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Thread: Yada yada, more dynos.

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Posts: 241-250 of 262
2010-03-14 00:58:34
#241
8.5:1 compression motor. I have friends who make the same compression numbers and make over 750whp. Again, these are cold numbers. I am going to go outside and do another test when warm to see what I get. But if a fresh DET gets 145psi across the board and I hit within 10psi of that then I know the motor is good.

The motor doesn't burn any oil. So bad rings? There is blowby on high boost when the oil gets really hot. But the catch doesn't fill up with oil.

If the motor is bad I have no problems putting new pistons in and doing a valve job to make sure things seal properly. But I don't want to waste money if there is nothing wrong. This motor cranks right over without issues and starts right up. It just doesn't seem like there is anything to worry about. Maybe bent valves?

Everytime I think my motor is blown I find out that the timing is off, or there are tons of boost leaks, or wastegates are stuck open. lol.

I will find out in about 20 min.
2010-03-14 01:17:12
#242
Again it doesnt mean something is wrong. Hell my motor cold made 110,120,130,130 cold as well with a low cranking amp batter, I did have blowby but again nothing serious and had it ever since first startup.

Low compression will affect his hp numbers but that wont keep him from going higher and higher hp say with added boost. You have to keep in mind that if his problem is a bad ring seal against the cylinder walls then under the intake and power stroke and in boost that is only gonna aid sealing of the rings. Thats why the only time i really get any blowby as well is at idle and crusing. Under boost it pretty much dissapears. I dont think his compression numbers are a bad sealing valves but again who knows. And with his numbers soo close together like that its unlikely all of the valves are not sealing correctly.

Who knows?

something is just not flowing right with his setup.

he makes 20whp less than my de made on the same boost levels. Again could be an altitude thing as well. I dynod at sea level whereas he is pretty freakin high up.
2010-03-14 01:22:36
#243
New numbers.

130 110 120 100

And video



Enjoy my massacre! Got the engine nice and hot for these tests. All those bouts of detonation have prob destroyed some things. I will be tearing into the motor soon to find out. That is for sure.
2010-03-14 02:12:50
#244
Wow, im impressed more of that the fact your factory rev limiter, if it is factory is keeping the rpms from ramping past that under full boost like that. Looks like it pulls well. haha 3rd is definetly not there anymore. haha

Just saying cuz if i were to do that and keep on full thottling it would pound a couple times off the limiter then just shoot past it as its no match for that kind of power.

here is what im talking about, you can see it almost hit 9k, lol. Unless the b14 limiters are stronger for some reason but on my buddies ve b14 his limiter seems pretty weak too and with constant pounding it will sometimes shoot past his limiter as well.

YouTube - Turbo Nissan Sentra SE-R B13 Build in action
2010-03-14 02:16:16
#245
YouTube - 3rd gear rolling burnout part 2

YouTube - 3rd gear rolling burnout
2010-03-14 02:19:36
#246
Originally Posted by ashtonsser
Wow, im impressed more of that the fact your factory rev limiter, if it is factory is keeping the rpms from ramping past that under full boost like that.
Just saying cuz if i were to do that and keep on full thottling it would pound a couple times off the limiter then just shoot past it as its no match for that kind of power.



Well that limiter isn't factory. MSD streetfire ignition box. Ignition cut.

I kept detonating with the stock limiter when I would hit it, so I went to this. And if anyone doesn't believe me that the fuel cut would cause det, ask my spark plugs. I cracked several ceramics on them after tapping the limiter on even 14psi of boost. Fuel cut FTL.
2010-03-14 02:28:21
#247
I Am Willing To Do A Small Bet With You Just For Fun That You Have At Least 8 Bent Valves At Least Jejejejejejeje.... I Have Seen Your Situation Before On A Ve-t... Those Ve Valves Are Weak....
2010-03-14 02:28:56
#248
I was gonna say, i thought i remember you switching to something else. No way the stock limiter would keep it right there like that. At least not from my experience with it. haha Its happened a couple times that i shot past 9k doing a 2nd gear burnout. Kinda scary. Thats why in the vids at the track im not just pounding the rev limiter heating up the slicks in 2nd gear. Just kinda playing with the throttle but hey it works and heated them up nicely. That and the fear of tossing a rocker pounding the limiter is not fun either. haha
2010-03-14 02:31:03
#249
Originally Posted by Payu
I Am Willing To Do A Small Bet With You Just For Fun That You Have At Least 8 Bent Valves At Least Jejejejejejeje.... I Have Seen Your Situation Before On A Ve-t... Those Ve Valves Are Weak....


What would you suggest if valves are the issue? Wouldn't blowby be caused by rings, not valves?

Valves being bent would cause low compression. But no extra blowby. I am getting enough blowby now that the dipstick pops out of the tube on 22+psi.
2010-03-14 02:31:11
#250
Simple as doing a leak down test. Get each piston at TDC one at a time and pressurize the cylinder with about 120psi of compressed air and see if your getting any leak past the valves. I had to do this to a buddies s14 motor that had burnt all 8 exhaust valves. No leaking through the intake side. But every cylinder though the exhaust side. This was after he detonated it after overheating the motor.
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