Greg90iroc

hey guys i have found why my car ran so slow last time at the track. it was missadjusted valves. I heard a tapping coming from my rocker cover so i readjusted the valves about a month ago. i put the valve cover back on and it did the same thing so i adjusted the valves tighter about 1.5 turns. I put the rocker cover back on and still the tapping sound. Then i took the valve cover off and reved a little (messy) there was no tapping the rocker was hitting the oil baffel on my aluminum valve cover. i pushed the valve cover back a little and it cured the problem. Well it turns out that i should have done about .75 turns on the valves after the taping stoped. the car ran fine at rpms below 4000 but after that it lost nearly all power. you should see the video of me stomping a mustang with the valves like that. i pulled 2 cars off the light and then 2 more every time my car gets back down below 4000. it is pretty funny it looks like i am just messing with him. Back to the point what should i adjust the valves too is 3/4 turn about right? I hear alot of people say 1/2 and some say 1 turn so i chose the middle. It apears that fuel and spark are not the only thing you can tune for better et's. what do you guys think? should i do a few tests at the track to determine the best adjustment of the valves?

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90 IROC l98
last season best corected 13.62 @102
mods
full exhaust, AFPR, pulley, jet stage 1 chip, billet servo, 52mm throttle body, slp runners and some 1.6 RR's and a few other little things.
243 RWHP and 342 RWTQ with hot engine and 90 octain fuel

ede

i make sure i go past 1/2 turn, maybe 5/8 to 3/4

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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

Steve89GTA

This is probably a stupid question but is there any adjustments to be made with a hydaulic system? I.E. Stock 89 TPI?

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89 GTA G92
305 TPI WC 5spd w/3.45
Accel Cap & 8mm Taylor's
Custom 4" Cold Air Induction
Jet Airfoil
K&N Airfilter
160 deg stat/fan switch TB Bypass - Steel Rad
Cat back 3" Exhaust w/Terminator Muff.
HiGh FlOw Dynomax Cat
Spohn LCA's - KYB GR-2's
Moroso Crank Bolt and roller pilot bearing.
New Fuel Pump!
Autometer Vac+Oil Temp
2000 Yamaha R1 150hp 385ibs

RW91B4C

No there isnt any adjustment with hydralic lifters, as long as you preload the plunger in the lifter (take the slack out) and go at least another 1/4 turn - you're done, thats all there is to it

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91 B4C 305 TPI - SOON TO BE 383
TREMEC 5-SP, STOCK 1-BOLT REAREAND w/342 GEARS, K&N, AIRFOIL
EDELBROCK HEADERS, DUAL CAT TO HOMEMADE Y-PIPE & 3.5" SINGLE PIPE W/ FLOWMASTER, CRANK PULLEY, MSD, FUEL PRESS REG, COWL HOOD, WELD WHEELS
14.1@ 98MPH
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OTHER RIDE
67 CAMARO - STREET CAR, BIG BLOCK, PUMP GAS
350TH w/ATI 10", 12-BOLT w/373 GEARS
10.94@124.13 ON MOTOR - ET-STREETs w/MUFFLERS

Nonni

Is it the same method adjusting valves when we have hyd. roller lifters? When I turn 1/4 turn then the rpm goes a little down

Nonni

RB83L69

Yes, hyd rollers adjust the same as hyd flats. Same little valve inside both. If you zero-lash a lifter on a flat-tappet cam and then run it down ¼ turn, it will make its RPMs drop too, for the same reason. The oil in the lifter takes some time to bleed out after you crank down on it; during that time, it's holding the valve open. It's not too bad when you do that to an exhaust; but an intake will nearly kill the motor sometimes.

What I do with a running motor is zero-lash all 16 with no preload; then shut the car off, and add my ¼ or ½ or ¾ turn, whatever I've decided for the particular circumstances, to all 16. Less mess, quicker, the motor doesn't ever have to deal with valves hanging open.

I set new stuff to ½ in a performance application, used to ¼, fixing broken stock stuff, I use ¾.

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"So many Mustangs, so little time..."
ICON Motorsports

Greg90iroc

oh yea just got back from a test drive after the engine had cooled. the car starts alot easier and it just anhilates the tires in 2nd now. there is a hell of a diffrence between a 14.3's and 13.6's. i never really noticed how much. Although my A$$ dynometer has not been calibrated in a while i am sure that i am back where i should be. also from my understanding it is the oil pressure that dictates how much preload you need to have. if you have high oil pressure then you can get away with less preload on the lifter. my engine is begining to show it's age at 79,000 miles should i have gone a full turn?

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90 IROC l98
last season best corected 13.62 @102
mods
full exhaust, AFPR, pulley, jet stage 1 chip, billet servo, 52mm throttle body, slp runners and some 1.6 RR's and a few other little things.
243 RWHP and 342 RWTQ with hot engine and 90 octain fuel