Sparks280zt Posted October 4, 2007 Share Posted October 4, 2007 whats the difference between testing at 25" vs 28" of water? jimbo More pressure at 28" of water I would say. Link to comment Share on other sites More sharing options...
JIM73240Z Posted October 4, 2007 Share Posted October 4, 2007 i can see there being more pressure, wont that skew the results? it seems that would be like comparing apples to oranges if the #'s are skewed. "my head flows 200 at 25"" "oh yeah, mine flows 210 at 28"" which is better or more common. im confused. jimbo Link to comment Share on other sites More sharing options...
Daeron Posted October 4, 2007 Share Posted October 4, 2007 testing at 28" sucks more!!!!! its a difference of pressure, 28" is a full atmosphere or ~14 PSI IIRC.. 25" is a bit less. i can see there being more pressure, wont that skew the results? it seems that would be like comparing apples to oranges if the #'s are skewed. jimbo Comparing flow bench numbers for two different heads is comparing apples to oranges. Comparing flow bench numbers from the same head on two BENCHES is comparing apples to oranges. Flow benches are tools to use in determining the difference made in machine work on one head. Take head, flow test it, work on it, flow test it again to see if you helped or hurt performance. Comparing flow test numbers is sketchy to say the least; it is ONE very loose specification on a very complex piece of equipment (the cylinder head.) Link to comment Share on other sites More sharing options...
hughdogz Posted October 4, 2007 Share Posted October 4, 2007 28" H20 = 1.0106 psi 1 atmosphere = ~407.2" H20 = 14.7 psi = 29.92" Hg (Mercury) So I assume they're talking about gage pressure (pressure above / below atmospheric) versus absolute pressure. Some trivia: If you had a vacuum on the top of a column of water in a tube, you could only "suck" the water high enough to get a column ~407" high. This is why we put well pumps at the bottom of the well versus the top. Even if you had an infinitely strong pump, you can't raise (suck) the water above 34 feet since you cannot get a pressure below a complete vacuum. -Hugh Link to comment Share on other sites More sharing options...
1 fast z Posted October 4, 2007 Author Share Posted October 4, 2007 testing at 28" sucks more!!!!! its a difference of pressure, 28" is a full atmosphere or ~14 PSI IIRC.. 25" is a bit less. Comparing flow bench numbers for two different heads is comparing apples to oranges. Comparing flow bench numbers from the same head on two BENCHES is comparing apples to oranges. Flow benches are tools to use in determining the difference made in machine work on one head. Take head, flow test it, work on it, flow test it again to see if you helped or hurt performance. Comparing flow test numbers is sketchy to say the least; it is ONE very loose specification on a very complex piece of equipment (the cylinder head.) Why do you think I compared a P90 to a KA head on MY bench, SAME bench. Link to comment Share on other sites More sharing options...
Daeron Posted October 4, 2007 Share Posted October 4, 2007 Why do you think I compared a P90 to a KA head on MY bench, SAME bench. I was just trying to explain it to jimbo, not to you.. youre among the LAST people I plan on trying to "explain" anything to Link to comment Share on other sites More sharing options...
rztmartini Posted October 5, 2007 Share Posted October 5, 2007 wow Ive been out of the loop for a while and I am utterly amazed. It looked sketchy from the early shots, but this is undeniable proof that careful and extensive calculations can make the impossible possible. as a student in mechanical engineering, I aspire to accomplish a feat of this magnitude, and you have proven yourself (at least in my eyes) to be included in the permanent history of the Z car. PS: was the head made from 2 KA heads, the ends of one and the center of another? or was is it the same end from 2 heads and the center from another??? Link to comment Share on other sites More sharing options...
BleachZee Posted October 5, 2007 Share Posted October 5, 2007 w00t! Link to comment Share on other sites More sharing options...
Daeron Posted October 5, 2007 Share Posted October 5, 2007 w00t! that is awesome, thanks! Link to comment Share on other sites More sharing options...
BleachZee Posted October 5, 2007 Share Posted October 5, 2007 ok, I made another one with a little less bounce to it. Sized it down for possible signature use. Link to comment Share on other sites More sharing options...
