C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Need Input Engine Work

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Old Feb 16, 2005 | 09:41 PM
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Default Need Input Engine Work

i AM SETTING UP MY NEW EINGINE IN MY 86 COUPE.
I just put in new roller rockers and I need to know the proper adjustment system to get them right the first time. what is the proper way to adjust them?


Ken-can
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Old Feb 16, 2005 | 10:04 PM
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I've used the EO/IC method twice with no problems:
-loosen all the rockers, starting with #1 cylinder, watch the pushrod motion as you turn the crank
-manually turn the crank till the exh valve pushrod is opening
-twirl the int valve pushrod while tightening the nut till you just feel resistance, this is zero lash
-tighten the int valve rocker nut 5/8 turn and lock it
-turn the crank till the int valve pushrod is closing
-set zero lash on the exh valve, tighten 5/8 turn and lock it down.
-proceed down the left bank and then the right bank in similar fashion

Don't worry about detecting zero lash accurately as I've found that there is only about 1/8 turn between where I just feel resistance till the point where I cannot twirl the pushrod. So when you tighten the nut 5/8 turn past zero lash the preload will be between 1/2 and 3/4 turn, which assures that it will be neither too tight nor too loose.
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Old Feb 17, 2005 | 03:23 AM
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heres several methods

http://www.2quicknovas.com/happyvalves.html
http://www.jimcookperformance.com/T...N7ValvLash.html

http://www.centuryperformance.com/valveadjustment.asp

http://www.babcox.com/editorial/us/uhs89720.htm

http://www.boostandfuel.com/support/setting_valves.htm

http://www.carcraft.com/techarticles/87998/index2.html

http://www.angelfire.com/fl4/pontia...8/valveadj.html

btw if your totally new at this the tappet feeler gauge measures the lash clearance between the valve and rocker on solid lifter cams

I just don,t think adjusting the valves without the oil pressure and the block up to operating temp. is the best way to adjust valves , but yes you can do it just fine with several methods discribed above

how do you adjust valves at idle without the mess of oil getting all over the engine and headers

HIT A FEW YARD SALES, SWAP MEETS UNTILL YOU FIND A DIRT CHEAP SET OF TALL CAST VALVE COVERS LIKE THESE, the CONDITION THEY ARE IN ,WITHIN REASONABLE LIMITS OF COURSE IS NOT THAT IMPORTANT

you simply cut the ribbed center section out of the valve cover, and glue the synthetic valve cover gaskets on them in the normal location,
when you go to adjust the valves you first remove the standard valve covers and install your VALVE ADJUSTMENT COVERS, they retain about 80%-90% of the oil that would normally be lost over the edge of the cylinder head while adjusting a running engine, they also catch much of the splashed oil, just leave a 1/4"-3/8" of the rolled top for strenth around the perimiter of the top surface. I bought my set for $10, they were old and slightly discolored but I could not care less! I took them home and used a drill and saber saw to remove the center ribbed area, theres several brands that are very similar in appearance, all will work! and Ive used them for over 25 years, if I remember correctly they are mickey thompson brand

now if the lifters are hydrolic of course you just back the adjustment nuts off the rocker studs with a wrench, slowly until the rocker JUST starts clicking , then slowly tighten the nut just up to the point that the clicking stops then add 1/4 to 3/8 turn to preload the lifter and move to the next rocker and repeat, the only differance with solid lifters is you use a feeler gauge inserted between the valve tip and rocker after they click slightly,to measure the lash distance recomended on the cam spec. card (normally .016-.028 thousands) and you tighten them just to the point at idle that the clicking stops... then you remove the feeler gauge and move to the next rocker
if your useing jam nuts dont forget to lock the allen key



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03-12-04, 10:46 PM #13
Ken
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Quote:
Originally Posted by grumpyvette
HIT A FEW YARD SALES, SWAP MEETS UNTILL YOU FIND A DIRT CHEAP SET OF TALL CAST VALVE COVERS ...
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Old Feb 18, 2005 | 10:01 PM
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Thanks everyone for your help. I think I can take it from here.

Again Tkank you all.

Ken
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Old Feb 18, 2005 | 10:53 PM
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I made a splash guards while I adjusted my valve lash with the engine running. However I found that I really didn't need them. As a test I goosed the engine until I saw the oil shooting out over the heads. It took about 1800 rpms for that to happen. Otherwise at idle my oil would just cascade over my rockers.

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