overheating and no coolant flow

[IOPort51]

OK so one more question: do you measure this before start up with "dry" lifters? or should you put an hour or so on the motor before trying to set these or better yet an engine with a few miles on it, like EBs?

 

[coldair]

The best way is a set of dry lifters. It can be done with a set that are pumped up but takes longer because you have to wait for them to bleed off.

 

[IOPort51]

I think I understand this now.

Elwood, was this lifter noise something that happened with the first start up or was this something that took a while to happen? if it happened right out of the box I would check pre load but if it took a while I would be aware of the possibility of a "lazy lifter". What does your vacuum look like? High enough and steady?

 

[elwood blues]

I think I understand this now.

Elwood, was this lifter noise something that happened with the first start up or was this something that took a while to happen? if it happened right out of the box I would check pre load but if it took a while I would be aware of the possibility of a "lazy lifter". What does your vacuum look like? High enough and steady?

Vacuum is at a steady 18 in Hg, already checked. This was something that I noticed almost immediately after first start-up, but originally misdiagnosed as an exhaust leak.

 

[IOPort51]

that would be easy to do.

this all looks doable, major PITA to pull the cover but I guess it could be worse. Are you thinking about changing out push rods or removing metal from the rocker assembly?? I would be a little leery of playing mix and match with the push rods.

Vacuum is at a steady 18 in Hg, already checked. This was something that I noticed almost immediately after first start-up, but originally misdiagnosed as an exhaust leak.

 

[elwood blues]

I think I'm going to do the measurements this afternoon, I'm not positive yet which route I'm going to go. Pushrods, shims or grinding.

 

[IOPort51]

I would want to keep as many things Identicle as possible, like push rods and rockers. So you didn't have to be sure they went back in the same place if it became necessary to re assemble. I would be tempted to remove some of the casting tower the rocker sets on. but thats just me and everybody knows I usually make things more complicated that they really need to be.

I think I'm going to do the measurements this afternoon, I'm not positive yet which route I'm going to go. Pushrods, shims or grinding.

 

[coldair]

I think I'm going to do the measurements this afternoon, I'm not positive yet which route I'm going to go. Pushrods, shims or grinding.

Elwood when i built my AMC 258 i6 / 4.2l I had to order a set of aftermarket push rods. I could only find them in hardened they where $9.33 a piece. hope you dont have to do the same. ( I did 0 deck my block and shaved the head 0.010 )

 

[elwood blues]

Finally I have an update to this thread. After several days of searching, I finally found instructions on how to properly use a COMP CAMS HI-TECH pushrod length checking tool. I bought part number 7704-1, which is 8.8" to 9.8" long. Here is the write-up I found on a Corvette forum;

Each turn of the adjustable pushrod is 0.050". When fully closed, it is 6.800". This is pushrod "gauge length" so you can't measure it directly as the pushrod length is actually based on the length between the ball ends where the ball end measures 0.140" in diameter. Assuming you are using stock rockers or a non-adjustable rocker.

1. Open the adjustable pushrod to the same length as your stock pushrods
2. Close it down two turns
3. Put your rocker rail on the head
4. Make sure your cylinder (typically #1) is at top dead center on the firing stroke so both valves would be closed
5. Put the pushrod in place on the intake valve and make sure it is in the lifter cup
6. Install the rocker and snug down the bolt (don't need to torque, just make sure it is snug)
7. Lift rocker tip up and down, if it "ticks" the pushrod is too short. If you can't easily move the rocker the pushrod is too long.
8. You can try and adjust the pushrod in place but my fingers are too fat so I end up pulling the rocker and adjusting the pushrod length. Go either shorter or longer 1/2 turn and try again.
9. You are trying to get to the point where the lifter doesn't "tick tick" with the pushrod in place nor is the rocker snug. When you get the pushrod length such that you just barely get rid of the "tick tick", you have found "zero lash".
10. When you have found zero lash, carefully remove the rocker and pushrod without rotating the pushrod.
11. Tighten the pushrod until it is fully closed counting the turns as you go.

To figure out your pushrod length you do the following. Let’s assume it took 10-1/2 turns to close the pushrod down to its shortest length after you reached zero lash. Each turn is 0.050".

Your length is then: 6.800" (fully closed length) + 10.5 X 0.050" (number of turns times the length change per turn) = pushrod length minus preload. So for this case:

6.800 +10.5 X 0.050 = 7.325"

This is the length you measured to zero lash without any lifter preload. Now let’s say you want to have 0.075" lifter preload, you add that to the measured number and you end up with 7.400" pushrods.

So I did the measurements on 3 cyclinders and got an average of 9.375" Intake and 9.875" exhaust.

I remember reading that I want pre-load, but I don't remember how much :dunno: can someone help me out?

 

[elwood blues]

I like to set mine at .040"

This is the number I was looking for, is this specific for the engine, or just a basic flat tapper lifter pre-load number?

 

[elwood blues]

So, I took this short video (please don't mind the really bad qaulity, I have no idea why it's so orange and out of focus, I took it with my phone ). I think it's too noisy, am I wrong? Here's the backstory, COMP X4250H-11 cam with COMP double valve spring (recommended), new COMP lifters, new pushrods (9.650"), new rocker arms, pivots and arms. I also have a .030" shims under each rocker arm.

So, I don't know if I should try the .060" shims, leave it as is and deal with it kind of sounding like a sewing machine :dunno:

As always, thanks for the inputs guys.

VIDEO0002-1.mp4 video by thurstonsXJ | Photobucket

 

[elwood blues]

I had time this afternoon, so I replaced all of the .030" shims with .060" shims. That was very obviously the wrong idea. It was visably evident that the .060" shims are way too much.

So, back in went the .030" shims, but this time, only on the exhaust side. When I originally did the math, which I'm starting to seriously doubt that I did correctly know, the exhaust side need to be shorter than the intake side.

There is a small issue though, when retorquing the rocker arms, I noticed that 1, possibly 2, of the rocker arm bridges are warped, not allowing the rocker arm to sit correctly on the valve spring. I questioned the new 2 piece design, and relative cheap thin metal of the new rocker bridges. The bridge and guide are 2 pieces, where my OE ones were a cast 1 piece design. I'll be going to NAPA in the morning to see if they have any in stock.

Anyway, this brings me to another question, has anyone seen, heard of, or done this; convert your bridged rocker arms to studs and pushrod guides? Like this pic, but with stock stamped rockers? This is what I'm looking at going to.

 

[elwood blues]

I had kind of forgotten about all of this until today for some reason. So, I figure I should close this out.

I did end up buying all new rocker bridges, 2 of the 6 were twisted, either from me taking them on and off, or just being weak. I ended up replacing all 6 with new ones.

My math was wrong for the pushrod length. I ended up back at the machine shop that I took my head to. I think part of my incorrect math was that I did not know that the machine shop had to deck the head. Anyway, for my setup I needed a 9.700" pushrod.

Now she purrs like a kitten. It's awesome, no more valve train noise, and I'm not worried about damaging anything. On to the next issue...

 

[CJ]

Very happy to see you worked it out!