Compcam xer281hr vacuum at idle
08-13-2012, 11:10 PM
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Compcam xer281hr vacuum at idle Wondering what vacuum everyone else has and of course at what rpm they get that reading.
Also, do any of you have issues with multiple misfire at idle and higher?
WB is showing a little rich at idle atm (around 14.0 afr) but nothing that should cause a misfire.
Also, do any of you have issues with multiple misfire at idle and higher?
WB is showing a little rich at idle atm (around 14.0 afr) but nothing that should cause a misfire.
Last edited by gokussx4; 08-13-2012 at 11:17 PM.
08-18-2012, 12:33 PM
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Comp cams said at least 15. Started investigating to find that my intake wasn't at the torque spec required. Tightened down just the middle 2 that I could get to and vacuum went from 8.5-9 to 10.5. So further down I find this damn 102 fast intake is resting right on the water pump after I ground it down as far as it could go.
Took the water pump out today and ground it some more to the point that I had nothing left and it was still touching. DON'T use a water pump from autozone as it will not fit, this is with the tb off. Almost 1/8" rests on the water pump.
I need some advice here guys what water pump did you use? Would going to an electric pump give me more clearance.
A very special thanks to FAST for their great testing and R&D!
I am so angry can you tell? lol
Took the water pump out today and ground it some more to the point that I had nothing left and it was still touching. DON'T use a water pump from autozone as it will not fit, this is with the tb off. Almost 1/8" rests on the water pump.
I need some advice here guys what water pump did you use? Would going to an electric pump give me more clearance.
A very special thanks to FAST for their great testing and R&D!
I am so angry can you tell? lol
Last edited by gokussx4; 08-18-2012 at 12:52 PM.
08-18-2012, 02:23 PM
#5
Comp cams said at least 15. Started investigating to find that my intake wasn't at the torque spec required. Tightened down just the middle 2 that I could get to and vacuum went from 8.5-9 to 10.5. So further down I find this damn 102 fast intake is resting right on the water pump after I ground it down as far as it could go.
Took the water pump out today and ground it some more to the point that I had nothing left and it was still touching. DON'T use a water pump from autozone as it will not fit, this is with the tb off. Almost 1/8" rests on the water pump.
I need some advice here guys what water pump did you use? Would going to an electric pump give me more clearance.
A very special thanks to FAST for their great testing and R&D!
I am so angry can you tell? lol
Took the water pump out today and ground it some more to the point that I had nothing left and it was still touching. DON'T use a water pump from autozone as it will not fit, this is with the tb off. Almost 1/8" rests on the water pump.
I need some advice here guys what water pump did you use? Would going to an electric pump give me more clearance.
A very special thanks to FAST for their great testing and R&D!
I am so angry can you tell? lol
08-19-2012, 11:44 AM
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Thanks very much! I took a look at the images and it looks like the upper part of the pump is significantly different. I will post my results on here when I get one and test it out.
08-25-2012, 10:06 AM
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Ls2 pump worked pretty well because the rear part is a pressed piece instead of bolted in. So that hump on top of the other designs isn't there which means less cutting on the water pump. I still, however, had to grind the pump down in order to get it to fit properly.
For my situation I think this primarily has to do with the machine shop "cleaning" the head area of the block where they shaved it off to make it even. This and my head being shaved a little too, I think caused enough of a drop that more shaving was needed on the pump.
Well after all of that, found the intake was not to 89" lbs so torqued it all down again and its tight. Now I am seeing 8" of vacuum at idle
For my situation I think this primarily has to do with the machine shop "cleaning" the head area of the block where they shaved it off to make it even. This and my head being shaved a little too, I think caused enough of a drop that more shaving was needed on the pump.
Well after all of that, found the intake was not to 89" lbs so torqued it all down again and its tight. Now I am seeing 8" of vacuum at idle
