Spec-944#70 Posted March 21, 2005 Share Posted March 21, 2005 For those of you who have herd I blew my head gasket at CSW Friday. This happened on my 2nd practice session. Talking with some shops I have come to the conclusion that either I am running too high of a CR as my head was shaved or the chip I have is maybe running the motor too far advanced. I will be returning to a stock head and a stock chip. This had absolutly nothing to do with the work John Anderson did for me. He built the bottom end only and did a fine job. This was not an issue with any work any of the people working on my car did. My gut tells me it's the chip as all my problems have been happening since the chip install, which was also the time I did my head. As of this I will be scaling back my involvement with racing as I can't justify the expense and time away fro my wife and kids anymore. I have some much needed work to be done to my house from all the rain we've had and need to spend some extra quality time with my 3 boys. I will be at the "Tribute to Le Mans" in April working and hanging out but probably not driving. Quote Link to comment Share on other sites More sharing options...
uberklasse Posted March 21, 2005 Share Posted March 21, 2005 Eric, That sucks...we have all been there at one time with the cars and the family! (call me when you get a chance) I didn't come out this weekend until Saturday. We had some wet, but good racing....a lot of good dicing! Quote Link to comment Share on other sites More sharing options...
DavidH Posted March 22, 2005 Share Posted March 22, 2005 Eric, I came out on Sunday as a spectator and heard the bad news. You may be able to turn this lemon into lemonade and have some great times with the familia...It is hard to balance family, work, racing and finances. I'm sure that you will be back when the time is right. Quote Link to comment Share on other sites More sharing options...
PeanutinCA Posted March 22, 2005 Share Posted March 22, 2005 Eric, you don't think your over heating had anything to do with that top radiator hose becoming dis-connected? Or do you think it got hot and blew that hose off? There is a few guys with shaved heads and they don't seem to be having the same issues? P.Dilly. Quote Link to comment Share on other sites More sharing options...
Spec-944#70 Posted March 22, 2005 Author Share Posted March 22, 2005 No I think the hose came off due to water paths getting over pressurized. Whether it was the shaved head or the chip making timing too far advanced or a combo of the 2. This is my 3rd head gasket since redoing my head and chip last summer. We'll see what plays out but the kicker were my boys telling me they were happy my car broke so I could stay home and be with them! Kinda makes you re-evaluate your situation. There may be a compromise or maybe a sebaticle (sp) is needed. We'll see! Quote Link to comment Share on other sites More sharing options...
944-Spec#94 Posted March 22, 2005 Share Posted March 22, 2005 Eric, Sorry to hear about the Head gasket issues. Yes it does seem like you have problem someplace. Having 3 headgaskets fail a result of some basic issue. Could be head related or chip related or both. I have heard of some Az guys with similar issues if they try to take compression ratio too high. This is why I have had them take off the minimum to ensure my head was flat when I had some repairs done to it a a couple years ago. The 2 hp was not worth the hassle of headgasket failures. The good news is headgaskets are cheaper to fix than rod bearings. As for the family. Yep I understand you. It is tough juggling family and racing. Of course racing is really a distant second compared to family. Just don't give up. Scale back if you have to, but keep the car and run selected events. Once you get bitten by the bug you have scratch the itch every now and then just to stay sane. Quote Link to comment Share on other sites More sharing options...
Packfill Posted March 23, 2005 Share Posted March 23, 2005 Okay, Its time for another episode of "educate the new guy.." Q: How would the chip and timing facilitate a blown head gasket.... Q: Assuming that we are all running the same piston volume, is there a simple way to take a compression test and determine C/R? Q: What color is the old grey mare? Quote Link to comment Share on other sites More sharing options...
jjgrow Posted March 23, 2005 Share Posted March 23, 2005 Is anyone dyno testing with the aid of a wide-band O2 sensor and/or air fuel monitor? Would this help identify the situation as being out of balance or is their something else? Quote Link to comment Share on other sites More sharing options...
Spec-944#70 Posted March 23, 2005 Author Share Posted March 23, 2005 Engine dyno'd at 138 RWHP with no pinging noise. The chip (FRWilks) could be too far advanced in timing. AS for CR there is still room left to shave more off and there is no easy way to check CR. You would have to mic the motor and carefully measure volume at BDC and TDC. I'm going back to stock!! Quote Link to comment Share on other sites More sharing options...
