prestige6

Got ready to get the big block going down the street today. Blead brakes,put on steering wheel,Started car up running beauitful,choke working fine and running great...This is a project started last year.Everything done on motor,new 3370 carb,valve job,all new gaskets etc.et. by the way 437-390 HP. adjusted valves last week, car was running great.After it warmed up today,started going down the block running great,turned around started back home got on it a little,started to miss. Checked it out when I got home 3 cylinders not firing way to rich. Pulled out the 43 plugs put 45's in same thing,checked cap and rotor both ok.carb and timing were dead on before this started.have a funny feeling valves need adjusting, Any IDEAS of an easy way to adust the vales without making a mess with the motor running.Tried an old valve cover with holes in it still makes a mess...

midyearvette

sounds like something may have let go when you jumped on it
remove the valve covers and look for a broken spring, bent pushrod and the like...also check for a bad intake or carb gasket
follow the sticky and adjust the valves with the mill not running
setting lifters while running is a waste of time and oil although others swear by it.....

prestige6

What is the sequence for adusting the valves. Is it the same as a small block where you only have to get the engine to # 1 And #6 to adjust all the valves????

Mossy66

Hard to believe that valves came out of adjustment on three cylinders at the same and relatively short time. Are the cylinders adjacent to each other?

midyearvette

yes, however in your case it would be best to do them one at a time so you can see the action and maybe see something wrong
on each cylinder, set the intake when the exhaust STARTS to open
set the exhaust when the intake is FULLY OPEN AND "STARTS" to close (come back up)

LSUvetteguy

I hate to bring this up but a cam lobe comes to mind.

DansYellow66

Yeah - if you really have 3 dead cylinders from what you believe to be a too rich condition, I think I would be looking at a fuel problem. Maybe a needle and seat has trash on it and is not sealing - and flooding the carb. If a 427/390 it would have a hydraulic cam if stock - unless this is a new engine and you wiped out the cam I don't think running the valves will help.

Mossy66

Also, if you did wipe some lobes, I would think there would be a lot of clattering, even with hydraulic lifters, and I don't think it would cause the plugs to foul. How are the rest of the plugs?

Gerry

prestige6

ttt

Mossy66

I guess you could use this. Post # 7:
http://forums.corvetteforum.com/c1-a...djustment.html

Or this:
http://www.lbfun.com/warehouse/tech_...ch%20paper.pdf

Gerry

prestige6

Pulled the valve covers,figured I would start the easy way... Bingo # 1 Intake bent pushrod.Now to get a pushrod and readjust and try again..Thanks for your help!!!!!!!!!!!

midyearvette

figure out first, WHY did the pushrod bend???
bb pushrods are tough....check for bad springs or the wrong springs for your engine..(coil bind comes to mind)
with out finding the cause, you are more than likely to repeat the failure and maybe not so lucky the second time around.....

also look for cut rocker studs...could be the wrong rockers for a high lift cam

prestige6

I think what happened is the car sat for a long time,I adjusted the lifters and one wasn't pumped up all the way and when I drove down the block, it pumped up and bent the pushrod. Everything is stock and new.I'll see when I get the new one and try again.Thanks for your help..

midyearvette

the lifters do not have to be pumped up to be adjusted properly....

Mossy66

Your original post mentioned three cylinders had trouble. Did you find anything wrong with the other two?

66BlkBB

More than likely it is the same thing on the other two. Just that they were not tightened down as far.

Mossy66

How would the plugs get fouled? With a bent intake pushrod I would assume the intake valve is staying closed or not opening all the way. In either case there would be no extra fuel or oil in the cylinder, or am I missing something?

Gerry

midyearvette

could be a bent valve ( intake) with blow back into the intake runners, polluting other runners with the intakes starting to open or fully open in other cylinders,....
maybe he did over adjust his lifters, but he would have to bottomed out the plungers and then kissed a piston with the valve ??..bwdik

prestige6

Put in the new pushrod tonight,adjusted the valves cold. Let it warm up and used a set of oil deflectors to adjust hot. Car is purring like a Dream now!!!!!!!!!

KC John

How did the oil deflectors work? Did you still make a mess?