1st fire up after cam swap
 

well I tried firing it up to adjust the valve lash but it ran like crap, really choppy with the idle bouncing around from 400-800, and it also smelled pretty bad so I shut it down. I tightened the rockers down till ~4 threads were showing on the studs before starting it up like my mechanic buddy told me to, so is that to tight on LT1's and what is likely the cause of the choppy-ness? or could it be something else? and is the bad smell normal for the first fire up with all new gaskets and stuff? tia

I would imagine the choppiness is coming from your valves being all f'ed up, there are numerous guides to aid in setting up your valve lash but as for tightening them all down until 4 threads are showing, there is too much room for error there. Depending on the size of your cam there are only a couple ways to effectively do it, I go cylinder by cylinder, roll it over until the intake valve is part way down and adjust the exhaust and once the exhaust is past max lift and starts to close I then adjust the intake. New headers and certain products do smell for the first few heat cycles.

I was going to adjust them while running cause I know how to do it that way. I'll back everything off a bit and try again. or should I do it that way ^ to be safe?

it is entirely up to you but if you feel more comfortable adjusting them while they are running than I would adjust them either like the way I had mentioned then do them while they are running or you might be able to get away with doing the #1 TDC and #6 TDC method then go back through them with it running. I like to get them close that way you can hear the rocker that you are adjusting as opposed to having a few of them on the same bank clacking while you are trying to adjust

On my first fire up my car smelt really bad it would make my eyes water and almost choke me out lol. After about 20-30 mins of run time it went away.

Dont listen to your "mechanic buddy" anymore. tightening them down until you see 4 threads is really stupid and i cant believe you actually adjusted them that way. even with the million write-ups and shoebox's website there is no reason to listen to him anymore :D

adjust them the correct way following shoebox's site and come back.....


Do it with the engine off and get them close. then if you want to run the engine go ahead. there really is no need to do it with the engine running. its just a mess.

he's a really expeirenced mechanic but not with gen II or III sbc's and he told me to use that as a starting point not as the final adjustment. and w/ the engine running method is a proper way of adjusting valve lash, its even on shbox's site. getting them close and then firing it up is sort of a no brainer:eyes:

hey your the moron that posted the question, not me. I was just trying to help you out. your dealing with hydraulic lifters so adjusting them with the engine off or on will achieve the same result if you do it right. So there shouldnt be a need to do them twice or however many times you feel you need to do them.


but whatever, your mechanic buddy obviously knows more then everyone. Just keep on counting how many threads you see when adjusting them :rolleyes:

and how the hell did he come up with 4 threads? rocker studs can vary if your using stock studs or 7/16th studs. since the threads are thinner or more course. so the whole "4 threads will get you close" is absolutely rediculous

If everyone knew everything about these cars then these forums would be pointless. Someone should be able to come in here and ask a question without being flamed for not knowing the answer

Jesus Christ...

this thread is a fail

Sounds like you're overtightening. I prefer the engine running method, and don't think it's all that messy, just use a couple pieces of cardboard.

I'm a moron cause I'm green at this stuff? this was the 1st time lifting a valve cover and I tore the engine apart and put it all back together by myself and it runs:gtfo: don't be an ass just cause I pointed out a comment of yours was a no brainer. I suppose he said 4threads cause thats what it usually is on sbc's idk not saying he knows it all but hes been building engines for 30years. I think most people in the same position would listen to their experienced friend no?

As far as I know adjusting rockers on a Gen I SBC is the same as doing it on an LT1. Simply saying tighten them until 4 threads are showing is retarded. I don't know how he has been building engines for 30 years.

Check out shoebox's website and follow one of the methods he has there.

this is a method on shoebox's site? I just had to back off the bolts a bit and it started right up, I got one side done and I'll finish the other tonight.

Yea the tighten till you see 4 threads method is the worst idea ive ever herd. Hell he prolly uses an impact to put them on too. "Aaa just tq them to 250lbs, youll be fine", j/k!

Hey op, no problem being new to these engines. I would jump shbox's website and turn all your free time into read time. This will save you a bunch of money and frustration in the end. G/L

alright so I got had them close and was doing it with the w/ engine running method but couldn't get them to quiet down all the way so I ended up adjusting the valves with the engine off..brought number 1 to TDC and did I: 1,2,5,7 E:1,3,4,8 then turned it over 360deg and did I:3,4,6,8 E:2,5,6,7 bringing it to zero lash and then did 3/4 of a turn.. and then the engine wouldn't fire up. I figured I messed something up so I did it over again and it still wouldn't start, so I did it 2 more times and know for sure I did it right but its not firing up. It fired right up before when I had the valves loose(but ran real rough) so I'm pretty confused right now. should I try backing them off a ~1/4 of a turn? or does it sound like something else is wrong?

how are you verifying #1 TDC?

by the mark on the hub which I lined up when installing.

when that mark on the hub is pointing up you could either be at #1 or #6 TDC, that may be your problem. The only way to really tell is by the position of the valve, #1 TDC both valves on #1 will be closed and #6 exhaust valve should be open. Also adjusting valves that way is good for stock valvetrains but not really that great of a method for aftermarket cams because of the valve overlap. If you want to do it right go cylinder by cylinder to ensure that the lifter is on base circle before you set your lash.