flat sounding motor
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Road Warrior
Joined: Jan 2008
Posts: 1,446
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From: greenwood, mo
flat sounding motor
Any body ever have a cam go flat,motor just seems to be losing power and motor sounds flat it has a comp cam in it I know guys who ran comp cams in racecars they had trouble with them going flat just wondering if thats my problem.The compression is still 130.so I dont know what else to check.Any body got any suggestions?
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Joined: Mar 2007
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From: Woodstock, Ont , Can
A quick check by lifting the pushrod covers should show if one or more don't seem to be moving as much as they should. Stick it on the lift, pull the plugs, throw it in high gear and turn the engine. Covers can be taped up and a dial indicator could be used if you like to compare lifts between them. Generally it will be visual if you've reached the point of power loss.
Ron
Ron
Outstanding HDF Member
Joined: May 2008
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From: South Jersey
Checking the cam as rbabos described could help. With an evo there are other things to consider. Carb, sumping, ignition timing and timing components. Check that the rotor pin isn't sheared and the advance is working.
Elite HDF Member
Joined: Mar 2008
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From: Reno, Nevada
A quick check by lifting the pushrod covers should show if one or more don't seem to be moving as much as they should. Stick it on the lift, pull the plugs, throw it in high gear and turn the engine. Covers can be taped up and a dial indicator could be used if you like to compare lifts between them. Generally it will be visual if you've reached the point of power loss.
Ron
Ron
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Road Warrior
Joined: Jan 2008
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From: greenwood, mo
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Ultimate HDF Member
Joined: Feb 2007
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From: Northeast Ohio
As others have said, but sumping is one that will cause and engine to go flat when all other things appear to be in order.
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Joined: Mar 2007
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From: Woodstock, Ont , Can
Sumping is when the crankcase starts to get too much oil in it impeding the flywheels and crankpin. It acts like a brake on the rotating parts, especially the rod big ends. General reason is the scavange side of the pump is not doing it's job. This can be varified by pulling he plug at the bottom of the engine and measuring how much oil comes out. I believe it should not be more than 8 ounces or something like that. If that's the wrong amount I will be corrected on that, but you got the idea of what could be happening.
Ron
Ron