Adjusted valves, difference in power band
 

Aight, so last night I adjusted the valves on the 97, went pretty slow, kinda tedious. I had a buddy of mine who is really pro watch and lend advice. Took me about 1-1.5 hours before I was satisfied, TDC was a pain to find. My question is this: The motor sounds more even, more in-synch, but I seem to have lost some low end. The truck's only mods are: stock fuel plate full forward, wastegate blocked off, bhaf. The truck had previously pulled pretty hard from 1300-2000rpms, had a seat-of-the-pants low end. Now the pedal is harder (SLIGHTLY) to push and it seems that the truck pulls better in mid and high rpms, overall I think the truck moves better. So what gives? Any ideas? Thanks in advance.

To clarify....from 1300-2000rpms....feels slower than before the adjustment.

Anybody?

Timing may slipped, ever have it set?

no...but how would that occur if the timing pin is engaged. Hmm...i didnt set it again after rotating the motor, but I marked the harmonic balancer so TDC was fairly obvious, and all the valves correct valves were closed, "loose" enough to be adjusted.

sorry...posted that under my bro's username....mine is a 97...this is sabreson.

how can I check the timing?

timing is checked with a dial indicator on top of delivery valve
go to faq for instructions. 16.5 degree is a conservative setting that gives good performance and mileage.

It wouldn't have anything to do with you adjusting the valves, just a coincidence that you just noticed it.It happens all the time with the 12v's, the nut on the gear in the pump wasn't torqued hard enough at install and they slip allowing the timing to retard.

ah, thanks....i'll check it out.

Valve lash will change upper and lower end performance. Racer's do it all the time. Cam duration cannot be changed from what the cam grind is. OEM specs on valve lash vs. looser or tighter will change the opening of the valve. Loose, later and longer. Tight, early and shorter. Will change RPM specs of any mechanical cam.. How far out were the valve lash on yours..

Ah...this is was what I thought. With the feeler gauges, about half were too tight, half were a tad loose. I know it wasn't a perfect job.....but when I was done the exhaust side on each cylinder were close to .020", the feeler would either slide through smoothly (without excess room) or it would slide through with a tiny bit of friction...same for intake with the .010" feeler

valve adjustment should be consistent across all cylinders. did your experienced buddy actually check final setting with feeler gauge?

my preference is to set with a slight amount of friction on feeler gauge. have adjusted a lot of valve over the years. what I call a slight friction may be different from yours.

they make a stepped feeler gauge... a go or no go indicator

I need one of those stepped feelers. Yes, and the adjustment was consistent...but I will assume not flawlessly....first time. Well....i'm gonna throw in some injectors next weekend, I will just go through them all while the hood is up. Thanks to all.