Yeah not cheap!
Same thing here
.004 with no seals. All is good.
Melting pistons.
- Thread starter McRat
- Start date
.004 with no seals. All is good.
For what it worth department, in my old 02 GMC my first venture into bigger hp, I used 50/50 H20/meth, propane, ATS tuner stacked on an hot edge with no timing, A2000 turbo, did the hill climb in Montana that The Diesel Page use to sponsor and climbed a 6.5% hill for a mile starting at about 5000 feet elevation from a standing stop in about 50 sec. EGT's pegged at 2000 degrees for the last 20 seconds or so. After that I yanked all that stuff off when I blew a head gasket, (on studs no less) and went to twins. Two years later the rods bent and I pulled the motor. pistons looked fine, cylinder walls were so heat scored they wouldn't use the block to built into one of our race engines.
that is exactly what has been recommended by a couple of different head experts. Seals will go as well, thanks for the info.
Pat, do you have a pressure plot from the melted piston tune? I would like to use it as a chamber temperature example.
You might have to wait a bit to get an answer to this. See the McRat Timeout Thread for details....:rofl:
Kat can get the info from Pat and post it. I did not ban Kat, just Pat.
Edit - hmmm she posted at the same time as me.
Edit - hmmm she posted at the same time as me.
Here are a couple plots of a mild LBZ with the estimated chamber temperature. (RED line, no data smoothing. degrees F) I am using 100* as the inlet temp. Real world would be closer to 140* or so when pulling hard with 30 PSI of boost. Sled pullers are even worse with IATs at the chamber in the 200* range or higher. So the peak temps could be 10% higher than plotted.
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Boost matters
Here are two similar example plots from an LBZ with the only major difference being the boost. Note the significant reduction in peak chamber temps. The first plot is with about 14 PSI of boost and the second about 9 PSI. This holds true for all the other plots I have looked at. Boost reduces chamber temps.
(The software messes up the injection stuff on LBZs with the post injection event as in these examples, but I am working on it.)
Here are two similar example plots from an LBZ with the only major difference being the boost. Note the significant reduction in peak chamber temps. The first plot is with about 14 PSI of boost and the second about 9 PSI. This holds true for all the other plots I have looked at. Boost reduces chamber temps.
(The software messes up the injection stuff on LBZs with the post injection event as in these examples, but I am working on it.)
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I'm wondering how this relationship holds with much higher boost numbers? Head flow rate has to play a major role as well wouldn't it. Boost is resistence to air flow and that also produces heat. More air moving due to high flowing heads the less the residual heat right and hence cooler cylinder and exhaust temps? Or am I all wet. I always figured the reason our dmax's don't see the boost numbers on a dyno we see on the street is due to our much better flowing heads.
Return on the increased boost goes down as pressure goes up. Not because of the boost number, but the increased IATs and the exhaust restriction needed to make the boost.
The numbers in the graphs are estimates of the actual chamber pressure when the inlet valve closes. The engine VE will determine how close that is to the manifold pressure.
I would venture that the heat generated from the air flow turbulence and resistance is minimal.
Most Dynos ramp up too fast to allow the turbos to spool compared to the road or track. But there are other factors, such as intercooler air flow.
Good heads improve the VE of the engine. Especially at higher RPMs. On my engine, with Stage II heads, I have noticed a significant reduction in piston suck on the intake stroke according to the pressure graphs. End result is more for a given indicated manifold boost when things start spinning faster.
Speaking of, have you done any testing to see how drive pressures increase chamber pressures and temps?
Drive pressures do not increase peak or power stroke chamber pressures. They do increase the exhaust stroke pressures. The transition from exhaust to intake is hard to examine because the values fade into the noise spectrum of the sensor. Even so, you can sometimes see it on the plots. Especially if the drive is high relative to boost.
Temp wise, I know drive pressure increases the heat in the chamber, but I can not measure it. Even what I have shown so far is assuming a fixed IAT of 100* F. Left overs from the exhaust stroke will no doubt impact that.
Temp wise, I know drive pressure increases the heat in the chamber, but I can not measure it. Even what I have shown so far is assuming a fixed IAT of 100* F. Left overs from the exhaust stroke will no doubt impact that.