Let’s Tune This Engine

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that seat damage sure looks like the result of the head or pushrod guide being offset to the side,
thus severely binding the pushrod during the valve train movement,
the clicking you hear is most likely the pushrods clicking in and out,
of the rocker pushrod seats as they bind and are forced out of proper alignment
yeah its all part of learning how engines are properly assembled and,
WE all:rolleyes: :mad:make a few mistakes along the path to knowledge
the key is recognizing and learning from and correcting those occasional screw-ups:D
 
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That was intake 1. I’ll check again.

In fact I’ll double check all the guide plates.
 
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Right. Pushrods came in today. I found another guide plate that was binding and corrected that.

I carefully reinstalled all the pushrods and adjusted the preload using the EOIC method. I think I’m spot on.

I fired the engine up and... no ominous knocking. PHEW !!!! That’s a good start.

On the other hand I think I’m back to square one. A narrow vibration of the vacuum needle and stethoscope picks up what sounds like a rocker that’s a bit loose.

I took it out for a small drive. Power feels good and smooth. Since it’s late, I didn’t bother checking again the vacuum and internal sounds.

More tomorrow.
 
Checked preload while running on left bank. I think it’s ok after a minor tweak. Then I went on to the right side. Again, a minor tweak.

On the other hand, a temp reading of 8 exhaust is reading low. Whereas all the other cylinders read around 660, number 8 is reading around 350.

When the engine is cool, I’ll pull out the plug and and check the cable.

I’m still getting a fast yet very regular (slow motion video) vibration between 16 and 19. I’m curious to know of an ignition related issue can cause that.
 
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I replaced the spark plug. Temp is now where it should be on 8. But still, there something bothering me. That needle is still vibrating in the same way.
 
I did notice that there are two sets of preload recommended by Comp Cams. 1/2 a turn and 1 turn.

I set mine at 1/2 a turn. I’ll call comp cams to see if that’s what these particular lifters require.

Correct me if I’m wrong: too little preload leads to clacking noise. (I think I’m getting that.). Too much preload means valves will not shut fully and I get a vibrating vacuum needle.

Or... will too little preload also lead to a vacuum needle vibration?

Overall I get the sense this engine should be running smoother.
 
I called Comp Cams tech support. They are telling me to bring it down to 3/4 turn.

They’re also saying they think it won’t fully solve the issue I’m having with the vacuum gauge.
 
IF THE ROCKER STUDS ARE TYPICAL,THE 3/8-24 THREAD COUNT on a SBC
RESULTS IN APROXIMATELY A,
.040 ROCKER MOVEMENT TOWARD THE HEAD PER ROCKER NUT REVOLUTION.
most hydraulic lifters have push rod seats that have a very limited amount of potential movement available,
pressurized oil fills the area under the hydraulic lifters push rod seats with the lifters on the cams base circle
the idea is for the pressurized oil to take up valve train slack,
the less the seats are compressed the more room is available ,
under the seat for oil to cushion the valve train,
Id be using a 1/4-3/8 turn in past the point at idle the lifter just stops clicking

tappet%20adjustment_zps8vi9yxmu.jpg
wrenchturna.gif
 
Added a 1/4 turn to the right bank and it’s indeed quieter. The idle quality seems to have improved and the vacuum needle seems to be rapidly oscillating between 19.5 and 21. We seem to have went from a 2.5 inch swing to 1.5.

I have a hunch, that if I do the left bank, it’ll be quieter still... but the vibration will still be there.

Say, would the lope of the cam have anything to do with this ? I’m idling at 850 rpm.
 
This is what the idle looks like.


One other detail; I’m reading vacuum from the manifold where the brake booster is. That shouldn’t make any difference, should it ?
 
Gentlemen I must admit, I am getting tired of this. The vacuum charts say that this is typically loose valve guides. That just doesn’t seem possible. The heads are new. I seem to recall I was reading a stable 14.5 before the cam swap. Could it be the lifters are crap ?

At this point I’m ready to just drive this and forget about it. Really fed up with this car. Nothing but problems.
 
I guess my patience is wearing thin. I just want to enjoy this car, drive it. I’m tired of the constant little problems (that the Tangerine Tornado never had). I’m also concerned that I will again have to yank the intake to replace the lifters. And again it’s going to be an expense. And again it might not solve the issue. I refuse to pull off that intake until I know for a fact what’s going on.
 
Well this is interesting

should I not be able to push the rockers down with my fingers while running ?

What are signs of bad lifters ?

These reviews are a quite bad.

55FAA147-F079-43D8-88EF-4E283991445F.jpeg F63956D9-97F0-4F81-A180-39575F53C1E4.jpeg 034B3F33-D798-4143-A222-B4B3AA5D036A.jpeg C0836860-E06F-4B65-95D0-EFCD4FF7E254.jpeg B1E9668F-3B50-4F12-91C5-702B7B6D0CC2.jpeg 6358A108-3E21-4CAF-9053-3BDD076E7B45.jpeg
 
I’m going to sleep on this and start over tomorrow with a clear mind.
 
Curiosity killed the cat but satisfaction brought it back.


Dunno if you hear what I hear but I don’t like it and no amount of adjusting seems to affect it.

Could valve springs have anything to do with this ?
 
You might want to walk away for a while and think and also you should not be able to collapse a lifter with finger pressure I wouldn't think
 
rlphvac said:
You might want to walk away for a while and think and also you should not be able to collapse a lifter with finger pressure I wouldn't think
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I’m sure you’re right. I tried again wasn’t able to do it. Brian fart. I can press them in quite easily when they bleed down tho
 
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