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post #1 of (permalink) Old 11-10-2008, 12:58 PM Thread Starter
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RV cam and valve adjustment question

Howdy all, I been away from this forum for a while, hope everyone is well.
A little help please. (I have this posted up in several locations)

1990 Chevy 350, with an RV cam
Is there any difference in the valve adjustment for the RV Cam from the normal adjustment?
Chevy manual calls for 1 full turn from Zero lash. I don't have any info about the RV Cam. I don't believe an RV Cam would change the height of the valve opening; only the time it's open ....... right??????

Reason for asking is that I found them all at Zero lash when I started this project? Rebuilder/installer error? or is that the way it should be with the new cam? This motor w/RV cam has approx 20K miles on it.

This all started because the motor is using oil (lots of blue smoke, seems worse at idle or slow speeds?) and is getting worse.
Compression tested good & balanced.
All spark plugs show oil damage on one side, so I assume the oil is entering through the intake valves. I suspected the PCV system sucking oil in but it appears normal: I disablabled the system for approx 1K miles and still had the blue smoke. No vac leaks found around the intake. Now I'm changing the valve stem oil seals and noticed the valve adjustment.

Thanks for any help/thoughts/ideas/imput.

"The Heep" 73 Commando, 258 I-6, T-18, Scout Dana 300 w/Tera 4:1 Kit, SOA, PS, Thru-dash Cage, Alcans, OBA, ARB's, HEI, Ft disc, MC 2100,Dents, Mud & Rust.
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post #2 of (permalink) Old 01-22-2009, 11:51 AM
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sometimes a compression check on a oil burning motor isnt the best indication of whats wrong or anything realy.

oil soaked rings can cause a bad cylinder to still read okay compression. the oil kinda seals around the ring and holds compression.

i would adjust vavles with the truck running at operating temp. slowly loosen till it clatters then tighten till clatter is gone and keep tighting 1/8 to 1/4 past where the clatter stops. do this on all of them and it should be good.

have to go slow cause the hydralic lifter is there try compensate for the change in rocker arm adjustment

blowing smoke at 20k isnt good.

mine is still running strong at 280k blows alittle blue smoke at start up then it goes away.

my first tbi 350 i installed a compu cam mild like rv camb in it and adjusted with the truck running after the initial adjustment while it was on the engine stand. i got it closenough to run while on the engine stand. 0 lash would be alright. then with it running i did the clatter then adjusted it out till it was all quite. it takes alittle bit cause during that first fire i had most all the 16 vavles clattering away.

im trying to think where the oiling problem would come from. not much is comeing to mind right off hand.

good luck and let us know what you find.


89 ifs-sfa truck tranplanted in a 83 K-5 blazer offroad only rig
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