Lunati Link Bar Lifters - Preload? Turbo motor
#1
Lunati Link Bar Lifters - Preload? Turbo motor
What's the recommendation on preload for these damn things? They're the street link bar lifters and I've read everything from 0.020"-0.030" and 0.030"- 0.050" !!!
Tried to stay at about 0.030" and ordered the pushrods to get that. I get a tiny bit over 1/4 turn (approx 0.020") with these and they were pretty noisy at startup, so I bumped up 0.025" in pushrod length so max I'm running about 0.045-0.050" now, which may be too much?
What I'm seeing engine going super lean after staying fat until about 4k (and running at about 3-4psi by then) and basically falling on its face. Fuel pressure stays at 52psi and doesn't fall. We've fattened up the tune to try to troubleshoot and it still goes super lean ... so we're thinking it's actually crazy rich and the wideband showing it as lean.
Plugs maybe gapped wrong causing blowout? Or too much preload causing valves to stick open?
Tried to stay at about 0.030" and ordered the pushrods to get that. I get a tiny bit over 1/4 turn (approx 0.020") with these and they were pretty noisy at startup, so I bumped up 0.025" in pushrod length so max I'm running about 0.045-0.050" now, which may be too much?
What I'm seeing engine going super lean after staying fat until about 4k (and running at about 3-4psi by then) and basically falling on its face. Fuel pressure stays at 52psi and doesn't fall. We've fattened up the tune to try to troubleshoot and it still goes super lean ... so we're thinking it's actually crazy rich and the wideband showing it as lean.
Plugs maybe gapped wrong causing blowout? Or too much preload causing valves to stick open?
#5
Yeah its definitely tricky and you have to watch out for lifter plunger etc., but I've had pretty good luck with it this way too. However most of that was with stock style lifters so it may not be accurate enough for such tight tolerances as on these lifters.
I just didn't want to start up a sewing machine every cold start, hence adding another 0.025 to the pushrods. I may go back to the shorter pushrods and do some logs to see if that has any effect.
Any suggestions on spark plug gap? I'm gonna check that too.
I just didn't want to start up a sewing machine every cold start, hence adding another 0.025 to the pushrods. I may go back to the shorter pushrods and do some logs to see if that has any effect.
Any suggestions on spark plug gap? I'm gonna check that too.
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#9
Well turns out my calculations were good without the pushrod checker and using the old counting turns method. Used the checker today and zero lash came in a hair over 7.300 and 7.3075 or so (as best as I could estimate with it). So what I used, 7.325 and 7.350 pushrods, got ~0.030" exhaust / ~0.045" intake ... so that was not the issue. Yeah, my valve stem heights are about 0.010 off.
Then pulled the plug ... I'm an idiot for not checking these before as I got the truck with them and they were new ... but they are wayyyy too cold of a plug I was told for my set up, and so I'm gonna get a set of TR6's tomorrow and swap them in.
Unfortunately takes pulling the fenderwell to get to the plugs ... ugh.
Then pulled the plug ... I'm an idiot for not checking these before as I got the truck with them and they were new ... but they are wayyyy too cold of a plug I was told for my set up, and so I'm gonna get a set of TR6's tomorrow and swap them in.
Unfortunately takes pulling the fenderwell to get to the plugs ... ugh.
#10
Formerly ScreamingL
I have lunati/moral tie bars
Mine per instructions require about 030 mine is .035
Using a 8.0" pushrod on my combo but everyone will be different
Mine are quiet with that amount of preload
Mine per instructions require about 030 mine is .035
Using a 8.0" pushrod on my combo but everyone will be different
Mine are quiet with that amount of preload