Tim Comeau Posted March 23, 2005 Share Posted March 23, 2005 Great question, Jeff. If the car is blowing head gaskets due to heat?............ C/R is too high causing too much heat in the combustion chamber? Chip is not matched to engine with regards to spark timing and fuel amount needs, i.e., too lean? I'm just guessing and learning here guys. I want to change the chip on my red rental car back to stock to regain a stock level rev limiter, but I'm afraid the stock chip might not be matched to the race engine's needs, thus causing more harm! I'm thinking, like Jeff, that I should include a dyno run when the chip is changed in order to monitor the A/F ratio. ?????? Hey, I'm just a driver..... Quote Link to comment Share on other sites More sharing options...
jjgrow Posted March 23, 2005 Share Posted March 23, 2005 that's kind of what I was thinking as I have a shaved head and an FRWilks chip (though with a lower than stock rev limit). I've always had a FRW chip and not experienced head gasket failures, but now I (presumably) have slightly higher C/R so I'm a little concerned about the balance among the fuel, air and timing map. the turbo guys seem to spend a lot of time on this because of the concern for running lean under increased boost. Quote Link to comment Share on other sites More sharing options...
944-Spec#94 Posted March 23, 2005 Share Posted March 23, 2005 My last dyno run had the Wideband O2 hooked up. A/F Ratio was between 13 to1 and 12:1. It was bit rich on the top end. Remember also that shaving the head changes the physical timing as the cam is fractionally closer to the main pulley therefore a sight timing change occurs. alot of blown headgakets are from detonation. Quote Link to comment Share on other sites More sharing options...
DOUBLEXL RACING Posted March 25, 2005 Share Posted March 25, 2005 KIND OF A NEW GUY HERE. MIGHT TRY TO OFFER SOMETHING!! 138 HP AT THE REAR WHEEL IS STOUT(SP)!! ON THE 944 SPEC SIGHT MOST WERE IN THE 130-135 RANGE. IF THE TIMING WAS TOO RADICALLY ADVANCED, HP WILL FALL OFF AS THE PISTON IS TRYING TO PUSH AGAINST A DOWNWARD MOVING FLAMEFRONT. THUS HP WOULD BE WAY DOWN!! ALSO, WITH NO PINGING AND ( I ASSUME) NO PISTON DAMAGE, DETONATION IS MORE THAN LIKELY NOT OCCURING. ALSO WITH THIS BEING THE THIRD HEAD GASKET THAT HAS BLOWN, HAVE YOU CHECKED THE BLOCK FOR STRAIGHTNESS AND TRUENESS? THAT TO ME SOUNDS LIKE A MORE VIABLE CAUSE FOR CONCERN. I AM FAIRLY NEW TO THE PORSCHE SCENE BUT HAVE BEEN WORKING ON RACE MOTORS FOR YEARS, SO PLEASE DON'T GET MAD IF I SOUND STUPID, DUE TO IGNORANCE OF PORSCHE INUENDOS. JUST THOUGHT I'D OFFER MY 2 CENTS. Quote Link to comment Share on other sites More sharing options...
Spec-944#70 Posted March 25, 2005 Author Share Posted March 25, 2005 There are several cars putting out 138 RWHP they just don't have the dyno posted. I know of 3 other cars. As for the block this is a new one since I had put my rod through my last one. So I have a new head with a complete rebuild and all new parts, new lifters and now a new block and bottome end. Either the CR is too high or something is wrong with the chip. Thats why I'll be back to stock soon. Wanna buy a car ready to go!! Quote Link to comment Share on other sites More sharing options...
DOUBLEXL RACING Posted March 25, 2005 Share Posted March 25, 2005 That sounds too tempting but 3/4 of the fun is in building and wrenching!!! Plus, with ALL the problems that car is having !! Just joking of course!!! Still has me stumped though, even though the block is new, did you check the trueness of it? Usually either CR or timing would cause a drop in HP, and you are definitely on the high side. Like I said I don't know all the intricacies(sp) of the 944, so just trying to help. Now, i have to get others in florida here to buy into this spec thing and i will be golden!!! Quote Link to comment Share on other sites More sharing options...
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