Budget '69 Camaro Track Car - NO WHINERS!

[Vegas69]

The question is, were the push rods spec'd with or without lash caps?

[Track Junky]

Originally Posted by GregWeld

Lash caps are a must for high revving motors to protect the valve tip.

Not sure I consider 6500 high reving Greg. In addition lash caps are used to correct drive train geometry.

Originally Posted by Vegas69

The question is, were the push rods spec'd with or without lash caps?

In order to reach a conclusion I imagine would probably have to put together all the variables and do the math.....how much was removed from the deck of the block, piston to deck dimension, valve stem length, spring assembled height, push rod length, gasket thickness, piston to valve clearance, etc, etc..
As soon as I get the other three rocker arms I'll run the drive train through it's motions and do a little more investigating.

[intocarss]

Originally Posted by GregWeld

Appears to me that you have contact with the retainer.... Not an uncommon issue with the aluminum rocker arms.


Make sure you check the rocker arm to retainer clearance. There should be at least .040” to .050” clearance at the closest point under the rocker arm and the top of the retainer.

^^^THIS^^^

It's not the proper way... but sometimes you have to grind some on alum rockers to clearence big OD retainers and springs Or install lash caps or longer tipped valves or different retainers if "installed hights" can still be achieved correctly

[QUOTE=Track Junky;471873]

Question is if the timing chain breaking had something to do with it......:headscratch:

If you're asking If the rockers hitting the retainers due to chain breakage The answer is...very unlikely..Hard to tell by the pics, Those look like they've been hitting for a while

Originally Posted by Track Junky

Not sure I consider 6500 high reving Greg. In addition lash caps are used to correct drive train geometry.

and or correct length push rods



In order to reach a conclusion I imagine would probably have to put together all the variables and do the math.....how much was removed from the deck of the block, piston to deck dimension, valve stem length, spring assembled height, push rod length, gasket thickness, piston to valve clearance, etc, etc..
As soon as I get the other three rocker arms I'll run the drive train through it's motions and do a little more investigating.

What exactly are you trying to figure out?? PM me if you like

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In this pic, is the roller on the rocker that far back on the valve tip w/ the valve closed, is there lash?? If so your push rods are wrong or that rocker is hitting the retainer and pushing it back

Here is a dumb video but will give you an idea
https://www.youtube.com/watch?v=XnS46ahJVqI

A couple of write ups

http://www.compcams.com/Products/CC-...rods%27-0.aspx

http://www.circletrack.com/techartic...h/viewall.html

[Track Junky]

[quote=intocarss;471936]It's not the proper way... but sometimes you have to grind some on alum rockers to clearence big OD retainers and springs Or install lash caps or longer tipped valves or different retainers if "installed hights" can still be achieved correctly

Thank Jer, I was not aware that engine builders sometimes have to grind on the rocker arms.

Originally Posted by Track Junky

Question is if the timing chain breaking had something to do with it......:headscratch:

If you're asking If the rockers hitting the retainers due to chain breakage The answer is...very unlikely..Hard to tell by the pics, Those look like they've been hitting for a while

I agree Jer. After further observation it's pretty obvious.






What exactly are you trying to figure out?? PM me if you like

Trying to figure out why the rocker arm is hitting the retainer and why the engine builder did not catch this.

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In this pic, is the roller on the rocker that far back on the valve tip w/ the valve closed, is there lash?? If so your push rods are wrong or that rocker is hitting the retainer and pushing it back

Stand by, the pic your refering to has not shown itself this time around
OK I see it now. In that pic #1 is at TDC and both valves are closed so to answer your question, yes. I hadn't checked lash yet as I was trying to figure out if I was going to need the lash caps or not.(Seriously do not recall having lash caps when I pulled the heads off)Obviously I do. I'll have to run down this morning and confirm but If I go with a longer pushrod I'm not sure I will be grabbing enough of the rocker stud.

Here is a dumb video but will give you an idea
https://www.youtube.com/watch?v=XnS46ahJVqI

A couple of write ups

http://www.compcams.com/Products/CC-...rods%27-0.aspx

http://www.circletrack.com/techartic...h/viewall.html

Thanks Jer

[GregWeld]

Originally Posted by Track Junky

Not sure I consider 6500 high reving Greg. In addition lash caps are used to correct drive train geometry.



In order to reach a conclusion I imagine would probably have to put together all the variables and do the math.....how much was removed from the deck of the block, piston to deck dimension, valve stem length, spring assembled height, push rod length, gasket thickness, piston to valve clearance, etc, etc..
As soon as I get the other three rocker arms I'll run the drive train through it's motions and do a little more investigating.

I hope you're just going to set the head on the block and use a push rod checker to check for the proper length.... At least that's how I check for proper VALVE TRAIN (I use a different tool for DRIVE trains) geometry. No real math needed using a push rod checker.

[Track Junky]

Originally Posted by GregWeld

I hope you're just going to set the head on the block and use a push rod checker to check for the proper length.... At least that's how I check for proper VALVE TRAIN (I use a different tool for DRIVE trains) geometry. No real math needed using a push rod checker.

Thanks Greg. I will order that tool this morning

Just hopeing a longer pushrod will allow me to grab enough of the rocker stud. Current pushrods are 8.00 in length.

[Vince@Meanstreets]

I believe those marks are from clearencing done by the machinist. But I do see one that looks stressed. I think its the one that Greg sees too. Remember this engine was rotated with a few valves stuck down. Could explain this.

Inspect them Geatano and replace or fix the ones that look hammered.

pretty easy to check push rod with white grease and a caliper. if need be buy longer studs

[Track Junky]

Here is a better view with the spec'd .026 lash. I used a sharpie to black out the top of the lash cap and verify where the roller tip was engaging the lash cap. Looks like it is just behind center.
At this time I'm grabbing about 3/8"-7/16" of the rocker arm bolt.

[intocarss]

What's it look like without lash?