Rocker arm PROBLEMS!!!

[andrewmckernon]

God. Im having real big problems with my rocker arms and lifters. I tighten them in the right order and everything. And once i do that i take the car for a spin. My 68 vette feels great for the first 10 minutes. After that the response from the accelerator is terrible. Loan and behold i take off the valve cover and there they are, loose as ever, my rocker arms....

Anyone got any ideas??

They just wont stop coming loose....

-andrew

 

[68Roadster]

Andrew,
Have you tried replacing the nuts that go on the rocker arm studs?? These may be self locking and yours may be worn.....

Are you doing this with the engine running?? Are you cranking down 1 full turn after the clatter stops??

Can you notice if the rocker arm stud is turning in the head or protruding any further than when you originally started??

Have you pulled any push rods to see if they are bent??

Let us know what ya got......


Cee

 

[andrewmckernon]

Rocker update

I haven't adjusted them when the engine is running. Should I? My shop manual told me to turn the nuts (new ones which i did purchase with new rocker arms) a half turn after play is gone. I have pulled the push rods to see if they were bent, and no damage was seen. The studs are not backing out, and im pretty sure that they are threaded and not just pushed in there studs (dont know term).

What ya think??

-andrew

 

[AKRAY4PLAY]

if you tighten the lifters with the motor running, go 1/2 to 3/4 turns after the ticking stops IF AND ONLY IF YOU HAVE HYDROLIC LIFTERS. solid lifters will be to tight and your valves will float and burn. try swapping to some posi-lock nuts, the ones with a set screw in the top. they will hold better than the stock acorn style. they will also allow you to use a stud gurdle. this is a device that clamps all the rocker studs together and keeps them from backing off and also aids in stabilizing them under high stress. most gurdles require tall valve covers and limited baffles, so they do have their drawbacks. lastly, and i know they're there, but are the washers under the nuts?? good luck getting it right, Brian

 

[sscam69]

Have you checked to make sure the valves are both closed before you tighten them?

 

[68Roadster]

Andrew,
Your engine should have hydraulic lifters and the shop manual recommends adjustment with the engine running.
You may need to get the little deflector clips to put on there so you don't get deluged with oil.....

After the engine has warmed, the book advises to turn each nut until the tick stops, go 1/4 turn more and then allow the valvetrain to stabilize for a few. One full turn is the max after ticking stops.

Adjust all, one at a time, replace the valve covers and try it.

Cee

 

[Blue82]

Andrew , I adjusted mine (hydraulic) lasst eweekend according to an article I read that said to use the IC (intake closing) EO (exhaust opening) method. Warm up the car and then turn it off. Remove the hot wire or coil wire from the distributor so the car will not start. Turn the engine over with the key until the front intake valve begins to close. Now you can adjust the ehaust valve to 0 lash on the pushrod and then turn 1/4 or 1/2 more according to your preferences.

Keep doing this to the other three exhaust valves and then do the same to the intake valves making sure that the appropriate exhaust valve is opening when you make the adjustment. Do this on both heads and you should be OK.

I have never used this method before, but it worked like a champ. Doing it this way makes sure that the valve you are adjusting is on the heel of the cam lobe and not on either ramp. Try this and make sure you don't need new lock nuts.

 

[vette-dude]

Tip for adjusting valves with engine running. Get an old set of stamped steel valve covers and cut out the top from end to end just enough to reach the adjusting nuts with the socket and wrench. Then when you are adjusting with engine running you don't get the oil all over everything including yourself. I have a set and put rubber gskts on them and actually bolt them to the head. this keeps any oil from seeping down the side of the engine while you are adjusting the valves. This will only work if you have hydraulic type lifters as you need to get at solids with a feeler gage and there is not enough clearance to do this operation.

Randy

 

[vette-dude]

Forgot to add that the clips do work but are a real pain to use and sometimes slip off when running. They do keep most of the oil contained but it still gets messy.

Randy

 

[page62]

I'm with Vette-dude! Valve covers are easy to find. I picked up an old pair at a swap meet for a buck. They would have been free, but I was feeling generous

 

[WayneLBurnham]

That's a neat sounding method - I may try that myself

I had always set them the same way, and always on a hydraulic cam. I personally REFUSE to own a solid lifter monster - I hate getting oil all over everything setting the lifters every 100 miles...Although at least they don't squirt oil like hydraulic lifters do - it still goes everywhere everytime you take off the covers.)

Assuming the engine wasn't just assembled, in which case you have to tighten them all a little more to start it or NONE of the valves will open...

I always did it running and hot. I would loosen one until it started clattering then tighten it only one-half turn. Others would tighten until the engine slowed slightly then back off half turn. That always seemed dangerous to me. By only tightening them half a turn past clattering I probably never got the full valve lift, which the standard methods the others here probably achieves.

Hey, you don't by any chance have some Rhoads or Crane Variable Lift Lifters in there do ya? I used those once and liked them, but setting them required a procedure unlike what I had been doing since the mid '70's or they would loosen. They always "ticked" when working and behave very differently once warm. They gave you a poor man's variable valvetrain though, if you could stand the constant lifter noise.

