Sounds like a good idea. Ill definitely give that a shot as well and see what happens, hopefully things will start making sense.
IIRC the evap box is two pieces and separates in the middle (left and right) . The hard part is the studs on the firewall behind the heads. You can shorten them with a hacksaw blade and the engine side of the box will come right off.
Alright.... so begins my Saturday and it’s looking like it’s going to be a long one. So far I tried using the propane method to look for vacuum leaks, checked the brake booster, all around the intake, carb, vacuum modulator. Couldn’t find any differences in idle or running conditions I did for the first time however, notice when I blip the throttle I can hear a light valve train tick from the drivers side of the engine while the rpms drop back to idle. First time I’ve really noticed it. Moved on to removing the valve covers, pulled the plugs and here’s what I found... First picture is the left Bank From back to Front.Next is the right bank Back to Front Seems like some plugs look ok, some not so great, and the last plug on the right bank has lots of carbon deposit. This is the same cylinder I though I heard the tick coming from. I’m going to run out and borrow my buddies leak down tester to do a leak down test and see what’s going on. But it seems like this cylinder may be cause for some or most of my problem. I’m going to keep going and keep updating, but this is what I have for now. Let me know if anyone has anything else I should try in addition.
Update: I went through and one at a time brought the cylinders up to top dead center and checked for any play between the push rods and the rocker arms. Out of all of the valves only 3 valves had any play in them. All the rest I was able to spin but had no vertical play. All three of the push rods that had any play in them came from one of the 3 cylinders with the more fouled spark plugs in them Next step I took the rockers off and pulled all of the push rods. I rolled each of them on both a granite counter top as well as glass. Again... All three of the push rods that had play from before, and one more, were all found to be slightly bent. Enough to cause the issue I've been having? I really cant say... I'm not sure how much a push rod needs to be bent before it really starts to cause an issue. So this is the point where I am at now. I feel I should at least replace these bent 4 bent push rods, but I am still tempted to think that the stock push rod lengths I have in the engine right now may be slightly too long since having the heads decked, and new cam installed. I feel like the low vacuum at idle and bouncing needle may be attributed to some of the intake valves staying open slightly and bleeding pressure back into the intake. But again, I could be wrong. Does anyone know how to measure for new push rod lengths for a shaft mounted rocker set up? I've seen videos for other engines with an adjustable valve train but cant find anything for the Buick 350. Also, I am having trouble even finding shorter lengths for buick 350 pushrods. Does anyone have any ideas on this as well, or should I just go with TA adjustable push rods.
Your valve stem tip heights need to be reasonably close to same, other wise you definately will need adjustables. I took a stock pushrod, cut off abt 1-1/2", plus cut additional 1/2" or so for jam nuts if you want. Tap each end 1/4-28" add in a stud & jam nuts, (I didn't ) & you have your adjustable pushrod checker. Mine were cut down much more for longer roller lifters. Didn't need the jam nuts, the knurling helps with oily fingers!
Oh nice, good idea. Sounds like I’m going with adjustables. One other thing I did since my last post was drop drain the oil and take a look to see anything unusual. This was the first oil change since break in and the car has about 300 miles on it. The oil have a very very slight hint of a metallic shimmer. No flakes, no big pieces, but just a metallic shimmer. Is this normal after breaking in a new engine and cam? Is there anything to worry about here?
You could turn engine over slowly by hand and check pushrod movement with magnetic base & indicator to measure cam lobe heights. With the rocker shafts removed, valve spring / valve opening action won't come into play. Dial indicator tip would stay/ locate inside the pushrod oil hole. That may tell you if everything is still at spec. If there are loose or very lightly preloaded lifters, could be the reason why, but I hope not.
If that is the break in oil in the pan, that could be all the assembly lube and what not. My oil looked like that. Even after 3 oil changes some stuff was still in there. Be sure to change the oil filter as well, that stuff can clog it.
The mystery is finally over... after finally pulling the intake yesterday I discovered 3 different lobes on the cam (TA284) with some troubling looking wear. I caught it early, but the engine is coming back out this weekend to head back to my engine builder for a complete tear down. When I told him what happened he was very surprised but quick to offered to do a complete shakedown for me. Thanks for all the input
