How fast do stock lifters bleed off?
09-02-2011, 11:57 PM
#1
How fast do stock lifters bleed off? I'm chasing down why my car smokes some. Pulled the plugs and found #5 to be oil fouled. Pulled the valve cover and found a piece of the valve seal next to the cylinder #5.
I was turning the engine over with a remote starter to better look at the seal and noticed when I get a valve on TDC it instantly bleeds down I'd say 1/8 of an inch. For some stupid reason when I did my H/C/I swap I re used my stock lifters, they only had 47k miles on them and I thought they would be OK.
I'm running comp 921 duals w/ a EPS 226/230 cam with upgraded stock rockers and as I mentioned, STOCK 47k lifters.
At the dyno my power dropped off early. I thought it might have been because I advanced the cam but now I'm wondering if the lifters are weak.
Thanks for any help.
Jason
I was turning the engine over with a remote starter to better look at the seal and noticed when I get a valve on TDC it instantly bleeds down I'd say 1/8 of an inch. For some stupid reason when I did my H/C/I swap I re used my stock lifters, they only had 47k miles on them and I thought they would be OK.
I'm running comp 921 duals w/ a EPS 226/230 cam with upgraded stock rockers and as I mentioned, STOCK 47k lifters.
At the dyno my power dropped off early. I thought it might have been because I advanced the cam but now I'm wondering if the lifters are weak.
Thanks for any help.
Jason
09-03-2011, 07:28 PM
#2
how much lifter preload do you have and what oil pump/pressures do you
have ?? Is the valvetrain ever noisy...cold start or hot oil ??? Honestly the
hydraulic lifters amaze me at the pressures we ask them to deal with. Duals
with like 140-150 on the seat and 380-400 open is alot to ask of the oil fed
plunger IMO.
have ?? Is the valvetrain ever noisy...cold start or hot oil ??? Honestly the
hydraulic lifters amaze me at the pressures we ask them to deal with. Duals
with like 140-150 on the seat and 380-400 open is alot to ask of the oil fed
plunger IMO.
09-04-2011, 12:02 PM
#6
You have a fairly wide range of preload, but still less than mine. I ended up using 2 different pushrod lengths, mixed & matched to get .080-.090". You might consider using a .025" shorter PR on the ones you have over .100".
BTW - I have the same question on stock or LS7 lifters. I can't imagine how they work properly with camshaft lift and spring pressures so much more than what they were originally used with.
BTW - I have the same question on stock or LS7 lifters. I can't imagine how they work properly with camshaft lift and spring pressures so much more than what they were originally used with.
