, but very, very, gradually gives it back over a period of days. Whenever the timing pulls, I reset the ECU and perform a procedure to get the max timing advance again. It feels like about a 25HP loss. The reset lasts until the next bad tank. It's a very pronounced power loss that I attribute to getting rooked at the pump. Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 19, 2008 Share Posted May 19, 2008 I wondered where you were today... Maybe time to get some more coolant flow out to the back two cylinders. My CHT sensor (what I use on the MS) reads about 20 degrees hotter going down the road than the one in the thermostat housing . Didn't hear anything, did you! Damn it sucks when it goes like that. Better the head gasket than the pistons. And people called BS on me for a 2 hour unassisted head gasket change! LOL On the Octane Police, I know CA and MI have them. Matter of fact right now my standard stop, the Flying J in Frasier Park is on the hook for 4 engines at least after a load of bad gas. They had an announcement on the evening news (local) for anybody with engine problems after filling up there to notify the station for reimbursement if they can prove it happened after their fillup (not to hard, really). In Michigan, Sunoco sells (and I don't know who would buy this stuff) 84 Octane SUB-Regular! Talk about a big "D'OH!" on your turbo car if you mistakenly punch the wrong button on THAT pump!!! Quote Link to comment Share on other sites More sharing options...
johnc Posted May 19, 2008 Share Posted May 19, 2008 Sounds like its time to buy a 15 gallon container of VP Racing C10. Quote Link to comment Share on other sites More sharing options...
vspec Posted May 19, 2008 Share Posted May 19, 2008 I wondered where you were today... Maybe time to get some more coolant flow out to the back two cylinders. My CHT sensor (what I use on the MS) reads about 20 degrees hotter going down the road than the one in the thermostat housing . Didn't hear anything, did you! Damn it sucks when it goes like that. Better the head gasket than the pistons. And people called BS on me for a 2 hour unassisted head gasket change! LOL On the Octane Police, I know CA and MI have them. Matter of fact right now my standard stop, the Flying J in Frasier Park is on the hook for 4 engines at least after a load of bad gas. They had an announcement on the evening news (local) for anybody with engine problems after filling up there to notify the station for reimbursement if they can prove it happened after their fillup (not to hard, really). In Michigan, Sunoco sells (and I don't know who would buy this stuff) 84 Octane SUB-Regular! Talk about a big "D'OH!" on your turbo car if you mistakenly punch the wrong button on THAT pump!!! There are Sunoco stations here in Florida that sell 100 octane at the pump. and where i live in inverness,fl there are a few stations that sell 110oct. Quote Link to comment Share on other sites More sharing options...
schwiplarkin Posted May 20, 2008 Share Posted May 20, 2008 i may have missed it but what head gasket do you use? Quote Link to comment Share on other sites More sharing options...
ktm Posted May 20, 2008 Author Share Posted May 20, 2008 Oem Quote Link to comment Share on other sites More sharing options...
schwiplarkin Posted May 20, 2008 Share Posted May 20, 2008 i understand that you have some detonation issues but why dont you upgrade to a metal gasket. Quote Link to comment Share on other sites More sharing options...
1 fast z Posted May 20, 2008 Share Posted May 20, 2008 I run a solid copper head gasket, and push as much HP as any of the guys here on the L series, with solid stainless orings, and never have a problem. Although, my block is in stock configuration, other than the two secondary coolant lines. I have had no cooling problems yet. I would add a manifold on the outside upper part of the head, to get the heat out faster. Quote Link to comment Share on other sites More sharing options...
schwiplarkin Posted May 20, 2008 Share Posted May 20, 2008 where did you get the copper head gasket. i have the 2mm three peice and want to change to 1mm but the only one i can find is $259. Quote Link to comment Share on other sites More sharing options...
ktm Posted May 20, 2008 Author Share Posted May 20, 2008 I would rather spend $80 and replace a head gasket than sink ringlands. I just need to tune for California gas. Brian, I am not going to run a manifold, but I am going to tap #5 and #6 and to get the hot coolant out faster. Quote Link to comment Share on other sites More sharing options...
1 fast z Posted May 20, 2008 Share Posted May 20, 2008 I built my own gasket. Quote Link to comment Share on other sites More sharing options...
Noddle Posted May 20, 2008 Share Posted May 20, 2008 I built my own gasket. How do you have it cut ?, laser, water, milled ? Nigel Quote Link to comment Share on other sites More sharing options...
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