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Thread: Yada yada, more dynos.

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Posts: 251-260 of 262
2010-03-14 02:32:22
Secure your dipstick better, lol. I had mine sitting between my turbo and upper crossover. Held it down nicely. Cuz mine would pop out on occassion. Not all the time though.
2010-03-14 02:33:56
I hope it is exhaust side. lol. DE valves are free!

I'm not going to bother with a leakdown test. I want to tear the motor down this thursday. Then I will know for sure without having to do leakdown. Last leakdown test I did came back good, (8-10%) but compression was low. This was like 9 mo ago.
2010-03-14 02:36:48
Why tear it apart? Doesnt take much to just pessurize the cylinder with air and see if its leaking out the intake valve, exhaust valves or past the rings? Simple easy and it will pinpoint your problem. Cuz otherwise it would require tearing down the head completely to check the valves. Find out before hand man.......
2010-03-14 02:40:30
I have a head guy that can check the valve seating without even removing the cams. I can literally take the head to him and he can tell me what kind of pressure it holds.

Might as well. Every gasket on the motor is leaking from too high of crankcase pressure anyway. The timing cover leaks particularly bad. Its gross.
2010-03-14 02:44:24
Better crankcase venting next time around too will help that. The only thing i have trouble getting to seal on my motor is my lower pan. No matter how many times ive tried it always ends up leaking, could be from the blowby or could be its an old pan and may be bent a bit. Im getting a brand new one this time around. lol

But non of my other gaskets or seals leak even with the blowby. Just sayin man, i would check before pulling. But thats just me.
2010-03-18 06:29:32
Took the motor out today. Only took 4 hrs. I will have it torn apart tomorrow morning. Hmmmm, I wonder what is causing the low compression?

Bad rings?
Melted piston?
Burned/bent valves?

Can't wait! OH JOY!!!

The motor coming apart gives me a ton of reason to do a lot of pointless stuff too. Like valve springs. Cams. Remove JWT 7500 redline. perhaps have the crank balanced?
2010-03-18 06:45:46
Just to chime in... when the first pulse or jump of the needle, how high did the reading go up to? It should go to 1/2 of whatever the final number was if the rings are good. If the rings are bad, it won't go to 1/2 of the final number. If it went above 80Psi on the first needle jump, it's your valves more than likely. Also you don't have to remove the head to check the valve seal, just the manifolds and cams so that the valves shut. There is a $80 tool that can pull a vacuum and measure the amount of inhg acheived. Perfect vacuum is 30 inhg (inches of Mercury). So if you still want to tear it all down...be my guest. Post up how the needle reacted the first compression stroke.
2010-03-18 16:05:56
It took about 8 compression strokes to get the numbers I got. It went up about 1/2 way on the first hit, but then it took a lot of cranking to hit my final numbers.
2010-03-18 19:53:32
Man I hope you did not bend some valves.
2010-03-18 20:02:30
I will have them fully checked out. Valves aren't a big deal to me, but the hassle of shims is frustrating to have to deal with again.
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