so i did loosened my roller rockers up like someone suggested due to trouble starting and i forgot to mention this is the last posting that when i crank my motor over it floods really easy and gas drips out of my y-pipe where i doin have it completely connected yet...should i loosen then studs up more? do i have some valves still open by chance? or could there be something else wrong...im gettin really frustrated


1994 z28---complete rebuild

 

How does it sound when you crank it over?You said in the previous post that 6 of the rocker nuts you coould loosen by hand.I would start over from the begining and re-lash the valves.

 

X2. Start with the basics. In your manual it will tell you specifically what pistons need to be at TDC to adjust those particular valves. Then rotate the engine until another cylinder is up to TDC and adjust those. Take your time and you will know for sure that your valves are adjusted correctly. Rocker arms that are too tight or too loose just won't get the job done.

 

i did it by the book when i had the motor on the stand but since i my new lifters were already pumped up they may of been why i did it wrong but i adjusted them by the book.....ill just start over i guess and see what happens

 

Use this guide to help you set the valves....

http://shbox.com/1/4th_gen_tech2.html#adjust_valves

Also, I'd be very concerned about fuel dripping out of the Y-pipe...there is no good reason for this to happen even with the valves mis-adjusted. Adjust the valves and report back with the other issues...

 

You should never "pump" your lifters up. All that does is fill them with oil and make it harder for the pushrods to depress into them, making the adjustment feel more like a solid (non-hydraulic) lifter.

 

o ok i was told to pump my lifters but know i know not to...ok thx ill let everyone know what happens in a few days

 

What?

 

ok now im confused....r u or r u not supposed to pump ur lifters up before installation?

 

We're all speaking english here right?

 

I have built several engines and have never pumped a lifter. I've also been told that by several quality engine builders. You can pump the lifters if you want, but it will act like a solid lifter, being filled with oil will make the lifter hard to depress. I'm sure there are tons of people on here who are going to disagree with me. That's their opinion, this is my opinion.

 

ok thats understandable but when u r tryin to adjust a already pumped lifter that would mean that the rocker isnt tight enough or to loose if u go by the book?

 

I've always just made sure the lifter plunger is at the top of the lifter when installing and setting valve lash. Even when you buy LS7 NEW lifters, they are pre-filled with oil for this purpose. And when the motor is running the lifters are pumped up, so wouldn't you want to set the valve lash to replicate running conditions? That's the purpose of adding PRELOAD - you preLOAD the lifter by depressing the plunger when it's at the top of its stroke. I've done this on my 383 several times, on several customers' cars, and several friends cars as well, all without a problem.

Are you saying that lifter plunger should not be at the top of the lifter when you adjust lash? Or maybe I'm completely missing the boat here...

 

Yeah I'm speaking English, and I'm saying that is the most ridiculous thing I have ever heard!! Why would you not want the plunger at it's highest position? Just saying something like that discredits you and your post....

 

Ok I guess discredit everything i'm saying. I guess I have no clue what the hell i'm talking about. I've built several engines and never had one problem. I just had my trusted engine builder specifically telling me not to fill the lifter with oil by pumping it with your hand. I am talking about a fresh engine rebuild, not an engine that's already been broken in. I guess I misunderstood the guy, sounded like he was building a fresh engine. To anyone reading this that thinks i'm an idiot: that is your opinion. Opinions are like a**holes, everybody has one, right? I guess from now on when people are asking for advice i'll wait for icematrix69 to chime in and tell everyone they are an idiot instead of someone like me stepping in and speaking from experience.