losing power above 6100rpms
Thread Starter
Le Mans Master
Joined: Oct 2001
Posts: 5,577
Likes: 3
From: Southern Maryland Maryland
losing power above 6100rpms
My car seems to lose power above 6100 RPMs. Symptons:
Vacuum Guage stays solid up to 6100
after 6100 it flutters very quickly
Power falls off very quickly
Phillip
Vacuum Guage stays solid up to 6100
after 6100 it flutters very quickly
Power falls off very quickly
Phillip
Thread Starter
Le Mans Master
Joined: Oct 2001
Posts: 5,577
Likes: 3
From: Southern Maryland Maryland
Re: losing power above 6100rpms (jmX)
Valvetrain:
Comp OEM replacement lifters
Comp Chromoly Pushrods
YT 1.7 rockers
Comp titanium retainers
Comp 987s
Ferrea valves
443/408 falling quickly @ 6100
Phillip
Comp OEM replacement lifters
Comp Chromoly Pushrods
YT 1.7 rockers
Comp titanium retainers
Comp 987s
Ferrea valves
443/408 falling quickly @ 6100
Phillip
Drifting
Joined: Jul 2000
Posts: 1,818
Likes: 3
From: SoCal
Re: losing power above 6100rpms (Phil97SVT)
Interesting, I had almost that exact valvetrain combo (not sure on what brand the valves were) and I had valve float just like you. I finally sent a head to a shop to have them inspect how the springs were setup, and they found they weren't setup with sufficient pressure for the weight of the valvetrain. At the time I was using 2.08 valves. This was all from ARE (the car never ran right with those heads, due to this setup issue).
I put on a new set of heads, again with 987's but this time...setup correctly, and the problem went away. It plauged me for a year. Tried new pushrods lengths, less preload, more preload, 3 different cams, different plugs, nothing worked. It was all about valve float.
Jon
I put on a new set of heads, again with 987's but this time...setup correctly, and the problem went away. It plauged me for a year. Tried new pushrods lengths, less preload, more preload, 3 different cams, different plugs, nothing worked. It was all about valve float.
Jon
Thread Starter
Le Mans Master
Joined: Oct 2001
Posts: 5,577
Likes: 3
From: Southern Maryland Maryland
Re: losing power above 6100rpms (jmX)
Jon,
That is pretty interesting....When my heads were setup the 2nd time around they used shims to increase seat pressure. Who knows, there is something wrong inside...Maybe LG or godspeed will chime in with their spring recommendations.
Phillip
That is pretty interesting....When my heads were setup the 2nd time around they used shims to increase seat pressure. Who knows, there is something wrong inside...Maybe LG or godspeed will chime in with their spring recommendations.
Phillip
Melting Slicks
Joined: Feb 2001
Posts: 3,360
Likes: 1
From: DFW TX
Senior Member
Cruise-In III Veteran
Cruise-In IV Veteran
Re: losing power above 6100rpms (Phil97SVT)
Phil, Lou is in route to Bowling Green right now for the Z06 event. I'll call his cell phone this evening when he arrives and ask him.
