[Shockwave78]

Originally Posted by 78w72

Did you do the adjustment right with the new nuts? Positive the engine was a TDC of compression stroke and you adjusted the correct lifters based on that link? Just asking since I/we dont know how much mechanical experience you have. I recently tried to help a guy from another country adjust his rockers and even after sending the link & a couple youtube videos... he just tightened all the rockers to "zero lash" then added 1/2 turn to all the rockers at one time, didnt work out to well and took him a few tries to get it right, engine is running good for him now.

Also, if the crower lifters say 1/2 turn, thats what they should be set to... 1/2 turn past zero lash is not a lot, most HFT lifters recommend that unless they are the type that say 1/4 turn.

Leak down tester- Check with local auto part stores, they may offer a free rental for this. or get the warm cranking compression numbers to help others on here diagnose the issue.

Gas droplets on the windshield- I have had that happen on a couple engines that ran great when I would remove the shaker scoop & add a velocity stack to look cool would very get small amounts of gas droplets from holley & q-jet carbs when driving at normal speeds... reverberation or not, the engine ran great with or without the air cleaner removed so i dont think thats part of the issue your having.

After trying some of the tests mentioned above to identify the issue, you may need to pull the timing cover to check cam timing & timing chain alignment... but if you are sure the chain/gears were installed right, i dont think not degreeing the cam is causing the problems, i have installed cams straight up that run great. its easy to get the timing chain off a tooth or even installed 180 off if following chevy manuals.

I did not do the rocker arm adjustment exactly like in the link, I rotated the engine over to each cylinder in firing order and adjusted each on tdc of the compression stroke, which should have the same result. I have not done a full engine teardown/rebuild before this, but have done basically everything else there is to do on a stock engine, I've been working on cars/engines similar to this one for about 7 years. As far as the gas droplets and vapor out of the top of the carb, it is only at WOT and it has enough velocity to curve back and hit the middle/top of the windshield. I will be checking the timing today with the method as Cliff said, I will look into renting a leak-down tester and doing the warm compression test as well. The more tests I do the more it looks like a cam timing issue as many have said, but if nothing else it is a learning experience.

[400 Lemans]

https://forums.maxperformanceinc.com...ower+degreeing See Cliffs post #6. The 60240 is the same deal.

[78w72]

Originally Posted by Shockwave78

I did not do the rocker arm adjustment exactly like in the link, I rotated the engine over to each cylinder in firing order and adjusted each on tdc of the compression stroke, which should have the same result. I have not done a full engine teardown/rebuild before this, but have done basically everything else there is to do on a stock engine, I've been working on cars/engines similar to this one for about 7 years. As far as the gas droplets and vapor out of the top of the carb, it is only at WOT and it has enough velocity to curve back and hit the middle/top of the windshield. I will be checking the timing today with the method as Cliff said, I will look into renting a leak-down tester and doing the warm compression test as well. The more tests I do the more it looks like a cam timing issue as many have said, but if nothing else it is a learning experience.

I will let others chime in on the adjustment... but I dont think thats the correct way to adjust them. Doing each piston at TDC does not get the lifter on the base of the cam lobe. If you can rotate the engine & know how to find TDC of COMPRESSION stroke (TDC can be on exhaust stroke too) then I would suggest you follow the procedure in the link I posted, its very important to do this adjustment the right way.

Just wanted to mention carbs can spit fuel droplets when exposed to the wind while driving, mine would do it at WOT too but also at lower speeds & less throttle, especially on the holley double pumper carb i had on a 455, could watch the droplets arch up onto the windshield just like you describe.

Learning experiences are good, that how we all learn, but this may be a time to learn how to adjust rockers correctly, the way i understand how you described it is not the correct way.

Hope you can figure it out.

[Gach]

Yeah he’s doing valve adjustment wrong.

[slowbird]

Originally Posted by Shockwave78

The last thing I noticed is, at WOT when the top flap of the secondaries open as much as they can (which isn't much, maybe a quarter open)

Can you clarify this statement?? You saying the secondary air valve is only opening about a quarter? If so have you verified that the secondary butterflies are opening fully? Have you pulled all the plugs to see what they look like?

[Shockwave78]

Originally Posted by slowbird

Can you clarify this statement?? You saying the secondary air valve is only opening about a quarter? If so have you verified that the secondary butterflies are opening fully? Have you pulled all the plugs to see what they look like?

Sorry, I just saw this post when you mentioned it, I did confirm that the secondaries do have the full range of motion and that the air valve only opens a quarter or so under wot. I pulled the plugs a few days ago and they were carboned up, so I cleaned and reinstalled them. I have not checked since, but I will be pulling the plugs today for compression testing so I will add what they look like.

[PunchT37]

Originally Posted by Shockwave78

Just checked the rocker nuts, and when they are torqued down per the manual, I can watch the valve open. I backed the nuts off to adjust them like you normally would with an adjustable valvetrain, did a compression test and it returned 175 psi, a bit more than I was expecting, given the whole engine is stock except the cam. Regardless I am definitely switching the nuts out today! I had to swap the valley pan after break in and had a chance to check the cam and there were no wiped lobes or abnormal wear, thank god. I have also been using the car as a daily for the past year or so, which narrows down other potential problems it might have, but this is a really good starting point (hopefully the only problem)!

Thanks for all the input and ill report back with updates after the new rocker nuts.

If he did this on the base circle, he found his problem.