please help, changed pushrods, lost power
08-29-2012, 09:22 AM
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please help, changed pushrods, lost power Hi fellas,
so my standard pushrods were getting a bit noisy, so installed new aftermarket one that are 25 thou longer to quiten her up. I noticed the car lost its responsiveness, so i put the old pushhrods back in. Still the same , very lazy, and very tappety. So i pulled the old pushrods out again, and i noticed one is definetly bent. So i put all the new longer ones back in. Again no change, still lazy, and probably even noisier. The the more speed you gain , the noisier it gets.
Whats Happening?? Does anyone have any ideas??
Another question, Ive just received my precision turbo pt8847 from getting the bearing rebuilt, and i decided to change location, from where i get the oil to the turbo.
Originally i used the fitting on the front of the side of the sump for the turbo, and the rear of the same side of the sump for my oil pressure gauge. I wanted to change to the back port cos i figured it was after the oil filter, so it would be cleaner oil.
I dont know if its coincidence, but now im only showing half the pressure from the front of the sump, compared to the back. Idle used to be 40 psi, and would shoot to 80-90 psi on power, now it idles between 17-20 psi on idle, and 40 psi on power.
CAn this be related to the pushrods-lifters??
Help is greatly appreciated.
My cam is 444-11
Ive tested compression, and all cylinders are 140psi, the bowls in the heads have had about 8cc taken out to drop the compression. Does this compression figure sound ok. It is turbocharged by the way.
so my standard pushrods were getting a bit noisy, so installed new aftermarket one that are 25 thou longer to quiten her up. I noticed the car lost its responsiveness, so i put the old pushhrods back in. Still the same , very lazy, and very tappety. So i pulled the old pushrods out again, and i noticed one is definetly bent. So i put all the new longer ones back in. Again no change, still lazy, and probably even noisier. The the more speed you gain , the noisier it gets.
Whats Happening?? Does anyone have any ideas??
Another question, Ive just received my precision turbo pt8847 from getting the bearing rebuilt, and i decided to change location, from where i get the oil to the turbo.
Originally i used the fitting on the front of the side of the sump for the turbo, and the rear of the same side of the sump for my oil pressure gauge. I wanted to change to the back port cos i figured it was after the oil filter, so it would be cleaner oil.
I dont know if its coincidence, but now im only showing half the pressure from the front of the sump, compared to the back. Idle used to be 40 psi, and would shoot to 80-90 psi on power, now it idles between 17-20 psi on idle, and 40 psi on power.
CAn this be related to the pushrods-lifters??
Help is greatly appreciated.
My cam is 444-11
Ive tested compression, and all cylinders are 140psi, the bowls in the heads have had about 8cc taken out to drop the compression. Does this compression figure sound ok. It is turbocharged by the way.
08-29-2012, 09:45 PM
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Did you measure lifter pre load with the new pushrods? There's a good chance they're too long and bottoming out the lifters. Which will make for a very noisy valvetrain and can cause oil pressure issues.
Get a pushrod length checker, and check what a proper length should be.
Get a pushrod length checker, and check what a proper length should be.
08-30-2012, 09:54 AM
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Yes , i can see how it looks moronic on my part, No ididnt measure anything, i just whacked them in.
The reason i did this is because my friend works at the biggest performance suppliers here in australia, for abot 15 years, and this is what he advised me to do.
Now, the reasoning behind changing to a 25 thou longer comp cam pushrod, was to quiten down the lifters. It was a preventative thing on my part so it wouldnt cuase any dramas later on.
since the motor was built 8 months ago, i was advised to put in the comp cams antipump lifters. It was all sweet until i changed to these longer pushrods.
The motor wasnt really missing, comp is 140psi throughout, but its turned really laggy.
It makes 700hp at the wheels, i rekon its lost about 100hp, and there is a more pronounced tap as you rise in revs when you drive it.
So i have pulled the heads off, everything looks fine, tomoorow i will get the lifters checked.
Im interested to know if these pushrods caused the lack of power, and if a collapsed lifter will cause this.
By the way, the oil pressure is back up, for some reaon the front port where i was getting oil for the turbo, shows half of what the back port was, that explains why my turbo's bearings were stuffed.
The reason i did this is because my friend works at the biggest performance suppliers here in australia, for abot 15 years, and this is what he advised me to do.
Now, the reasoning behind changing to a 25 thou longer comp cam pushrod, was to quiten down the lifters. It was a preventative thing on my part so it wouldnt cuase any dramas later on.
since the motor was built 8 months ago, i was advised to put in the comp cams antipump lifters. It was all sweet until i changed to these longer pushrods.
The motor wasnt really missing, comp is 140psi throughout, but its turned really laggy.
It makes 700hp at the wheels, i rekon its lost about 100hp, and there is a more pronounced tap as you rise in revs when you drive it.
So i have pulled the heads off, everything looks fine, tomoorow i will get the lifters checked.
Im interested to know if these pushrods caused the lack of power, and if a collapsed lifter will cause this.
By the way, the oil pressure is back up, for some reaon the front port where i was getting oil for the turbo, shows half of what the back port was, that explains why my turbo's bearings were stuffed.
