Engine Knock after headgasket job HELP

Cheapskate207

The left one hangs a little lower
Jan 12, 2020
447
336
73
29
Maine
Jut got done swapping head gaskets and upon initial fire up I have a loud knock. Heads are edelbrock performers that were cut down .013. They were also pressure checked, looked over and new valve spring seats installed. Old rockers were worn (crane 1.7 golds) so I swapped in some new crane 1.7's. I did not get new pushrods, or even check them for that matter. I used a thick and thin shim on each rocker and hit 18 ft/lb's in about 3/4 of a turn on each rocker. I adjusted rockers by finding cylinder 1 TDC, adjusting intake and exhaust, then rotating balancer a quarter turn and adjusting the next in the firing order. Unknown cam. Car ran great before and did not make this sound. Could a bled down lifter cause this? Maybe misadjusted rockers?? PTV??? I will attach a link for a video of the car running. I'm going in for knee surgery tomorrow and was hoping to have the car squared away before hand. I hope to get this addressed ASAP once I am able to move around enough to work on the car. This was a big job for me and my first time doing any motor work on a SBF. As you could imagine I'm feeling pretty down on my luck. Any help is greatly appreciate.


Thanks,
Drew
 
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Cheapskate207

The left one hangs a little lower
Jan 12, 2020
447
336
73
29
Maine
Thanks. That's my plan. New balancer, verify pushrod length, and readjust rockers as needed. I hope that takes care of it, but I'd like to find out why. Would a loose rocker cause a sound like that?
 

Cheapskate207

The left one hangs a little lower
Jan 12, 2020
447
336
73
29
Maine
Just thought I would update this in case anyone else runs into an issue like this. I reset valve lash and in doing so found 3 lifters that had bled down. They all hit 20 ft/lbs in 1/4-1/2 turns like all the other rockers did so I put it back together. Upon starting it back up it still made the noise, no surprise. At this point I took it for a drive and the lifters pumped back up. It's now nice and quiet.
 
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Gs87GT

Active Member
Sep 25, 2019
256
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Penn's Woods
Glad to hear that. I was going to post that was absolutely valve train related. Glad you got it squared away.