I just got done installing a TPIS ZZ-9 Camshaft in my L98 TPI (1988 GTA 5.7L). I have Comp Cams 1.52 Ratio Self-aligning Roller Rockers. With the increased lift on the camshaft, the rocker arm travels so much more that I can't get a socket on the adjusting nut on the rocker arm. I tried to adjust the valve lash while the engine is running but it is impossible. The socket keeps being thrown from the rocker arm. I called TPIS for some advice but they told me to:
Adjusting lifters is the last of the assembly steps. It is also a good place to get messed up. The following procedure works for all 4-stroke engines:

1. Insert all pushrods.

2. Pick any cylinder to start with.

3. Turn motor over until you just see the exhaust pushrod move.

4. Install the intake rocker arm.

5. Install the rocker arm adjusting nut.

6. Tighten nut until all free play is gone. (Be careful not to collapse lifter)

7. Turn motor over until intake pushrod opens all the way and then just close. Now repeat steps 4 through 6 for the exhaust rockers.

8. Do all the other cylinders.

9. Now tighten all adjusting nuts one more turn.


Should I follow this advice? Will i have to do a readjustment after the engine is running or can I stick to this? Thanks.

Joe

 

For future reference you might want to post a thread like this on the general engine board, it would probably give you a better range of response then the TPI board. Do you have a Haynes or Chilton repair manual? I adjust valves just like it says to in the manual. Set #1 at TDC on firing stroke and adjust intake and exhaust valves on 4 of the cyls (I dont have the book here so I can't remember which 4 it is) Then rotate the motor so that #6 is at TDC on firing stroke and adjust intake and exhaust valves on the other 4. You might want to just go 1/4 or half turn more after tension is felt just to be on the safe side the first time you start up. Then you can adjust again later if you want.

 

Was your engine originally equipped with a hydraulic roller camshaft? If not, you'll need much shorter pushrods.

I'm not familar with the 88 GTA engine specs, but I knows from previous experience with an 86 Vette engine that without installing the correct shorter pushrods, you cannot make lifter adjustments.

Because the pushrods are too long, it fauses the rocker to sit to high and just about eliminates access to the adjusting nuts.

Also self-aligning rockers, I'm told, need to be used without guide plates.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

My block originally did not have a roller cam but I installed everything to make it a roller, including the shorter pushrods. The heads do not have guide paltes, requiring self-aligning roller rockers.

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1988 GTA 5.7L Auto
355 ci. block, SLP Cold Air Intake w/ K&N, fully modified MAF Sensor, TPIS 52mm Throttle Body w/Air Foil, Fully Ported and Polished Plenum, Nikel-plated Ported SLP Siamesed Runners, Ported TPIS Big Mouth Intake Manifold, stock heads w/ 1.52 Comp Cams Self-aligning Roller Rockers, TPIS ZZ-9 Roller Camshaft, TPIS Valve Springs, Cloyes True Double Roller Timing Chain, TPIS Adjustable Fuel Pressure Regulator, Balanced Bosch 22 lb/hr Fuel Injectors, MSD 6AL, Taylor 10mm Wires, Bosch Platinum +4 Spark Plugs, MSD Blaster Coil, March Underdrive Pulleys, 6 3/4" Vibratech Streetdamper, TPIS Level 3 PROM, 160 T-stat, Low Temp. Fan Switch, Stock Distributor w/ Bronze Gear, SLP 1 3/4" Headers, Random Technologies High Flow Cat., Adjustable Borla Cat Back Exhaust, Level 10 PTS-3 700R4 Trans, B&M Holeshot 2400 Stall Converter, B&M Trans Cooler, TCI Aluminum Finned Trans Pan, 3" Balanced Aluminum Driveshaft, 3.73 Richmond Gears, Auburn Pro-Series Differential, LPE Aluminum Differential Cover w/ Main Cap Preloads, BF Goodrich Drag Radials, Hotchkis Lower Control Arms, Hotchkis Panhard Rod, Bilstein Heavy Duty Shocks and Struts, 1LE Springs, Energy Suspension Polyeurethane Bushings, Global West Tubular Subframe Connectors, Global West Steering Box Brace, HP Motorsports 3 Point Strut Tower Brace

"Why ride a stang when birds can fly?"

 

Yeah, what is the best way to do this. I'm building a L98 w/ a ZZ4 cam and heavier springs. Do I follow my Haynes or what? THANKS!!

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'91 GTA:5.0TPI-5-spd, Hypertech Stage 2 chip, 160stat,!TB,!Cat, K&N, Flowmaster muffler, Accel Coil,TPI Air Foil, 1LE Alum DS, poly-tranny mount, KYB's all around, & a Hotchkis Strut tower brace.
Mods in progress:
-L98 w/ZZ4 cam/springs
-Edelbrock headers
-3" flow setup
Future:
-T56/heavier clutch
-Hurst or Ripper
-4.10's
-Ram Air II Hood
-1.5" Springs
-Rebuild suspension!
Others:
-39 Chevy coupe
350/350/3.55posi
-52 Chevy p/u
-77 Bonneville 400PONTIAC/400turbo/posi
Original 50k mile 2 door... Gramp's old car!
*** Gotta love those Poncho's***