Other than intial building an engine, I've never even considered setting lifters with the engine off. I know you CAN use feeler gauges, but I never knew people who did.

That even includes mechanical ones. Those you just tighten more carefully and the SECOND the clattering stops, so do you! (I'll never forget Mike's damned 396 Chevelle. He always had two sets of bent socket drivers (not ratchets) and every night we'd go cruising we stopped in some gas station or another to "quick - we need to set the lifters again!" Never. Again.)

Only other thought I can add to the one of change nuts is are you sure they ARE functioning rocker arm nuts and not some matched set of regular nuts somebody put on there (without any pinch to them)?

 

[Rowdy1]

Solid Lifter Monster?

I have solids, I adjust them cold, not running, and I also only do it once a year No fuss, no mess

 

[WayneLBurnham]

I always wondered if Mike had us doing something wrong...

I couldn't believe anybody would put out a product that worked that badly...

So what do you do with solid roller cammed puppies which are so popular now? When roller cams came out to "common" availability they were so expensive people always went with hydraulic lifter versions. I was not then in either league but may consider one now.

 

[GWHITE75]

WayneLBurnham I ran a Comp Cam 288AR street roller in my 496" motor for several years. I checked/adjusted the lifters about once a year. I did run a stud girdle on the heads, due to them being aluminum and the spring tension.

The street roller does not require a brass distributor gear and was very streetable with the 496" motor. I believe I paid about $230 for the cam. Of course the other parts came with the motor when I bought it and they do cost more than the same parts for a solid lifter or hydrualic cam, but I think you really need solid lift and roller cams, if you want to run some high RPM numbers on a motor. Otherwise, hydrualic is the way to go. I know some people who really like the newer hydraulic roller stuff, but it's not cheap.

 

[WayneLBurnham]

I think you just replaced Chris as my new Hero

;worship

(Actually, I think we talked earlier...)

I am trying to put everything on hold on all other fronts to get. my. OverDrive. NOW. (...even a $1750 upgrade of the baby small block in my '75....)

I wish I could find an intermediate cost OD to the GV. But even a new 700R is $1500 - so that's money wasted when it wouldn't take the final engine. Everyone has me terrified of a junkyard 700R, even with "bolt in" upgrades. I thought about your 6 speed, but they're $2500 too, without clutches and conversion fun. I even briefly considered putting in some lower gears again in the 12 bolt, but they are modified from standard 12 bolt and would require an expensive set up in the $500-750 range probably, if not a whole new altered carrier.

Just last night I caught myself from even selling off an expensive gun I hadn't yet got transferred to me - that was too far....

Just hope the valve springs, timing chain, lifters and bearings and everything else keep taking a steady diet of 4,000-4,500....

But I have never lost sight of the original plan that got me into this thing in the first place, which was building a really sillily (if that's not a word it should be) big block and find a car to put it in....

I will be picking on your experiences over time.

BTW, are you going to the Houston Vette thing on the weekend of the 25th? I'm going to try to drive down Sunday.

 

[vigman]

Not to further open the can O worms

http://www.corvetteactioncenter.com/forums/showthread.php?s=&threadid=22555

We went throught this in the C-4 forum a while back... FYI!


Vig

 

[page62]

Where are you spending $1500 on a 700R4? My 200-4R was only $1000 (for a Level 2 unit.) Or do you mean the entire package, including accessories?

 

[andrewmckernon]

Rocker's Gone to Hell

I thought i had adjusted my rocker arms correctly. I thought I had found absolute zero, and to my surprise, some 30 miles away from my home, my 68 broke down. Cost me 100 bucks to get it towed home. Now what??

Could I have damaged anything.... Is my SB done for??

-andrew

 

[Ol Blue]

andrewmckernon

In putting together a big block recently I had some problems with rocker stud nuts loosening, bought new nuts and still had problems. Finally went with new studs too and that fixed the problem.

The threads looked ok, but just wouldn't hold. I'm running solids on a 595 lift cam.

Sorry for such a simple answer, but that's what worked for me.
Ol Blue
http://www.knology.net/~corvettes/Alspaugh-68Racer

 

[WayneLBurnham]

GWhite75 joins 69MyWay on the Discard List....

Andrew, sorry for hijacking your thread.

NO!!! Again, I doubt your engine is trashed. A really bad event could have holed a piston, but that's not real likely. Likely you have a valvetrainonly event - maybe including a broken timing chain. At worst you could be looking at a head being redone.

Page62, you - YOU are my newest, bestest buddy!!!

A "Level II" 200R for $1K sounds EXCELLENT!!!

I haven't looked super hard, but everywhere I looked for 700R's just on the web were in the $1500 range.

I could float $1K to save my Holy engine from my lead foot

I have some questions on the definitions of "Level II" and what all is required to swap from a Turbo 400 to a 200R (which I know is stronger than a 700R), how much power it will handle, expected lifespan and where you got it and so forth. I will try to email you shortly.