LT1 stumbles at 5000rpm
#1
LT1 stumbles at 5000rpm
so, i just finish changing head gaskets, a job i never want to do again. and i am still chasing a few bugs down, but nothing too big. i head out to the "street warriors" thing at bristol and a car that repeatedly goes 13.8-13.9 runs a blistering 14.6.
anyway, during the run i notice that right at 5k rpm the thing stumbles. it comes right back to life though, it feels more like a "bump" at 5k. every time, run after run, on the interstate, hot, cold it doesn't matter. at 5k, it just "bumps". all i can think is it is electrical/ignition. have any of you LT1 folks ever came across something like this?
the car;
'97 T/A w/ 106000miles
SLP cold air and LM exhuast
4:10 gear
head gaskets replaced
heads trued w/slight shave.
93 octane
anyway, during the run i notice that right at 5k rpm the thing stumbles. it comes right back to life though, it feels more like a "bump" at 5k. every time, run after run, on the interstate, hot, cold it doesn't matter. at 5k, it just "bumps". all i can think is it is electrical/ignition. have any of you LT1 folks ever came across something like this?
the car;
'97 T/A w/ 106000miles
SLP cold air and LM exhuast
4:10 gear
head gaskets replaced
heads trued w/slight shave.
93 octane
#5
how tight did you lash the valves??
by 'shaved" heads....how much was taken off?
I would think not enough to alter valve train geometry and if you still have stock cam and head gasket thickness and 1:5 rockers geometry should still be fine...but worth checking. A quick check on one valve will show a "witness" mark on the valve stem tip.
Like Dwayne said...very possible cap/rotor are wearing.
by 'shaved" heads....how much was taken off?
I would think not enough to alter valve train geometry and if you still have stock cam and head gasket thickness and 1:5 rockers geometry should still be fine...but worth checking. A quick check on one valve will show a "witness" mark on the valve stem tip.
Like Dwayne said...very possible cap/rotor are wearing.
#7
i went with what the book said. tighten right to the point of no play and go another 3/4 turn. i havn't felt comfy with setting the preload on these (my other vehicle has solid lifters). i was wanting to check it one more time to be sure. how do you all set preload on hydrualic lifters?