Failure analysis leads to rebuild along with a cleanup.
03-14-2012, 11:05 AM
#64
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Just read this whole post. I give you props Alchemist for going about this on your own. Just an expensive learning curve! I'm a test engineer by trade so I break stuff everyday, it's my job, but it's on someone elses dime! LOL. Good luck! I look forward to the outcome.
03-14-2012, 11:36 AM
#65
I was talking with the machinist/engine builder, and I plan to do it with him. Obviously, he's doing all the machining, but he's going to explain what he's doing, and why it's critical.
For some people, it's all about the et's, while for others it's the trophies at car shows, but for me, it's the knowledge and the experience of building something myself. Yeah, it sucks when it breaks, but that's why it's not my daily driver. I work on it for a little bit, have a beer, then walk away when it stops being productive.
03-14-2012, 01:12 PM
#69
I've talked to more than few people who have extensive years of LS1 knowledge and they said I'd be okay at 10.1:1. They said it, if I dropped lower it would make it mushy out of boost and not as responsive.
Specifically I talked to Kurt Urban for a while and he said I'd be fine running 14psi of boost at 10.1:1. For a street car that rarely see's extended periods of boost, I'll be fine.
Specifically I talked to Kurt Urban for a while and he said I'd be fine running 14psi of boost at 10.1:1. For a street car that rarely see's extended periods of boost, I'll be fine.
03-14-2012, 02:47 PM
#71
Not trying to argue with you. I just think that for many years, people resorted to dropping compression as a way to combat lack of tuning ability of the systems.
The more people I talk to, the more I hear about people pushing more and more compression in forced induction motors. Is it from a better combustion chamber, or from aluminum heads, or better tuning capabilities, I don't know, but I've heard of higher and higher compression motors getting boost lately with great success.
The more people I talk to, the more I hear about people pushing more and more compression in forced induction motors. Is it from a better combustion chamber, or from aluminum heads, or better tuning capabilities, I don't know, but I've heard of higher and higher compression motors getting boost lately with great success.
03-14-2012, 09:52 PM
#72
Not trying to argue with you. I just think that for many years, people resorted to dropping compression as a way to combat lack of tuning ability of the systems.
The more people I talk to, the more I hear about people pushing more and more compression in forced induction motors. Is it from a better combustion chamber, or from aluminum heads, or better tuning capabilities, I don't know, but I've heard of higher and higher compression motors getting boost lately with great success.
The more people I talk to, the more I hear about people pushing more and more compression in forced induction motors. Is it from a better combustion chamber, or from aluminum heads, or better tuning capabilities, I don't know, but I've heard of higher and higher compression motors getting boost lately with great success.
03-14-2012, 11:09 PM
#74
Glad to see you are making progress. You and I are both moving quicker than anticipated. My longblock is going to be ordered here around the first of the month, and I am going with a 9:5:1 ratio, because I want the extra insurance that it will provide. The 10:1 is a common setup that more people are running that we all think, but to be safe I would run 100 percent methanol alchemist like Julio and god and everybody suggests. The only reason you may wanna run water is if you are having cooling issues, and since we are all running Chris's bracket, and have ls2 pumps most likely running straight water, then just leave it at that....if you start overheating....you know for a fact that you either dont have enough fan, or enough radiator. I have my rough draft tune laid out already based on a buddies car from FTP performance and all that I have absorbed through hundreds of pages of threads. Max 17-18* of timing, not that the Iron 390 cant handle more, but the gains are just not there, and by that I mean track times not dynos. That plus a 11.5-11.7 AFR and 100 percent methanol with 93/111 Mix should last for a long time. The worst part of all this is going to be breaking in the new motor before dyno time. I am just biding my time, doing small things like cleaning the engine bay, and painting the ls6 intake, and buying motor dressup items.
03-15-2012, 06:21 AM
#75
Overheating isn't simply measured at the front of the engine or at the radiator. I spoke in length with some very knowledgable people and localized overheating is as much of a 'hidden' issue that a lot of people don't realize. Overheating in the combustion chamber is what causes big problems. If you can't get heat out of the combustion chamber, then you will get detonation and have issues. That is why I plan to run water/meoh. Sure, meoh burns cooler than gas alone, but it doesn't pull as much heat out of the combustion chamber and exhaust valve area as does injecting water with it.
But what do I know... it's not like I have any scientific background or experience with this stuff.
But what do I know... it's not like I have any scientific background or experience with this stuff.
03-15-2012, 09:01 AM
#78
I also would have chosen a lower CR. 1 point in compression is worth MAYBE 3% of your NA hp.....so if your 346 made 400rwhp NA, you're talking about 12rwhp, big woop. However, that 1 point lower, say going from 10:1 to 9:1 would have gone a LONG way to giving you some safety margin and cushion for the amount of boost you're wanting to run. The meth will definitely help you out, but I still wouldnt go near the 17-18* of timing that was mentioned above. With that much boost (14psi), set the timing in the 11-12* range with meth, and give it hell. There are others on here that have boosted the stock shortblock in the 14psi range on pump and it was fine for a long time, but if you were going to rebuilt it anyways, why not give yourself some error margin?
03-15-2012, 09:15 AM
#79
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Does the ls2 pump flow more then a ls1 pump or something?
And this whole af ratio with meth thing. How are you guys doing it? Dial in your a/f w/o meth then you go back in and spray the meth and then pull fuel out?
And this whole af ratio with meth thing. How are you guys doing it? Dial in your a/f w/o meth then you go back in and spray the meth and then pull fuel out?
03-15-2012, 10:31 AM
#80
I also would have chosen a lower CR. 1 point in compression is worth MAYBE 3% of your NA hp.....so if your 346 made 400rwhp NA, you're talking about 12rwhp, big woop. However, that 1 point lower, say going from 10:1 to 9:1 would have gone a LONG way to giving you some safety margin and cushion for the amount of boost you're wanting to run. The meth will definitely help you out, but I still wouldnt go near the 17-18* of timing that was mentioned above. With that much boost (14psi), set the timing in the 11-12* range with meth, and give it hell. There are others on here that have boosted the stock shortblock in the 14psi range on pump and it was fine for a long time, but if you were going to rebuilt it anyways, why not give yourself some error margin?
I always said when I had my turbo car that the reason turbo lag is there is to let the other guy think he is going to win just long enough to let your turbo light off and you then proceed to reel his *** in and suck the paint of his **** as you blow the door handles off his ride.
Bad6as- Yes you will either change the PE divisor your using to command your AFR or BE divisor and bring it back down closer to lamda to pull fuel out while adding methanol in through secondary injection.
Alchemist have you ever spilled room temperature methanol on your skin before? It feels like someone dumped ice water on your skin, because it has such great latent heat properties. Now take that same amount of room temperature water and see what happens, I bet the methanol feels a lot cooler than the water.