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Discussion Starter · #1 ·
trying to figure out why after i set my valves, my fresh rebuilt 355 is hard to crank over, no spark plugs, throttle blades open, new charged battery, booster cables straight to starter, slow cranking, before i set my valves the engine was easy to crank by hand, but now its really hard to crank, with spark plugs in cant hardly crank it over by hand, tried to use the starter and melted booster cables, after i crank it with no plugs i can hear something under valve covers creaking, took valve covers off and everything looks normal, had some oil flowing out of a couple pushrods, the reason i was cranking it was to prime the engine with oil, just wondering if the Pac 1212x springs, or ls7 lifter, 1.6rr and hotcam would be causing this, kinda seems like its something to do with valve train, i only put 1/4 turn preload on lifters. Seems like without spark plugs when i rotate it by hand to goes good for a bit then brings up in something. springs binding up maybe? anybody have any thoughts on this? starting to think bad valve adjustment? bad lifter?
 

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it'll be harder to turn over with the valvetrain in play, you're fighting spring tension. but it's a roller valvetrain, so effort should be fairly low.

a "fresh rebuilt" full of assembly lube should be really easy to turn over....
 

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Discussion Starter · #4 ·
it was really easy until i set the valves, used your adjustment instruction on your page Steveo, took me no time at all, think i will start over, back off all the rockers, and try cranking the engine by hand again. i will report back. wonder if i might have done it backwards, second guessing myself now.
 

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Once you get the engine running, the ******* valve adjustment never fails. You idle engine, back rocker nut off until clatter occurs. Tighten nut until clatter stops. Tighten nut 1/8 to 1/4 turn more. That rocker is adjusted. Move to next rocker.

After each rocker adjustment, stop engine and lock the nut in place. Start engine and do the next rocker.
 

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Discussion Starter · #6 ·
with the engine running method i guess there's no order? go down 1 side then the other?
 

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Discussion Starter · #8 ·
thanks for the info, if i can get it running, i will try that method, i will report back.
 

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Discussion Starter · #10 ·
update: backed off all the lock nuts on rockers, and engine cranks easily, going to try readjusting rockers again.
 

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Discussion Starter · #11 ·
noticed that after i backed off all the lock nuts, at max lift, i cant even get a turn on the lock nut on a couple rockers, like the stud is too short, or pushrod too long maybe? still stock length pushrods. is that normal? but when the valves are closed i can put the nuts on no problem, also noticed when adjusting preload 2 rockers were hard to turn the nuts, like lifters would not compress, any thoughts anyone.
 

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Were the heads decked? Block re-surfaced? If so - there goes your stock-pushrod length. Did you use a solid lifter to check clearance between the valves and pistons before you did final assembly? Since you cranked it and melted the cables in the process, I would be concerned that you had a collision between the piston(s) and valve(s) and now something is bent. Were it my car, I'd stick a borescope in each plug hole and look for plug indentations indicating a collision occurred.
 

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Discussion Starter · #13 ·
the heads were decked, i did check the pushrod length, new they were a little long, the pattern was a bit towards the exhaust, did not think that the piston and valve would connect tho. i used a weak spring to measure pushrod length. so i guess what your saying is, at max lift with a long pushrod there's a chance that my valve and piston would connect? that would suck. but seems like to me couple lifter are not compressing, when i set preload the spring compresses, not lifter, is that normal?
 

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Discussion Starter · #15 ·
I think there might be a little misunderstanding here, just to clear it up, I did set my valves when they were closed, not at max lift. I just noticed that when I was setting preload 2 rockers nuts where hard to turn a 1/4, I should be able to turn up to 3/4 I believe, not sure why the 2 were like that. I thought I would be able to start all the nuts on the rocker studs but I can't, there's always 2 that won't thread on until I crank engine over. With stock stamped rocker's I can put the nuts on all 16. Going to try again. I would hate to have to take the intake and heads off. If I did, do you guys think I could reuse the gaskets? I don't mind buying new ones but, it took a month to get these ones shipped here. Thanks for all input.
 

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I think there might be a little misunderstanding here, just to clear it up, I did set my valves when they were closed, not at max lift. I just noticed that when I was setting preload 2 rockers nuts where hard to turn a 1/4, I should be able to turn up to 3/4 I believe, not sure why the 2 were like that. I thought I would be able to start all the nuts on the rocker studs but I can't, there's always 2 that won't thread on until I crank engine over. With stock stamped rocker's I can put the nuts on all 16. Going to try again. I would hate to have to take the intake and heads off. If I did, do you guys think I could reuse the gaskets? I don't mind buying new ones but, it took a month to get these ones shipped here. Thanks for all input.
If the studs are all the same length, and you can't get the nuts on only two of the rockers until you "crank the engine over", there is something wrong in regards to where the cam lobe is in relation to the rocker. How sure are you that your crank-hub is keyed correctly and that the cam was installed correctly and properly aligned to the crank and TDC-1?

Also, if the heads were decked, you certainly are running the wrong length pushrods. If the heads and the block were decked, you're WAY off. And if the engine would not turn over via the starter, and locked it up to the point that the cables smoked when you tried, but the engine turns fine without rockers installed - there are things that ran into each other that never should have, and did so under some rather significant torque.

Do you live near a Harbor Freight? This thing would be $90 well spent
 

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Discussion Starter · #17 ·
I can get 14 rocker nuts on, in order to get the other 2 on i gotta turn over the engine. I installed the cam, timing set, and hub myself. I used pic's I saw on here to do it all, the cam dowel was at 3 o'clock, crank key at about 2 o'clock, crank gear dot at 12 o'clock, cam gear dot at 6 o'clock, cylinder 6 TDC, think i done it right? this is the third LT1 I put together, didn't have any off these problems before with stock stuff. going to try it again tomorrow, if the engine is still hard to crank its all coming apart again, I will report back on my progress.
 

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having the wrong length of pushrods wouldn't be causing all of this nonsense, definitely not just from having the heads decked a bit. marginally bad valvetrain geometry wears out components and blows up engines at high rpm, but certainly wouldn't stop an engine from turning over.

i think you should go back, loosen all the nuts, then take your time and bring each cylinder to top dead center and set zero lash on that cylinder (leave the rocker just slightly loose). if you're using poly locks (you should be) you should be doing this BY HAND. there's no need to use a wrench to zero a lifter with a polylock on the rocker.

then make sure the engine turns over...

if it does, do a compression test to make sure you didn't break anything, add 1/4 turn preload and call it a day.
 

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Discussion Starter · #20 ·
I don't think so, cam dowel is at 3 o'clock, crank key at 2 o'clock, crank gear dot at 12 o'clock and cam gear at 6 o'clock, cylinder 6 TDC .
 
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