| New LTX running well but..... |
Subject: New LTX running well but..... by rklessdriver on 2008/10/22 18:39:46 I'm still having freaking valve train problems. The car was making good power then just took a crap at 5800RPM. I have a boat load of dyno sheets and it's making 440RWHP at 5800RPM then taking a nose dive. Over 400RWTQ from 3800RPM until 5800RPM (DEAD FLAT TQ CURVE) where it suddenly just takes a dive.... [IMG]http://i50.photobucket.com/albums/f303/rklessdriver/Corvette/BillyWillams92Vette.jpg[/IMG] Aparantly everybody who swore to me that Morel lifters would take 400lbs of valve spring over the nose (no problem) was full of crap. I pulled a valve cover (again) and my .620 lift cam is measuring just shy of .530 @the valve when its warmed up, I'm sure its doing wonders for the effective duration as well. When its cold I'm getting the full .620, but anythime the oil temp goes over 200F the lifters bleed down. I've had this motor on an engine dyno quite a few times figuring out a valve float problem early on and my current springs solved that problem, I can't for the life of me figure out why the lifters are bleeding down, NOW that I've got it in the car. Maybe they got damaged from all the previous dyno time and finally failed. SO Sweet!! I get to change valve springs (again), except this time motors in the car not on a dyno stand. PSI and my cam grinder are working with me and I've got a spring on the way that's 135lbs @1.800(seat) and 360lbs@1.150 (over the nose). Should solve the lifter bleed down problem but if not, I guess I'll be pulling the Intake, Rev Kit and replacing the Lifters. At least the car runs and drives kinda. I got the car back from Ed (The HP Factory) a few weeks ago and he has it tuned really well for WOT, but since I've still got single wire O2's, it won't go closed loop.... The driveability is pretty much crap with an open loop tune. He has a bunch of timing taken out at low throttle openings and the car goes from occasionally trying to die or spitting back and no power (under 1/4 throttle) to explosive wheel spin (anything over 1/4 throttle). Its like an on/off switch. Then to add insult to injury it just runs out of steam right when it should be pulling the hardest, althou you can't tell anything in the lower 3 gears because of the tune situation it just lights the tires up for no reason and anything approaching WOT results in an instant trip to the Rev Limiter. However if you get it hooked up in 3rd gear and slowly roll into the throttle you can feel it pin you in the seat right up to about 6000RPM where it slowly tapers off to the rev limiter at 7200RPM. I really wish I had better results to post for myself (well at least Nolands engine turned out like I expected right). With a carb my engine dyno'd 608HP@6800RPM, and pulled cleanly well past 7400RPM once everything was sorted. If the freaking thing would keep pulling/climbing at the same rate it is pulling/climbing now on the chassis dyno, it would be right around 490-500RWHP@6800RPM. I will keep everyone posted on what happens. I've got a few other little things I have to fix first (massive rocker cover leak, changing the dash cluster and wiring the car for heated O2's) that are pissing me off (even more than the valve springs/lifters) before I tackle chainging the springs/lifters. Will |