TimZ Posted October 6, 2007 Share Posted October 6, 2007 Go read what these smart guys are saying. I love how they can critisize when they know NOTHING about internal combustion engines! As someone said on there, "I would of welded up the headbolt holes" Holy geeze. http://www.genmay.com/showthread.php?t=754004 ...and when you dyno it, they'll say you fudged the dyno calibration to make it read an extra 300hp. ...Ask me how I know:mad::mad: Link to comment Share on other sites More sharing options...
slownrusty Posted October 6, 2007 Share Posted October 6, 2007 ...and when you dyno it, they'll say you fudged the dyno calibration to make it read an extra 300hp....Ask me how I know:mad::mad: Tim - I am in your corner flying your flag! You have inspired me to keep going with my L30 Build-up! The nay-sayers are just that! Yasin Link to comment Share on other sites More sharing options...
1 fast z Posted October 7, 2007 Author Share Posted October 7, 2007 Well I made it 550 straight miles to california, to the JCCS show. Car Crazy of Speed Vision did a interveiw with me about the car, so this motor is going to be on TV, So I thought that was pretty cool. But the reliablity part is there, except for a rusty gas tank. Link to comment Share on other sites More sharing options...
stony Posted October 7, 2007 Share Posted October 7, 2007 Do you know when the show will air with the interview? Link to comment Share on other sites More sharing options...
Gollum Posted October 7, 2007 Share Posted October 7, 2007 My gawd, my pc has been OFF for 1 whole week and now he's gonna be on TV?!?! I picked a bad week to start a new job! Congrats. And these guys calling the project ghetto don't know what in the world they're talking about. Apparently anything they don't think will work is deemed ghetto it seems. I bet they would have called the moon landing ghetto... Link to comment Share on other sites More sharing options...
1 fast z Posted October 8, 2007 Author Share Posted October 8, 2007 Ok, I just got home. I got 1300 miles of driving with the car, then it breaks down 5 miles from my house, GRRRRRRRRRRRRRR. After lots of testing, it turns out the DB37 connector fell off the Megasquirt, AHHHHHHHHHHHH. But it ran perfect, just perfect. I have an oil leak, out the valve cover gasket, and out of the front turbo, but other than that perfect. I didnt loose a DROP of water. The show was a blast, I sorta lost count on how many Magazene articles took a story on it, I had a blast. Although I didnt get to walk around the jccs show at all. I raced a couple cars on the way home, which one was a souped up LS400, that thought he was fast, yea no competition. HAHA. I had it to about 145 in 5th gear, pulls pretty hard. Although the wastegate cant pull enough pressure off of the hot side of the turbos as the boost creeps in high gear. Link to comment Share on other sites More sharing options...
Daeron Posted October 8, 2007 Share Posted October 8, 2007 sounds like a million dollar wound to me... I bet it got your heart racing (in a bad way) for a moment, though. How did you make your valve cover gasket? Link to comment Share on other sites More sharing options...
TimZ Posted October 8, 2007 Share Posted October 8, 2007 After lots of testing, it turns out the DB37 connector fell off the Megasquirt, AHHHHHHHHHHHH. But it ran perfect, just perfect. DB37? Man that's ghetto - I could've made a connector that was better than that. :mrgreen: Link to comment Share on other sites More sharing options...
johnc Posted October 8, 2007 Share Posted October 8, 2007 I'm impressed as hell. 1,300 trip miles, a couple full power top speed runs, and all you have is a couple oil leaks and a bum connector. Great news! Link to comment Share on other sites More sharing options...
1 fast z Posted October 8, 2007 Author Share Posted October 8, 2007 I was suprised not to see you at the show John C. Jeff Priddy called me abount noon and said he was trying his best to get off of work, but didnt get a chance to. I was manily impressed about the no water leaks, as that was the main concern with this project. There is no oil in the head except for the first two inches from the front. My electric fan pretty much cant flow enough air for 100 degree heat in traffic backups, as the temp guage starts creaping after about 20 minutes of just sitting there and barely moving, so I will add a pusher also. Valve cover gasket is a oring. Link to comment Share on other sites More sharing options...
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